/*
 * Generic driver for the MPSC (UART mode) on Marvell parts (e.g., GT64240,
 * GT64260, MV64340, MV64360, GT96100, ... ).
 *
 * Author: Mark A. Greer <mgreer@mvista.com>
 *
 * Based on an old MPSC driver that was in the linuxppc tree.  It appears to
 * have been created by Chris Zankel (formerly of MontaVista) but there
 * is no proper Copyright so I'm not sure.  Apparently, parts were also
 * taken from PPCBoot (now U-Boot).  Also based on drivers/serial/8250.c
 * by Russell King.
 *
 * 2004 (c) MontaVista, Software, Inc.  This file is licensed under
 * the terms of the GNU General Public License version 2.  This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */
/*
 * The MPSC interface is much like a typical network controller's interface.
 * That is, you set up separate rings of descriptors for transmitting and
 * receiving data.  There is also a pool of buffers with (one buffer per
 * descriptor) that incoming data are dma'd into or outgoing data are dma'd
 * out of.
 *
 * The MPSC requires two other controllers to be able to work.  The Baud Rate
 * Generator (BRG) provides a clock at programmable frequencies which determines
 * the baud rate.  The Serial DMA Controller (SDMA) takes incoming data from the
 * MPSC and DMA's it into memory or DMA's outgoing data and passes it to the
 * MPSC.  It is actually the SDMA interrupt that the driver uses to keep the
 * transmit and receive "engines" going (i.e., indicate data has been
 * transmitted or received).
 *
 * NOTES:
 *
 * 1) Some chips have an erratum where several regs cannot be
 * read.  To work around that, we keep a local copy of those regs in
 * 'mpsc_port_info'.
 *
 * 2) Some chips have an erratum where the ctlr will hang when the SDMA ctlr
 * accesses system mem with coherency enabled.  For that reason, the driver
 * assumes that coherency for that ctlr has been disabled.  This means
 * that when in a cache coherent system, the driver has to manually manage
 * the data cache on the areas that it touches because the dma_* macro are
 * basically no-ops.
 *
 * 3) There is an erratum (on PPC) where you can't use the instruction to do
 * a DMA_TO_DEVICE/cache clean so DMA_BIDIRECTIONAL/flushes are used in places
 * where a DMA_TO_DEVICE/clean would have [otherwise] sufficed.
 *
 * 4) AFAICT, hardware flow control isn't supported by the controller --MAG.
 */


#if defined(CONFIG_SERIAL_MPSC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/mv643xx.h>
#include <linux/platform_device.h>
#include <linux/gfp.h>

#include <asm/io.h>
#include <asm/irq.h>

#define MPSC_NUM_CTLRS          2

/*
 * Descriptors and buffers must be cache line aligned.
 * Buffers lengths must be multiple of cache line size.
 * Number of Tx & Rx descriptors must be powers of 2.
 */
#define MPSC_RXR_ENTRIES        32
#define MPSC_RXRE_SIZE          dma_get_cache_alignment()
#define MPSC_RXR_SIZE           (MPSC_RXR_ENTRIES * MPSC_RXRE_SIZE)
#define MPSC_RXBE_SIZE          dma_get_cache_alignment()
#define MPSC_RXB_SIZE           (MPSC_RXR_ENTRIES * MPSC_RXBE_SIZE)

#define MPSC_TXR_ENTRIES        32
#define MPSC_TXRE_SIZE          dma_get_cache_alignment()
#define MPSC_TXR_SIZE           (MPSC_TXR_ENTRIES * MPSC_TXRE_SIZE)
#define MPSC_TXBE_SIZE          dma_get_cache_alignment()
#define MPSC_TXB_SIZE           (MPSC_TXR_ENTRIES * MPSC_TXBE_SIZE)

#define MPSC_DMA_ALLOC_SIZE     (MPSC_RXR_SIZE + MPSC_RXB_SIZE + MPSC_TXR_SIZE \
                + MPSC_TXB_SIZE + dma_get_cache_alignment() /* for alignment */)

/* Rx and Tx Ring entry descriptors -- assume entry size is <= cacheline size */
struct mpsc_rx_desc {
        u16 bufsize;
        u16 bytecnt;
        u32 cmdstat;
        u32 link;
        u32 buf_ptr;
} __attribute((packed));

struct mpsc_tx_desc {
        u16 bytecnt;
        u16 shadow;
        u32 cmdstat;
        u32 link;
        u32 buf_ptr;
} __attribute((packed));

/*
 * Some regs that have the erratum that you can't read them are are shared
 * between the two MPSC controllers.  This struct contains those shared regs.
 */
struct mpsc_shared_regs {
        phys_addr_t mpsc_routing_base_p;
        phys_addr_t sdma_intr_base_p;

        void __iomem *mpsc_routing_base;
        void __iomem *sdma_intr_base;

        u32 MPSC_MRR_m;
        u32 MPSC_RCRR_m;
        u32 MPSC_TCRR_m;
        u32 SDMA_INTR_CAUSE_m;
        u32 SDMA_INTR_MASK_m;
};

/* The main driver data structure */
struct mpsc_port_info {
        struct uart_port port;  /* Overlay uart_port structure */

        /* Internal driver state for this ctlr */
        u8 ready;
        u8 rcv_data;
        tcflag_t c_iflag;       /* save termios->c_iflag */
        tcflag_t c_cflag;       /* save termios->c_cflag */

        /* Info passed in from platform */
        u8 mirror_regs;         /* Need to mirror regs? */
        u8 cache_mgmt;          /* Need manual cache mgmt? */
        u8 brg_can_tune;        /* BRG has baud tuning? */
        u32 brg_clk_src;
        u16 mpsc_max_idle;
        int default_baud;
        int default_bits;
        int default_parity;
        int default_flow;

        /* Physical addresses of various blocks of registers (from platform) */
        phys_addr_t mpsc_base_p;
        phys_addr_t sdma_base_p;
        phys_addr_t brg_base_p;

        /* Virtual addresses of various blocks of registers (from platform) */
        void __iomem *mpsc_base;
        void __iomem *sdma_base;
        void __iomem *brg_base;

        /* Descriptor ring and buffer allocations */
        void *dma_region;
        dma_addr_t dma_region_p;

        dma_addr_t rxr;         /* Rx descriptor ring */
        dma_addr_t rxr_p;       /* Phys addr of rxr */
        u8 *rxb;                /* Rx Ring I/O buf */
        u8 *rxb_p;              /* Phys addr of rxb */
        u32 rxr_posn;           /* First desc w/ Rx data */

        dma_addr_t txr;         /* Tx descriptor ring */
        dma_addr_t txr_p;       /* Phys addr of txr */
        u8 *txb;                /* Tx Ring I/O buf */
        u8 *txb_p;              /* Phys addr of txb */
        int txr_head;           /* Where new data goes */
        int txr_tail;           /* Where sent data comes off */
        spinlock_t tx_lock;     /* transmit lock */

        /* Mirrored values of regs we can't read (if 'mirror_regs' set) */
        u32 MPSC_MPCR_m;
        u32 MPSC_CHR_1_m;
        u32 MPSC_CHR_2_m;
        u32 MPSC_CHR_10_m;
        u32 BRG_BCR_m;
        struct mpsc_shared_regs *shared_regs;
};

/* Hooks to platform-specific code */
int mpsc_platform_register_driver(void);
void mpsc_platform_unregister_driver(void);

/* Hooks back in to mpsc common to be called by platform-specific code */
struct mpsc_port_info *mpsc_device_probe(int index);
struct mpsc_port_info *mpsc_device_remove(int index);

/* Main MPSC Configuration Register Offsets */
#define MPSC_MMCRL                      0x0000
#define MPSC_MMCRH                      0x0004
#define MPSC_MPCR                       0x0008
#define MPSC_CHR_1                      0x000c
#define MPSC_CHR_2                      0x0010
#define MPSC_CHR_3                      0x0014
#define MPSC_CHR_4                      0x0018
#define MPSC_CHR_5                      0x001c
#define MPSC_CHR_6                      0x0020
#define MPSC_CHR_7                      0x0024
#define MPSC_CHR_8                      0x0028
#define MPSC_CHR_9                      0x002c
#define MPSC_CHR_10                     0x0030
#define MPSC_CHR_11                     0x0034

#define MPSC_MPCR_FRZ                   (1 << 9)
#define MPSC_MPCR_CL_5                  0
#define MPSC_MPCR_CL_6                  1
#define MPSC_MPCR_CL_7                  2
#define MPSC_MPCR_CL_8                  3
#define MPSC_MPCR_SBL_1                 0
#define MPSC_MPCR_SBL_2                 1

#define MPSC_CHR_2_TEV                  (1<<1)
#define MPSC_CHR_2_TA                   (1<<7)
#define MPSC_CHR_2_TTCS                 (1<<9)
#define MPSC_CHR_2_REV                  (1<<17)
#define MPSC_CHR_2_RA                   (1<<23)
#define MPSC_CHR_2_CRD                  (1<<25)
#define MPSC_CHR_2_EH                   (1<<31)
#define MPSC_CHR_2_PAR_ODD              0
#define MPSC_CHR_2_PAR_SPACE            1
#define MPSC_CHR_2_PAR_EVEN             2
#define MPSC_CHR_2_PAR_MARK             3

/* MPSC Signal Routing */
#define MPSC_MRR                        0x0000
#define MPSC_RCRR                       0x0004
#define MPSC_TCRR                       0x0008

/* Serial DMA Controller Interface Registers */
#define SDMA_SDC                        0x0000
#define SDMA_SDCM                       0x0008
#define SDMA_RX_DESC                    0x0800
#define SDMA_RX_BUF_PTR                 0x0808
#define SDMA_SCRDP                      0x0810
#define SDMA_TX_DESC                    0x0c00
#define SDMA_SCTDP                      0x0c10
#define SDMA_SFTDP                      0x0c14

