// SPDX-License-Identifier: GPL-2.0
#undef  BLOCKMOVE
#define Z_WAKE
#undef  Z_EXT_CHARS_IN_BUFFER

/*
 * This file contains the driver for the Cyclades async multiport
 * serial boards.
 *
 * Initially written by Randolph Bentson <bentson@grieg.seaslug.org>.
 * Modified and maintained by Marcio Saito <marcio@cyclades.com>.
 *
 * Copyright (C) 2007-2009 Jiri Slaby <jirislaby@gmail.com>
 *
 * Much of the design and some of the code came from serial.c
 * which was copyright (C) 1991, 1992  Linus Torvalds.  It was
 * extensively rewritten by Theodore Ts'o, 8/16/92 -- 9/14/92,
 * and then fixed as suggested by Michael K. Johnson 12/12/92.
 * Converted to pci probing and cleaned up by Jiri Slaby.
 *
 */

#define CY_VERSION      "2.6"

/* If you need to install more boards than NR_CARDS, change the constant
   in the definition below. No other change is necessary to support up to
   eight boards. Beyond that you'll have to extend cy_isa_addresses. */

#define NR_CARDS        4

/*
   If the total number of ports is larger than NR_PORTS, change this
   constant in the definition below. No other change is necessary to
   support more boards/ports. */

#define NR_PORTS        256

#define ZO_V1   0
#define ZO_V2   1
#define ZE_V1   2

#define SERIAL_PARANOIA_CHECK
#undef  CY_DEBUG_OPEN
#undef  CY_DEBUG_THROTTLE
#undef  CY_DEBUG_OTHER
#undef  CY_DEBUG_IO
#undef  CY_DEBUG_COUNT
#undef  CY_DEBUG_DTR
#undef  CY_DEBUG_INTERRUPTS
#undef  CY_16Y_HACK
#undef  CY_ENABLE_MONITORING
#undef  CY_PCI_DEBUG

/*
 * Include section
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/cyclades.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/firmware.h>
#include <linux/device.h>
#include <linux/slab.h>

#include <linux/io.h>
#include <linux/uaccess.h>

#include <linux/kernel.h>
#include <linux/pci.h>

#include <linux/stat.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

static void cy_send_xchar(struct tty_struct *tty, char ch);

#ifndef SERIAL_XMIT_SIZE
#define SERIAL_XMIT_SIZE        (min(PAGE_SIZE, 4096))
#endif

/* firmware stuff */
#define ZL_MAX_BLOCKS   16
#define DRIVER_VERSION  0x02010203
#define RAM_SIZE 0x80000

enum zblock_type {
        ZBLOCK_PRG = 0,
        ZBLOCK_FPGA = 1
};

struct zfile_header {
        char name[64];
        char date[32];
        char aux[32];
        u32 n_config;
        u32 config_offset;
        u32 n_blocks;
        u32 block_offset;
        u32 reserved[9];
} __attribute__ ((packed));

struct zfile_config {
        char name[64];
        u32 mailbox;
        u32 function;
        u32 n_blocks;
        u32 block_list[ZL_MAX_BLOCKS];
} __attribute__ ((packed));

struct zfile_block {
        u32 type;
        u32 file_offset;
        u32 ram_offset;
        u32 size;
} __attribute__ ((packed));

static struct tty_driver *cy_serial_driver;

#ifdef CONFIG_ISA
/* This is the address lookup table. The driver will probe for
   Cyclom-Y/ISA boards at all addresses in here. If you want the
   driver to probe addresses at a different address, add it to
   this table.  If the driver is probing some other board and
   causing problems, remove the offending address from this table.
*/

static unsigned int cy_isa_addresses[] = {
        0xD0000,
        0xD2000,
        0xD4000,
        0xD6000,
        0xD8000,
        0xDA000,
        0xDC000,
        0xDE000,
        0, 0, 0, 0, 0, 0, 0, 0
};

#define NR_ISA_ADDRS ARRAY_SIZE(cy_isa_addresses)

static long maddr[NR_CARDS];
static int irq[NR_CARDS];

module_param_hw_array(maddr, long, iomem, NULL, 0);
module_param_hw_array(irq, int, irq, NULL, 0);

#endif                          /* CONFIG_ISA */

/* This is the per-card data structure containing address, irq, number of
   channels, etc. This driver supports a maximum of NR_CARDS cards.
*/
static struct cyclades_card cy_card[NR_CARDS];

static int cy_next_channel;     /* next minor available */

/*
 * This is used to look up the divisor speeds and the timeouts
 * We're normally limited to 15 distinct baud rates.  The extra
 * are accessed via settings in info->port.flags.
 *      0,     1,     2,     3,     4,     5,     6,     7,     8,     9,
 *     10,    11,    12,    13,    14,    15,    16,    17,    18,    19,
 *                                               HI            VHI
 *     20
 */
static const int baud_table[] = {
        0, 50, 75, 110, 134, 150, 200, 300, 600, 1200,
        1800, 2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200, 150000,
        230400, 0
};

static const char baud_co_25[] = {      /* 25 MHz clock option table */
        /* value =>    00    01   02    03    04 */
        /* divide by    8    32   128   512  2048 */
        0x00, 0x04, 0x04, 0x04, 0x04, 0x04, 0x03, 0x03, 0x03, 0x02,
        0x02, 0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

static const char baud_bpr_25[] = {     /* 25 MHz baud rate period table */
        0x00, 0xf5, 0xa3, 0x6f, 0x5c, 0x51, 0xf5, 0xa3, 0x51, 0xa3,
        0x6d, 0x51, 0xa3, 0x51, 0xa3, 0x51, 0x36, 0x29, 0x1b, 0x15
};

static const char baud_co_60[] = {      /* 60 MHz clock option table (CD1400 J) */
        /* value =>    00    01   02    03    04 */
        /* divide by    8    32   128   512  2048 */
        0x00, 0x00, 0x00, 0x04, 0x04, 0x04, 0x04, 0x04, 0x03, 0x03,
        0x03, 0x02, 0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00
};

static const char baud_bpr_60[] = {     /* 60 MHz baud rate period table (CD1400 J) */
        0x00, 0x82, 0x21, 0xff, 0xdb, 0xc3, 0x92, 0x62, 0xc3, 0x62,
        0x41, 0xc3, 0x62, 0xc3, 0x62, 0xc3, 0x82, 0x62, 0x41, 0x32,
        0x21
};

static const char baud_cor3[] = {       /* receive threshold */
        0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a,
        0x0a, 0x0a, 0x0a, 0x09, 0x09, 0x08, 0x08, 0x08, 0x08, 0x07,
        0x07
};

/*
 * The Cyclades driver implements HW flow control as any serial driver.
 * The cyclades_port structure member rflow and the vector rflow_thr
 * allows us to take advantage of a special feature in the CD1400 to avoid
 * data loss even when the system interrupt latency is too high. These flags
 * are to be used only with very special applications. Setting these flags
 * requires the use of a special cable (DTR and RTS reversed). In the new
 * CD1400-based boards (rev. 6.00 or later), there is no need for special
 * cables.
 */

static const char rflow_thr[] = {       /* rflow threshold */
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a,
        0x0a
};

/*  The Cyclom-Ye has placed the sequential chips in non-sequential
 *  address order.  This look-up table overcomes that problem.
 */
static const unsigned int cy_chip_offset[] = { 0x0000,
        0x0400,
        0x0800,
        0x0C00,
        0x0200,
        0x0600,
        0x0A00,
        0x0E00
};

/* PCI related definitions */

#ifdef CONFIG_PCI
static const struct pci_device_id cy_pci_dev_id[] = {
        /* PCI < 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_Y_Lo) },
        /* PCI > 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_Y_Hi) },
        /* 4Y PCI < 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_4Y_Lo) },
        /* 4Y PCI > 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_4Y_Hi) },
        /* 8Y PCI < 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_8Y_Lo) },
        /* 8Y PCI > 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_8Y_Hi) },
        /* Z PCI < 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_Z_Lo) },
        /* Z PCI > 1Mb */
        { PCI_DEVICE(PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_CYCLOM_Z_Hi) },
        { }                     /* end of table */
};
MODULE_DEVICE_TABLE(pci, cy_pci_dev_id);
#endif

static void cy_start(struct tty_struct *);
static void cy_set_line_char(struct cyclades_port *, struct tty_struct *);
static int cyz_issue_cmd(struct cyclades_card *, __u32, __u8, __u32);
#ifdef CONFIG_ISA
static unsigned detect_isa_irq(void __iomem *);
#endif                          /* CONFIG_ISA */

#ifndef CONFIG_CYZ_INTR
static void cyz_poll(struct timer_list *);

/* The Cyclades-Z polling cycle is defined by this variable */
static long cyz_polling_cycle = CZ_DEF_POLL;

static DEFINE_TIMER(cyz_timerlist, cyz_poll);

#else                           /* CONFIG_CYZ_INTR */
static void cyz_rx_restart(struct timer_list *);
#endif                          /* CONFIG_CYZ_INTR */

static void cyy_writeb(struct cyclades_port *port, u32 reg, u8 val)
{
        struct cyclades_card *card = port->card;

        cy_writeb(port->u.cyy.base_addr + (reg << card->bus_index), val);
}

static u8 cyy_readb(struct cyclades_port *port, u32 reg)
{
        struct cyclades_card *card = port->card;

        return readb(port->u.cyy.base_addr + (reg << card->bus_index));
}

static inline bool cy_is_Z(struct cyclades_card *card)
{
        return card->num_chips == (unsigned int)-1;
}

static inline bool __cyz_fpga_loaded(struct RUNTIME_9060 __iomem *ctl_addr)
{
        return readl(&ctl_addr->init_ctrl) & (1 << 17);
}

static inline bool cyz_fpga_loaded(struct cyclades_card *card)
{
        return __cyz_fpga_loaded(card->ctl_addr.p9060);
}

static bool cyz_is_loaded(struct cyclades_card *card)
{
        struct FIRM_ID __iomem *fw_id = card->base_addr + ID_ADDRESS;

        return (card->hw_ver == ZO_V1 || cyz_fpga_loaded(card)) &&
                        readl(&fw_id->signature) == ZFIRM_ID;
}

static int serial_paranoia_check(struct cyclades_port *info,
                const char *name, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
        if (!info) {
                printk(KERN_WARNING "cyc Warning: null cyclades_port for (%s) "
                                "in %s\n", name, routine);
                return 1;
        }

        if (info->magic != CYCLADES_MAGIC) {
                printk(KERN_WARNING "cyc Warning: bad magic number for serial "
                                "struct (%s) in %s\n", name, routine);
                return 1;
        }
#endif
        return 0;
}

/***********************************************************/
/********* Start of block of Cyclom-Y specific code ********/

/* This routine waits up to 1000 micro-seconds for the previous
   command to the Cirrus chip to complete and then issues the
   new command.  An error is returned if the previous command
   didn't finish within the time limit.

