1 files changed, 521 insertions, 0 deletions
diff --git a/arch/ia64/hp/sim/simserial.c b/arch/ia64/hp/sim/simserial.c
new file mode 100644
index 000000000..663388a73
--- /dev/null
+++ b/arch/ia64/hp/sim/simserial.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simulated Serial Driver (fake serial)
+ *
+ * This driver is mostly used for bringup purposes and will go away.
+ * It has a strong dependency on the system console. All outputs
+ * are rerouted to the same facility as the one used by printk which, in our
+ * case means sys_sim.c console (goes via the simulator).
+ *
+ * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
+ *	Stephane Eranian <eranian@hpl.hp.com>
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/capability.h>
+#include <linux/circ_buf.h>
+#include <linux/console.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/uaccess.h>
+
+#include <asm/hpsim.h>
+
+#include "hpsim_ssc.h"
+
+#undef SIMSERIAL_DEBUG	/* define this to get some debug information */
+
+#define KEYBOARD_INTR	3	/* must match with simulator! */
+
+#define NR_PORTS	1	/* only one port for now */
+
+struct serial_state {
+	struct tty_port port;
+	struct circ_buf xmit;
+	int irq;
+	int x_char;
+};
+
+static struct serial_state rs_table[NR_PORTS];
+
+struct tty_driver *hp_simserial_driver;
+
+static struct console *console;
+
+static void receive_chars(struct tty_port *port)
+{
+	unsigned char ch;
+	static unsigned char seen_esc = 0;
+
+	while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
+		if (ch == 27 && seen_esc == 0) {
+			seen_esc = 1;
+			continue;
+		} else if (seen_esc == 1 && ch == 'O') {
+			seen_esc = 2;
+			continue;
+		} else if (seen_esc == 2) {
+			if (ch == 'P') /* F1 */
+				show_state();
+#ifdef CONFIG_MAGIC_SYSRQ
+			if (ch == 'S') { /* F4 */
+				do {
+					ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR);
+				} while (!ch);
+				handle_sysrq(ch);
+			}
+#endif
+			seen_esc = 0;
+			continue;
+		}
+		seen_esc = 0;
+
+		if (tty_insert_flip_char(port, ch, TTY_NORMAL) == 0)
+			break;
+	}
+	tty_flip_buffer_push(port);
+}
+
+/*
+ * This is the serial driver's interrupt routine for a single port
+ */
+static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
+{
+	struct serial_state *info = dev_id;
+
+	receive_chars(&info->port);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the serial interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+static int rs_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	if (!info->xmit.buf)
+		return 0;
+
+	local_irq_save(flags);
+	if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
+		local_irq_restore(flags);
+		return 0;
+	}
+	info->xmit.buf[info->xmit.head] = ch;
+	info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
+	local_irq_restore(flags);
+	return 1;
+}
+
+static void transmit_chars(struct tty_struct *tty, struct serial_state *info,
+		int *intr_done)
+{
+	int count;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	if (info->x_char) {
+		char c = info->x_char;
+
+		console->write(console, &c, 1);
+
+		info->x_char = 0;
+
+		goto out;
+	}
+
+	if (info->xmit.head == info->xmit.tail || tty->stopped) {
+#ifdef SIMSERIAL_DEBUG
+		printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
+		       info->xmit.head, info->xmit.tail, tty->stopped);
+#endif
+		goto out;
+	}
+	/*
+	 * We removed the loop and try to do it in to chunks. We need
+	 * 2 operations maximum because it's a ring buffer.
+	 *
+	 * First from current to tail if possible.