#define SDMA_DESC_CMDSTAT_PE            (1<<0)
#define SDMA_DESC_CMDSTAT_CDL           (1<<1)
#define SDMA_DESC_CMDSTAT_FR            (1<<3)
#define SDMA_DESC_CMDSTAT_OR            (1<<6)
#define SDMA_DESC_CMDSTAT_BR            (1<<9)
#define SDMA_DESC_CMDSTAT_MI            (1<<10)
#define SDMA_DESC_CMDSTAT_A             (1<<11)
#define SDMA_DESC_CMDSTAT_AM            (1<<12)
#define SDMA_DESC_CMDSTAT_CT            (1<<13)
#define SDMA_DESC_CMDSTAT_C             (1<<14)
#define SDMA_DESC_CMDSTAT_ES            (1<<15)
#define SDMA_DESC_CMDSTAT_L             (1<<16)
#define SDMA_DESC_CMDSTAT_F             (1<<17)
#define SDMA_DESC_CMDSTAT_P             (1<<18)
#define SDMA_DESC_CMDSTAT_EI            (1<<23)
#define SDMA_DESC_CMDSTAT_O             (1<<31)

#define SDMA_DESC_DFLT                  (SDMA_DESC_CMDSTAT_O \
                | SDMA_DESC_CMDSTAT_EI)

#define SDMA_SDC_RFT                    (1<<0)
#define SDMA_SDC_SFM                    (1<<1)
#define SDMA_SDC_BLMR                   (1<<6)
#define SDMA_SDC_BLMT                   (1<<7)
#define SDMA_SDC_POVR                   (1<<8)
#define SDMA_SDC_RIFB                   (1<<9)

#define SDMA_SDCM_ERD                   (1<<7)
#define SDMA_SDCM_AR                    (1<<15)
#define SDMA_SDCM_STD                   (1<<16)
#define SDMA_SDCM_TXD                   (1<<23)
#define SDMA_SDCM_AT                    (1<<31)

#define SDMA_0_CAUSE_RXBUF              (1<<0)
#define SDMA_0_CAUSE_RXERR              (1<<1)
#define SDMA_0_CAUSE_TXBUF              (1<<2)
#define SDMA_0_CAUSE_TXEND              (1<<3)
#define SDMA_1_CAUSE_RXBUF              (1<<8)
#define SDMA_1_CAUSE_RXERR              (1<<9)
#define SDMA_1_CAUSE_TXBUF              (1<<10)
#define SDMA_1_CAUSE_TXEND              (1<<11)

#define SDMA_CAUSE_RX_MASK      (SDMA_0_CAUSE_RXBUF | SDMA_0_CAUSE_RXERR \
                | SDMA_1_CAUSE_RXBUF | SDMA_1_CAUSE_RXERR)
#define SDMA_CAUSE_TX_MASK      (SDMA_0_CAUSE_TXBUF | SDMA_0_CAUSE_TXEND \
                | SDMA_1_CAUSE_TXBUF | SDMA_1_CAUSE_TXEND)

/* SDMA Interrupt registers */
#define SDMA_INTR_CAUSE                 0x0000
#define SDMA_INTR_MASK                  0x0080

/* Baud Rate Generator Interface Registers */
#define BRG_BCR                         0x0000
#define BRG_BTR                         0x0004

/*
 * Define how this driver is known to the outside (we've been assigned a
 * range on the "Low-density serial ports" major).
 */
#define MPSC_MAJOR                      204
#define MPSC_MINOR_START                44
#define MPSC_DRIVER_NAME                "MPSC"
#define MPSC_DEV_NAME                   "ttyMM"
#define MPSC_VERSION                    "1.00"

static struct mpsc_port_info mpsc_ports[MPSC_NUM_CTLRS];
static struct mpsc_shared_regs mpsc_shared_regs;
static struct uart_driver mpsc_reg;

static void mpsc_start_rx(struct mpsc_port_info *pi);
static void mpsc_free_ring_mem(struct mpsc_port_info *pi);
static void mpsc_release_port(struct uart_port *port);
/*
 ******************************************************************************
 *
 * Baud Rate Generator Routines (BRG)
 *
 ******************************************************************************
 */
static void mpsc_brg_init(struct mpsc_port_info *pi, u32 clk_src)
{
        u32     v;

        v = (pi->mirror_regs) ? pi->BRG_BCR_m : readl(pi->brg_base + BRG_BCR);
        v = (v & ~(0xf << 18)) | ((clk_src & 0xf) << 18);

        if (pi->brg_can_tune)
                v &= ~(1 << 25);

        if (pi->mirror_regs)
                pi->BRG_BCR_m = v;
        writel(v, pi->brg_base + BRG_BCR);

        writel(readl(pi->brg_base + BRG_BTR) & 0xffff0000,
                pi->brg_base + BRG_BTR);
}

static void mpsc_brg_enable(struct mpsc_port_info *pi)
{
        u32     v;

        v = (pi->mirror_regs) ? pi->BRG_BCR_m : readl(pi->brg_base + BRG_BCR);
        v |= (1 << 16);

        if (pi->mirror_regs)
                pi->BRG_BCR_m = v;
        writel(v, pi->brg_base + BRG_BCR);
}

static void mpsc_brg_disable(struct mpsc_port_info *pi)
{
        u32     v;

        v = (pi->mirror_regs) ? pi->BRG_BCR_m : readl(pi->brg_base + BRG_BCR);
        v &= ~(1 << 16);

        if (pi->mirror_regs)
                pi->BRG_BCR_m = v;
        writel(v, pi->brg_base + BRG_BCR);
}

/*
 * To set the baud, we adjust the CDV field in the BRG_BCR reg.
 * From manual: Baud = clk / ((CDV+1)*2) ==> CDV = (clk / (baud*2)) - 1.
 * However, the input clock is divided by 16 in the MPSC b/c of how
 * 'MPSC_MMCRH' was set up so we have to divide the 'clk' used in our
 * calculation by 16 to account for that.  So the real calculation
 * that accounts for the way the mpsc is set up is:
 * CDV = (clk / (baud*2*16)) - 1 ==> CDV = (clk / (baud << 5)) - 1.
 */
static void mpsc_set_baudrate(struct mpsc_port_info *pi, u32 baud)
{
        u32     cdv = (pi->port.uartclk / (baud << 5)) - 1;
        u32     v;

        mpsc_brg_disable(pi);
        v = (pi->mirror_regs) ? pi->BRG_BCR_m : readl(pi->brg_base + BRG_BCR);
        v = (v & 0xffff0000) | (cdv & 0xffff);

        if (pi->mirror_regs)
                pi->BRG_BCR_m = v;
        writel(v, pi->brg_base + BRG_BCR);
        mpsc_brg_enable(pi);
}

/*
 ******************************************************************************
 *
 * Serial DMA Routines (SDMA)
 *
 ******************************************************************************
 */

static void mpsc_sdma_burstsize(struct mpsc_port_info *pi, u32 burst_size)
{
        u32     v;

        pr_debug("mpsc_sdma_burstsize[%d]: burst_size: %d\n",
                        pi->port.line, burst_size);

        burst_size >>= 3; /* Divide by 8 b/c reg values are 8-byte chunks */

        if (burst_size < 2)
                v = 0x0;        /* 1 64-bit word */
        else if (burst_size < 4)
                v = 0x1;        /* 2 64-bit words */
        else if (burst_size < 8)
                v = 0x2;        /* 4 64-bit words */
        else
                v = 0x3;        /* 8 64-bit words */

        writel((readl(pi->sdma_base + SDMA_SDC) & (0x3 << 12)) | (v << 12),
                pi->sdma_base + SDMA_SDC);
}

static void mpsc_sdma_init(struct mpsc_port_info *pi, u32 burst_size)
{
        pr_debug("mpsc_sdma_init[%d]: burst_size: %d\n", pi->port.line,
                burst_size);

        writel((readl(pi->sdma_base + SDMA_SDC) & 0x3ff) | 0x03f,
                pi->sdma_base + SDMA_SDC);
        mpsc_sdma_burstsize(pi, burst_size);
}

static u32 mpsc_sdma_intr_mask(struct mpsc_port_info *pi, u32 mask)
{
        u32     old, v;

        pr_debug("mpsc_sdma_intr_mask[%d]: mask: 0x%x\n", pi->port.line, mask);

        old = v = (pi->mirror_regs) ? pi->shared_regs->SDMA_INTR_MASK_m :
                readl(pi->shared_regs->sdma_intr_base + SDMA_INTR_MASK);

        mask &= 0xf;
        if (pi->port.line)
                mask <<= 8;
        v &= ~mask;

        if (pi->mirror_regs)
                pi->shared_regs->SDMA_INTR_MASK_m = v;
        writel(v, pi->shared_regs->sdma_intr_base + SDMA_INTR_MASK);

        if (pi->port.line)
                old >>= 8;
        return old & 0xf;
}

static void mpsc_sdma_intr_unmask(struct mpsc_port_info *pi, u32 mask)
{
        u32     v;

        pr_debug("mpsc_sdma_intr_unmask[%d]: mask: 0x%x\n", pi->port.line,mask);

        v = (pi->mirror_regs) ? pi->shared_regs->SDMA_INTR_MASK_m
                : readl(pi->shared_regs->sdma_intr_base + SDMA_INTR_MASK);

        mask &= 0xf;
        if (pi->port.line)
                mask <<= 8;
        v |= mask;

        if (pi->mirror_regs)
                pi->shared_regs->SDMA_INTR_MASK_m = v;
        writel(v, pi->shared_regs->sdma_intr_base + SDMA_INTR_MASK);
}

static void mpsc_sdma_intr_ack(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_sdma_intr_ack[%d]: Acknowledging IRQ\n", pi->port.line);

        if (pi->mirror_regs)
                pi->shared_regs->SDMA_INTR_CAUSE_m = 0;
        writeb(0x00, pi->shared_regs->sdma_intr_base + SDMA_INTR_CAUSE
                        + pi->port.line);
}

static void mpsc_sdma_set_rx_ring(struct mpsc_port_info *pi,
                struct mpsc_rx_desc *rxre_p)
{
        pr_debug("mpsc_sdma_set_rx_ring[%d]: rxre_p: 0x%x\n",
                pi->port.line, (u32)rxre_p);

        writel((u32)rxre_p, pi->sdma_base + SDMA_SCRDP);
}

static void mpsc_sdma_set_tx_ring(struct mpsc_port_info *pi,
                struct mpsc_tx_desc *txre_p)
{
        writel((u32)txre_p, pi->sdma_base + SDMA_SFTDP);
        writel((u32)txre_p, pi->sdma_base + SDMA_SCTDP);
}

static void mpsc_sdma_cmd(struct mpsc_port_info *pi, u32 val)
{
        u32     v;

        v = readl(pi->sdma_base + SDMA_SDCM);
        if (val)
                v |= val;
        else
                v = 0;
        wmb();
        writel(v, pi->sdma_base + SDMA_SDCM);
        wmb();
}

static uint mpsc_sdma_tx_active(struct mpsc_port_info *pi)
{
        return readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_TXD;
}

static void mpsc_sdma_start_tx(struct mpsc_port_info *pi)
{
        struct mpsc_tx_desc *txre, *txre_p;