   This function is only called from inside spinlock-protected code.
 */
static int __cyy_issue_cmd(void __iomem *base_addr, u8 cmd, int index)
{
        void __iomem *ccr = base_addr + (CyCCR << index);
        unsigned int i;

        /* Check to see that the previous command has completed */
        for (i = 0; i < 100; i++) {
                if (readb(ccr) == 0)
                        break;
                udelay(10L);
        }
        /* if the CCR never cleared, the previous command
           didn't finish within the "reasonable time" */
        if (i == 100)
                return -1;

        /* Issue the new command */
        cy_writeb(ccr, cmd);

        return 0;
}

static inline int cyy_issue_cmd(struct cyclades_port *port, u8 cmd)
{
        return __cyy_issue_cmd(port->u.cyy.base_addr, cmd,
                        port->card->bus_index);
}

#ifdef CONFIG_ISA
/* ISA interrupt detection code */
static unsigned detect_isa_irq(void __iomem *address)
{
        int irq;
        unsigned long irqs, flags;
        int save_xir, save_car;
        int index = 0;          /* IRQ probing is only for ISA */

        /* forget possible initially masked and pending IRQ */
        irq = probe_irq_off(probe_irq_on());

        /* Clear interrupts on the board first */
        cy_writeb(address + (Cy_ClrIntr << index), 0);
        /* Cy_ClrIntr is 0x1800 */

        irqs = probe_irq_on();
        /* Wait ... */
        msleep(5);

        /* Enable the Tx interrupts on the CD1400 */
        local_irq_save(flags);
        cy_writeb(address + (CyCAR << index), 0);
        __cyy_issue_cmd(address, CyCHAN_CTL | CyENB_XMTR, index);

        cy_writeb(address + (CyCAR << index), 0);
        cy_writeb(address + (CySRER << index),
                  readb(address + (CySRER << index)) | CyTxRdy);
        local_irq_restore(flags);

        /* Wait ... */
        msleep(5);

        /* Check which interrupt is in use */
        irq = probe_irq_off(irqs);

        /* Clean up */
        save_xir = (u_char) readb(address + (CyTIR << index));
        save_car = readb(address + (CyCAR << index));
        cy_writeb(address + (CyCAR << index), (save_xir & 0x3));
        cy_writeb(address + (CySRER << index),
                  readb(address + (CySRER << index)) & ~CyTxRdy);
        cy_writeb(address + (CyTIR << index), (save_xir & 0x3f));
        cy_writeb(address + (CyCAR << index), (save_car));
        cy_writeb(address + (Cy_ClrIntr << index), 0);
        /* Cy_ClrIntr is 0x1800 */

        return (irq > 0) ? irq : 0;
}
#endif                          /* CONFIG_ISA */

static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
                void __iomem *base_addr)
{
        struct cyclades_port *info;
        struct tty_port *port;
        int len, index = cinfo->bus_index;
        u8 ivr, save_xir, channel, save_car, data, char_count;

#ifdef CY_DEBUG_INTERRUPTS
        printk(KERN_DEBUG "cyy_interrupt: rcvd intr, chip %d\n", chip);
#endif
        /* determine the channel & change to that context */
        save_xir = readb(base_addr + (CyRIR << index));
        channel = save_xir & CyIRChannel;
        info = &cinfo->ports[channel + chip * 4];
        port = &info->port;
        save_car = cyy_readb(info, CyCAR);
        cyy_writeb(info, CyCAR, save_xir);
        ivr = cyy_readb(info, CyRIVR) & CyIVRMask;

        /* there is an open port for this data */
        if (ivr == CyIVRRxEx) { /* exception */
                data = cyy_readb(info, CyRDSR);

                /* For statistics only */
                if (data & CyBREAK)
                        info->icount.brk++;
                else if (data & CyFRAME)
                        info->icount.frame++;
                else if (data & CyPARITY)
                        info->icount.parity++;
                else if (data & CyOVERRUN)
                        info->icount.overrun++;

                if (data & info->ignore_status_mask) {
                        info->icount.rx++;
                        return;
                }
                if (tty_buffer_request_room(port, 1)) {
                        if (data & info->read_status_mask) {
                                if (data & CyBREAK) {
                                        tty_insert_flip_char(port,
                                                cyy_readb(info, CyRDSR),
                                                TTY_BREAK);
                                        info->icount.rx++;
                                        if (port->flags & ASYNC_SAK) {
                                                struct tty_struct *tty =
                                                        tty_port_tty_get(port);
                                                if (tty) {
                                                        do_SAK(tty);
                                                        tty_kref_put(tty);
                                                }
                                        }
                                } else if (data & CyFRAME) {
                                        tty_insert_flip_char(port,
                                                cyy_readb(info, CyRDSR),
                                                TTY_FRAME);
                                        info->icount.rx++;
                                        info->idle_stats.frame_errs++;
                                } else if (data & CyPARITY) {
                                        /* Pieces of seven... */
                                        tty_insert_flip_char(port,
                                                cyy_readb(info, CyRDSR),
                                                TTY_PARITY);
                                        info->icount.rx++;
                                        info->idle_stats.parity_errs++;
                                } else if (data & CyOVERRUN) {
                                        tty_insert_flip_char(port, 0,
                                                        TTY_OVERRUN);
                                        info->icount.rx++;
                                        /* If the flip buffer itself is
                                           overflowing, we still lose
                                           the next incoming character.
                                         */
                                        tty_insert_flip_char(port,
                                                cyy_readb(info, CyRDSR),
                                                TTY_FRAME);
                                        info->icount.rx++;
                                        info->idle_stats.overruns++;
                                /* These two conditions may imply */
                                /* a normal read should be done. */
                                /* } else if(data & CyTIMEOUT) { */
                                /* } else if(data & CySPECHAR) { */
                                } else {
                                        tty_insert_flip_char(port, 0,
                                                        TTY_NORMAL);
                                        info->icount.rx++;
                                }
                        } else {
                                tty_insert_flip_char(port, 0, TTY_NORMAL);
                                info->icount.rx++;
                        }
                } else {
                        /* there was a software buffer overrun and nothing
                         * could be done about it!!! */
                        info->icount.buf_overrun++;
                        info->idle_stats.overruns++;
                }
        } else {        /* normal character reception */
                /* load # chars available from the chip */
                char_count = cyy_readb(info, CyRDCR);

#ifdef CY_ENABLE_MONITORING
                ++info->mon.int_count;
                info->mon.char_count += char_count;
                if (char_count > info->mon.char_max)
                        info->mon.char_max = char_count;
                info->mon.char_last = char_count;
#endif
                len = tty_buffer_request_room(port, char_count);
                while (len--) {
                        data = cyy_readb(info, CyRDSR);
                        tty_insert_flip_char(port, data, TTY_NORMAL);
                        info->idle_stats.recv_bytes++;
                        info->icount.rx++;
#ifdef CY_16Y_HACK
                        udelay(10L);
#endif
                }
                info->idle_stats.recv_idle = jiffies;
        }
        tty_schedule_flip(port);

        /* end of service */
        cyy_writeb(info, CyRIR, save_xir & 0x3f);
        cyy_writeb(info, CyCAR, save_car);
}

static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip,
                void __iomem *base_addr)
{
        struct cyclades_port *info;
        struct tty_struct *tty;
        int char_count, index = cinfo->bus_index;
        u8 save_xir, channel, save_car, outch;

        /* Since we only get here when the transmit buffer
           is empty, we know we can always stuff a dozen
           characters. */
#ifdef CY_DEBUG_INTERRUPTS
        printk(KERN_DEBUG "cyy_interrupt: xmit intr, chip %d\n", chip);
#endif

        /* determine the channel & change to that context */
        save_xir = readb(base_addr + (CyTIR << index));
        channel = save_xir & CyIRChannel;
        save_car = readb(base_addr + (CyCAR << index));
        cy_writeb(base_addr + (CyCAR << index), save_xir);

        info = &cinfo->ports[channel + chip * 4];
        tty = tty_port_tty_get(&info->port);
        if (tty == NULL) {
                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) & ~CyTxRdy);
                goto end;
        }

        /* load the on-chip space for outbound data */
        char_count = info->xmit_fifo_size;

        if (info->x_char) {     /* send special char */
                outch = info->x_char;
                cyy_writeb(info, CyTDR, outch);
                char_count--;
                info->icount.tx++;
                info->x_char = 0;
        }

        if (info->breakon || info->breakoff) {
                if (info->breakon) {
                        cyy_writeb(info, CyTDR, 0);
                        cyy_writeb(info, CyTDR, 0x81);
                        info->breakon = 0;
                        char_count -= 2;
                }
                if (info->breakoff) {
                        cyy_writeb(info, CyTDR, 0);
                        cyy_writeb(info, CyTDR, 0x83);
                        info->breakoff = 0;
                        char_count -= 2;
                }
        }

        while (char_count-- > 0) {
                if (!info->xmit_cnt) {
                        if (cyy_readb(info, CySRER) & CyTxMpty) {
                                cyy_writeb(info, CySRER,
                                        cyy_readb(info, CySRER) & ~CyTxMpty);
                        } else {
                                cyy_writeb(info, CySRER, CyTxMpty |
                                        (cyy_readb(info, CySRER) & ~CyTxRdy));
                        }
                        goto done;
                }
                if (info->port.xmit_buf == NULL) {
                        cyy_writeb(info, CySRER,
                                cyy_readb(info, CySRER) & ~CyTxRdy);
                        goto done;
                }
                if (tty->stopped || tty->hw_stopped) {
                        cyy_writeb(info, CySRER,
                                cyy_readb(info, CySRER) & ~CyTxRdy);
                        goto done;
                }
                /* Because the Embedded Transmit Commands have been enabled,
                 * we must check to see if the escape character, NULL, is being
                 * sent. If it is, we must ensure that there is room for it to
                 * be doubled in the output stream.  Therefore we no longer
                 * advance the pointer when the character is fetched, but
                 * rather wait until after the check for a NULL output
                 * character. This is necessary because there may not be room
                 * for the two chars needed to send a NULL.)
                 */
                outch = info->port.xmit_buf[info->xmit_tail];
                if (outch) {
                        info->xmit_cnt--;
                        info->xmit_tail = (info->xmit_tail + 1) &
                                        (SERIAL_XMIT_SIZE - 1);
                        cyy_writeb(info, CyTDR, outch);
                        info->icount.tx++;
                } else {
                        if (char_count > 1) {
                                info->xmit_cnt--;
                                info->xmit_tail = (info->xmit_tail + 1) &
                                        (SERIAL_XMIT_SIZE - 1);
                                cyy_writeb(info, CyTDR, outch);
                                cyy_writeb(info, CyTDR, 0);
                                info->icount.tx++;
                                char_count--;
                        }
                }
        }

done:
        tty_wakeup(tty);
        tty_kref_put(tty);
end:
        /* end of service */
        cyy_writeb(info, CyTIR, save_xir & 0x3f);
        cyy_writeb(info, CyCAR, save_car);
}

static void cyy_chip_modem(struct cyclades_card *cinfo, int chip,
                void __iomem *base_addr)
{
        struct cyclades_port *info;
        struct tty_struct *tty;
        int index = cinfo->bus_index;
        u8 save_xir, channel, save_car, mdm_change, mdm_status;

        /* determine the channel & change to that context */
        save_xir = readb(base_addr + (CyMIR << index));
        channel = save_xir & CyIRChannel;
        info = &cinfo->ports[channel + chip * 4];
        save_car = cyy_readb(info, CyCAR);
        cyy_writeb(info, CyCAR, save_xir);

        mdm_change = cyy_readb(info, CyMISR);
        mdm_status = cyy_readb(info, CyMSVR1);

        tty = tty_port_tty_get(&info->port);
        if (!tty)
                goto end;

        if (mdm_change & CyANY_DELTA) {
                /* For statistics only */
                if (mdm_change & CyDCD)
                        info->icount.dcd++;
                if (mdm_change & CyCTS)
                        info->icount.cts++;
                if (mdm_change & CyDSR)
                        info->icount.dsr++;
                if (mdm_change & CyRI)
                        info->icount.rng++;

                wake_up_interruptible(&info->port.delta_msr_wait);
        }

        if ((mdm_change & CyDCD) && tty_port_check_carrier(&info->port)) {
                if (mdm_status & CyDCD)
                        wake_up_interruptible(&info->port.open_wait);
                else
                        tty_hangup(tty);
        }
        if ((mdm_change & CyCTS) && tty_port_cts_enabled(&info->port)) {
                if (tty->hw_stopped) {
                        if (mdm_status & CyCTS) {
                                /* cy_start isn't used
                                   because... !!! */
                                tty->hw_stopped = 0;
                                cyy_writeb(info, CySRER,
                                        cyy_readb(info, CySRER) | CyTxRdy);
                                tty_wakeup(tty);
                        }
                } else {
                        if (!(mdm_status & CyCTS)) {
                                /* cy_stop isn't used
                                   because ... !!! */
                                tty->hw_stopped = 1;
                                cyy_writeb(info, CySRER,
                                        cyy_readb(info, CySRER) & ~CyTxRdy);
                        }
                }
        }
/*      if (mdm_change & CyDSR) {
        }
        if (mdm_change & CyRI) {
        }*/
        tty_kref_put(tty);
end:
        /* end of service */
        cyy_writeb(info, CyMIR, save_xir & 0x3f);
        cyy_writeb(info, CyCAR, save_car);
}

