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path: root/drivers/accessibility/speakup/serialio.c
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Diffstat (limited to 'drivers/accessibility/speakup/serialio.c')
-rw-r--r--drivers/accessibility/speakup/serialio.c318
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..3418ea31d
--- /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(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);