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