kernel/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 #ifndef SERIAL_PORT_DFNS
  10 #define SERIAL_PORT_DFNS
  11 #endif
  12
  13 static void start_serial_interrupt(int irq);
  14
  15 static const struct old_serial_port rs_table[] = {
  16         SERIAL_PORT_DFNS
  17 };
  18 static const struct old_serial_port *serstate;
  19 static int timeouts;
  20
  21 const struct old_serial_port *spk_serial_init(int index)
  22 {
  23         int baud = 9600, quot = 0;
  24         unsigned int cval = 0;
  25         int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8;
  26         const struct old_serial_port *ser = rs_table + index;
  27         int err;
  28
  29         /*      Divisor, bytesize and parity */
  30         quot = ser->baud_base / baud;
  31         cval = cflag & (CSIZE | CSTOPB);
  32 #if defined(__powerpc__) || defined(__alpha__)
  33         cval >>= 8;
  34 #else /* !__powerpc__ && !__alpha__ */
  35         cval >>= 4;
  36 #endif /* !__powerpc__ && !__alpha__ */
  37         if (cflag & PARENB)
  38                 cval |= UART_LCR_PARITY;
  39         if (!(cflag & PARODD))
  40                 cval |= UART_LCR_EPAR;
  41         if (synth_request_region(ser->port, 8)) {
  42                 /* try to take it back. */
  43                 pr_info("Ports not available, trying to steal them\n");
  44                 __release_region(&ioport_resource, ser->port, 8);
  45                 err = synth_request_region(ser->port, 8);
  46                 if (err) {
  47                         pr_warn("Unable to allocate port at %x, errno %i",
  48                                 ser->port, err);
  49                         return NULL;
  50                 }
  51         }
  52
  53         /*      Disable UART interrupts, set DTR and RTS high
  54          *      and set speed. */
  55         outb(cval | UART_LCR_DLAB, ser->port + UART_LCR);       /* set DLAB */
  56         outb(quot & 0xff, ser->port + UART_DLL);        /* LS of divisor */
  57         outb(quot >> 8, ser->port + UART_DLM);          /* MS of divisor */
  58         outb(cval, ser->port + UART_LCR);               /* reset DLAB */
  59
  60         /* Turn off Interrupts */
  61         outb(0, ser->port + UART_IER);
  62         outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR);
  63
  64         /* If we read 0xff from the LSR, there is no UART here. */
  65         if (inb(ser->port + UART_LSR) == 0xff) {
  66                 synth_release_region(ser->port, 8);
  67                 serstate = NULL;
  68                 return NULL;
  69         }
  70
  71         mdelay(1);
  72         speakup_info.port_tts = ser->port;
  73         serstate = ser;
  74
  75         start_serial_interrupt(ser->irq);
  76
  77         return ser;
  78 }
  79
  80 static irqreturn_t synth_readbuf_handler(int irq, void *dev_id)
  81 {
  82         unsigned long flags;
  83 /*printk(KERN_ERR "in irq\n"); */
  84 /*pr_warn("in IRQ\n"); */
  85         int c;
  86
  87         spin_lock_irqsave(&speakup_info.spinlock, flags);
  88         while (inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR) {
  89
  90                 c = inb_p(speakup_info.port_tts+UART_RX);
  91                 synth->read_buff_add((u_char) c);
  92 /*printk(KERN_ERR "c = %d\n", c); */
  93 /*pr_warn("C = %d\n", c); */
  94         }
  95         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
  96         return IRQ_HANDLED;
  97 }
  98
  99 static void start_serial_interrupt(int irq)
 100 {
 101         int rv;
 102
 103         if (synth->read_buff_add == NULL)
 104                 return;
 105
 106         rv = request_irq(irq, synth_readbuf_handler, IRQF_SHARED,
 107                          "serial", (void *) synth_readbuf_handler);
 108
 109         if (rv)
 110                 pr_err("Unable to request Speakup serial I R Q\n");
 111         /* Set MCR */