        /* If tx isn't running & there's a desc ready to go, start it */
        if (!mpsc_sdma_tx_active(pi)) {
                txre = (struct mpsc_tx_desc *)(pi->txr
                                + (pi->txr_tail * MPSC_TXRE_SIZE));
                dma_cache_sync(pi->port.dev, (void *)txre, MPSC_TXRE_SIZE,
                                DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        invalidate_dcache_range((ulong)txre,
                                        (ulong)txre + MPSC_TXRE_SIZE);
#endif

                if (be32_to_cpu(txre->cmdstat) & SDMA_DESC_CMDSTAT_O) {
                        txre_p = (struct mpsc_tx_desc *)
                                (pi->txr_p + (pi->txr_tail * MPSC_TXRE_SIZE));

                        mpsc_sdma_set_tx_ring(pi, txre_p);
                        mpsc_sdma_cmd(pi, SDMA_SDCM_STD | SDMA_SDCM_TXD);
                }
        }
}

static void mpsc_sdma_stop(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_sdma_stop[%d]: Stopping SDMA\n", pi->port.line);

        /* Abort any SDMA transfers */
        mpsc_sdma_cmd(pi, 0);
        mpsc_sdma_cmd(pi, SDMA_SDCM_AR | SDMA_SDCM_AT);

        /* Clear the SDMA current and first TX and RX pointers */
        mpsc_sdma_set_tx_ring(pi, NULL);
        mpsc_sdma_set_rx_ring(pi, NULL);

        /* Disable interrupts */
        mpsc_sdma_intr_mask(pi, 0xf);
        mpsc_sdma_intr_ack(pi);
}

/*
 ******************************************************************************
 *
 * Multi-Protocol Serial Controller Routines (MPSC)
 *
 ******************************************************************************
 */

static void mpsc_hw_init(struct mpsc_port_info *pi)
{
        u32     v;

        pr_debug("mpsc_hw_init[%d]: Initializing hardware\n", pi->port.line);

        /* Set up clock routing */
        if (pi->mirror_regs) {
                v = pi->shared_regs->MPSC_MRR_m;
                v &= ~0x1c7;
                pi->shared_regs->MPSC_MRR_m = v;
                writel(v, pi->shared_regs->mpsc_routing_base + MPSC_MRR);

                v = pi->shared_regs->MPSC_RCRR_m;
                v = (v & ~0xf0f) | 0x100;
                pi->shared_regs->MPSC_RCRR_m = v;
                writel(v, pi->shared_regs->mpsc_routing_base + MPSC_RCRR);

                v = pi->shared_regs->MPSC_TCRR_m;
                v = (v & ~0xf0f) | 0x100;
                pi->shared_regs->MPSC_TCRR_m = v;
                writel(v, pi->shared_regs->mpsc_routing_base + MPSC_TCRR);
        } else {
                v = readl(pi->shared_regs->mpsc_routing_base + MPSC_MRR);
                v &= ~0x1c7;
                writel(v, pi->shared_regs->mpsc_routing_base + MPSC_MRR);

                v = readl(pi->shared_regs->mpsc_routing_base + MPSC_RCRR);
                v = (v & ~0xf0f) | 0x100;
                writel(v, pi->shared_regs->mpsc_routing_base + MPSC_RCRR);

                v = readl(pi->shared_regs->mpsc_routing_base + MPSC_TCRR);
                v = (v & ~0xf0f) | 0x100;
                writel(v, pi->shared_regs->mpsc_routing_base + MPSC_TCRR);
        }

        /* Put MPSC in UART mode & enabel Tx/Rx egines */
        writel(0x000004c4, pi->mpsc_base + MPSC_MMCRL);

        /* No preamble, 16x divider, low-latency, */
        writel(0x04400400, pi->mpsc_base + MPSC_MMCRH);
        mpsc_set_baudrate(pi, pi->default_baud);

        if (pi->mirror_regs) {
                pi->MPSC_CHR_1_m = 0;
                pi->MPSC_CHR_2_m = 0;
        }
        writel(0, pi->mpsc_base + MPSC_CHR_1);
        writel(0, pi->mpsc_base + MPSC_CHR_2);
        writel(pi->mpsc_max_idle, pi->mpsc_base + MPSC_CHR_3);
        writel(0, pi->mpsc_base + MPSC_CHR_4);
        writel(0, pi->mpsc_base + MPSC_CHR_5);
        writel(0, pi->mpsc_base + MPSC_CHR_6);
        writel(0, pi->mpsc_base + MPSC_CHR_7);
        writel(0, pi->mpsc_base + MPSC_CHR_8);
        writel(0, pi->mpsc_base + MPSC_CHR_9);
        writel(0, pi->mpsc_base + MPSC_CHR_10);
}

static void mpsc_enter_hunt(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_enter_hunt[%d]: Hunting...\n", pi->port.line);

        if (pi->mirror_regs) {
                writel(pi->MPSC_CHR_2_m | MPSC_CHR_2_EH,
                        pi->mpsc_base + MPSC_CHR_2);
                /* Erratum prevents reading CHR_2 so just delay for a while */
                udelay(100);
        } else {
                writel(readl(pi->mpsc_base + MPSC_CHR_2) | MPSC_CHR_2_EH,
                                pi->mpsc_base + MPSC_CHR_2);

                while (readl(pi->mpsc_base + MPSC_CHR_2) & MPSC_CHR_2_EH)
                        udelay(10);
        }
}

static void mpsc_freeze(struct mpsc_port_info *pi)
{
        u32     v;

        pr_debug("mpsc_freeze[%d]: Freezing\n", pi->port.line);

        v = (pi->mirror_regs) ? pi->MPSC_MPCR_m :
                readl(pi->mpsc_base + MPSC_MPCR);
        v |= MPSC_MPCR_FRZ;

        if (pi->mirror_regs)
                pi->MPSC_MPCR_m = v;
        writel(v, pi->mpsc_base + MPSC_MPCR);
}

static void mpsc_unfreeze(struct mpsc_port_info *pi)
{
        u32     v;

        v = (pi->mirror_regs) ? pi->MPSC_MPCR_m :
                readl(pi->mpsc_base + MPSC_MPCR);
        v &= ~MPSC_MPCR_FRZ;

        if (pi->mirror_regs)
                pi->MPSC_MPCR_m = v;
        writel(v, pi->mpsc_base + MPSC_MPCR);

        pr_debug("mpsc_unfreeze[%d]: Unfrozen\n", pi->port.line);
}

static void mpsc_set_char_length(struct mpsc_port_info *pi, u32 len)
{
        u32     v;

        pr_debug("mpsc_set_char_length[%d]: char len: %d\n", pi->port.line,len);

        v = (pi->mirror_regs) ? pi->MPSC_MPCR_m :
                readl(pi->mpsc_base + MPSC_MPCR);
        v = (v & ~(0x3 << 12)) | ((len & 0x3) << 12);

        if (pi->mirror_regs)
                pi->MPSC_MPCR_m = v;
        writel(v, pi->mpsc_base + MPSC_MPCR);
}

static void mpsc_set_stop_bit_length(struct mpsc_port_info *pi, u32 len)
{
        u32     v;

        pr_debug("mpsc_set_stop_bit_length[%d]: stop bits: %d\n",
                pi->port.line, len);

        v = (pi->mirror_regs) ? pi->MPSC_MPCR_m :
                readl(pi->mpsc_base + MPSC_MPCR);

        v = (v & ~(1 << 14)) | ((len & 0x1) << 14);

        if (pi->mirror_regs)
                pi->MPSC_MPCR_m = v;
        writel(v, pi->mpsc_base + MPSC_MPCR);
}

static void mpsc_set_parity(struct mpsc_port_info *pi, u32 p)
{
        u32     v;

        pr_debug("mpsc_set_parity[%d]: parity bits: 0x%x\n", pi->port.line, p);

        v = (pi->mirror_regs) ? pi->MPSC_CHR_2_m :
                readl(pi->mpsc_base + MPSC_CHR_2);

        p &= 0x3;
        v = (v & ~0xc000c) | (p << 18) | (p << 2);

        if (pi->mirror_regs)
                pi->MPSC_CHR_2_m = v;
        writel(v, pi->mpsc_base + MPSC_CHR_2);
}