/* The real interrupt service routine is called
   whenever the card wants its hand held--chars
   received, out buffer empty, modem change, etc.
 */
static irqreturn_t cyy_interrupt(int irq, void *dev_id)
{
        int status;
        struct cyclades_card *cinfo = dev_id;
        void __iomem *base_addr, *card_base_addr;
        unsigned int chip, too_many, had_work;
        int index;

        if (unlikely(cinfo == NULL)) {
#ifdef CY_DEBUG_INTERRUPTS
                printk(KERN_DEBUG "cyy_interrupt: spurious interrupt %d\n",
                                irq);
#endif
                return IRQ_NONE;        /* spurious interrupt */
        }

        card_base_addr = cinfo->base_addr;
        index = cinfo->bus_index;

        /* card was not initialized yet (e.g. DEBUG_SHIRQ) */
        if (unlikely(card_base_addr == NULL))
                return IRQ_HANDLED;

        /* This loop checks all chips in the card.  Make a note whenever
           _any_ chip had some work to do, as this is considered an
           indication that there will be more to do.  Only when no chip
           has any work does this outermost loop exit.
         */
        do {
                had_work = 0;
                for (chip = 0; chip < cinfo->num_chips; chip++) {
                        base_addr = cinfo->base_addr +
                                        (cy_chip_offset[chip] << index);
                        too_many = 0;
                        while ((status = readb(base_addr +
                                                (CySVRR << index))) != 0x00) {
                                had_work++;
                        /* The purpose of the following test is to ensure that
                           no chip can monopolize the driver.  This forces the
                           chips to be checked in a round-robin fashion (after
                           draining each of a bunch (1000) of characters).
                         */
                                if (1000 < too_many++)
                                        break;
                                spin_lock(&cinfo->card_lock);
                                if (status & CySRReceive) /* rx intr */
                                        cyy_chip_rx(cinfo, chip, base_addr);
                                if (status & CySRTransmit) /* tx intr */
                                        cyy_chip_tx(cinfo, chip, base_addr);
                                if (status & CySRModem) /* modem intr */
                                        cyy_chip_modem(cinfo, chip, base_addr);
                                spin_unlock(&cinfo->card_lock);
                        }
                }
        } while (had_work);

        /* clear interrupts */
        spin_lock(&cinfo->card_lock);
        cy_writeb(card_base_addr + (Cy_ClrIntr << index), 0);
        /* Cy_ClrIntr is 0x1800 */
        spin_unlock(&cinfo->card_lock);
        return IRQ_HANDLED;
}                               /* cyy_interrupt */

static void cyy_change_rts_dtr(struct cyclades_port *info, unsigned int set,
                unsigned int clear)
{
        struct cyclades_card *card = info->card;
        int channel = info->line - card->first_line;
        u32 rts, dtr, msvrr, msvrd;

        channel &= 0x03;

        if (info->rtsdtr_inv) {
                msvrr = CyMSVR2;
                msvrd = CyMSVR1;
                rts = CyDTR;
                dtr = CyRTS;
        } else {
                msvrr = CyMSVR1;
                msvrd = CyMSVR2;
                rts = CyRTS;
                dtr = CyDTR;
        }
        if (set & TIOCM_RTS) {
                cyy_writeb(info, CyCAR, channel);
                cyy_writeb(info, msvrr, rts);
        }
        if (clear & TIOCM_RTS) {
                cyy_writeb(info, CyCAR, channel);
                cyy_writeb(info, msvrr, ~rts);
        }
        if (set & TIOCM_DTR) {
                cyy_writeb(info, CyCAR, channel);
                cyy_writeb(info, msvrd, dtr);
#ifdef CY_DEBUG_DTR
                printk(KERN_DEBUG "cyc:set_modem_info raising DTR\n");
                printk(KERN_DEBUG "     status: 0x%x, 0x%x\n",
                        cyy_readb(info, CyMSVR1),
                        cyy_readb(info, CyMSVR2));
#endif
        }
        if (clear & TIOCM_DTR) {
                cyy_writeb(info, CyCAR, channel);
                cyy_writeb(info, msvrd, ~dtr);
#ifdef CY_DEBUG_DTR
                printk(KERN_DEBUG "cyc:set_modem_info dropping DTR\n");
                printk(KERN_DEBUG "     status: 0x%x, 0x%x\n",
                        cyy_readb(info, CyMSVR1),
                        cyy_readb(info, CyMSVR2));
#endif
        }
}

/***********************************************************/
/********* End of block of Cyclom-Y specific code **********/
/******** Start of block of Cyclades-Z specific code *******/
/***********************************************************/

static int
cyz_fetch_msg(struct cyclades_card *cinfo,
                __u32 *channel, __u8 *cmd, __u32 *param)
{
        struct BOARD_CTRL __iomem *board_ctrl = cinfo->board_ctrl;
        unsigned long loc_doorbell;

        loc_doorbell = readl(&cinfo->ctl_addr.p9060->loc_doorbell);
        if (loc_doorbell) {
                *cmd = (char)(0xff & loc_doorbell);
                *channel = readl(&board_ctrl->fwcmd_channel);
                *param = (__u32) readl(&board_ctrl->fwcmd_param);
                cy_writel(&cinfo->ctl_addr.p9060->loc_doorbell, 0xffffffff);
                return 1;
        }
        return 0;
}                               /* cyz_fetch_msg */

static int
cyz_issue_cmd(struct cyclades_card *cinfo,
                __u32 channel, __u8 cmd, __u32 param)
{
        struct BOARD_CTRL __iomem *board_ctrl = cinfo->board_ctrl;
        __u32 __iomem *pci_doorbell;
        unsigned int index;

        if (!cyz_is_loaded(cinfo))
                return -1;

        index = 0;
        pci_doorbell = &cinfo->ctl_addr.p9060->pci_doorbell;
        while ((readl(pci_doorbell) & 0xff) != 0) {
                if (index++ == 1000)
                        return (int)(readl(pci_doorbell) & 0xff);
                udelay(50L);
        }
        cy_writel(&board_ctrl->hcmd_channel, channel);
        cy_writel(&board_ctrl->hcmd_param, param);
        cy_writel(pci_doorbell, (long)cmd);

        return 0;
}                               /* cyz_issue_cmd */

static void cyz_handle_rx(struct cyclades_port *info)
{
        struct BUF_CTRL __iomem *buf_ctrl = info->u.cyz.buf_ctrl;
        struct cyclades_card *cinfo = info->card;
        struct tty_port *port = &info->port;
        unsigned int char_count;
        int len;
#ifdef BLOCKMOVE
        unsigned char *buf;
#else
        char data;
#endif
        __u32 rx_put, rx_get, new_rx_get, rx_bufsize, rx_bufaddr;

        rx_get = new_rx_get = readl(&buf_ctrl->rx_get);
        rx_put = readl(&buf_ctrl->rx_put);
        rx_bufsize = readl(&buf_ctrl->rx_bufsize);
        rx_bufaddr = readl(&buf_ctrl->rx_bufaddr);
        if (rx_put >= rx_get)
                char_count = rx_put - rx_get;
        else
                char_count = rx_put - rx_get + rx_bufsize;

        if (!char_count)
                return;

#ifdef CY_ENABLE_MONITORING
        info->mon.int_count++;
        info->mon.char_count += char_count;
        if (char_count > info->mon.char_max)
                info->mon.char_max = char_count;
        info->mon.char_last = char_count;
#endif

#ifdef BLOCKMOVE
        /* we'd like to use memcpy(t, f, n) and memset(s, c, count)
           for performance, but because of buffer boundaries, there
           may be several steps to the operation */
        while (1) {
                len = tty_prepare_flip_string(port, &buf,
                                char_count);
                if (!len)
                        break;

                len = min_t(unsigned int, min(len, char_count),
                                rx_bufsize - new_rx_get);

                memcpy_fromio(buf, cinfo->base_addr +
                                rx_bufaddr + new_rx_get, len);

                new_rx_get = (new_rx_get + len) &
                                (rx_bufsize - 1);
                char_count -= len;
                info->icount.rx += len;
                info->idle_stats.recv_bytes += len;
        }
#else
        len = tty_buffer_request_room(port, char_count);
        while (len--) {
                data = readb(cinfo->base_addr + rx_bufaddr +
                                new_rx_get);
                new_rx_get = (new_rx_get + 1) &
                                        (rx_bufsize - 1);
                tty_insert_flip_char(port, data, TTY_NORMAL);
                info->idle_stats.recv_bytes++;
                info->icount.rx++;
        }
#endif
#ifdef CONFIG_CYZ_INTR
        /* Recalculate the number of chars in the RX buffer and issue
           a cmd in case it's higher than the RX high water mark */
        rx_put = readl(&buf_ctrl->rx_put);
        if (rx_put >= rx_get)
                char_count = rx_put - rx_get;
        else
                char_count = rx_put - rx_get + rx_bufsize;
        if (char_count >= readl(&buf_ctrl->rx_threshold) &&
                        !timer_pending(&info->rx_full_timer))
                mod_timer(&info->rx_full_timer, jiffies + 1);
#endif
        info->idle_stats.recv_idle = jiffies;
        tty_schedule_flip(&info->port);

        /* Update rx_get */
        cy_writel(&buf_ctrl->rx_get, new_rx_get);
}

static void cyz_handle_tx(struct cyclades_port *info)
{
        struct BUF_CTRL __iomem *buf_ctrl = info->u.cyz.buf_ctrl;
        struct cyclades_card *cinfo = info->card;
        struct tty_struct *tty;
        u8 data;
        unsigned int char_count;
#ifdef BLOCKMOVE
        int small_count;
#endif
        __u32 tx_put, tx_get, tx_bufsize, tx_bufaddr;

        if (info->xmit_cnt <= 0)        /* Nothing to transmit */
                return;

        tx_get = readl(&buf_ctrl->tx_get);
        tx_put = readl(&buf_ctrl->tx_put);
        tx_bufsize = readl(&buf_ctrl->tx_bufsize);
        tx_bufaddr = readl(&buf_ctrl->tx_bufaddr);
        if (tx_put >= tx_get)
                char_count = tx_get - tx_put - 1 + tx_bufsize;
        else
                char_count = tx_get - tx_put - 1;

        if (!char_count)
                return;
                
        tty = tty_port_tty_get(&info->port);
        if (tty == NULL)
                goto ztxdone;

        if (info->x_char) {     /* send special char */
                data = info->x_char;

                cy_writeb(cinfo->base_addr + tx_bufaddr + tx_put, data);
                tx_put = (tx_put + 1) & (tx_bufsize - 1);
                info->x_char = 0;
                char_count--;
                info->icount.tx++;
        }
#ifdef BLOCKMOVE
        while (0 < (small_count = min_t(unsigned int,
                        tx_bufsize - tx_put, min_t(unsigned int,
                                (SERIAL_XMIT_SIZE - info->xmit_tail),
                                min_t(unsigned int, info->xmit_cnt,
                                        char_count))))) {

                memcpy_toio((char *)(cinfo->base_addr + tx_bufaddr + tx_put),
                                &info->port.xmit_buf[info->xmit_tail],
                                small_count);

                tx_put = (tx_put + small_count) & (tx_bufsize - 1);
                char_count -= small_count;
                info->icount.tx += small_count;
                info->xmit_cnt -= small_count;
                info->xmit_tail = (info->xmit_tail + small_count) &
                                (SERIAL_XMIT_SIZE - 1);
        }
#else
        while (info->xmit_cnt && char_count) {
                data = info->port.xmit_buf[info->xmit_tail];
                info->xmit_cnt--;
                info->xmit_tail = (info->xmit_tail + 1) &
                                (SERIAL_XMIT_SIZE - 1);

                cy_writeb(cinfo->base_addr + tx_bufaddr + tx_put, data);
                tx_put = (tx_put + 1) & (tx_bufsize - 1);
                char_count--;
                info->icount.tx++;
        }
#endif
        tty_wakeup(tty);
        tty_kref_put(tty);
ztxdone:
        /* Update tx_put */
        cy_writel(&buf_ctrl->tx_put, tx_put);
}

static void cyz_handle_cmd(struct cyclades_card *cinfo)
{
        struct BOARD_CTRL __iomem *board_ctrl = cinfo->board_ctrl;
        struct cyclades_port *info;
        __u32 channel, param, fw_ver;
        __u8 cmd;
        int special_count;
        int delta_count;

        fw_ver = readl(&board_ctrl->fw_version);

