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

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/interrupt.h>
   3#include <linux/ioport.h>
   4
   5#include "spk_types.h"
   6#include "speakup.h"
   7#include "spk_priv.h"
   8#include "serialio.h"
   9
  10#include <linux/serial_core.h>
  11/* WARNING:  Do not change this to <linux/serial.h> without testing that
  12 * SERIAL_PORT_DFNS does get defined to the appropriate value.
  13 */
  14#include <asm/serial.h>
  15
  16#ifndef SERIAL_PORT_DFNS
  17#define SERIAL_PORT_DFNS
  18#endif
  19
  20static void start_serial_interrupt(int irq);
  21
  22static const struct old_serial_port rs_table[] = {
  23        SERIAL_PORT_DFNS
  24};
  25
  26static const struct old_serial_port *serstate;
  27static int timeouts;
  28
  29static int spk_serial_out(struct spk_synth *in_synth, const char ch);
  30static void spk_serial_send_xchar(char ch);
  31static void spk_serial_tiocmset(unsigned int set, unsigned int clear);
  32static unsigned char spk_serial_in(void);
  33static unsigned char spk_serial_in_nowait(void);
  34static void spk_serial_flush_buffer(void);
  35
  36struct spk_io_ops spk_serial_io_ops = {
  37        .synth_out = spk_serial_out,
  38        .send_xchar = spk_serial_send_xchar,
  39        .tiocmset = spk_serial_tiocmset,
  40        .synth_in = spk_serial_in,
  41        .synth_in_nowait = spk_serial_in_nowait,
  42        .flush_buffer = spk_serial_flush_buffer,
  43};
  44EXPORT_SYMBOL_GPL(spk_serial_io_ops);
  45
  46const struct old_serial_port *spk_serial_init(int index)
  47{
  48        int baud = 9600, quot = 0;
  49        unsigned int cval = 0;
  50        int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8;
  51        const struct old_serial_port *ser;
  52        int err;
  53
  54        if (index >= ARRAY_SIZE(rs_table)) {
  55                pr_info("no port info for ttyS%d\n", index);
  56                return NULL;
  57        }
  58        ser = rs_table + index;
  59
  60        /*      Divisor, bytesize and parity */
  61        quot = ser->baud_base / baud;
  62        cval = cflag & (CSIZE | CSTOPB);
  63#if defined(__powerpc__) || defined(__alpha__)
  64        cval >>= 8;
  65#else /* !__powerpc__ && !__alpha__ */
  66        cval >>= 4;
  67#endif /* !__powerpc__ && !__alpha__ */
  68        if (cflag & PARENB)
  69                cval |= UART_LCR_PARITY;
  70        if (!(cflag & PARODD))
  71                cval |= UART_LCR_EPAR;
  72        if (synth_request_region(ser->port, 8)) {
  73                /* try to take it back. */
  74                pr_info("Ports not available, trying to steal them\n");
  75                __release_region(&ioport_resource, ser->port, 8);
  76                err = synth_request_region(ser->port, 8);
  77                if (err) {
  78                        pr_warn("Unable to allocate port at %x, errno %i",
  79                                ser->port, err);
  80                        return NULL;
  81                }
  82        }
  83
  84        /*      Disable UART interrupts, set DTR and RTS high
  85         *      and set speed.
  86         */
  87        outb(cval | UART_LCR_DLAB, ser->port + UART_LCR);       /* set DLAB */
  88        outb(quot & 0xff, ser->port + UART_DLL);        /* LS of divisor */
  89        outb(quot >> 8, ser->port + UART_DLM);          /* MS of divisor */
  90        outb(cval, ser->port + UART_LCR);               /* reset DLAB */
  91
  92        /* Turn off Interrupts */
  93        outb(0, ser->port + UART_IER);
  94        outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR);
  95
  96        /* If we read 0xff from the LSR, there is no UART here. */
  97        if (inb(ser->port + UART_LSR) == 0xff) {
  98                synth_release_region(ser->port, 8);
  99                serstate = NULL;
 100                return NULL;
 101        }
 102
 103        mdelay(1);
 104        speakup_info.port_tts = ser->port;
 105        serstate = ser;
 106
 107        start_serial_interrupt(ser->irq);
 108
 109        return ser;
 110}
 111
 112static irqreturn_t synth_readbuf_handler(int irq, void *dev_id)
 113{
 114        unsigned long flags;
 115        int c;
 116
 117        spin_lock_irqsave(&speakup_info.spinlock, flags);
 118        while (inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR) {
 119                c = inb_p(speakup_info.port_tts + UART_RX);
 120                synth->read_buff_add((u_char)c);
 121        }
 122        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
 123        return IRQ_HANDLED;
 124}
 125
 126static void start_serial_interrupt(int irq)
 127{
 128        int rv;
 129
 130        if (!synth->read_buff_add)
 131                return;
 132
 133        rv = request_irq(irq, synth_readbuf_handler, IRQF_SHARED,
 134                         "serial", (void *)synth_readbuf_handler);
 135
 136        if (rv)
 137                pr_err("Unable to request Speakup serial I R Q\n");
 138        /* Set MCR */
 139        outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2,
 140             speakup_info.port_tts + UART_MCR);
 141        /* Turn on Interrupts */
 142        outb(UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI,
 143             speakup_info.port_tts + UART_IER);
 144        inb(speakup_info.port_tts + UART_LSR);
 145        inb(speakup_info.port_tts + UART_RX);
 146        inb(speakup_info.port_tts + UART_IIR);
 147        inb(speakup_info.port_tts + UART_MSR);
 148        outb(1, speakup_info.port_tts + UART_FCR);      /* Turn FIFO On */