/*
 ******************************************************************************
 *
 * Driver Init Routines
 *
 ******************************************************************************
 */

static void mpsc_init_hw(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_init_hw[%d]: Initializing\n", pi->port.line);

        mpsc_brg_init(pi, pi->brg_clk_src);
        mpsc_brg_enable(pi);
        mpsc_sdma_init(pi, dma_get_cache_alignment());  /* burst a cacheline */
        mpsc_sdma_stop(pi);
        mpsc_hw_init(pi);
}

static int mpsc_alloc_ring_mem(struct mpsc_port_info *pi)
{
        int rc = 0;

        pr_debug("mpsc_alloc_ring_mem[%d]: Allocating ring mem\n",
                pi->port.line);

        if (!pi->dma_region) {
                if (!dma_supported(pi->port.dev, 0xffffffff)) {
                        printk(KERN_ERR "MPSC: Inadequate DMA support\n");
                        rc = -ENXIO;
                } else if ((pi->dma_region = dma_alloc_noncoherent(pi->port.dev,
                                                MPSC_DMA_ALLOC_SIZE,
                                                &pi->dma_region_p, GFP_KERNEL))
                                == NULL) {
                        printk(KERN_ERR "MPSC: Can't alloc Desc region\n");
                        rc = -ENOMEM;
                }
        }

        return rc;
}

static void mpsc_free_ring_mem(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_free_ring_mem[%d]: Freeing ring mem\n", pi->port.line);

        if (pi->dma_region) {
                dma_free_noncoherent(pi->port.dev, MPSC_DMA_ALLOC_SIZE,
                                pi->dma_region, pi->dma_region_p);
                pi->dma_region = NULL;
                pi->dma_region_p = (dma_addr_t)NULL;
        }
}

static void mpsc_init_rings(struct mpsc_port_info *pi)
{
        struct mpsc_rx_desc *rxre;
        struct mpsc_tx_desc *txre;
        dma_addr_t dp, dp_p;
        u8 *bp, *bp_p;
        int i;

        pr_debug("mpsc_init_rings[%d]: Initializing rings\n", pi->port.line);

        BUG_ON(pi->dma_region == NULL);

        memset(pi->dma_region, 0, MPSC_DMA_ALLOC_SIZE);

        /*
         * Descriptors & buffers are multiples of cacheline size and must be
         * cacheline aligned.
         */
        dp = ALIGN((u32)pi->dma_region, dma_get_cache_alignment());
        dp_p = ALIGN((u32)pi->dma_region_p, dma_get_cache_alignment());

        /*
         * Partition dma region into rx ring descriptor, rx buffers,
         * tx ring descriptors, and tx buffers.
         */
        pi->rxr = dp;
        pi->rxr_p = dp_p;
        dp += MPSC_RXR_SIZE;
        dp_p += MPSC_RXR_SIZE;

        pi->rxb = (u8 *)dp;
        pi->rxb_p = (u8 *)dp_p;
        dp += MPSC_RXB_SIZE;
        dp_p += MPSC_RXB_SIZE;

        pi->rxr_posn = 0;

        pi->txr = dp;
        pi->txr_p = dp_p;
        dp += MPSC_TXR_SIZE;
        dp_p += MPSC_TXR_SIZE;

        pi->txb = (u8 *)dp;
        pi->txb_p = (u8 *)dp_p;

        pi->txr_head = 0;
        pi->txr_tail = 0;

        /* Init rx ring descriptors */
        dp = pi->rxr;
        dp_p = pi->rxr_p;
        bp = pi->rxb;
        bp_p = pi->rxb_p;

        for (i = 0; i < MPSC_RXR_ENTRIES; i++) {
                rxre = (struct mpsc_rx_desc *)dp;

                rxre->bufsize = cpu_to_be16(MPSC_RXBE_SIZE);
                rxre->bytecnt = cpu_to_be16(0);
                rxre->cmdstat = cpu_to_be32(SDMA_DESC_CMDSTAT_O
                                | SDMA_DESC_CMDSTAT_EI | SDMA_DESC_CMDSTAT_F
                                | SDMA_DESC_CMDSTAT_L);
                rxre->link = cpu_to_be32(dp_p + MPSC_RXRE_SIZE);
                rxre->buf_ptr = cpu_to_be32(bp_p);

                dp += MPSC_RXRE_SIZE;
                dp_p += MPSC_RXRE_SIZE;
                bp += MPSC_RXBE_SIZE;
                bp_p += MPSC_RXBE_SIZE;
        }
        rxre->link = cpu_to_be32(pi->rxr_p);    /* Wrap last back to first */

        /* Init tx ring descriptors */
        dp = pi->txr;
        dp_p = pi->txr_p;
        bp = pi->txb;
        bp_p = pi->txb_p;

        for (i = 0; i < MPSC_TXR_ENTRIES; i++) {
                txre = (struct mpsc_tx_desc *)dp;

                txre->link = cpu_to_be32(dp_p + MPSC_TXRE_SIZE);
                txre->buf_ptr = cpu_to_be32(bp_p);

                dp += MPSC_TXRE_SIZE;
                dp_p += MPSC_TXRE_SIZE;
                bp += MPSC_TXBE_SIZE;
                bp_p += MPSC_TXBE_SIZE;
        }
        txre->link = cpu_to_be32(pi->txr_p);    /* Wrap last back to first */

        dma_cache_sync(pi->port.dev, (void *)pi->dma_region,
                        MPSC_DMA_ALLOC_SIZE, DMA_BIDIRECTIONAL);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        flush_dcache_range((ulong)pi->dma_region,
                                        (ulong)pi->dma_region
                                        + MPSC_DMA_ALLOC_SIZE);
#endif

        return;
}

static void mpsc_uninit_rings(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_uninit_rings[%d]: Uninitializing rings\n",pi->port.line);

        BUG_ON(pi->dma_region == NULL);

        pi->rxr = 0;
        pi->rxr_p = 0;
        pi->rxb = NULL;
        pi->rxb_p = NULL;
        pi->rxr_posn = 0;

        pi->txr = 0;
        pi->txr_p = 0;
        pi->txb = NULL;
        pi->txb_p = NULL;
        pi->txr_head = 0;
        pi->txr_tail = 0;
}

static int mpsc_make_ready(struct mpsc_port_info *pi)
{
        int rc;

        pr_debug("mpsc_make_ready[%d]: Making cltr ready\n", pi->port.line);

        if (!pi->ready) {
                mpsc_init_hw(pi);
                if ((rc = mpsc_alloc_ring_mem(pi)))
                        return rc;
                mpsc_init_rings(pi);
                pi->ready = 1;
        }

        return 0;
}

#ifdef CONFIG_CONSOLE_POLL
static int serial_polled;
#endif

/*
 ******************************************************************************
 *
 * Interrupt Handling Routines
 *
 ******************************************************************************
 */

static int mpsc_rx_intr(struct mpsc_port_info *pi, unsigned long *flags)
{
        struct mpsc_rx_desc *rxre;
        struct tty_port *port = &pi->port.state->port;
        u32     cmdstat, bytes_in, i;
        int     rc = 0;
        u8      *bp;
        char    flag = TTY_NORMAL;

        pr_debug("mpsc_rx_intr[%d]: Handling Rx intr\n", pi->port.line);

        rxre = (struct mpsc_rx_desc *)(pi->rxr + (pi->rxr_posn*MPSC_RXRE_SIZE));

        dma_cache_sync(pi->port.dev, (void *)rxre, MPSC_RXRE_SIZE,
                        DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
        if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                invalidate_dcache_range((ulong)rxre,
                                (ulong)rxre + MPSC_RXRE_SIZE);
#endif

        /*
         * Loop through Rx descriptors handling ones that have been completed.
         */
        while (!((cmdstat = be32_to_cpu(rxre->cmdstat))
                                & SDMA_DESC_CMDSTAT_O)) {
                bytes_in = be16_to_cpu(rxre->bytecnt);
#ifdef CONFIG_CONSOLE_POLL
                if (unlikely(serial_polled)) {
                        serial_polled = 0;
                        return 0;
                }
#endif
                /* Following use of tty struct directly is deprecated */
                if (tty_buffer_request_room(port, bytes_in) < bytes_in) {
                        if (port->low_latency) {
                                spin_unlock_irqrestore(&pi->port.lock, *flags);
                                tty_flip_buffer_push(port);
                                spin_lock_irqsave(&pi->port.lock, *flags);
                        }
                        /*
                         * If this failed then we will throw away the bytes
                         * but must do so to clear interrupts.
                         */
                }

                bp = pi->rxb + (pi->rxr_posn * MPSC_RXBE_SIZE);
                dma_cache_sync(pi->port.dev, (void *)bp, MPSC_RXBE_SIZE,
                                DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        invalidate_dcache_range((ulong)bp,
                                        (ulong)bp + MPSC_RXBE_SIZE);
#endif

                /*
                 * Other than for parity error, the manual provides little
                 * info on what data will be in a frame flagged by any of
                 * these errors.  For parity error, it is the last byte in
                 * the buffer that had the error.  As for the rest, I guess
                 * we'll assume there is no data in the buffer.
                 * If there is...it gets lost.
                 */
                if (unlikely(cmdstat & (SDMA_DESC_CMDSTAT_BR

                                                | SDMA_DESC_CMDSTAT_FR
                                                | SDMA_DESC_CMDSTAT_OR))) {

                        pi->port.icount.rx++;

                        if (cmdstat & SDMA_DESC_CMDSTAT_BR) {   /* Break */
                                pi->port.icount.brk++;

                                if (uart_handle_break(&pi->port))
                                        goto next_frame;
                        } else if (cmdstat & SDMA_DESC_CMDSTAT_FR) {
                                pi->port.icount.frame++;
                        } else if (cmdstat & SDMA_DESC_CMDSTAT_OR) {
                                pi->port.icount.overrun++;
                        }

                        cmdstat &= pi->port.read_status_mask;