        while (cyz_fetch_msg(cinfo, &channel, &cmd, &param) == 1) {
                special_count = 0;
                delta_count = 0;
                info = &cinfo->ports[channel];

                switch (cmd) {
                case C_CM_PR_ERROR:
                        tty_insert_flip_char(&info->port, 0, TTY_PARITY);
                        info->icount.rx++;
                        special_count++;
                        break;
                case C_CM_FR_ERROR:
                        tty_insert_flip_char(&info->port, 0, TTY_FRAME);
                        info->icount.rx++;
                        special_count++;
                        break;
                case C_CM_RXBRK:
                        tty_insert_flip_char(&info->port, 0, TTY_BREAK);
                        info->icount.rx++;
                        special_count++;
                        break;
                case C_CM_MDCD:
                        info->icount.dcd++;
                        delta_count++;
                        if (tty_port_check_carrier(&info->port)) {
                                u32 dcd = fw_ver > 241 ? param :
                                        readl(&info->u.cyz.ch_ctrl->rs_status);
                                if (dcd & C_RS_DCD)
                                        wake_up_interruptible(&info->port.open_wait);
                                else
                                        tty_port_tty_hangup(&info->port, false);
                        }
                        break;
                case C_CM_MCTS:
                        info->icount.cts++;
                        delta_count++;
                        break;
                case C_CM_MRI:
                        info->icount.rng++;
                        delta_count++;
                        break;
                case C_CM_MDSR:
                        info->icount.dsr++;
                        delta_count++;
                        break;
#ifdef Z_WAKE
                case C_CM_IOCTLW:
                        complete(&info->shutdown_wait);
                        break;
#endif
#ifdef CONFIG_CYZ_INTR
                case C_CM_RXHIWM:
                case C_CM_RXNNDT:
                case C_CM_INTBACK2:
                        /* Reception Interrupt */
#ifdef CY_DEBUG_INTERRUPTS
                        printk(KERN_DEBUG "cyz_interrupt: rcvd intr, card %d, "
                                        "port %ld\n", info->card, channel);
#endif
                        cyz_handle_rx(info);
                        break;
                case C_CM_TXBEMPTY:
                case C_CM_TXLOWWM:
                case C_CM_INTBACK:
                        /* Transmission Interrupt */
#ifdef CY_DEBUG_INTERRUPTS
                        printk(KERN_DEBUG "cyz_interrupt: xmit intr, card %d, "
                                        "port %ld\n", info->card, channel);
#endif
                        cyz_handle_tx(info);
                        break;
#endif                          /* CONFIG_CYZ_INTR */
                case C_CM_FATAL:
                        /* should do something with this !!! */
                        break;
                default:
                        break;
                }
                if (delta_count)
                        wake_up_interruptible(&info->port.delta_msr_wait);
                if (special_count)
                        tty_schedule_flip(&info->port);
        }
}

#ifdef CONFIG_CYZ_INTR
static irqreturn_t cyz_interrupt(int irq, void *dev_id)
{
        struct cyclades_card *cinfo = dev_id;

        if (unlikely(!cyz_is_loaded(cinfo))) {
#ifdef CY_DEBUG_INTERRUPTS
                printk(KERN_DEBUG "cyz_interrupt: board not yet loaded "
                                "(IRQ%d).\n", irq);
#endif
                return IRQ_NONE;
        }

        /* Handle the interrupts */
        cyz_handle_cmd(cinfo);

        return IRQ_HANDLED;
}                               /* cyz_interrupt */

static void cyz_rx_restart(struct timer_list *t)
{
        struct cyclades_port *info = from_timer(info, t, rx_full_timer);
        struct cyclades_card *card = info->card;
        int retval;
        __u32 channel = info->line - card->first_line;
        unsigned long flags;

        spin_lock_irqsave(&card->card_lock, flags);
        retval = cyz_issue_cmd(card, channel, C_CM_INTBACK2, 0L);
        if (retval != 0) {
                printk(KERN_ERR "cyc:cyz_rx_restart retval on ttyC%d was %x\n",
                        info->line, retval);
        }
        spin_unlock_irqrestore(&card->card_lock, flags);
}

#else                           /* CONFIG_CYZ_INTR */

static void cyz_poll(struct timer_list *unused)
{
        struct cyclades_card *cinfo;
        struct cyclades_port *info;
        unsigned long expires = jiffies + HZ;
        unsigned int port, card;

        for (card = 0; card < NR_CARDS; card++) {
                cinfo = &cy_card[card];

                if (!cy_is_Z(cinfo))
                        continue;
                if (!cyz_is_loaded(cinfo))
                        continue;

        /* Skip first polling cycle to avoid racing conditions with the FW */
                if (!cinfo->intr_enabled) {
                        cinfo->intr_enabled = 1;
                        continue;
                }

                cyz_handle_cmd(cinfo);

                for (port = 0; port < cinfo->nports; port++) {
                        info = &cinfo->ports[port];

                        if (!info->throttle)
                                cyz_handle_rx(info);
                        cyz_handle_tx(info);
                }
                /* poll every 'cyz_polling_cycle' period */
                expires = jiffies + cyz_polling_cycle;
        }
        mod_timer(&cyz_timerlist, expires);
}                               /* cyz_poll */

#endif                          /* CONFIG_CYZ_INTR */

/********** End of block of Cyclades-Z specific code *********/
/***********************************************************/

/* This is called whenever a port becomes active;
   interrupts are enabled and DTR & RTS are turned on.
 */
static int cy_startup(struct cyclades_port *info, struct tty_struct *tty)
{
        struct cyclades_card *card;
        unsigned long flags;
        int retval = 0;
        int channel;
        unsigned long page;

        card = info->card;
        channel = info->line - card->first_line;

        page = get_zeroed_page(GFP_KERNEL);
        if (!page)
                return -ENOMEM;

        spin_lock_irqsave(&card->card_lock, flags);

        if (tty_port_initialized(&info->port))
                goto errout;

        if (!info->type) {
                set_bit(TTY_IO_ERROR, &tty->flags);
                goto errout;
        }

        if (info->port.xmit_buf)
                free_page(page);
        else
                info->port.xmit_buf = (unsigned char *)page;

        spin_unlock_irqrestore(&card->card_lock, flags);

        cy_set_line_char(info, tty);

        if (!cy_is_Z(card)) {
                channel &= 0x03;

                spin_lock_irqsave(&card->card_lock, flags);

                cyy_writeb(info, CyCAR, channel);

                cyy_writeb(info, CyRTPR,
                        (info->default_timeout ? info->default_timeout : 0x02));
                /* 10ms rx timeout */

                cyy_issue_cmd(info, CyCHAN_CTL | CyENB_RCVR | CyENB_XMTR);

                cyy_change_rts_dtr(info, TIOCM_RTS | TIOCM_DTR, 0);

                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) | CyRxData);
        } else {
                struct CH_CTRL __iomem *ch_ctrl = info->u.cyz.ch_ctrl;

                if (!cyz_is_loaded(card))
                        return -ENODEV;

#ifdef CY_DEBUG_OPEN
                printk(KERN_DEBUG "cyc startup Z card %d, channel %d, "
                        "base_addr %p\n", card, channel, card->base_addr);
#endif
                spin_lock_irqsave(&card->card_lock, flags);

                cy_writel(&ch_ctrl->op_mode, C_CH_ENABLE);
#ifdef Z_WAKE
#ifdef CONFIG_CYZ_INTR
                cy_writel(&ch_ctrl->intr_enable,
                          C_IN_TXBEMPTY | C_IN_TXLOWWM | C_IN_RXHIWM |
                          C_IN_RXNNDT | C_IN_IOCTLW | C_IN_MDCD);
#else
                cy_writel(&ch_ctrl->intr_enable,
                          C_IN_IOCTLW | C_IN_MDCD);
#endif                          /* CONFIG_CYZ_INTR */
#else
#ifdef CONFIG_CYZ_INTR
                cy_writel(&ch_ctrl->intr_enable,
                          C_IN_TXBEMPTY | C_IN_TXLOWWM | C_IN_RXHIWM |
                          C_IN_RXNNDT | C_IN_MDCD);
#else
                cy_writel(&ch_ctrl->intr_enable, C_IN_MDCD);
#endif                          /* CONFIG_CYZ_INTR */
#endif                          /* Z_WAKE */

                retval = cyz_issue_cmd(card, channel, C_CM_IOCTL, 0L);
                if (retval != 0) {
                        printk(KERN_ERR "cyc:startup(1) retval on ttyC%d was "
                                "%x\n", info->line, retval);
                }

                /* Flush RX buffers before raising DTR and RTS */
                retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_RX, 0L);
                if (retval != 0) {
                        printk(KERN_ERR "cyc:startup(2) retval on ttyC%d was "
                                "%x\n", info->line, retval);
                }

                /* set timeout !!! */
                /* set RTS and DTR !!! */
                tty_port_raise_dtr_rts(&info->port);

                /* enable send, recv, modem !!! */
        }

        tty_port_set_initialized(&info->port, 1);

        clear_bit(TTY_IO_ERROR, &tty->flags);
        info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
        info->breakon = info->breakoff = 0;
        memset((char *)&info->idle_stats, 0, sizeof(info->idle_stats));
        info->idle_stats.in_use =
        info->idle_stats.recv_idle =
        info->idle_stats.xmit_idle = jiffies;

        spin_unlock_irqrestore(&card->card_lock, flags);

#ifdef CY_DEBUG_OPEN
        printk(KERN_DEBUG "cyc startup done\n");
#endif
        return 0;

errout:
        spin_unlock_irqrestore(&card->card_lock, flags);
        free_page(page);
        return retval;
}                               /* startup */

static void start_xmit(struct cyclades_port *info)
{
        struct cyclades_card *card = info->card;
        unsigned long flags;
        int channel = info->line - card->first_line;

        if (!cy_is_Z(card)) {
                spin_lock_irqsave(&card->card_lock, flags);
                cyy_writeb(info, CyCAR, channel & 0x03);
                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) | CyTxRdy);
                spin_unlock_irqrestore(&card->card_lock, flags);
        } else {
#ifdef CONFIG_CYZ_INTR
                int retval;

                spin_lock_irqsave(&card->card_lock, flags);
                retval = cyz_issue_cmd(card, channel, C_CM_INTBACK, 0L);
                if (retval != 0) {
                        printk(KERN_ERR "cyc:start_xmit retval on ttyC%d was "
                                "%x\n", info->line, retval);
                }
                spin_unlock_irqrestore(&card->card_lock, flags);
#else                           /* CONFIG_CYZ_INTR */
                /* Don't have to do anything at this time */
#endif                          /* CONFIG_CYZ_INTR */
        }
}                               /* start_xmit */

/*
 * This routine shuts down a serial port; interrupts are disabled,
 * and DTR is dropped if the hangup on close termio flag is on.
 */
static void cy_shutdown(struct cyclades_port *info, struct tty_struct *tty)
{
        struct cyclades_card *card;
        unsigned long flags;

        if (!tty_port_initialized(&info->port))
                return;

        card = info->card;
        if (!cy_is_Z(card)) {
                spin_lock_irqsave(&card->card_lock, flags);

                /* Clear delta_msr_wait queue to avoid mem leaks. */
                wake_up_interruptible(&info->port.delta_msr_wait);

                if (info->port.xmit_buf) {
                        unsigned char *temp;
                        temp = info->port.xmit_buf;
                        info->port.xmit_buf = NULL;
                        free_page((unsigned long)temp);
                }
                if (C_HUPCL(tty))
                        cyy_change_rts_dtr(info, 0, TIOCM_RTS | TIOCM_DTR);

                cyy_issue_cmd(info, CyCHAN_CTL | CyDIS_RCVR);
                /* it may be appropriate to clear _XMIT at
                   some later date (after testing)!!! */

                set_bit(TTY_IO_ERROR, &tty->flags);
                tty_port_set_initialized(&info->port, 0);
                spin_unlock_irqrestore(&card->card_lock, flags);
        } else {
#ifdef CY_DEBUG_OPEN
                int channel = info->line - card->first_line;
                printk(KERN_DEBUG "cyc shutdown Z card %d, channel %d, "
                        "base_addr %p\n", card, channel, card->base_addr);
#endif

                if (!cyz_is_loaded(card))
                        return;

                spin_lock_irqsave(&card->card_lock, flags);

                if (info->port.xmit_buf) {
                        unsigned char *temp;
                        temp = info->port.xmit_buf;
                        info->port.xmit_buf = NULL;
                        free_page((unsigned long)temp);
                }

                if (C_HUPCL(tty))
                        tty_port_lower_dtr_rts(&info->port);

                set_bit(TTY_IO_ERROR, &tty->flags);
                tty_port_set_initialized(&info->port, 0);

                spin_unlock_irqrestore(&card->card_lock, flags);
        }

#ifdef CY_DEBUG_OPEN
        printk(KERN_DEBUG "cyc shutdown done\n");
#endif
}                               /* shutdown */

