diff options
Diffstat (limited to 'drivers/accessibility/speakup/serialio.c')
-rw-r--r-- | drivers/accessibility/speakup/serialio.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/drivers/accessibility/speakup/serialio.c b/drivers/accessibility/speakup/serialio.c new file mode 100644 index 000000000..403b01d66 --- /dev/null +++ b/drivers/accessibility/speakup/serialio.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/interrupt.h> +#include <linux/ioport.h> + +#include "spk_types.h" +#include "speakup.h" +#include "spk_priv.h" +#include "serialio.h" + +#include <linux/serial_core.h> +/* WARNING: Do not change this to <linux/serial.h> without testing that + * SERIAL_PORT_DFNS does get defined to the appropriate value. + */ +#include <asm/serial.h> + +#ifndef SERIAL_PORT_DFNS +#define SERIAL_PORT_DFNS +#endif + +static void start_serial_interrupt(int irq); + +static const struct old_serial_port rs_table[] = { + SERIAL_PORT_DFNS +}; + +static const struct old_serial_port *serstate; +static int timeouts; + +static int spk_serial_out(struct spk_synth *in_synth, const char ch); +static void spk_serial_send_xchar(char ch); +static void spk_serial_tiocmset(unsigned int set, unsigned int clear); +static unsigned char spk_serial_in(void); +static unsigned char spk_serial_in_nowait(void); +static void spk_serial_flush_buffer(void); +static int spk_serial_wait_for_xmitr(struct spk_synth *in_synth); + +struct spk_io_ops spk_serial_io_ops = { + .synth_out = spk_serial_out, + .send_xchar = spk_serial_send_xchar, + .tiocmset = spk_serial_tiocmset, + .synth_in = spk_serial_in, + .synth_in_nowait = spk_serial_in_nowait, + .flush_buffer = spk_serial_flush_buffer, + .wait_for_xmitr = spk_serial_wait_for_xmitr, +}; +EXPORT_SYMBOL_GPL(spk_serial_io_ops); + +const struct old_serial_port *spk_serial_init(int index) +{ + int baud = 9600, quot = 0; + unsigned int cval = 0; + int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8; + const struct old_serial_port *ser; + int err; + + if (index >= ARRAY_SIZE(rs_table)) { + pr_info("no port info for ttyS%d\n", index); + return NULL; + } + ser = rs_table + index; + + /* Divisor, bytesize and parity */ + quot = ser->baud_base / baud; + cval = cflag & (CSIZE | CSTOPB); +#if defined(__powerpc__) || defined(__alpha__) + cval >>= 8; +#else /* !__powerpc__ && !__alpha__ */ + cval >>= 4; +#endif /* !__powerpc__ && !__alpha__ */ + if (cflag & PARENB) + cval |= UART_LCR_PARITY; + if (!(cflag & PARODD)) + cval |= UART_LCR_EPAR; + if (synth_request_region(ser->port, 8)) { + /* try to take it back. */ + pr_info("Ports not available, trying to steal them\n"); + __release_region(&ioport_resource, ser->port, 8); + err = synth_request_region(ser->port, 8); + if (err) { + pr_warn("Unable to allocate port at %x, errno %i", + ser->port, err); + return NULL; + } + } + + /* Disable UART interrupts, set DTR and RTS high + * and set speed. + */ + outb(cval | UART_LCR_DLAB, ser->port + UART_LCR); /* set DLAB */ + outb(quot & 0xff, ser->port + UART_DLL); /* LS of divisor */ + outb(quot >> 8, ser->port + UART_DLM); /* MS of divisor */ + outb(cval, ser->port + UART_LCR); /* reset DLAB */ + + /* Turn off Interrupts */ + outb(0, ser->port + UART_IER); + outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR); + + /* If we read 0xff from the LSR, there is no UART here. */ + if (inb(ser->port + UART_LSR) == 0xff) { + synth_release_region(ser->port, 8); + serstate = NULL; + return NULL; + } + + mdelay(1); + speakup_info.port_tts = ser->port; + serstate = ser; + + start_serial_interrupt(ser->irq); + + return ser; +} + +static irqreturn_t synth_readbuf_handler(int irq, void *dev_id) +{ + unsigned long flags; + int c; + + spin_lock_irqsave(&speakup_info.spinlock, flags); + while (inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR) { + c = inb_p(speakup_info.port_tts + UART_RX); + synth->read_buff_add((u_char)c); + } + spin_unlock_irqrestore(&speakup_info.spinlock, flags); + return IRQ_HANDLED; +} + +static void start_serial_interrupt(int irq) +{ + int rv; + + if (!synth->read_buff_add) + return; + + rv = request_irq(irq, synth_readbuf_handler, IRQF_SHARED, + "serial", (void *)synth_readbuf_handler); + + if (rv) + pr_err("Unable