 149}
 150
 151static void spk_serial_send_xchar(char ch)
 152{
 153        int timeout = SPK_XMITR_TIMEOUT;
 154
 155        while (spk_serial_tx_busy()) {
 156                if (!--timeout)
 157                        break;
 158                udelay(1);
 159        }
 160        outb(ch, speakup_info.port_tts);
 161}
 162
 163static void spk_serial_tiocmset(unsigned int set, unsigned int clear)
 164{
 165        int old = inb(speakup_info.port_tts + UART_MCR);
 166
 167        outb((old & ~clear) | set, speakup_info.port_tts + UART_MCR);
 168}
 169
 170int spk_serial_synth_probe(struct spk_synth *synth)
 171{
 172        const struct old_serial_port *ser;
 173        int failed = 0;
 174
 175        if ((synth->ser >= SPK_LO_TTY) && (synth->ser <= SPK_HI_TTY)) {
 176                ser = spk_serial_init(synth->ser);
 177                if (!ser) {
 178                        failed = -1;
 179                } else {
 180                        outb_p(0, ser->port);
 181                        mdelay(1);
 182                        outb_p('\r', ser->port);
 183                }
 184        } else {
 185                failed = -1;
 186                pr_warn("ttyS%i is an invalid port\n", synth->ser);
 187        }
 188        if (failed) {
 189                pr_info("%s: not found\n", synth->long_name);
 190                return -ENODEV;
 191        }
 192        pr_info("%s: ttyS%i, Driver Version %s\n",
 193                synth->long_name, synth->ser, synth->version);
 194        synth->alive = 1;
 195        return 0;
 196}
 197EXPORT_SYMBOL_GPL(spk_serial_synth_probe);
 198
 199void spk_stop_serial_interrupt(void)
 200{
 201        if (speakup_info.port_tts == 0)
 202                return;
 203
 204        if (!synth->read_buff_add)
 205                return;
 206
 207        /* Turn off interrupts */
 208        outb(0, speakup_info.port_tts + UART_IER);
 209        /* Free IRQ */
 210        free_irq(serstate->irq, (void *)synth_readbuf_handler);
 211}
 212EXPORT_SYMBOL_GPL(spk_stop_serial_interrupt);
 213
 214int spk_wait_for_xmitr(struct spk_synth *in_synth)
 215{
 216        int tmout = SPK_XMITR_TIMEOUT;
 217
 218        if ((in_synth->alive) && (timeouts >= NUM_DISABLE_TIMEOUTS)) {
 219                pr_warn("%s: too many timeouts, deactivating speakup\n",
 220                        in_synth->long_name);
 221                in_synth->alive = 0;
 222                /* No synth any more, so nobody will restart TTYs, and we thus
 223                 * need to do it ourselves.  Now that there is no synth we can
 224                 * let application flood anyway
 225                 */
 226                speakup_start_ttys();
 227                timeouts = 0;
 228                return 0;
 229        }
 230        while (spk_serial_tx_busy()) {
 231                if (--tmout == 0) {
 232                        pr_warn("%s: timed out (tx busy)\n",
 233                                in_synth->long_name);
 234                        timeouts++;
 235                        return 0;
 236                }
 237                udelay(1);
 238        }
 239        tmout = SPK_CTS_TIMEOUT;
 240        while (!((inb_p(speakup_info.port_tts + UART_MSR)) & UART_MSR_CTS)) {
 241                /* CTS */
 242                if (--tmout == 0) {
 243                        timeouts++;
 244                        return 0;
 245                }
 246                udelay(1);
 247        }
 248        timeouts = 0;
 249        return 1;
 250}
 251
 252static unsigned char spk_serial_in(void)
 253{
 254        int tmout = SPK_SERIAL_TIMEOUT;
 255
 256        while (!(inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR)) {
 257                if (--tmout == 0) {
 258                        pr_warn("time out while waiting for input.\n");
 259                        return 0xff;
 260                }
 261                udelay(1);
 262        }
 263        return inb_p(speakup_info.port_tts + UART_RX);
 264}
 265
 266static unsigned char spk_serial_in_nowait(void)
 267{
 268        unsigned char lsr;
 269
 270        lsr = inb_p(speakup_info.port_tts + UART_LSR);
 271        if (!(lsr & UART_LSR_DR))
 272                return 0;
 273        return inb_p(speakup_info.port_tts + UART_RX);
 274}
 275
 276static void spk_serial_flush_buffer(void)
 277{
 278        /* TODO: flush the UART 16550 buffer */
 279}
 280
 281static int spk_serial_out(struct spk_synth *in_synth, const char ch)
 282{
 283        if (in_synth->alive && spk_wait_for_xmitr(in_synth)) {
 284                outb_p(ch, speakup_info.port_tts);
 285                return 1;
 286        }
 287        return 0;
 288}
 289
 290const char *spk_serial_synth_immediate(struct spk_synth *synth,
 291                                       const char *buff)
 292{
 293        u_char ch;
 294
 295        while ((ch = *buff)) {
 296                if (ch == '\n')
 297                        ch = synth->procspeech;
 298                if (spk_wait_for_xmitr(synth))
 299                        outb(ch, speakup_info.port_tts);
 300                else
 301                        return buff;
 302                buff++;
 303        }
 304        return NULL;
 305}
 306EXPORT_SYMBOL_GPL(spk_serial_synth_immediate);
 307
 308void spk_serial_release(void)
 309{
 310        spk_stop_serial_interrupt();
 311        if (speakup_info.port_tts == 0)
 312                return;
 313        synth_release_region(speakup_info.port_tts, 8);
 314        speakup_info.port_tts = 0;
 315}
 316EXPORT_SYMBOL_GPL(spk_serial_release);
 317