 112         outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2,
 113                         speakup_info.port_tts + UART_MCR);
 114         /* Turn on Interrupts */
 115         outb(UART_IER_MSI|UART_IER_RLSI|UART_IER_RDI,
 116                         speakup_info.port_tts + UART_IER);
 117         inb(speakup_info.port_tts+UART_LSR);
 118         inb(speakup_info.port_tts+UART_RX);
 119         inb(speakup_info.port_tts+UART_IIR);
 120         inb(speakup_info.port_tts+UART_MSR);
 121         outb(1, speakup_info.port_tts + UART_FCR);      /* Turn FIFO On */
 122 }
 123
 124 void spk_stop_serial_interrupt(void)
 125 {
 126         if (speakup_info.port_tts == 0)
 127                 return;
 128
 129         if (synth->read_buff_add == NULL)
 130                 return;
 131
 132         /* Turn off interrupts */
 133         outb(0, speakup_info.port_tts+UART_IER);
 134         /* Free IRQ */
 135         free_irq(serstate->irq, (void *) synth_readbuf_handler);
 136 }
 137
 138 int spk_wait_for_xmitr(void)
 139 {
 140         int tmout = SPK_XMITR_TIMEOUT;
 141
 142         if ((synth->alive) && (timeouts >= NUM_DISABLE_TIMEOUTS)) {
 143                 pr_warn("%s: too many timeouts, deactivating speakup\n",
 144                         synth->long_name);
 145                 synth->alive = 0;
 146                 /* No synth any more, so nobody will restart TTYs, and we thus
 147                  * need to do it ourselves.  Now that there is no synth we can
 148                  * let application flood anyway */
 149                 speakup_start_ttys();
 150                 timeouts = 0;
 151                 return 0;
 152         }
 153         while (spk_serial_tx_busy()) {
 154                 if (--tmout == 0) {
 155                         pr_warn("%s: timed out (tx busy)\n", synth->long_name);
 156                         timeouts++;
 157                         return 0;
 158                 }
 159                 udelay(1);
 160         }
 161         tmout = SPK_CTS_TIMEOUT;
 162         while (!((inb_p(speakup_info.port_tts + UART_MSR)) & UART_MSR_CTS)) {
 163                 /* CTS */
 164                 if (--tmout == 0) {
 165                         /* pr_warn("%s: timed out (cts)\n",
 166                          * synth->long_name); */
 167                         timeouts++;
 168                         return 0;
 169                 }
 170                 udelay(1);
 171         }
 172         timeouts = 0;
 173         return 1;
 174 }
 175
 176 unsigned char spk_serial_in(void)
 177 {
 178         int tmout = SPK_SERIAL_TIMEOUT;
 179
 180         while (!(inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR)) {
 181                 if (--tmout == 0) {
 182                         pr_warn("time out while waiting for input.\n");
 183                         return 0xff;
 184                 }
 185                 udelay(1);
 186         }
 187         return inb_p(speakup_info.port_tts + UART_RX);
 188 }
 189 EXPORT_SYMBOL_GPL(spk_serial_in);
 190
 191 unsigned char spk_serial_in_nowait(void)
 192 {
 193         unsigned char lsr;
 194
 195         lsr = inb_p(speakup_info.port_tts + UART_LSR);
 196         if (!(lsr & UART_LSR_DR))
 197                 return 0;
 198         return inb_p(speakup_info.port_tts + UART_RX);
 199 }
 200 EXPORT_SYMBOL_GPL(spk_serial_in_nowait);
 201
 202 int spk_serial_out(const char ch)
 203 {
 204         if (synth->alive && spk_wait_for_xmitr()) {
 205                 outb_p(ch, speakup_info.port_tts);
 206                 return 1;
 207         }
 208         return 0;
 209 }
 210 EXPORT_SYMBOL_GPL(spk_serial_out);
 211
 212 void spk_serial_release(void)
 213 {
 214         if (speakup_info.port_tts == 0)
 215                 return;
 216         synth_release_region(speakup_info.port_tts, 8);
 217         speakup_info.port_tts = 0;
 218 }
 219 EXPORT_SYMBOL_GPL(spk_serial_release);
 220