1 files changed, 316 insertions, 0 deletions
diff --git a/drivers/accessibility/speakup/serialio.c b/drivers/accessibility/speakup/serialio.c
new file mode 100644
index 000000000000..177a2988641c
--- /dev/null
+++ b/drivers/accessibility/speakup/serialio.c
@@ -0,0 +1,316 @@
+// 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);
+
+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,
+};
+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);
+
+int spk_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_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_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);