                        if (cmdstat & SDMA_DESC_CMDSTAT_BR)
                                flag = TTY_BREAK;
                        else if (cmdstat & SDMA_DESC_CMDSTAT_FR)
                                flag = TTY_FRAME;
                        else if (cmdstat & SDMA_DESC_CMDSTAT_OR)
                                flag = TTY_OVERRUN;
                        else if (cmdstat & SDMA_DESC_CMDSTAT_PE)
                                flag = TTY_PARITY;
                }

                if (uart_handle_sysrq_char(&pi->port, *bp)) {
                        bp++;
                        bytes_in--;
#ifdef CONFIG_CONSOLE_POLL
                        if (unlikely(serial_polled)) {
                                serial_polled = 0;
                                return 0;
                        }
#endif
                        goto next_frame;
                }

                if ((unlikely(cmdstat & (SDMA_DESC_CMDSTAT_BR
                                                | SDMA_DESC_CMDSTAT_FR
                                                | SDMA_DESC_CMDSTAT_OR)))
                                && !(cmdstat & pi->port.ignore_status_mask)) {
                        tty_insert_flip_char(port, *bp, flag);
                } else {
                        for (i=0; i<bytes_in; i++)
                                tty_insert_flip_char(port, *bp++, TTY_NORMAL);

                        pi->port.icount.rx += bytes_in;
                }

next_frame:
                rxre->bytecnt = cpu_to_be16(0);
                wmb();
                rxre->cmdstat = cpu_to_be32(SDMA_DESC_CMDSTAT_O
                                | SDMA_DESC_CMDSTAT_EI | SDMA_DESC_CMDSTAT_F
                                | SDMA_DESC_CMDSTAT_L);
                wmb();
                dma_cache_sync(pi->port.dev, (void *)rxre, MPSC_RXRE_SIZE,
                                DMA_BIDIRECTIONAL);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        flush_dcache_range((ulong)rxre,
                                        (ulong)rxre + MPSC_RXRE_SIZE);
#endif

                /* Advance to next descriptor */
                pi->rxr_posn = (pi->rxr_posn + 1) & (MPSC_RXR_ENTRIES - 1);
                rxre = (struct mpsc_rx_desc *)
                        (pi->rxr + (pi->rxr_posn * MPSC_RXRE_SIZE));
                dma_cache_sync(pi->port.dev, (void *)rxre, MPSC_RXRE_SIZE,
                                DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        invalidate_dcache_range((ulong)rxre,
                                        (ulong)rxre + MPSC_RXRE_SIZE);
#endif
                rc = 1;
        }

        /* Restart rx engine, if its stopped */
        if ((readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_ERD) == 0)
                mpsc_start_rx(pi);

        spin_unlock_irqrestore(&pi->port.lock, *flags);
        tty_flip_buffer_push(port);
        spin_lock_irqsave(&pi->port.lock, *flags);
        return rc;
}

static void mpsc_setup_tx_desc(struct mpsc_port_info *pi, u32 count, u32 intr)
{
        struct mpsc_tx_desc *txre;

        txre = (struct mpsc_tx_desc *)(pi->txr
                        + (pi->txr_head * MPSC_TXRE_SIZE));

        txre->bytecnt = cpu_to_be16(count);
        txre->shadow = txre->bytecnt;
        wmb();                  /* ensure cmdstat is last field updated */
        txre->cmdstat = cpu_to_be32(SDMA_DESC_CMDSTAT_O | SDMA_DESC_CMDSTAT_F
                        | SDMA_DESC_CMDSTAT_L
                        | ((intr) ? SDMA_DESC_CMDSTAT_EI : 0));
        wmb();
        dma_cache_sync(pi->port.dev, (void *)txre, MPSC_TXRE_SIZE,
                        DMA_BIDIRECTIONAL);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
        if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                flush_dcache_range((ulong)txre,
                                (ulong)txre + MPSC_TXRE_SIZE);
#endif
}

static void mpsc_copy_tx_data(struct mpsc_port_info *pi)
{
        struct circ_buf *xmit = &pi->port.state->xmit;
        u8 *bp;
        u32 i;

        /* Make sure the desc ring isn't full */
        while (CIRC_CNT(pi->txr_head, pi->txr_tail, MPSC_TXR_ENTRIES)
                        < (MPSC_TXR_ENTRIES - 1)) {
                if (pi->port.x_char) {
                        /*
                         * Ideally, we should use the TCS field in
                         * CHR_1 to put the x_char out immediately but
                         * errata prevents us from being able to read
                         * CHR_2 to know that its safe to write to
                         * CHR_1.  Instead, just put it in-band with
                         * all the other Tx data.
                         */
                        bp = pi->txb + (pi->txr_head * MPSC_TXBE_SIZE);
                        *bp = pi->port.x_char;
                        pi->port.x_char = 0;
                        i = 1;
                } else if (!uart_circ_empty(xmit)
                                && !uart_tx_stopped(&pi->port)) {
                        i = min((u32)MPSC_TXBE_SIZE,
                                (u32)uart_circ_chars_pending(xmit));
                        i = min(i, (u32)CIRC_CNT_TO_END(xmit->head, xmit->tail,
                                UART_XMIT_SIZE));
                        bp = pi->txb + (pi->txr_head * MPSC_TXBE_SIZE);
                        memcpy(bp, &xmit->buf[xmit->tail], i);
                        xmit->tail = (xmit->tail + i) & (UART_XMIT_SIZE - 1);

                        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                                uart_write_wakeup(&pi->port);
                } else { /* All tx data copied into ring bufs */
                        return;
                }

                dma_cache_sync(pi->port.dev, (void *)bp, MPSC_TXBE_SIZE,
                                DMA_BIDIRECTIONAL);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        flush_dcache_range((ulong)bp,
                                        (ulong)bp + MPSC_TXBE_SIZE);
#endif
                mpsc_setup_tx_desc(pi, i, 1);

                /* Advance to next descriptor */
                pi->txr_head = (pi->txr_head + 1) & (MPSC_TXR_ENTRIES - 1);
        }
}

static int mpsc_tx_intr(struct mpsc_port_info *pi)
{
        struct mpsc_tx_desc *txre;
        int rc = 0;
        unsigned long iflags;

        spin_lock_irqsave(&pi->tx_lock, iflags);

        if (!mpsc_sdma_tx_active(pi)) {
                txre = (struct mpsc_tx_desc *)(pi->txr
                                + (pi->txr_tail * MPSC_TXRE_SIZE));

                dma_cache_sync(pi->port.dev, (void *)txre, MPSC_TXRE_SIZE,
                                DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        invalidate_dcache_range((ulong)txre,
                                        (ulong)txre + MPSC_TXRE_SIZE);
#endif

                while (!(be32_to_cpu(txre->cmdstat) & SDMA_DESC_CMDSTAT_O)) {
                        rc = 1;
                        pi->port.icount.tx += be16_to_cpu(txre->bytecnt);
                        pi->txr_tail = (pi->txr_tail+1) & (MPSC_TXR_ENTRIES-1);

                        /* If no more data to tx, fall out of loop */
                        if (pi->txr_head == pi->txr_tail)
                                break;

                        txre = (struct mpsc_tx_desc *)(pi->txr
                                        + (pi->txr_tail * MPSC_TXRE_SIZE));
                        dma_cache_sync(pi->port.dev, (void *)txre,
                                        MPSC_TXRE_SIZE, DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                        if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                                invalidate_dcache_range((ulong)txre,
                                                (ulong)txre + MPSC_TXRE_SIZE);
#endif
                }

                mpsc_copy_tx_data(pi);
                mpsc_sdma_start_tx(pi); /* start next desc if ready */
        }

        spin_unlock_irqrestore(&pi->tx_lock, iflags);
        return rc;
}

/*
 * This is the driver's interrupt handler.  To avoid a race, we first clear
 * the interrupt, then handle any completed Rx/Tx descriptors.  When done
 * handling those descriptors, we restart the Rx/Tx engines if they're stopped.
 */
static irqreturn_t mpsc_sdma_intr(int irq, void *dev_id)
{
        struct mpsc_port_info *pi = dev_id;
        ulong iflags;
        int rc = IRQ_NONE;

        pr_debug("mpsc_sdma_intr[%d]: SDMA Interrupt Received\n",pi->port.line);

        spin_lock_irqsave(&pi->port.lock, iflags);
        mpsc_sdma_intr_ack(pi);
        if (mpsc_rx_intr(pi, &iflags))
                rc = IRQ_HANDLED;
        if (mpsc_tx_intr(pi))
                rc = IRQ_HANDLED;
        spin_unlock_irqrestore(&pi->port.lock, iflags);

        pr_debug("mpsc_sdma_intr[%d]: SDMA Interrupt Handled\n", pi->port.line);
        return rc;
}

