LXR linux/drivers/staging/speakup/serialio.c

   1#include <linux/interrupt.h>
   2#include <linux/ioport.h>
   3
   4#include "spk_types.h"
   5#include "speakup.h"
   6#include "spk_priv.h"
   7#include "serialio.h"
   8
   9#include <linux/serial_core.h>
  10/* WARNING:  Do not change this to <linux/serial.h> without testing that
  11 * SERIAL_PORT_DFNS does get defined to the appropriate value.
  12 */
  13#include <asm/serial.h>
  14
  15#ifndef SERIAL_PORT_DFNS
  16#define SERIAL_PORT_DFNS
  17#endif
  18
  19static void start_serial_interrupt(int irq);
  20
  21static const struct old_serial_port rs_table[] = {
  22        SERIAL_PORT_DFNS
  23};
  24static const struct old_serial_port *serstate;
  25static int timeouts;
  26
  27const struct old_serial_port *spk_serial_init(int index)
  28{
  29        int baud = 9600, quot = 0;
  30        unsigned int cval = 0;
  31        int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8;
  32        const struct old_serial_port *ser;
  33        int err;
  34
  35        if (index >= ARRAY_SIZE(rs_table)) {
  36                pr_info("no port info for ttyS%d\n", index);
  37                return NULL;
  38        }
  39        ser = rs_table + index;
  40
  41        /*      Divisor, bytesize and parity */
  42        quot = ser->baud_base / baud;
  43        cval = cflag & (CSIZE | CSTOPB);
  44#if defined(__powerpc__) || defined(__alpha__)
  45        cval >>= 8;
  46#else /* !__powerpc__ && !__alpha__ */
  47        cval >>= 4;
  48#endif /* !__powerpc__ && !__alpha__ */
  49        if (cflag & PARENB)
  50                cval |= UART_LCR_PARITY;
  51        if (!(cflag & PARODD))
  52                cval |= UART_LCR_EPAR;
  53        if (synth_request_region(ser->port, 8)) {
  54                /* try to take it back. */
  55                pr_info("Ports not available, trying to steal them\n");
  56                __release_region(&ioport_resource, ser->port, 8);
  57                err = synth_request_region(ser->port, 8);
  58                if (err) {
  59                        pr_warn("Unable to allocate port at %x, errno %i",
  60                                ser->port, err);
  61                        return NULL;
  62                }
  63        }
  64
  65        /*      Disable UART interrupts, set DTR and RTS high
  66         *      and set speed.
  67         */
  68        outb(cval | UART_LCR_DLAB, ser->port + UART_LCR);       /* set DLAB */
  69        outb(quot & 0xff, ser->port + UART_DLL);        /* LS of divisor */
  70        outb(quot >> 8, ser->port + UART_DLM);          /* MS of divisor */
  71        outb(cval, ser->port + UART_LCR);               /* reset DLAB */
  72
  73        /* Turn off Interrupts */
  74        outb(0, ser->port + UART_IER);
  75        outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR);
  76
  77        /* If we read 0xff from the LSR, there is no UART here. */
  78        if (inb(ser->port + UART_LSR) == 0xff) {
  79                synth_release_region(ser->port, 8);
  80                serstate = NULL;
  81                return NULL;
  82        }
  83
  84        mdelay(1);
  85        speakup_info.port_tts = ser->port;
  86        serstate = ser;
  87
  88        start_serial_interrupt(ser->irq);
  89
  90        return ser;
  91}
  92
  93static irqreturn_t synth_readbuf_handler(int irq, void *dev_id)
  94{
  95        unsigned long flags;
  96        int c;
  97
  98        spin_lock_irqsave(&speakup_info.spinlock, flags);
  99        while (inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR) {
 100
 101                c = inb_p(speakup_info.port_tts+UART_RX);
 102                synth->read_buff_add((u_char) c);
 103        }
 104        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
 105        return IRQ_HANDLED;
 106}
 107
 108static void start_serial_interrupt(int irq)
 109{
 110        int rv;
 111
 112        if (!synth->read_buff_add)
 113                return;
 114