+	 * Then from the beginning of the buffer until necessary
+	 */
+
+	count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
+		    SERIAL_XMIT_SIZE - info->xmit.tail);
+	console->write(console, info->xmit.buf+info->xmit.tail, count);
+
+	info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);
+
+	/*
+	 * We have more at the beginning of the buffer
+	 */
+	count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+	if (count) {
+		console->write(console, info->xmit.buf, count);
+		info->xmit.tail += count;
+	}
+out:
+	local_irq_restore(flags);
+}
+
+static void rs_flush_chars(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	if (info->xmit.head == info->xmit.tail || tty->stopped ||
+			!info->xmit.buf)
+		return;
+
+	transmit_chars(tty, info, NULL);
+}
+
+static int rs_write(struct tty_struct * tty,
+		    const unsigned char *buf, int count)
+{
+	struct serial_state *info = tty->driver_data;
+	int	c, ret = 0;
+	unsigned long flags;
+
+	if (!info->xmit.buf)
+		return 0;
+
+	local_irq_save(flags);
+	while (1) {
+		c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+		if (count < c)
+			c = count;
+		if (c <= 0) {
+			break;
+		}
+		memcpy(info->xmit.buf + info->xmit.head, buf, c);
+		info->xmit.head = ((info->xmit.head + c) &
+				   (SERIAL_XMIT_SIZE-1));
+		buf += c;
+		count -= c;
+		ret += c;
+	}
+	local_irq_restore(flags);
+	/*
+	 * Hey, we transmit directly from here in our case
+	 */
+	if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) &&
+			!tty->stopped)
+		transmit_chars(tty, info, NULL);
+
+	return ret;
+}
+
+static int rs_write_room(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static int rs_chars_in_buffer(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static void rs_flush_buffer(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	info->xmit.head = info->xmit.tail = 0;
+	local_irq_restore(flags);
+
+	tty_wakeup(tty);
+}
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ */
+static void rs_send_xchar(struct tty_struct *tty, char ch)
+{
+	struct serial_state *info = tty->driver_data;
+
+	info->x_char = ch;
+	if (ch) {
+		/*
+		 * I guess we could call console->write() directly but
+		 * let's do that for now.
+		 */
+		transmit_chars(tty, info, NULL);
+	}
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_throttle()
+ *
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ * ------------------------------------------------------------
+ */
+static void rs_throttle(struct tty_struct * tty)
+{
+	if (I_IXOFF(tty))
+		rs_send_xchar(tty, STOP_CHAR(tty));
+
+	printk(KERN_INFO "simrs_throttle called\n");
+}
+
+static void rs_unthrottle(struct tty_struct * tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	if (I_IXOFF(tty)) {
+		if (info->x_char)
+			info->x_char = 0;
+		else
+			rs_send_xchar(tty, START_CHAR(tty));
+	}
+	printk(KERN_INFO "simrs_unthrottle called\n");
+}
+
+static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
+{
+	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
+	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
+	    (cmd != TIOCMIWAIT)) {
+		if (tty_io_error(tty))
+		    return -EIO;
+	}
+
+	switch (cmd) {
+	case TIOCGSERIAL:
+	case TIOCSSERIAL:
+	case TIOCSERGSTRUCT:
+	case TIOCMIWAIT:
+		return 0;
+	case TIOCSERCONFIG:
+	case TIOCSERGETLSR: /* Get line status register */
+		return -EINVAL;
+	case TIOCSERGWILD:
+	case TIOCSERSWILD:
+		/* "setserial -W" is called in Debian boot */
+		printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
+		return 0;
+	}
+	return -ENOIOCTLCMD;
+}
+
+#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
+
+/*
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.
+ */
+static void shutdown(struct tty_port *port)
+{
+	struct serial_state *info = container_of(port, struct serial_state,
+			port);
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (info->irq)
+		free_irq(info->irq, info);
+
+	if (info->xmit.buf) {
+		free_page((unsigned long) info->xmit.buf);
+		info->xmit.buf = NULL;
+	}
+	local_irq_restore(flags);
+}
+
+static void rs_close(struct tty_struct *tty, struct file * filp)
+{
+	struct serial_state *info = tty->driver_data;
+
+	tty_port_close(&info->port, tty, filp);
+}
+
+static void rs_hangup(struct tty_struct *tty)
+{
+	struct serial_state *info = tty->driver_data;
+
+	rs_flush_buffer(tty);
+	tty_port_hangup(&info->port);
+}
+
+static int activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct serial_state *state = container_of(port, struct serial_state,
+			port);
+	unsigned long flags, page;
+	int retval = 0;
+
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	local_irq_save(flags);
+
+	if (state->xmit.buf)
+		free_page(page);
+	else
+		state->xmit.buf = (unsigned char *) page;
+
+	if (state->irq) {
+		retval = request_irq(state->irq, rs_interrupt_single, 0,
+				"simserial", state);
+		if (retval)
+			goto errout;
+	}
+
+	state->xmit.head = state->xmit.tail = 0;
+errout:
+	local_irq_restore(flags);
+	return retval;
+}
+
+
+/*
+ * This routine is called whenever a serial port is opened.  It
+ * enables interrupts for a serial port, linking in its async structure into
+ * the IRQ chain.   It also performs the serial-specific
+ * initialization for the tty structure.