/*
 * ------------------------------------------------------------
 * cy_open() and friends
 * ------------------------------------------------------------
 */

/*
 * This routine is called whenever a serial port is opened.  It
 * performs the serial-specific initialization for the tty structure.
 */
static int cy_open(struct tty_struct *tty, struct file *filp)
{
        struct cyclades_port *info;
        unsigned int i, line = tty->index;
        int retval;

        for (i = 0; i < NR_CARDS; i++)
                if (line < cy_card[i].first_line + cy_card[i].nports &&
                                line >= cy_card[i].first_line)
                        break;
        if (i >= NR_CARDS)
                return -ENODEV;
        info = &cy_card[i].ports[line - cy_card[i].first_line];
        if (info->line < 0)
                return -ENODEV;

        /* If the card's firmware hasn't been loaded,
           treat it as absent from the system.  This
           will make the user pay attention.
         */
        if (cy_is_Z(info->card)) {
                struct cyclades_card *cinfo = info->card;
                struct FIRM_ID __iomem *firm_id = cinfo->base_addr + ID_ADDRESS;

                if (!cyz_is_loaded(cinfo)) {
                        if (cinfo->hw_ver == ZE_V1 && cyz_fpga_loaded(cinfo) &&
                                        readl(&firm_id->signature) ==
                                        ZFIRM_HLT) {
                                printk(KERN_ERR "cyc:Cyclades-Z Error: you "
                                        "need an external power supply for "
                                        "this number of ports.\nFirmware "
                                        "halted.\n");
                        } else {
                                printk(KERN_ERR "cyc:Cyclades-Z firmware not "
                                        "yet loaded\n");
                        }
                        return -ENODEV;
                }
#ifdef CONFIG_CYZ_INTR
                else {
                /* In case this Z board is operating in interrupt mode, its
                   interrupts should be enabled as soon as the first open
                   happens to one of its ports. */
                        if (!cinfo->intr_enabled) {
                                u16 intr;

                                /* Enable interrupts on the PLX chip */
                                intr = readw(&cinfo->ctl_addr.p9060->
                                                intr_ctrl_stat) | 0x0900;
                                cy_writew(&cinfo->ctl_addr.p9060->
                                                intr_ctrl_stat, intr);
                                /* Enable interrupts on the FW */
                                retval = cyz_issue_cmd(cinfo, 0,
                                                C_CM_IRQ_ENBL, 0L);
                                if (retval != 0) {
                                        printk(KERN_ERR "cyc:IRQ enable retval "
                                                "was %x\n", retval);
                                }
                                cinfo->intr_enabled = 1;
                        }
                }
#endif                          /* CONFIG_CYZ_INTR */
                /* Make sure this Z port really exists in hardware */
                if (info->line > (cinfo->first_line + cinfo->nports - 1))
                        return -ENODEV;
        }
#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_open ttyC%d\n", info->line);
#endif
        tty->driver_data = info;
        if (serial_paranoia_check(info, tty->name, "cy_open"))
                return -ENODEV;

#ifdef CY_DEBUG_OPEN
        printk(KERN_DEBUG "cyc:cy_open ttyC%d, count = %d\n", info->line,
                        info->port.count);
#endif
        info->port.count++;
#ifdef CY_DEBUG_COUNT
        printk(KERN_DEBUG "cyc:cy_open (%d): incrementing count to %d\n",
                current->pid, info->port.count);
#endif

        /*
         * Start up serial port
         */
        retval = cy_startup(info, tty);
        if (retval)
                return retval;

        retval = tty_port_block_til_ready(&info->port, tty, filp);
        if (retval) {
#ifdef CY_DEBUG_OPEN
                printk(KERN_DEBUG "cyc:cy_open returning after block_til_ready "
                        "with %d\n", retval);
#endif
                return retval;
        }

        info->throttle = 0;
        tty_port_tty_set(&info->port, tty);

#ifdef CY_DEBUG_OPEN
        printk(KERN_DEBUG "cyc:cy_open done\n");
#endif
        return 0;
}                               /* cy_open */

/*
 * cy_wait_until_sent() --- wait until the transmitter is empty
 */
static void cy_wait_until_sent(struct tty_struct *tty, int timeout)
{
        struct cyclades_card *card;
        struct cyclades_port *info = tty->driver_data;
        unsigned long orig_jiffies;
        int char_time;

        if (serial_paranoia_check(info, tty->name, "cy_wait_until_sent"))
                return;

        if (info->xmit_fifo_size == 0)
                return;         /* Just in case.... */

        orig_jiffies = jiffies;
        /*
         * Set the check interval to be 1/5 of the estimated time to
         * send a single character, and make it at least 1.  The check
         * interval should also be less than the timeout.
         *
         * Note: we have to use pretty tight timings here to satisfy
         * the NIST-PCTS.
         */
        char_time = (info->timeout - HZ / 50) / info->xmit_fifo_size;
        char_time = char_time / 5;
        if (char_time <= 0)
                char_time = 1;
        if (timeout < 0)
                timeout = 0;
        if (timeout)
                char_time = min(char_time, timeout);
        /*
         * If the transmitter hasn't cleared in twice the approximate
         * amount of time to send the entire FIFO, it probably won't
         * ever clear.  This assumes the UART isn't doing flow
         * control, which is currently the case.  Hence, if it ever
         * takes longer than info->timeout, this is probably due to a
         * UART bug of some kind.  So, we clamp the timeout parameter at
         * 2*info->timeout.
         */
        if (!timeout || timeout > 2 * info->timeout)
                timeout = 2 * info->timeout;

        card = info->card;
        if (!cy_is_Z(card)) {
                while (cyy_readb(info, CySRER) & CyTxRdy) {
                        if (msleep_interruptible(jiffies_to_msecs(char_time)))
                                break;
                        if (timeout && time_after(jiffies, orig_jiffies +
                                        timeout))
                                break;
                }
        }
        /* Run one more char cycle */
        msleep_interruptible(jiffies_to_msecs(char_time * 5));
}

static void cy_flush_buffer(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        int channel, retval;
        unsigned long flags;

#ifdef CY_DEBUG_IO
        printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))
                return;

        card = info->card;
        channel = info->line - card->first_line;

        spin_lock_irqsave(&card->card_lock, flags);
        info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
        spin_unlock_irqrestore(&card->card_lock, flags);

        if (cy_is_Z(card)) {    /* If it is a Z card, flush the on-board
                                           buffers as well */
                spin_lock_irqsave(&card->card_lock, flags);
                retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);
                if (retval != 0) {
                        printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "
                                "was %x\n", info->line, retval);
                }
                spin_unlock_irqrestore(&card->card_lock, flags);
        }
        tty_wakeup(tty);
}                               /* cy_flush_buffer */


static void cy_do_close(struct tty_port *port)
{
        struct cyclades_port *info = container_of(port, struct cyclades_port,
                                                                port);
        struct cyclades_card *card;
        unsigned long flags;
        int channel;

        card = info->card;
        channel = info->line - card->first_line;
        spin_lock_irqsave(&card->card_lock, flags);

        if (!cy_is_Z(card)) {
                /* Stop accepting input */
                cyy_writeb(info, CyCAR, channel & 0x03);
                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) & ~CyRxData);
                if (tty_port_initialized(&info->port)) {
                        /* Waiting for on-board buffers to be empty before
                           closing the port */
                        spin_unlock_irqrestore(&card->card_lock, flags);
                        cy_wait_until_sent(port->tty, info->timeout);
                        spin_lock_irqsave(&card->card_lock, flags);
                }
        } else {
#ifdef Z_WAKE
                /* Waiting for on-board buffers to be empty before closing
                   the port */
                struct CH_CTRL __iomem *ch_ctrl = info->u.cyz.ch_ctrl;
                int retval;

                if (readl(&ch_ctrl->flow_status) != C_FS_TXIDLE) {
                        retval = cyz_issue_cmd(card, channel, C_CM_IOCTLW, 0L);
                        if (retval != 0) {
                                printk(KERN_DEBUG "cyc:cy_close retval on "
                                        "ttyC%d was %x\n", info->line, retval);
                        }
                        spin_unlock_irqrestore(&card->card_lock, flags);
                        wait_for_completion_interruptible(&info->shutdown_wait);
                        spin_lock_irqsave(&card->card_lock, flags);
                }
#endif
        }
        spin_unlock_irqrestore(&card->card_lock, flags);
        cy_shutdown(info, port->tty);
}

/*
 * This routine is called when a particular tty device is closed.
 */
static void cy_close(struct tty_struct *tty, struct file *filp)
{
        struct cyclades_port *info = tty->driver_data;
        if (!info || serial_paranoia_check(info, tty->name, "cy_close"))
                return;
        tty_port_close(&info->port, tty, filp);
}                               /* cy_close */

/* This routine gets called when tty_write has put something into
 * the write_queue.  The characters may come from user space or
 * kernel space.
 *
 * This routine will return the number of characters actually
 * accepted for writing.
 *
 * If the port is not already transmitting stuff, start it off by
 * enabling interrupts.  The interrupt service routine will then
 * ensure that the characters are sent.
 * If the port is already active, there is no need to kick it.
 *
 */
static int cy_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
        struct cyclades_port *info = tty->driver_data;
        unsigned long flags;
        int c, ret = 0;

#ifdef CY_DEBUG_IO
        printk(KERN_DEBUG "cyc:cy_write ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_write"))
                return 0;

        if (!info->port.xmit_buf)
                return 0;

        spin_lock_irqsave(&info->card->card_lock, flags);
        while (1) {
                c = min(count, (int)(SERIAL_XMIT_SIZE - info->xmit_cnt - 1));
                c = min(c, (int)(SERIAL_XMIT_SIZE - info->xmit_head));

                if (c <= 0)
                        break;

                memcpy(info->port.xmit_buf + info->xmit_head, buf, c);
                info->xmit_head = (info->xmit_head + c) &
                        (SERIAL_XMIT_SIZE - 1);
                info->xmit_cnt += c;
                buf += c;
                count -= c;
                ret += c;
        }
        spin_unlock_irqrestore(&info->card->card_lock, flags);

        info->idle_stats.xmit_bytes += ret;
        info->idle_stats.xmit_idle = jiffies;

        if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped)
                start_xmit(info);

        return ret;
}                               /* cy_write */

/*
 * This routine is called by the kernel to write a single
 * character to the tty device.  If the kernel uses this routine,
 * it must call the flush_chars() routine (if defined) when it is
 * done stuffing characters into the driver.  If there is no room
 * in the queue, the character is ignored.
 */
static int cy_put_char(struct tty_struct *tty, unsigned char ch)
{
        struct cyclades_port *info = tty->driver_data;
        unsigned long flags;

#ifdef CY_DEBUG_IO
        printk(KERN_DEBUG "cyc:cy_put_char ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_put_char"))
                return 0;

        if (!info->port.xmit_buf)
                return 0;

        spin_lock_irqsave(&info->card->card_lock, flags);
        if (info->xmit_cnt >= (int)(SERIAL_XMIT_SIZE - 1)) {
                spin_unlock_irqrestore(&info->card->card_lock, flags);
                return 0;
        }

        info->port.xmit_buf[info->xmit_head++] = ch;
        info->xmit_head &= SERIAL_XMIT_SIZE - 1;
        info->xmit_cnt++;
        info->idle_stats.xmit_bytes++;
        info->idle_stats.xmit_idle = jiffies;
        spin_unlock_irqrestore(&info->card->card_lock, flags);
        return 1;
}                               /* cy_put_char */

/*
 * This routine is called by the kernel after it has written a
 * series of characters to the tty device using put_char().
 */
static void cy_flush_chars(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;