 115        rv = request_irq(irq, synth_readbuf_handler, IRQF_SHARED,
 116                         "serial", (void *) synth_readbuf_handler);
 117
 118        if (rv)
 119                pr_err("Unable to request Speakup serial I R Q\n");
 120        /* Set MCR */
 121        outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2,
 122                        speakup_info.port_tts + UART_MCR);
 123        /* Turn on Interrupts */
 124        outb(UART_IER_MSI|UART_IER_RLSI|UART_IER_RDI,
 125                        speakup_info.port_tts + UART_IER);
 126        inb(speakup_info.port_tts+UART_LSR);
 127        inb(speakup_info.port_tts+UART_RX);
 128        inb(speakup_info.port_tts+UART_IIR);
 129        inb(speakup_info.port_tts+UART_MSR);
 130        outb(1, speakup_info.port_tts + UART_FCR);      /* Turn FIFO On */
 131}
 132
 133void spk_stop_serial_interrupt(void)
 134{
 135        if (speakup_info.port_tts == 0)
 136                return;
 137
 138        if (!synth->read_buff_add)
 139                return;
 140
 141        /* Turn off interrupts */
 142        outb(0, speakup_info.port_tts+UART_IER);
 143        /* Free IRQ */
 144        free_irq(serstate->irq, (void *) synth_readbuf_handler);
 145}
 146
 147int spk_wait_for_xmitr(void)
 148{
 149        int tmout = SPK_XMITR_TIMEOUT;
 150
 151        if ((synth->alive) && (timeouts >= NUM_DISABLE_TIMEOUTS)) {
 152                pr_warn("%s: too many timeouts, deactivating speakup\n",
 153                        synth->long_name);
 154                synth->alive = 0;
 155                /* No synth any more, so nobody will restart TTYs, and we thus
 156                 * need to do it ourselves.  Now that there is no synth we can
 157                 * let application flood anyway
 158                 */
 159                speakup_start_ttys();
 160                timeouts = 0;
 161                return 0;
 162        }
 163        while (spk_serial_tx_busy()) {
 164                if (--tmout == 0) {
 165                        pr_warn("%s: timed out (tx busy)\n", synth->long_name);
 166                        timeouts++;
 167                        return 0;
 168                }
 169                udelay(1);
 170        }
 171        tmout = SPK_CTS_TIMEOUT;
 172        while (!((inb_p(speakup_info.port_tts + UART_MSR)) & UART_MSR_CTS)) {
 173                /* CTS */
 174                if (--tmout == 0) {
 175                        timeouts++;
 176                        return 0;
 177                }
 178                udelay(1);
 179        }
 180        timeouts = 0;
 181        return 1;
 182}
 183
 184unsigned char spk_serial_in(void)
 185{
 186        int tmout = SPK_SERIAL_TIMEOUT;
 187
 188        while (!(inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR)) {
 189                if (--tmout == 0) {
 190                        pr_warn("time out while waiting for input.\n");
 191                        return 0xff;
 192                }
 193                udelay(1);
 194        }
 195        return inb_p(speakup_info.port_tts + UART_RX);
 196}
 197EXPORT_SYMBOL_GPL(spk_serial_in);
 198
 199unsigned char spk_serial_in_nowait(void)
 200{
 201        unsigned char lsr;
 202
 203        lsr = inb_p(speakup_info.port_tts + UART_LSR);
 204        if (!(lsr & UART_LSR_DR))
 205                return 0;
 206        return inb_p(speakup_info.port_tts + UART_RX);
 207}
 208EXPORT_SYMBOL_GPL(spk_serial_in_nowait);
 209
 210int spk_serial_out(const char ch)
 211{
 212        if (synth->alive && spk_wait_for_xmitr()) {
 213                outb_p(ch, speakup_info.port_tts);
 214                return 1;
 215        }
 216        return 0;
 217}
 218EXPORT_SYMBOL_GPL(spk_serial_out);
 219
 220void spk_serial_release(void)
 221{
 222        if (speakup_info.port_tts == 0)
 223                return;
 224        synth_release_region(speakup_info.port_tts, 8);
 225        speakup_info.port_tts = 0;
 226}
 227EXPORT_SYMBOL_GPL(spk_serial_release);
 228