to request Speakup serial I R Q\n"); + /* Set MCR */ + outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2, + speakup_info.port_tts + UART_MCR); + /* Turn on Interrupts */ + outb(UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI, + speakup_info.port_tts + UART_IER); + inb(speakup_info.port_tts + UART_LSR); + inb(speakup_info.port_tts + UART_RX); + inb(speakup_info.port_tts + UART_IIR); + inb(speakup_info.port_tts + UART_MSR); + outb(1, speakup_info.port_tts + UART_FCR); /* Turn FIFO On */ +} + +static void spk_serial_send_xchar(char ch) +{ + int timeout = SPK_XMITR_TIMEOUT; + + while (spk_serial_tx_busy()) { + if (!--timeout) + break; + udelay(1); + } + outb(ch, speakup_info.port_tts); +} + +static void spk_serial_tiocmset(unsigned int set, unsigned int clear) +{ + int old = inb(speakup_info.port_tts + UART_MCR); + + outb((old & ~clear) | set, speakup_info.port_tts + UART_MCR); +} + +int spk_serial_synth_probe(struct spk_synth *synth) +{ + const struct old_serial_port *ser; + int failed = 0; + + if ((synth->ser >= SPK_LO_TTY) && (synth->ser <= SPK_HI_TTY)) { + ser = spk_serial_init(synth->ser); + if (!ser) { + failed = -1; + } else { + outb_p(0, ser->port); + mdelay(1); + outb_p('\r', ser->port); + } + } else { + failed = -1; + pr_warn("ttyS%i is an invalid port\n", synth->ser); + } + if (failed) { + pr_info("%s: not found\n", synth->long_name); + return -ENODEV; + } + pr_info("%s: ttyS%i, Driver Version %s\n", + synth->long_name, synth->ser, synth->version); + synth->alive = 1; + return 0; +} +EXPORT_SYMBOL_GPL(spk_serial_synth_probe); + +void spk_stop_serial_interrupt(void) +{ + if (speakup_info.port_tts == 0) + return; + + if (!synth->read_buff_add) + return; + + /* Turn off interrupts */ + outb(0, speakup_info.port_tts + UART_IER); + /* Free IRQ */ + free_irq(serstate->irq, (void *)synth_readbuf_handler); +} +EXPORT_SYMBOL_GPL(spk_stop_serial_interrupt); + +static int spk_serial_wait_for_xmitr(struct spk_synth *in_synth) +{ + int tmout = SPK_XMITR_TIMEOUT; + + if ((in_synth->alive) && (timeouts >= NUM_DISABLE_TIMEOUTS)) { + pr_warn("%s: too many timeouts, deactivating speakup\n", + in_synth->long_name); + in_synth->alive = 0; + /* No synth any more, so nobody will restart TTYs, and we thus + * need to do it ourselves. Now that there is no synth we can + * let application flood anyway + */ + speakup_start_ttys(); + timeouts = 0; + return 0; + } + while (spk_serial_tx_busy()) { + if (--tmout == 0) { + pr_warn("%s: timed out (tx busy)\n", + in_synth->long_name); + timeouts++; + return 0; + } + udelay(1); + } + tmout = SPK_CTS_TIMEOUT; + while (!((inb_p(speakup_info.port_tts + UART_MSR)) & UART_MSR_CTS)) { + /* CTS */ + if (--tmout == 0) { + timeouts++; + return 0; + } + udelay(1); + } + timeouts = 0; + return 1; +} + +static unsigned char spk_serial_in(void) +{ + int tmout = SPK_SERIAL_TIMEOUT; + + while (!(inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR)) { + if (--tmout == 0) { + pr_warn("time out while waiting for input.\n"); + return 0xff; + } + udelay(1); + } + return inb_p(speakup_info.port_tts + UART_RX); +} + +static unsigned char spk_serial_in_nowait(void) +{ + unsigned char lsr; + + lsr = inb_p(speakup_info.port_tts + UART_LSR); + if (!(lsr & UART_LSR_DR)) + return 0; + return inb_p(speakup_info.port_tts + UART_RX); +} + +static void spk_serial_flush_buffer(void) +{ + /* TODO: flush the UART 16550 buffer */ +} + +static int spk_serial_out(struct spk_synth *in_synth, const char ch) +{ + if (in_synth->alive && spk_serial_wait_for_xmitr(in_synth)) { + outb_p(ch, speakup_info.port_tts); + return 1; + } + return 0; +} + +const char *spk_serial_synth_immediate(struct spk_synth *synth, + const char *buff) +{ + u_char ch; + + while ((ch = *buff)) { + if (ch == '\n') + ch = synth->procspeech; + if (spk_serial_wait_for_xmitr(synth)) + outb(ch, speakup_info.port_tts); + else + return buff; + buff++; + } + return NULL; +} +EXPORT_SYMBOL_GPL(spk_serial_synth_immediate); + +void spk_serial_release(void) +{ + spk_stop_serial_interrupt(); + if (speakup_info.port_tts == 0) + return; + synth_release_region(speakup_info.port_tts, 8); + speakup_info.port_tts = 0; +} +EXPORT_SYMBOL_GPL(spk_serial_release); |