+ */
+static int rs_open(struct tty_struct *tty, struct file * filp)
+{
+	struct serial_state *info = rs_table + tty->index;
+	struct tty_port *port = &info->port;
+
+	tty->driver_data = info;
+	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+	/*
+	 * figure out which console to use (should be one already)
+	 */
+	console = console_drivers;
+	while (console) {
+		if ((console->flags & CON_ENABLED) && console->write) break;
+		console = console->next;
+	}
+
+	return tty_port_open(port, tty, filp);
+}
+
+/*
+ * /proc fs routines....
+ */
+
+static int rs_proc_show(struct seq_file *m, void *v)
+{
+	int i;
+
+	seq_printf(m, "simserinfo:1.0\n");
+	for (i = 0; i < NR_PORTS; i++)
+		seq_printf(m, "%d: uart:16550 port:3F8 irq:%d\n",
+		       i, rs_table[i].irq);
+	return 0;
+}
+
+static const struct tty_operations hp_ops = {
+	.open = rs_open,
+	.close = rs_close,
+	.write = rs_write,
+	.put_char = rs_put_char,
+	.flush_chars = rs_flush_chars,
+	.write_room = rs_write_room,
+	.chars_in_buffer = rs_chars_in_buffer,
+	.flush_buffer = rs_flush_buffer,
+	.ioctl = rs_ioctl,
+	.throttle = rs_throttle,
+	.unthrottle = rs_unthrottle,
+	.send_xchar = rs_send_xchar,
+	.hangup = rs_hangup,
+	.proc_show = rs_proc_show,
+};
+
+static const struct tty_port_operations hp_port_ops = {
+	.activate = activate,
+	.shutdown = shutdown,
+};
+
+static int __init simrs_init(void)
+{
+	struct serial_state *state;
+	int retval;
+
+	if (!ia64_platform_is("hpsim"))
+		return -ENODEV;
+
+	hp_simserial_driver = alloc_tty_driver(NR_PORTS);
+	if (!hp_simserial_driver)
+		return -ENOMEM;
+
+	printk(KERN_INFO "SimSerial driver with no serial options enabled\n");
+
+	/* Initialize the tty_driver structure */
+
+	hp_simserial_driver->driver_name = "simserial";
+	hp_simserial_driver->name = "ttyS";
+	hp_simserial_driver->major = TTY_MAJOR;
+	hp_simserial_driver->minor_start = 64;
+	hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
+	hp_simserial_driver->init_termios = tty_std_termios;
+	hp_simserial_driver->init_termios.c_cflag =
+		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(hp_simserial_driver, &hp_ops);
+
+	state = rs_table;
+	tty_port_init(&state->port);
+	state->port.ops = &hp_port_ops;
+	state->port.close_delay = 0; /* XXX really 0? */
+
+	retval = hpsim_get_irq(KEYBOARD_INTR);
+	if (retval < 0) {
+		printk(KERN_ERR "%s: out of interrupt vectors!\n",
+				__func__);
+		goto err_free_tty;
+	}
+
+	state->irq = retval;
+
+	/* the port is imaginary */
+	printk(KERN_INFO "ttyS0 at 0x03f8 (irq = %d) is a 16550\n", state->irq);
+
+	tty_port_link_device(&state->port, hp_simserial_driver, 0);
+	retval = tty_register_driver(hp_simserial_driver);
+	if (retval) {
+		printk(KERN_ERR "Couldn't register simserial driver\n");
+		goto err_free_tty;
+	}
+
+	return 0;
+err_free_tty:
+	put_tty_driver(hp_simserial_driver);
+	tty_port_destroy(&state->port);
+	return retval;
+}
+
+#ifndef MODULE
+__initcall(simrs_init);
+#endif