/*
 ******************************************************************************
 *
 * serial_core.c Interface routines
 *
 ******************************************************************************
 */
static uint mpsc_tx_empty(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        ulong iflags;
        uint rc;

        spin_lock_irqsave(&pi->port.lock, iflags);
        rc = mpsc_sdma_tx_active(pi) ? 0 : TIOCSER_TEMT;
        spin_unlock_irqrestore(&pi->port.lock, iflags);

        return rc;
}

static void mpsc_set_mctrl(struct uart_port *port, uint mctrl)
{
        /* Have no way to set modem control lines AFAICT */
}

static uint mpsc_get_mctrl(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        u32 mflags, status;

        status = (pi->mirror_regs) ? pi->MPSC_CHR_10_m
                : readl(pi->mpsc_base + MPSC_CHR_10);

        mflags = 0;
        if (status & 0x1)
                mflags |= TIOCM_CTS;
        if (status & 0x2)
                mflags |= TIOCM_CAR;

        return mflags | TIOCM_DSR;      /* No way to tell if DSR asserted */
}

static void mpsc_stop_tx(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;

        pr_debug("mpsc_stop_tx[%d]\n", port->line);

        mpsc_freeze(pi);
}

static void mpsc_start_tx(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        unsigned long iflags;

        spin_lock_irqsave(&pi->tx_lock, iflags);

        mpsc_unfreeze(pi);
        mpsc_copy_tx_data(pi);
        mpsc_sdma_start_tx(pi);

        spin_unlock_irqrestore(&pi->tx_lock, iflags);

        pr_debug("mpsc_start_tx[%d]\n", port->line);
}

static void mpsc_start_rx(struct mpsc_port_info *pi)
{
        pr_debug("mpsc_start_rx[%d]: Starting...\n", pi->port.line);

        if (pi->rcv_data) {
                mpsc_enter_hunt(pi);
                mpsc_sdma_cmd(pi, SDMA_SDCM_ERD);
        }
}

static void mpsc_stop_rx(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;

        pr_debug("mpsc_stop_rx[%d]: Stopping...\n", port->line);

        if (pi->mirror_regs) {
                writel(pi->MPSC_CHR_2_m | MPSC_CHR_2_RA,
                                pi->mpsc_base + MPSC_CHR_2);
                /* Erratum prevents reading CHR_2 so just delay for a while */
                udelay(100);
        } else {
                writel(readl(pi->mpsc_base + MPSC_CHR_2) | MPSC_CHR_2_RA,
                                pi->mpsc_base + MPSC_CHR_2);

                while (readl(pi->mpsc_base + MPSC_CHR_2) & MPSC_CHR_2_RA)
                        udelay(10);
        }

        mpsc_sdma_cmd(pi, SDMA_SDCM_AR);
}

static void mpsc_break_ctl(struct uart_port *port, int ctl)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        ulong   flags;
        u32     v;

        v = ctl ? 0x00ff0000 : 0;

        spin_lock_irqsave(&pi->port.lock, flags);
        if (pi->mirror_regs)
                pi->MPSC_CHR_1_m = v;
        writel(v, pi->mpsc_base + MPSC_CHR_1);
        spin_unlock_irqrestore(&pi->port.lock, flags);
}

static int mpsc_startup(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        u32 flag = 0;
        int rc;

        pr_debug("mpsc_startup[%d]: Starting up MPSC, irq: %d\n",
                port->line, pi->port.irq);

        if ((rc = mpsc_make_ready(pi)) == 0) {
                /* Setup IRQ handler */
                mpsc_sdma_intr_ack(pi);

                /* If irq's are shared, need to set flag */
                if (mpsc_ports[0].port.irq == mpsc_ports[1].port.irq)
                        flag = IRQF_SHARED;

                if (request_irq(pi->port.irq, mpsc_sdma_intr, flag,
                                        "mpsc-sdma", pi))
                        printk(KERN_ERR "MPSC: Can't get SDMA IRQ %d\n",
                                        pi->port.irq);

                mpsc_sdma_intr_unmask(pi, 0xf);
                mpsc_sdma_set_rx_ring(pi, (struct mpsc_rx_desc *)(pi->rxr_p
                                        + (pi->rxr_posn * MPSC_RXRE_SIZE)));
        }

        return rc;
}

static void mpsc_shutdown(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;

        pr_debug("mpsc_shutdown[%d]: Shutting down MPSC\n", port->line);

        mpsc_sdma_stop(pi);
        free_irq(pi->port.irq, pi);
}

static void mpsc_set_termios(struct uart_port *port, struct ktermios *termios,
                 struct ktermios *old)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        u32 baud;
        ulong flags;
        u32 chr_bits, stop_bits, par;

        pi->c_iflag = termios->c_iflag;
        pi->c_cflag = termios->c_cflag;

        switch (termios->c_cflag & CSIZE) {
        case CS5:
                chr_bits = MPSC_MPCR_CL_5;
                break;
        case CS6:
                chr_bits = MPSC_MPCR_CL_6;
                break;
        case CS7:
                chr_bits = MPSC_MPCR_CL_7;
                break;
        case CS8:
        default:
                chr_bits = MPSC_MPCR_CL_8;
                break;
        }

        if (termios->c_cflag & CSTOPB)
                stop_bits = MPSC_MPCR_SBL_2;
        else
                stop_bits = MPSC_MPCR_SBL_1;

        par = MPSC_CHR_2_PAR_EVEN;
        if (termios->c_cflag & PARENB)
                if (termios->c_cflag & PARODD)
                        par = MPSC_CHR_2_PAR_ODD;
#ifdef  CMSPAR
                if (termios->c_cflag & CMSPAR) {
                        if (termios->c_cflag & PARODD)
                                par = MPSC_CHR_2_PAR_MARK;
                        else
                                par = MPSC_CHR_2_PAR_SPACE;
                }
#endif

        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk);

        spin_lock_irqsave(&pi->port.lock, flags);

        uart_update_timeout(port, termios->c_cflag, baud);

        mpsc_set_char_length(pi, chr_bits);
        mpsc_set_stop_bit_length(pi, stop_bits);
        mpsc_set_parity(pi, par);
        mpsc_set_baudrate(pi, baud);

        /* Characters/events to read */
        pi->port.read_status_mask = SDMA_DESC_CMDSTAT_OR;

        if (termios->c_iflag & INPCK)
                pi->port.read_status_mask |= SDMA_DESC_CMDSTAT_PE
                        | SDMA_DESC_CMDSTAT_FR;

        if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
                pi->port.read_status_mask |= SDMA_DESC_CMDSTAT_BR;

        /* Characters/events to ignore */
        pi->port.ignore_status_mask = 0;

        if (termios->c_iflag & IGNPAR)
                pi->port.ignore_status_mask |= SDMA_DESC_CMDSTAT_PE
                        | SDMA_DESC_CMDSTAT_FR;

        if (termios->c_iflag & IGNBRK) {
                pi->port.ignore_status_mask |= SDMA_DESC_CMDSTAT_BR;

                if (termios->c_iflag & IGNPAR)
                        pi->port.ignore_status_mask |= SDMA_DESC_CMDSTAT_OR;
        }

        if ((termios->c_cflag & CREAD)) {
                if (!pi->rcv_data) {
                        pi->rcv_data = 1;
                        mpsc_start_rx(pi);
                }
        } else if (pi->rcv_data) {
                mpsc_stop_rx(port);
                pi->rcv_data = 0;
        }

        spin_unlock_irqrestore(&pi->port.lock, flags);
}

static const char *mpsc_type(struct uart_port *port)
{
        pr_debug("mpsc_type[%d]: port type: %s\n", port->line,MPSC_DRIVER_NAME);
        return MPSC_DRIVER_NAME;
}

static int mpsc_request_port(struct uart_port *port)
{
        /* Should make chip/platform specific call */
        return 0;
}

static void mpsc_release_port(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;

        if (pi->ready) {
                mpsc_uninit_rings(pi);
                mpsc_free_ring_mem(pi);
                pi->ready = 0;
        }
}

static void mpsc_config_port(struct uart_port *port, int flags)
{
}

static int mpsc_verify_port(struct uart_port *port, struct serial_struct *ser)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        int rc = 0;

        pr_debug("mpsc_verify_port[%d]: Verifying port data\n", pi->port.line);

        if (ser->type != PORT_UNKNOWN && ser->type != PORT_MPSC)
                rc = -EINVAL;
        else if (pi->port.irq != ser->irq)
                rc = -EINVAL;
        else if (ser->io_type != SERIAL_IO_MEM)
                rc = -EINVAL;
        else if (pi->port.uartclk / 16 != ser->baud_base) /* Not sure */
                rc = -EINVAL;
        else if ((void *)pi->port.mapbase != ser->iomem_base)
                rc = -EINVAL;
        else if (pi->port.iobase != ser->port)
                rc = -EINVAL;
        else if (ser->hub6 != 0)
                rc = -EINVAL;

        return rc;
}
#ifdef CONFIG_CONSOLE_POLL
/* Serial polling routines for writing and reading from the uart while
 * in an interrupt or debug context.
 */

static char poll_buf[2048];
static int poll_ptr;
static int poll_cnt;
static void mpsc_put_poll_char(struct uart_port *port,
                                                           unsigned char c);

static int mpsc_get_poll_char(struct uart_port *port)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        struct mpsc_rx_desc *rxre;
        u32     cmdstat, bytes_in, i;
        u8      *bp;

        if (!serial_polled)
                serial_polled = 1;

        pr_debug("mpsc_rx_intr[%d]: Handling Rx intr\n", pi->port.line);

        if (poll_cnt) {
                poll_cnt--;
                return poll_buf[poll_ptr++];
        }
        poll_ptr = 0;
        poll_cnt = 0;

        while (poll_cnt == 0) {
                rxre = (struct mpsc_rx_desc *)(pi->rxr +
                       (pi->rxr_posn*MPSC_RXRE_SIZE));
                dma_cache_sync(pi->port.dev, (void *)rxre,
                               MPSC_RXRE_SIZE, DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        invalidate_dcache_range((ulong)rxre,
                        (ulong)rxre + MPSC_RXRE_SIZE);
#endif
                /*
                 * Loop through Rx descriptors handling ones that have
                 * been completed.
                 */
                while (poll_cnt == 0 &&
                       !((cmdstat = be32_to_cpu(rxre->cmdstat)) &
                         SDMA_DESC_CMDSTAT_O)){
                        bytes_in = be16_to_cpu(rxre->bytecnt);
                        bp = pi->rxb + (pi->rxr_posn * MPSC_RXBE_SIZE);
                        dma_cache_sync(pi->port.dev, (void *) bp,
                                       MPSC_RXBE_SIZE, DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                        if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                                invalidate_dcache_range((ulong)bp,
                                        (ulong)bp + MPSC_RXBE_SIZE);
#endif
                        if ((unlikely(cmdstat & (SDMA_DESC_CMDSTAT_BR |
                         SDMA_DESC_CMDSTAT_FR | SDMA_DESC_CMDSTAT_OR))) &&
                                !(cmdstat & pi->port.ignore_status_mask)) {
                                poll_buf[poll_cnt] = *bp;
                                poll_cnt++;
                        } else {
                                for (i = 0; i < bytes_in; i++) {
                                        poll_buf[poll_cnt] = *bp++;
                                        poll_cnt++;
                                }
                                pi->port.icount.rx += bytes_in;
                        }
                        rxre->bytecnt = cpu_to_be16(0);
                        wmb();
                        rxre->cmdstat = cpu_to_be32(SDMA_DESC_CMDSTAT_O |
                                                    SDMA_DESC_CMDSTAT_EI |
                                                    SDMA_DESC_CMDSTAT_F |
                                                    SDMA_DESC_CMDSTAT_L);
                        wmb();
                        dma_cache_sync(pi->port.dev, (void *)rxre,
                                       MPSC_RXRE_SIZE, DMA_BIDIRECTIONAL);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                        if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                                flush_dcache_range((ulong)rxre,
                                           (ulong)rxre + MPSC_RXRE_SIZE);
#endif

