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 static const struct old_serial_port *serstate;
  25 static int timeouts;
  26
  27 const 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
  93 static 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
 108 static 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
 133 void 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
 147 int 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
 184 unsigned 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 }
 197 EXPORT_SYMBOL_GPL(spk_serial_in);
 198
 199 unsigned 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 }
 208 EXPORT_SYMBOL_GPL(spk_serial_in_nowait);
 209
 210 int 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 }
 218 EXPORT_SYMBOL_GPL(spk_serial_out);
 219
 220 void 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 }
 227 EXPORT_SYMBOL_GPL(spk_serial_release);