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