#ifdef CY_DEBUG_IO
        printk(KERN_DEBUG "cyc:cy_flush_chars ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_flush_chars"))
                return;

        if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
                        !info->port.xmit_buf)
                return;

        start_xmit(info);
}                               /* cy_flush_chars */

/*
 * This routine returns the numbers of characters the tty driver
 * will accept for queuing to be written.  This number is subject
 * to change as output buffers get emptied, or if the output flow
 * control is activated.
 */
static int cy_write_room(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;
        int ret;

#ifdef CY_DEBUG_IO
        printk(KERN_DEBUG "cyc:cy_write_room ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_write_room"))
                return 0;
        ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
        if (ret < 0)
                ret = 0;
        return ret;
}                               /* cy_write_room */

static int cy_chars_in_buffer(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;

        if (serial_paranoia_check(info, tty->name, "cy_chars_in_buffer"))
                return 0;

#ifdef Z_EXT_CHARS_IN_BUFFER
        if (!cy_is_Z(info->card)) {
#endif                          /* Z_EXT_CHARS_IN_BUFFER */
#ifdef CY_DEBUG_IO
                printk(KERN_DEBUG "cyc:cy_chars_in_buffer ttyC%d %d\n",
                        info->line, info->xmit_cnt);
#endif
                return info->xmit_cnt;
#ifdef Z_EXT_CHARS_IN_BUFFER
        } else {
                struct BUF_CTRL __iomem *buf_ctrl = info->u.cyz.buf_ctrl;
                int char_count;
                __u32 tx_put, tx_get, tx_bufsize;

                tx_get = readl(&buf_ctrl->tx_get);
                tx_put = readl(&buf_ctrl->tx_put);
                tx_bufsize = readl(&buf_ctrl->tx_bufsize);
                if (tx_put >= tx_get)
                        char_count = tx_put - tx_get;
                else
                        char_count = tx_put - tx_get + tx_bufsize;
#ifdef CY_DEBUG_IO
                printk(KERN_DEBUG "cyc:cy_chars_in_buffer ttyC%d %d\n",
                        info->line, info->xmit_cnt + char_count);
#endif
                return info->xmit_cnt + char_count;
        }
#endif                          /* Z_EXT_CHARS_IN_BUFFER */
}                               /* cy_chars_in_buffer */

/*
 * ------------------------------------------------------------
 * cy_ioctl() and friends
 * ------------------------------------------------------------
 */

static void cyy_baud_calc(struct cyclades_port *info, __u32 baud)
{
        int co, co_val, bpr;
        __u32 cy_clock = ((info->chip_rev >= CD1400_REV_J) ? 60000000 :
                        25000000);

        if (baud == 0) {
                info->tbpr = info->tco = info->rbpr = info->rco = 0;
                return;
        }

        /* determine which prescaler to use */
        for (co = 4, co_val = 2048; co; co--, co_val >>= 2) {
                if (cy_clock / co_val / baud > 63)
                        break;
        }

        bpr = (cy_clock / co_val * 2 / baud + 1) / 2;
        if (bpr > 255)
                bpr = 255;

        info->tbpr = info->rbpr = bpr;
        info->tco = info->rco = co;
}

/*
 * This routine finds or computes the various line characteristics.
 * It used to be called config_setup
 */
static void cy_set_line_char(struct cyclades_port *info, struct tty_struct *tty)
{
        struct cyclades_card *card;
        unsigned long flags;
        int channel;
        unsigned cflag, iflag;
        int baud, baud_rate = 0;
        int i;

        if (info->line == -1)
                return;

        cflag = tty->termios.c_cflag;
        iflag = tty->termios.c_iflag;

        card = info->card;
        channel = info->line - card->first_line;

        if (!cy_is_Z(card)) {
                u32 cflags;

                /* baud rate */
                baud = tty_get_baud_rate(tty);
                if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                ASYNC_SPD_CUST) {
                        if (info->custom_divisor)
                                baud_rate = info->baud / info->custom_divisor;
                        else
                                baud_rate = info->baud;
                } else if (baud > CD1400_MAX_SPEED) {
                        baud = CD1400_MAX_SPEED;
                }
                /* find the baud index */
                for (i = 0; i < 20; i++) {
                        if (baud == baud_table[i])
                                break;
                }
                if (i == 20)
                        i = 19; /* CD1400_MAX_SPEED */

                if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                ASYNC_SPD_CUST) {
                        cyy_baud_calc(info, baud_rate);
                } else {
                        if (info->chip_rev >= CD1400_REV_J) {
                                /* It is a CD1400 rev. J or later */
                                info->tbpr = baud_bpr_60[i];    /* Tx BPR */
                                info->tco = baud_co_60[i];      /* Tx CO */
                                info->rbpr = baud_bpr_60[i];    /* Rx BPR */
                                info->rco = baud_co_60[i];      /* Rx CO */
                        } else {
                                info->tbpr = baud_bpr_25[i];    /* Tx BPR */
                                info->tco = baud_co_25[i];      /* Tx CO */
                                info->rbpr = baud_bpr_25[i];    /* Rx BPR */
                                info->rco = baud_co_25[i];      /* Rx CO */
                        }
                }
                if (baud_table[i] == 134) {
                        /* get it right for 134.5 baud */
                        info->timeout = (info->xmit_fifo_size * HZ * 30 / 269) +
                                        2;
                } else if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                ASYNC_SPD_CUST) {
                        info->timeout = (info->xmit_fifo_size * HZ * 15 /
                                        baud_rate) + 2;
                } else if (baud_table[i]) {
                        info->timeout = (info->xmit_fifo_size * HZ * 15 /
                                        baud_table[i]) + 2;
                        /* this needs to be propagated into the card info */
                } else {
                        info->timeout = 0;
                }
                /* By tradition (is it a standard?) a baud rate of zero
                   implies the line should be/has been closed.  A bit
                   later in this routine such a test is performed. */

                /* byte size and parity */
                info->cor5 = 0;
                info->cor4 = 0;
                /* receive threshold */
                info->cor3 = (info->default_threshold ?
                                info->default_threshold : baud_cor3[i]);
                info->cor2 = CyETC;
                switch (cflag & CSIZE) {
                case CS5:
                        info->cor1 = Cy_5_BITS;
                        break;
                case CS6:
                        info->cor1 = Cy_6_BITS;
                        break;
                case CS7:
                        info->cor1 = Cy_7_BITS;
                        break;
                case CS8:
                        info->cor1 = Cy_8_BITS;
                        break;
                }
                if (cflag & CSTOPB)
                        info->cor1 |= Cy_2_STOP;

                if (cflag & PARENB) {
                        if (cflag & PARODD)
                                info->cor1 |= CyPARITY_O;
                        else
                                info->cor1 |= CyPARITY_E;
                } else
                        info->cor1 |= CyPARITY_NONE;

                /* CTS flow control flag */
                tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
                if (cflag & CRTSCTS)
                        info->cor2 |= CyCtsAE;
                else
                        info->cor2 &= ~CyCtsAE;
                tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);

         /***********************************************
            The hardware option, CyRtsAO, presents RTS when
            the chip has characters to send.  Since most modems
            use RTS as reverse (inbound) flow control, this
            option is not used.  If inbound flow control is
            necessary, DTR can be programmed to provide the
            appropriate signals for use with a non-standard
            cable.  Contact Marcio Saito for details.
         ***********************************************/

                channel &= 0x03;

                spin_lock_irqsave(&card->card_lock, flags);
                cyy_writeb(info, CyCAR, channel);

                /* tx and rx baud rate */

                cyy_writeb(info, CyTCOR, info->tco);
                cyy_writeb(info, CyTBPR, info->tbpr);
                cyy_writeb(info, CyRCOR, info->rco);
                cyy_writeb(info, CyRBPR, info->rbpr);

                /* set line characteristics  according configuration */

                cyy_writeb(info, CySCHR1, START_CHAR(tty));
                cyy_writeb(info, CySCHR2, STOP_CHAR(tty));
                cyy_writeb(info, CyCOR1, info->cor1);
                cyy_writeb(info, CyCOR2, info->cor2);
                cyy_writeb(info, CyCOR3, info->cor3);
                cyy_writeb(info, CyCOR4, info->cor4);
                cyy_writeb(info, CyCOR5, info->cor5);

                cyy_issue_cmd(info, CyCOR_CHANGE | CyCOR1ch | CyCOR2ch |
                                CyCOR3ch);

                /* !!! Is this needed? */
                cyy_writeb(info, CyCAR, channel);
                cyy_writeb(info, CyRTPR,
                        (info->default_timeout ? info->default_timeout : 0x02));
                /* 10ms rx timeout */

                cflags = CyCTS;
                if (!C_CLOCAL(tty))
                        cflags |= CyDSR | CyRI | CyDCD;
                /* without modem intr */
                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) | CyMdmCh);
                /* act on 1->0 modem transitions */
                if ((cflag & CRTSCTS) && info->rflow)
                        cyy_writeb(info, CyMCOR1, cflags | rflow_thr[i]);
                else
                        cyy_writeb(info, CyMCOR1, cflags);
                /* act on 0->1 modem transitions */
                cyy_writeb(info, CyMCOR2, cflags);

                if (i == 0)     /* baud rate is zero, turn off line */
                        cyy_change_rts_dtr(info, 0, TIOCM_DTR);
                else
                        cyy_change_rts_dtr(info, TIOCM_DTR, 0);

                clear_bit(TTY_IO_ERROR, &tty->flags);
                spin_unlock_irqrestore(&card->card_lock, flags);

        } else {
                struct CH_CTRL __iomem *ch_ctrl = info->u.cyz.ch_ctrl;
                __u32 sw_flow;
                int retval;

                if (!cyz_is_loaded(card))
                        return;

                /* baud rate */
                baud = tty_get_baud_rate(tty);
                if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                ASYNC_SPD_CUST) {
                        if (info->custom_divisor)
                                baud_rate = info->baud / info->custom_divisor;
                        else
                                baud_rate = info->baud;
                } else if (baud > CYZ_MAX_SPEED) {
                        baud = CYZ_MAX_SPEED;
                }
                cy_writel(&ch_ctrl->comm_baud, baud);

                if (baud == 134) {
                        /* get it right for 134.5 baud */
                        info->timeout = (info->xmit_fifo_size * HZ * 30 / 269) +
                                        2;
                } else if (baud == 38400 && (info->port.flags & ASYNC_SPD_MASK) ==
                                ASYNC_SPD_CUST) {
                        info->timeout = (info->xmit_fifo_size * HZ * 15 /
                                        baud_rate) + 2;
                } else if (baud) {
                        info->timeout = (info->xmit_fifo_size * HZ * 15 /
                                        baud) + 2;
                        /* this needs to be propagated into the card info */
                } else {
                        info->timeout = 0;
                }

                /* byte size and parity */
                switch (cflag & CSIZE) {
                case CS5:
                        cy_writel(&ch_ctrl->comm_data_l, C_DL_CS5);
                        break;
                case CS6:
                        cy_writel(&ch_ctrl->comm_data_l, C_DL_CS6);
                        break;
                case CS7:
                        cy_writel(&ch_ctrl->comm_data_l, C_DL_CS7);
                        break;
                case CS8:
                        cy_writel(&ch_ctrl->comm_data_l, C_DL_CS8);
                        break;
                }
                if (cflag & CSTOPB) {
                        cy_writel(&ch_ctrl->comm_data_l,
                                  readl(&ch_ctrl->comm_data_l) | C_DL_2STOP);
                } else {
                        cy_writel(&ch_ctrl->comm_data_l,
                                  readl(&ch_ctrl->comm_data_l) | C_DL_1STOP);
                }
                if (cflag & PARENB) {
                        if (cflag & PARODD)
                                cy_writel(&ch_ctrl->comm_parity, C_PR_ODD);
                        else
                                cy_writel(&ch_ctrl->comm_parity, C_PR_EVEN);
                } else
                        cy_writel(&ch_ctrl->comm_parity, C_PR_NONE);

