linux-zen-server/drivers/accessibility/speakup/serialio.c

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2023-08-30 17:53:23 +02:00
// 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(struct spk_synth *in_synth, char ch);
static void spk_serial_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear);
static unsigned char spk_serial_in(struct spk_synth *in_synth);
static unsigned char spk_serial_in_nowait(struct spk_synth *in_synth);
static void spk_serial_flush_buffer(struct spk_synth *in_synth);
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, byte size 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(struct spk_synth *synth, 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(struct spk_synth *in_synth, 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(struct spk_synth *in_synth)
{
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(struct spk_synth *in_synth)
{
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(struct spk_synth *in_synth)
{
/* 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(struct spk_synth *synth)
{
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);