                        /* Advance to next descriptor */
                        pi->rxr_posn = (pi->rxr_posn + 1) &
                                (MPSC_RXR_ENTRIES - 1);
                        rxre = (struct mpsc_rx_desc *)(pi->rxr +
                                       (pi->rxr_posn * MPSC_RXRE_SIZE));
                        dma_cache_sync(pi->port.dev, (void *)rxre,
                                       MPSC_RXRE_SIZE, DMA_FROM_DEVICE);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                        if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                                invalidate_dcache_range((ulong)rxre,
                                                (ulong)rxre + MPSC_RXRE_SIZE);
#endif
                }

                /* Restart rx engine, if its stopped */
                if ((readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_ERD) == 0)
                        mpsc_start_rx(pi);
        }
        if (poll_cnt) {
                poll_cnt--;
                return poll_buf[poll_ptr++];
        }

        return 0;
}


static void mpsc_put_poll_char(struct uart_port *port,
                         unsigned char c)
{
        struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
        u32 data;

        data = readl(pi->mpsc_base + MPSC_MPCR);
        writeb(c, pi->mpsc_base + MPSC_CHR_1);
        mb();
        data = readl(pi->mpsc_base + MPSC_CHR_2);
        data |= MPSC_CHR_2_TTCS;
        writel(data, pi->mpsc_base + MPSC_CHR_2);
        mb();

        while (readl(pi->mpsc_base + MPSC_CHR_2) & MPSC_CHR_2_TTCS);
}
#endif

static struct uart_ops mpsc_pops = {
        .tx_empty       = mpsc_tx_empty,
        .set_mctrl      = mpsc_set_mctrl,
        .get_mctrl      = mpsc_get_mctrl,
        .stop_tx        = mpsc_stop_tx,
        .start_tx       = mpsc_start_tx,
        .stop_rx        = mpsc_stop_rx,
        .break_ctl      = mpsc_break_ctl,
        .startup        = mpsc_startup,
        .shutdown       = mpsc_shutdown,
        .set_termios    = mpsc_set_termios,
        .type           = mpsc_type,
        .release_port   = mpsc_release_port,
        .request_port   = mpsc_request_port,
        .config_port    = mpsc_config_port,
        .verify_port    = mpsc_verify_port,
#ifdef CONFIG_CONSOLE_POLL
        .poll_get_char = mpsc_get_poll_char,
        .poll_put_char = mpsc_put_poll_char,
#endif
};

/*
 ******************************************************************************
 *
 * Console Interface Routines
 *
 ******************************************************************************
 */

#ifdef CONFIG_SERIAL_MPSC_CONSOLE
static void mpsc_console_write(struct console *co, const char *s, uint count)
{
        struct mpsc_port_info *pi = &mpsc_ports[co->index];
        u8 *bp, *dp, add_cr = 0;
        int i;
        unsigned long iflags;

        spin_lock_irqsave(&pi->tx_lock, iflags);

        while (pi->txr_head != pi->txr_tail) {
                while (mpsc_sdma_tx_active(pi))
                        udelay(100);
                mpsc_sdma_intr_ack(pi);
                mpsc_tx_intr(pi);
        }

        while (mpsc_sdma_tx_active(pi))
                udelay(100);

        while (count > 0) {
                bp = dp = pi->txb + (pi->txr_head * MPSC_TXBE_SIZE);

                for (i = 0; i < MPSC_TXBE_SIZE; i++) {
                        if (count == 0)
                                break;

                        if (add_cr) {
                                *(dp++) = '\r';
                                add_cr = 0;
                        } else {
                                *(dp++) = *s;

                                if (*(s++) == '\n') { /* add '\r' after '\n' */
                                        add_cr = 1;
                                        count++;
                                }
                        }

                        count--;
                }

                dma_cache_sync(pi->port.dev, (void *)bp, MPSC_TXBE_SIZE,
                                DMA_BIDIRECTIONAL);
#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
                if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
                        flush_dcache_range((ulong)bp,
                                        (ulong)bp + MPSC_TXBE_SIZE);
#endif
                mpsc_setup_tx_desc(pi, i, 0);
                pi->txr_head = (pi->txr_head + 1) & (MPSC_TXR_ENTRIES - 1);
                mpsc_sdma_start_tx(pi);

                while (mpsc_sdma_tx_active(pi))
                        udelay(100);

                pi->txr_tail = (pi->txr_tail + 1) & (MPSC_TXR_ENTRIES - 1);
        }

        spin_unlock_irqrestore(&pi->tx_lock, iflags);
}

static int __init mpsc_console_setup(struct console *co, char *options)
{
        struct mpsc_port_info *pi;
        int baud, bits, parity, flow;

        pr_debug("mpsc_console_setup[%d]: options: %s\n", co->index, options);

        if (co->index >= MPSC_NUM_CTLRS)
                co->index = 0;

        pi = &mpsc_ports[co->index];

        baud = pi->default_baud;
        bits = pi->default_bits;
        parity = pi->default_parity;
        flow = pi->default_flow;

        if (!pi->port.ops)
                return -ENODEV;

        spin_lock_init(&pi->port.lock); /* Temporary fix--copied from 8250.c */

        if (options)
                uart_parse_options(options, &baud, &parity, &bits, &flow);

        return uart_set_options(&pi->port, co, baud, parity, bits, flow);
}

static struct console mpsc_console = {
        .name   = MPSC_DEV_NAME,
        .write  = mpsc_console_write,
        .device = uart_console_device,
        .setup  = mpsc_console_setup,
        .flags  = CON_PRINTBUFFER,
        .index  = -1,
        .data   = &mpsc_reg,
};

static int __init mpsc_late_console_init(void)
{
        pr_debug("mpsc_late_console_init: Enter\n");

        if (!(mpsc_console.flags & CON_ENABLED))
                register_console(&mpsc_console);
        return 0;
}

late_initcall(mpsc_late_console_init);

#define MPSC_CONSOLE    &mpsc_console
#else
#define MPSC_CONSOLE    NULL
#endif
/*
 ******************************************************************************
 *
 * Dummy Platform Driver to extract & map shared register regions
 *
 ******************************************************************************
 */
static void mpsc_resource_err(char *s)
{
        printk(KERN_WARNING "MPSC: Platform device resource error in %s\n", s);
}

static int mpsc_shared_map_regs(struct platform_device *pd)
{
        struct resource *r;

        if ((r = platform_get_resource(pd, IORESOURCE_MEM,
                                        MPSC_ROUTING_BASE_ORDER))
                        && request_mem_region(r->start,
                                MPSC_ROUTING_REG_BLOCK_SIZE,
                                "mpsc_routing_regs")) {
                mpsc_shared_regs.mpsc_routing_base = ioremap(r->start,
                                MPSC_ROUTING_REG_BLOCK_SIZE);
                mpsc_shared_regs.mpsc_routing_base_p = r->start;
        } else {
                mpsc_resource_err("MPSC routing base");
                return -ENOMEM;
        }

        if ((r = platform_get_resource(pd, IORESOURCE_MEM,
                                        MPSC_SDMA_INTR_BASE_ORDER))
                        && request_mem_region(r->start,
                                MPSC_SDMA_INTR_REG_BLOCK_SIZE,
                                "sdma_intr_regs")) {
                mpsc_shared_regs.sdma_intr_base = ioremap(r->start,
                        MPSC_SDMA_INTR_REG_BLOCK_SIZE);
                mpsc_shared_regs.sdma_intr_base_p = r->start;
        } else {
                iounmap(mpsc_shared_regs.mpsc_routing_base);
                release_mem_region(mpsc_shared_regs.mpsc_routing_base_p,
                                MPSC_ROUTING_REG_BLOCK_SIZE);
                mpsc_resource_err("SDMA intr base");
                return -ENOMEM;
        }

        return 0;
}

static void mpsc_shared_unmap_regs(void)
{
        if (!mpsc_shared_regs.mpsc_routing_base) {
                iounmap(mpsc_shared_regs.mpsc_routing_base);
                release_mem_region(mpsc_shared_regs.mpsc_routing_base_p,
                                MPSC_ROUTING_REG_BLOCK_SIZE);
        }
        if (!mpsc_shared_regs.sdma_intr_base) {
                iounmap(mpsc_shared_regs.sdma_intr_base);
                release_mem_region(mpsc_shared_regs.sdma_intr_base_p,
                                MPSC_SDMA_INTR_REG_BLOCK_SIZE);
        }

        mpsc_shared_regs.mpsc_routing_base = NULL;
        mpsc_shared_regs.sdma_intr_base = NULL;

        mpsc_shared_regs.mpsc_routing_base_p = 0;
        mpsc_shared_regs.sdma_intr_base_p = 0;
}

static int mpsc_shared_drv_probe(struct platform_device *dev)
{
        struct mpsc_shared_pdata        *pdata;
        int                              rc = -ENODEV;

        if (dev->id == 0) {
                if (!(rc = mpsc_shared_map_regs(dev))) {
                        pdata = (struct mpsc_shared_pdata *)
                                dev_get_platdata(&dev->dev);