                /* CTS flow control flag */
                if (cflag & CRTSCTS) {
                        cy_writel(&ch_ctrl->hw_flow,
                                readl(&ch_ctrl->hw_flow) | C_RS_CTS | C_RS_RTS);
                } else {
                        cy_writel(&ch_ctrl->hw_flow, readl(&ch_ctrl->hw_flow) &
                                        ~(C_RS_CTS | C_RS_RTS));
                }
                /* As the HW flow control is done in firmware, the driver
                   doesn't need to care about it */
                tty_port_set_cts_flow(&info->port, 0);

                /* XON/XOFF/XANY flow control flags */
                sw_flow = 0;
                if (iflag & IXON) {
                        sw_flow |= C_FL_OXX;
                        if (iflag & IXANY)
                                sw_flow |= C_FL_OIXANY;
                }
                cy_writel(&ch_ctrl->sw_flow, sw_flow);

                retval = cyz_issue_cmd(card, channel, C_CM_IOCTL, 0L);
                if (retval != 0) {
                        printk(KERN_ERR "cyc:set_line_char retval on ttyC%d "
                                "was %x\n", info->line, retval);
                }

                /* CD sensitivity */
                tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);

                if (baud == 0) {        /* baud rate is zero, turn off line */
                        cy_writel(&ch_ctrl->rs_control,
                                  readl(&ch_ctrl->rs_control) & ~C_RS_DTR);
#ifdef CY_DEBUG_DTR
                        printk(KERN_DEBUG "cyc:set_line_char dropping Z DTR\n");
#endif
                } else {
                        cy_writel(&ch_ctrl->rs_control,
                                  readl(&ch_ctrl->rs_control) | C_RS_DTR);
#ifdef CY_DEBUG_DTR
                        printk(KERN_DEBUG "cyc:set_line_char raising Z DTR\n");
#endif
                }

                retval = cyz_issue_cmd(card, channel, C_CM_IOCTLM, 0L);
                if (retval != 0) {
                        printk(KERN_ERR "cyc:set_line_char(2) retval on ttyC%d "
                                "was %x\n", info->line, retval);
                }

                clear_bit(TTY_IO_ERROR, &tty->flags);
        }
}                               /* set_line_char */

static int cy_get_serial_info(struct tty_struct *tty,
                                struct serial_struct *ss)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *cinfo = info->card;

        if (serial_paranoia_check(info, tty->name, "cy_ioctl"))
                return -ENODEV;
        ss->type = info->type;
        ss->line = info->line;
        ss->port = (info->card - cy_card) * 0x100 + info->line -
                        cinfo->first_line;
        ss->irq = cinfo->irq;
        ss->flags = info->port.flags;
        ss->close_delay = info->port.close_delay;
        ss->closing_wait = info->port.closing_wait;
        ss->baud_base = info->baud;
        ss->custom_divisor = info->custom_divisor;
        return 0;
}

static int cy_set_serial_info(struct tty_struct *tty,
                                struct serial_struct *ss)
{
        struct cyclades_port *info = tty->driver_data;
        int old_flags;
        int ret;

        if (serial_paranoia_check(info, tty->name, "cy_ioctl"))
                return -ENODEV;

        mutex_lock(&info->port.mutex);

        old_flags = info->port.flags;

        if (!capable(CAP_SYS_ADMIN)) {
                if (ss->close_delay != info->port.close_delay ||
                                ss->baud_base != info->baud ||
                                (ss->flags & ASYNC_FLAGS &
                                        ~ASYNC_USR_MASK) !=
                                (info->port.flags & ASYNC_FLAGS & ~ASYNC_USR_MASK))
                {
                        mutex_unlock(&info->port.mutex);
                        return -EPERM;
                }
                info->port.flags = (info->port.flags & ~ASYNC_USR_MASK) |
                                (ss->flags & ASYNC_USR_MASK);
                info->baud = ss->baud_base;
                info->custom_divisor = ss->custom_divisor;
                goto check_and_exit;
        }

        /*
         * OK, past this point, all the error checking has been done.
         * At this point, we start making changes.....
         */

        info->baud = ss->baud_base;
        info->custom_divisor = ss->custom_divisor;
        info->port.flags = (info->port.flags & ~ASYNC_FLAGS) |
                        (ss->flags & ASYNC_FLAGS);
        info->port.close_delay = ss->close_delay * HZ / 100;
        info->port.closing_wait = ss->closing_wait * HZ / 100;

check_and_exit:
        if (tty_port_initialized(&info->port)) {
                if ((ss->flags ^ old_flags) & ASYNC_SPD_MASK) {
                        /* warn about deprecation unless clearing */
                        if (ss->flags & ASYNC_SPD_MASK)
                                dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
                }
                cy_set_line_char(info, tty);
                ret = 0;
        } else {
                ret = cy_startup(info, tty);
        }
        mutex_unlock(&info->port.mutex);
        return ret;
}                               /* set_serial_info */

/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 *          is emptied.  On bus types like RS485, the transmitter must
 *          release the bus after transmitting. This must be done when
 *          the transmit shift register is empty, not be done when the
 *          transmit holding register is empty.  This functionality
 *          allows an RS485 driver to be written in user space.
 */
static int get_lsr_info(struct cyclades_port *info, unsigned int __user *value)
{
        struct cyclades_card *card = info->card;
        unsigned int result;
        unsigned long flags;
        u8 status;

        if (!cy_is_Z(card)) {
                spin_lock_irqsave(&card->card_lock, flags);
                status = cyy_readb(info, CySRER) & (CyTxRdy | CyTxMpty);
                spin_unlock_irqrestore(&card->card_lock, flags);
                result = (status ? 0 : TIOCSER_TEMT);
        } else {
                /* Not supported yet */
                return -EINVAL;
        }
        return put_user(result, value);
}

static int cy_tiocmget(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        int result;

        if (serial_paranoia_check(info, tty->name, __func__))
                return -ENODEV;

        card = info->card;

        if (!cy_is_Z(card)) {
                unsigned long flags;
                int channel = info->line - card->first_line;
                u8 status;

                spin_lock_irqsave(&card->card_lock, flags);
                cyy_writeb(info, CyCAR, channel & 0x03);
                status = cyy_readb(info, CyMSVR1);
                status |= cyy_readb(info, CyMSVR2);
                spin_unlock_irqrestore(&card->card_lock, flags);

                if (info->rtsdtr_inv) {
                        result = ((status & CyRTS) ? TIOCM_DTR : 0) |
                                ((status & CyDTR) ? TIOCM_RTS : 0);
                } else {
                        result = ((status & CyRTS) ? TIOCM_RTS : 0) |
                                ((status & CyDTR) ? TIOCM_DTR : 0);
                }
                result |= ((status & CyDCD) ? TIOCM_CAR : 0) |
                        ((status & CyRI) ? TIOCM_RNG : 0) |
                        ((status & CyDSR) ? TIOCM_DSR : 0) |
                        ((status & CyCTS) ? TIOCM_CTS : 0);
        } else {
                u32 lstatus;

                if (!cyz_is_loaded(card)) {
                        result = -ENODEV;
                        goto end;
                }

                lstatus = readl(&info->u.cyz.ch_ctrl->rs_status);
                result = ((lstatus & C_RS_RTS) ? TIOCM_RTS : 0) |
                        ((lstatus & C_RS_DTR) ? TIOCM_DTR : 0) |
                        ((lstatus & C_RS_DCD) ? TIOCM_CAR : 0) |
                        ((lstatus & C_RS_RI) ? TIOCM_RNG : 0) |
                        ((lstatus & C_RS_DSR) ? TIOCM_DSR : 0) |
                        ((lstatus & C_RS_CTS) ? TIOCM_CTS : 0);
        }
end:
        return result;
}                               /* cy_tiomget */

static int
cy_tiocmset(struct tty_struct *tty,
                unsigned int set, unsigned int clear)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        unsigned long flags;

        if (serial_paranoia_check(info, tty->name, __func__))
                return -ENODEV;

        card = info->card;
        if (!cy_is_Z(card)) {
                spin_lock_irqsave(&card->card_lock, flags);
                cyy_change_rts_dtr(info, set, clear);
                spin_unlock_irqrestore(&card->card_lock, flags);
        } else {
                struct CH_CTRL __iomem *ch_ctrl = info->u.cyz.ch_ctrl;
                int retval, channel = info->line - card->first_line;
                u32 rs;

                if (!cyz_is_loaded(card))
                        return -ENODEV;

                spin_lock_irqsave(&card->card_lock, flags);
                rs = readl(&ch_ctrl->rs_control);
                if (set & TIOCM_RTS)
                        rs |= C_RS_RTS;
                if (clear & TIOCM_RTS)
                        rs &= ~C_RS_RTS;
                if (set & TIOCM_DTR) {
                        rs |= C_RS_DTR;
#ifdef CY_DEBUG_DTR
                        printk(KERN_DEBUG "cyc:set_modem_info raising Z DTR\n");
#endif
                }
                if (clear & TIOCM_DTR) {
                        rs &= ~C_RS_DTR;
#ifdef CY_DEBUG_DTR
                        printk(KERN_DEBUG "cyc:set_modem_info clearing "
                                "Z DTR\n");
#endif
                }
                cy_writel(&ch_ctrl->rs_control, rs);
                retval = cyz_issue_cmd(card, channel, C_CM_IOCTLM, 0L);
                spin_unlock_irqrestore(&card->card_lock, flags);
                if (retval != 0) {
                        printk(KERN_ERR "cyc:set_modem_info retval on ttyC%d "
                                "was %x\n", info->line, retval);
                }
        }
        return 0;
}

/*
 * cy_break() --- routine which turns the break handling on or off
 */
static int cy_break(struct tty_struct *tty, int break_state)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        unsigned long flags;
        int retval = 0;

        if (serial_paranoia_check(info, tty->name, "cy_break"))
                return -EINVAL;

        card = info->card;

        spin_lock_irqsave(&card->card_lock, flags);
        if (!cy_is_Z(card)) {
                /* Let the transmit ISR take care of this (since it
                   requires stuffing characters into the output stream).
                 */
                if (break_state == -1) {
                        if (!info->breakon) {
                                info->breakon = 1;
                                if (!info->xmit_cnt) {
                                        spin_unlock_irqrestore(&card->card_lock, flags);
                                        start_xmit(info);
                                        spin_lock_irqsave(&card->card_lock, flags);
                                }
                        }
                } else {
                        if (!info->breakoff) {
                                info->breakoff = 1;
                                if (!info->xmit_cnt) {
                                        spin_unlock_irqrestore(&card->card_lock, flags);
                                        start_xmit(info);
                                        spin_lock_irqsave(&card->card_lock, flags);
                                }
                        }
                }
        } else {
                if (break_state == -1) {
                        retval = cyz_issue_cmd(card,
                                info->line - card->first_line,
                                C_CM_SET_BREAK, 0L);
                        if (retval != 0) {
                                printk(KERN_ERR "cyc:cy_break (set) retval on "
                                        "ttyC%d was %x\n", info->line, retval);
                        }
                } else {
                        retval = cyz_issue_cmd(card,
                                info->line - card->first_line,
                                C_CM_CLR_BREAK, 0L);
                        if (retval != 0) {
                                printk(KERN_DEBUG "cyc:cy_break (clr) retval "
                                        "on ttyC%d was %x\n", info->line,
                                        retval);
                        }
                }
        }
        spin_unlock_irqrestore(&card->card_lock, flags);
        return retval;
}                               /* cy_break */

static int set_threshold(struct cyclades_port *info, unsigned long value)
{
        struct cyclades_card *card = info->card;
        unsigned long flags;

        if (!cy_is_Z(card)) {
                info->cor3 &= ~CyREC_FIFO;
                info->cor3 |= value & CyREC_FIFO;

                spin_lock_irqsave(&card->card_lock, flags);
                cyy_writeb(info, CyCOR3, info->cor3);
                cyy_issue_cmd(info, CyCOR_CHANGE | CyCOR3ch);
                spin_unlock_irqrestore(&card->card_lock, flags);
        }
        return 0;
}                               /* set_threshold */

static int get_threshold(struct cyclades_port *info,
                                                unsigned long __user *value)
{
        struct cyclades_card *card = info->card;

        if (!cy_is_Z(card)) {
                u8 tmp = cyy_readb(info, CyCOR3) & CyREC_FIFO;
                return put_user(tmp, value);
        }
        return 0;
}                               /* get_threshold */

static int set_timeout(struct cyclades_port *info, unsigned long value)
{
        struct cyclades_card *card = info->card;
        unsigned long flags;

        if (!cy_is_Z(card)) {
                spin_lock_irqsave(&card->card_lock, flags);
                cyy_writeb(info, CyRTPR, value & 0xff);
                spin_unlock_irqrestore(&card->card_lock, flags);
        }
        return 0;
}                               /* set_timeout */

static int get_timeout(struct cyclades_port *info,
                                                unsigned long __user *value)
{
        struct cyclades_card *card = info->card;

        if (!cy_is_Z(card)) {
                u8 tmp = cyy_readb(info, CyRTPR);
                return put_user(tmp, value);
        }
        return 0;
}                               /* get_timeout */

static int cy_cflags_changed(struct cyclades_port *info, unsigned long arg,
                struct cyclades_icount *cprev)
{
        struct cyclades_icount cnow;
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&info->card->card_lock, flags);
        cnow = info->icount;    /* atomic copy */
        spin_unlock_irqrestore(&info->card->card_lock, flags);

        ret =   ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
                ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
                ((arg & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||
                ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));

        *cprev = cnow;

        return ret;
}

/*
 * This routine allows the tty driver to implement device-
 * specific ioctl's.  If the ioctl number passed in cmd is
 * not recognized by the driver, it should return ENOIOCTLCMD.
 */
static int
cy_ioctl(struct tty_struct *tty,
         unsigned int cmd, unsigned long arg)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_icount cnow;    /* kernel counter temps */
        int ret_val = 0;
        unsigned long flags;
        void __user *argp = (void __user *)arg;

        if (serial_paranoia_check(info, tty->name, "cy_ioctl"))
                return -ENODEV;

#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_ioctl ttyC%d, cmd = %x arg = %lx\n",
                info->line, cmd, arg);
#endif

        switch (cmd) {
        case CYGETMON:
                if (copy_to_user(argp, &info->mon, sizeof(info->mon))) {
                        ret_val = -EFAULT;
                        break;
                }
                memset(&info->mon, 0, sizeof(info->mon));
                break;
        case CYGETTHRESH:
                ret_val = get_threshold(info, argp);
                break;
        case CYSETTHRESH:
                ret_val = set_threshold(info, arg);
                break;
        case CYGETDEFTHRESH:
                ret_val = put_user(info->default_threshold,
                                (unsigned long __user *)argp);
                break;
        case CYSETDEFTHRESH:
                info->default_threshold = arg & 0x0f;
                break;
        case CYGETTIMEOUT:
                ret_val = get_timeout(info, argp);
                break;
        case CYSETTIMEOUT:
                ret_val = set_timeout(info, arg);
                break;
        case CYGETDEFTIMEOUT:
                ret_val = put_user(info->default_timeout,
                                (unsigned long __user *)argp);
                break;
        case CYSETDEFTIMEOUT:
                info->default_timeout = arg & 0xff;
                break;
        case CYSETRFLOW:
                info->rflow = (int)arg;
                break;
        case CYGETRFLOW:
                ret_val = info->rflow;
                break;
        case CYSETRTSDTR_INV:
                info->rtsdtr_inv = (int)arg;
                break;
        case CYGETRTSDTR_INV:
                ret_val = info->rtsdtr_inv;
                break;
        case CYGETCD1400VER:
                ret_val = info->chip_rev;
                break;
#ifndef CONFIG_CYZ_INTR
        case CYZSETPOLLCYCLE:
                if (arg > LONG_MAX / HZ)
                        return -ENODEV;
                cyz_polling_cycle = (arg * HZ) / 1000;
                break;
        case CYZGETPOLLCYCLE:
                ret_val = (cyz_polling_cycle * 1000) / HZ;
                break;
#endif                          /* CONFIG_CYZ_INTR */
        case CYSETWAIT:
                info->port.closing_wait = (unsigned short)arg * HZ / 100;
                break;
        case CYGETWAIT:
                ret_val = info->port.closing_wait / (HZ / 100);
                break;
        case TIOCSERGETLSR:     /* Get line status register */
                ret_val = get_lsr_info(info, argp);
                break;
                /*
                 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
                 * - mask passed in arg for lines of interest
                 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
                 * Caller should use TIOCGICOUNT to see which one it was
                 */
        case TIOCMIWAIT:
                spin_lock_irqsave(&info->card->card_lock, flags);
                /* note the counters on entry */
                cnow = info->icount;
                spin_unlock_irqrestore(&info->card->card_lock, flags);
                ret_val = wait_event_interruptible(info->port.delta_msr_wait,
                                cy_cflags_changed(info, arg, &cnow));
                break;

                /*
                 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
                 * Return: write counters to the user passed counter struct
                 * NB: both 1->0 and 0->1 transitions are counted except for
                 *     RI where only 0->1 is counted.
                 */
        default:
                ret_val = -ENOIOCTLCMD;
        }

#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_ioctl done\n");
#endif
        return ret_val;
}                               /* cy_ioctl */

static int cy_get_icount(struct tty_struct *tty,
                                struct serial_icounter_struct *sic)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_icount cnow;    /* Used to snapshot */
        unsigned long flags;

        spin_lock_irqsave(&info->card->card_lock, flags);
        cnow = info->icount;
        spin_unlock_irqrestore(&info->card->card_lock, flags);

        sic->cts = cnow.cts;
        sic->dsr = cnow.dsr;
        sic->rng = cnow.rng;
        sic->dcd = cnow.dcd;
        sic->rx = cnow.rx;
        sic->tx = cnow.tx;
        sic->frame = cnow.frame;
        sic->overrun = cnow.overrun;
        sic->parity = cnow.parity;
        sic->brk = cnow.brk;
        sic->buf_overrun = cnow.buf_overrun;
        return 0;
}

/*
 * This routine allows the tty driver to be notified when
 * device's termios settings have changed.  Note that a
 * well-designed tty driver should be prepared to accept the case
 * where old == NULL, and try to do something rational.
 */
static void cy_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
        struct cyclades_port *info = tty->driver_data;

#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_set_termios ttyC%d\n", info->line);
#endif

        cy_set_line_char(info, tty);

        if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
                tty->hw_stopped = 0;
                cy_start(tty);
        }
#if 0
        /*
         * No need to wake up processes in open wait, since they
         * sample the CLOCAL flag once, and don't recheck it.
         * XXX  It's not clear whether the current behavior is correct
         * or not.  Hence, this may change.....
         */
        if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
                wake_up_interruptible(&info->port.open_wait);
#endif
}                               /* cy_set_termios */

/* This function is used to send a high-priority XON/XOFF character to
   the device.
*/
static void cy_send_xchar(struct tty_struct *tty, char ch)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        int channel;

        if (serial_paranoia_check(info, tty->name, "cy_send_xchar"))
                return;

        info->x_char = ch;

        if (ch)
                cy_start(tty);

        card = info->card;
        channel = info->line - card->first_line;

        if (cy_is_Z(card)) {
                if (ch == STOP_CHAR(tty))
                        cyz_issue_cmd(card, channel, C_CM_SENDXOFF, 0L);
                else if (ch == START_CHAR(tty))
                        cyz_issue_cmd(card, channel, C_CM_SENDXON, 0L);
        }
}

/* This routine is called by the upper-layer tty layer to signal
   that incoming characters should be throttled because the input
   buffers are close to full.
 */
static void cy_throttle(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        unsigned long flags;

#ifdef CY_DEBUG_THROTTLE
        printk(KERN_DEBUG "cyc:throttle %s ...ttyC%d\n", tty_name(tty),
                         info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_throttle"))
                return;

        card = info->card;

        if (I_IXOFF(tty)) {
                if (!cy_is_Z(card))
                        cy_send_xchar(tty, STOP_CHAR(tty));
                else
                        info->throttle = 1;
        }

        if (C_CRTSCTS(tty)) {
                if (!cy_is_Z(card)) {
                        spin_lock_irqsave(&card->card_lock, flags);
                        cyy_change_rts_dtr(info, 0, TIOCM_RTS);
                        spin_unlock_irqrestore(&card->card_lock, flags);
                } else {
                        info->throttle = 1;
                }
        }
}                               /* cy_throttle */

/*
 * This routine notifies the tty driver that it should signal
 * that characters can now be sent to the tty without fear of
 * overrunning the input buffers of the line disciplines.
 */
static void cy_unthrottle(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;
        struct cyclades_card *card;
        unsigned long flags;

#ifdef CY_DEBUG_THROTTLE
        printk(KERN_DEBUG "cyc:unthrottle %s ...ttyC%d\n",
                tty_name(tty), info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_unthrottle"))
                return;

        if (I_IXOFF(tty)) {
                if (info->x_char)
                        info->x_char = 0;
                else
                        cy_send_xchar(tty, START_CHAR(tty));
        }

        if (C_CRTSCTS(tty)) {
                card = info->card;
                if (!cy_is_Z(card)) {
                        spin_lock_irqsave(&card->card_lock, flags);
                        cyy_change_rts_dtr(info, TIOCM_RTS, 0);
                        spin_unlock_irqrestore(&card->card_lock, flags);
                } else {
                        info->throttle = 0;
                }
        }
}                               /* cy_unthrottle */

/* cy_start and cy_stop provide software output flow control as a
   function of XON/XOFF, software CTS, and other such stuff.
*/
static void cy_stop(struct tty_struct *tty)
{
        struct cyclades_card *cinfo;
        struct cyclades_port *info = tty->driver_data;
        int channel;
        unsigned long flags;

#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_stop ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_stop"))
                return;

        cinfo = info->card;
        channel = info->line - cinfo->first_line;
        if (!cy_is_Z(cinfo)) {
                spin_lock_irqsave(&cinfo->card_lock, flags);
                cyy_writeb(info, CyCAR, channel & 0x03);
                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) & ~CyTxRdy);
                spin_unlock_irqrestore(&cinfo->card_lock, flags);
        }
}                               /* cy_stop */

static void cy_start(struct tty_struct *tty)
{
        struct cyclades_card *cinfo;
        struct cyclades_port *info = tty->driver_data;
        int channel;
        unsigned long flags;

#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_start ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_start"))
                return;

        cinfo = info->card;
        channel = info->line - cinfo->first_line;
        if (!cy_is_Z(cinfo)) {
                spin_lock_irqsave(&cinfo->card_lock, flags);
                cyy_writeb(info, CyCAR, channel & 0x03);
                cyy_writeb(info, CySRER, cyy_readb(info, CySRER) | CyTxRdy);
                spin_unlock_irqrestore(&cinfo->card_lock, flags);
        }
}                               /* cy_start */

/*
 * cy_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
static void cy_hangup(struct tty_struct *tty)
{
        struct cyclades_port *info = tty->driver_data;

#ifdef CY_DEBUG_OTHER
        printk(KERN_DEBUG "cyc:cy_hangup ttyC%d\n", info->line);
#endif

        if (serial_paranoia_check(info, tty->name, "cy_hangup"))
                return;

        cy_flush_buffer(tty);
        cy_shutdown(info, tty);
        tty_port_hangup(&info->port);
}                               /* cy_hangup */

static int cyy_carrier_raised(struct tty_port *port)
{
        struct cyclades_port *info = container_of(port, struct cyclades_port,
                        port);
        struct cyclades_card *cinfo = info->card;
        unsigned long flags;
        int channel = info->line - cinfo->first_line;
        u32 cd;

        spin_lock_irqsave(&cinfo->card_lock, flags);
        cyy_writeb(info, CyCAR, channel & 0x03);
        cd = cyy_readb(info, CyMSVR1) & CyDCD;
        spin_unlock_irqrestore(&cinfo->card_lock, flags);

        return cd;
}

static void cyy_dtr_rts(struct tty_port *port, int raise)
{
        struct cyclades_port *info = container_of(port, struct cyclades_port,
                        port);
        struct cyclades_card *cinfo = info->card;
        unsigned long flags;

        spin_lock_irqsave(&cinfo->card_lock, flags);
        cyy_change_rts_dtr(info, raise ? TIOCM_RTS | TIOCM_DTR : 0,
                        raise ? 0 : TIOCM_RTS | TIOCM_DTR);
        spin_unlock_irqrestore(&cinfo->card_lock, flags);
}

static int cyz_carrier_raised(struct tty_port *port)
{
        struct cyclades_port *info = container_of(port, struct cyclades_port,
                        port);