                        mpsc_shared_regs.MPSC_MRR_m = pdata->mrr_val;
                        mpsc_shared_regs.MPSC_RCRR_m= pdata->rcrr_val;
                        mpsc_shared_regs.MPSC_TCRR_m= pdata->tcrr_val;
                        mpsc_shared_regs.SDMA_INTR_CAUSE_m =
                                pdata->intr_cause_val;
                        mpsc_shared_regs.SDMA_INTR_MASK_m =
                                pdata->intr_mask_val;

                        rc = 0;
                }
        }

        return rc;
}

static int mpsc_shared_drv_remove(struct platform_device *dev)
{
        int     rc = -ENODEV;

        if (dev->id == 0) {
                mpsc_shared_unmap_regs();
                mpsc_shared_regs.MPSC_MRR_m = 0;
                mpsc_shared_regs.MPSC_RCRR_m = 0;
                mpsc_shared_regs.MPSC_TCRR_m = 0;
                mpsc_shared_regs.SDMA_INTR_CAUSE_m = 0;
                mpsc_shared_regs.SDMA_INTR_MASK_m = 0;
                rc = 0;
        }

        return rc;
}

static struct platform_driver mpsc_shared_driver = {
        .probe  = mpsc_shared_drv_probe,
        .remove = mpsc_shared_drv_remove,
        .driver = {
                .name   = MPSC_SHARED_NAME,
        },
};

/*
 ******************************************************************************
 *
 * Driver Interface Routines
 *
 ******************************************************************************
 */
static struct uart_driver mpsc_reg = {
        .owner          = THIS_MODULE,
        .driver_name    = MPSC_DRIVER_NAME,
        .dev_name       = MPSC_DEV_NAME,
        .major          = MPSC_MAJOR,
        .minor          = MPSC_MINOR_START,
        .nr             = MPSC_NUM_CTLRS,
        .cons           = MPSC_CONSOLE,
};

static int mpsc_drv_map_regs(struct mpsc_port_info *pi,
                struct platform_device *pd)
{
        struct resource *r;

        if ((r = platform_get_resource(pd, IORESOURCE_MEM, MPSC_BASE_ORDER))
                        && request_mem_region(r->start, MPSC_REG_BLOCK_SIZE,
                        "mpsc_regs")) {
                pi->mpsc_base = ioremap(r->start, MPSC_REG_BLOCK_SIZE);
                pi->mpsc_base_p = r->start;
        } else {
                mpsc_resource_err("MPSC base");
                goto err;
        }

        if ((r = platform_get_resource(pd, IORESOURCE_MEM,
                                        MPSC_SDMA_BASE_ORDER))
                        && request_mem_region(r->start,
                                MPSC_SDMA_REG_BLOCK_SIZE, "sdma_regs")) {
                pi->sdma_base = ioremap(r->start,MPSC_SDMA_REG_BLOCK_SIZE);
                pi->sdma_base_p = r->start;
        } else {
                mpsc_resource_err("SDMA base");
                if (pi->mpsc_base) {
                        iounmap(pi->mpsc_base);
                        pi->mpsc_base = NULL;
                }
                goto err;
        }

        if ((r = platform_get_resource(pd,IORESOURCE_MEM,MPSC_BRG_BASE_ORDER))
                        && request_mem_region(r->start,
                                MPSC_BRG_REG_BLOCK_SIZE, "brg_regs")) {
                pi->brg_base = ioremap(r->start, MPSC_BRG_REG_BLOCK_SIZE);
                pi->brg_base_p = r->start;
        } else {
                mpsc_resource_err("BRG base");
                if (pi->mpsc_base) {
                        iounmap(pi->mpsc_base);
                        pi->mpsc_base = NULL;
                }
                if (pi->sdma_base) {
                        iounmap(pi->sdma_base);
                        pi->sdma_base = NULL;
                }
                goto err;
        }
        return 0;

err:
        return -ENOMEM;
}

static void mpsc_drv_unmap_regs(struct mpsc_port_info *pi)
{

        if (!pi->mpsc_base) {
                iounmap(pi->mpsc_base);
                release_mem_region(pi->mpsc_base_p, MPSC_REG_BLOCK_SIZE);
        }
        if (!pi->sdma_base) {
                iounmap(pi->sdma_base);
                release_mem_region(pi->sdma_base_p, MPSC_SDMA_REG_BLOCK_SIZE);
        }
        if (!pi->brg_base) {
                iounmap(pi->brg_base);
                release_mem_region(pi->brg_base_p, MPSC_BRG_REG_BLOCK_SIZE);
        }

        pi->mpsc_base = NULL;
        pi->sdma_base = NULL;
        pi->brg_base = NULL;

        pi->mpsc_base_p = 0;
        pi->sdma_base_p = 0;
        pi->brg_base_p = 0;
}

static void mpsc_drv_get_platform_data(struct mpsc_port_info *pi,
                struct platform_device *pd, int num)
{
        struct mpsc_pdata       *pdata;

        pdata = dev_get_platdata(&pd->dev);

        pi->port.uartclk = pdata->brg_clk_freq;
        pi->port.iotype = UPIO_MEM;
        pi->port.line = num;
        pi->port.type = PORT_MPSC;
        pi->port.fifosize = MPSC_TXBE_SIZE;
        pi->port.membase = pi->mpsc_base;
        pi->port.mapbase = (ulong)pi->mpsc_base;
        pi->port.ops = &mpsc_pops;

        pi->mirror_regs = pdata->mirror_regs;
        pi->cache_mgmt = pdata->cache_mgmt;
        pi->brg_can_tune = pdata->brg_can_tune;
        pi->brg_clk_src = pdata->brg_clk_src;
        pi->mpsc_max_idle = pdata->max_idle;
        pi->default_baud = pdata->default_baud;
        pi->default_bits = pdata->default_bits;
        pi->default_parity = pdata->default_parity;
        pi->default_flow = pdata->default_flow;

        /* Initial values of mirrored regs */
        pi->MPSC_CHR_1_m = pdata->chr_1_val;
        pi->MPSC_CHR_2_m = pdata->chr_2_val;
        pi->MPSC_CHR_10_m = pdata->chr_10_val;
        pi->MPSC_MPCR_m = pdata->mpcr_val;
        pi->BRG_BCR_m = pdata->bcr_val;

        pi->shared_regs = &mpsc_shared_regs;

        pi->port.irq = platform_get_irq(pd, 0);
}

static int mpsc_drv_probe(struct platform_device *dev)
{
        struct mpsc_port_info   *pi;
        int                     rc = -ENODEV;

        pr_debug("mpsc_drv_probe: Adding MPSC %d\n", dev->id);

        if (dev->id < MPSC_NUM_CTLRS) {
                pi = &mpsc_ports[dev->id];

                if (!(rc = mpsc_drv_map_regs(pi, dev))) {
                        mpsc_drv_get_platform_data(pi, dev, dev->id);
                        pi->port.dev = &dev->dev;

                        if (!(rc = mpsc_make_ready(pi))) {
                                spin_lock_init(&pi->tx_lock);
                                if (!(rc = uart_add_one_port(&mpsc_reg,
                                                                &pi->port))) {
                                        rc = 0;
                                } else {
                                        mpsc_release_port((struct uart_port *)
                                                        pi);
                                        mpsc_drv_unmap_regs(pi);
                                }
                        } else {
                                mpsc_drv_unmap_regs(pi);
                        }
                }
        }

        return rc;
}

static int mpsc_drv_remove(struct platform_device *dev)
{
        pr_debug("mpsc_drv_exit: Removing MPSC %d\n", dev->id);

        if (dev->id < MPSC_NUM_CTLRS) {
                uart_remove_one_port(&mpsc_reg, &mpsc_ports[dev->id].port);
                mpsc_release_port((struct uart_port *)
                                &mpsc_ports[dev->id].port);
                mpsc_drv_unmap_regs(&mpsc_ports[dev->id]);
                return 0;
        } else {
                return -ENODEV;
        }
}

static struct platform_driver mpsc_driver = {
        .probe  = mpsc_drv_probe,
        .remove = mpsc_drv_remove,
        .driver = {
                .name   = MPSC_CTLR_NAME,
                .owner  = THIS_MODULE,
        },
};

static int __init mpsc_drv_init(void)
{
        int     rc;

        printk(KERN_INFO "Serial: MPSC driver\n");

        memset(mpsc_ports, 0, sizeof(mpsc_ports));
        memset(&mpsc_shared_regs, 0, sizeof(mpsc_shared_regs));

        if (!(rc = uart_register_driver(&mpsc_reg))) {
                if (!(rc = platform_driver_register(&mpsc_shared_driver))) {
                        if ((rc = platform_driver_register(&mpsc_driver))) {
                                platform_driver_unregister(&mpsc_shared_driver);
                                uart_unregister_driver(&mpsc_reg);
                        }
                } else {
                        uart_unregister_driver(&mpsc_reg);
                }
        }

        return rc;
}

static void __exit mpsc_drv_exit(void)
{
        platform_driver_unregister(&mpsc_driver);
        platform_driver_unregister(&mpsc_shared_driver);
        uart_unregister_driver(&mpsc_reg);
        memset(mpsc_ports, 0, sizeof(mpsc_ports));
        memset(&mpsc_shared_regs, 0, sizeof(mpsc_shared_regs));
}

module_init(mpsc_drv_init);
module_exit(mpsc_drv_exit);

MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
MODULE_DESCRIPTION("Generic Marvell MPSC serial/UART driver");
MODULE_VERSION(MPSC_VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(MPSC_MAJOR);
MODULE_ALIAS("platform:" MPSC_CTLR_NAME);