patch-2.4.21 linux-2.4.21/drivers/char/mux.c

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diff -urN linux-2.4.20/drivers/char/mux.c linux-2.4.21/drivers/char/mux.c
@@ -0,0 +1,638 @@
+/*
+** mux.c:
+**      MUX console for the NOVA and K-Class systems.
+**
+**	(c) Copyright 2002 Ryan Bradetich
+**	(c) Copyright 2002 Hewlett-Packard Company
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+**
+** This Driver used Christoph Plattner's pdc_console.c as a driver
+** template.
+**
+** This Driver currently only supports the console (port 0) on the MUX.
+** Additional work will be needed on this driver to enable the full
+** functionality of the MUX.
+**
+*/
+
+static char *mux_drv_version = "0.1";
+
+#include <linux/config.h>
+#include <linux/version.h>
+
+#undef SERIAL_PARANOIA_CHECK
+#define CONFIG_SERIAL_NOPAUSE_IO
+#define SERIAL_DO_RESTART
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/serialP.h>
+#include <linux/tty.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <asm/uaccess.h>
+
+#ifdef CONFIG_MAGIC_SYSRQ
+#include <linux/sysrq.h>
+static unsigned long break_pressed;
+#endif
+
+#ifdef CONFIG_GSC
+#include <asm/gsc.h>
+#endif
+
+static unsigned long hpa;
+
+#define MUX_OFFSET 0x800
+#define MUX_LINE_OFFSET 0x80
+
+#define MUX_FIFO_SIZE 255
+#define MUX_MIN_FREE_SIZE 32
+
+#define MUX_FIFO_DRAIN_DELAY 1
+#define MUX_POLL_DELAY (30 * HZ / 1000)
+
+#define IO_COMMAND_REG_OFFSET 0x30
+#define IO_STATUS_REG_OFFSET 0x34
+#define IO_DATA_REG_OFFSET 0x3c
+#define IO_DCOUNT_REG_OFFSET 0x40
+#define IO_UCOUNT_REG_OFFSET 0x44
+#define IO_FIFOS_REG_OFFSET 0x48
+
+#define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
+#define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
+#define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
+
+static int mux_drv_refcount; /* = 0 */
+static struct tty_driver mux_drv_driver;
+static struct async_struct *mux_drv_info;
+static struct timer_list mux_drv_timer;
+
+#define NR_PORTS 1
+static struct tty_struct *mux_drv_table[NR_PORTS];
+static struct termios *mux_drv_termios[NR_PORTS];
+static struct termios *mux_drv_termios_locked[NR_PORTS];
+
+/**
+ * mux_read_fifo - Read chars from the mux fifo.
+ * @info: Ptr to the async structure.
+ *
+ * This reads all available data from the mux's fifo and pushes
+ * the data to the tty layer.
+ */
+static void
+mux_read_fifo(struct async_struct *info)
+{
+	int data;
+	struct tty_struct *tty = info->tty;
+
+	while(1) {
+		data = __raw_readl((unsigned long)info->iomem_base 
+				   + IO_DATA_REG_OFFSET);
+
+		if (MUX_STATUS(data))
+			continue;
+
+		if (MUX_EOFIFO(data))
+			break;
+
+		if (tty->flip.count >= TTY_FLIPBUF_SIZE)
+			continue;
+
+		*tty->flip.char_buf_ptr = data & 0xffu;
+		*tty->flip.flag_buf_ptr = 0;
+
+#ifdef CONFIG_MAGIC_SYSRQ
+		if (MUX_BREAK(data) && !break_pressed) {
+ 			break_pressed = jiffies;
+			continue;
+		}
+
+		if(MUX_BREAK(data)) {
+			*tty->flip.flag_buf_ptr = TTY_BREAK;
+		}
+
+		if(break_pressed) {
+			if(time_before(jiffies, break_pressed + HZ * 5)) {
+				handle_sysrq(data & 0xffu, NULL, NULL, NULL);
+				break_pressed = 0;
+				continue; 
+			}
+			break_pressed = 0;
+		}
+#endif
+
+		tty->flip.flag_buf_ptr++;
+		tty->flip.char_buf_ptr++;
+		tty->flip.count++;
+	}
+
+	tty_flip_buffer_push(tty);
+}
+
+
+/**
+ * mux_drv_poll - Mux poll function.
+ * @unused: Unused variable
+ *
+ * This function periodically polls the Mux to check for new data.
+ */
+static void
+mux_drv_poll(unsigned long unused)
+{
+	struct async_struct *info = mux_drv_info;
+
+	if(info && info->tty && mux_drv_refcount) {
+		mux_read_fifo(info);
+		info->last_active = jiffies;
+	}
+
+	mod_timer(&mux_drv_timer, jiffies + MUX_POLL_DELAY);
+}
+
+/**
+ * mux_chars_in_buffer - Returns the number of chars present in the outbound fifo.
+ * @tty: Ptr to the tty structure.
+ *
+ * This function returns the number of chars sitting in the outbound fifo.
+ * [Note: This function is required for the normal_poll function in 
+ *  drivers/char/n_tty.c].
+ */
+static int
+mux_chars_in_buffer(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	return __raw_readl((unsigned long)info->iomem_base 
+			   + IO_DCOUNT_REG_OFFSET);
+}
+
+/**
+ * mux_flush_buffer - Pause until the fifo is empty.
+ * @tty: Ptr to the tty structure.
+ *
+ * Since the mux fifo is self draining, this function just
+ * waits until the fifo has completely drained.
+ */
+static void
+mux_flush_buffer(struct tty_struct *tty)
+{
+	while(mux_chars_in_buffer(tty))
+		mdelay(MUX_FIFO_DRAIN_DELAY);
+}
+
+/**
+ * mux_write_room - How much room is left in the fifo.
+ * @tty: Ptr to the tty structure.
+ *
+ * This function returns how much room is in the fifo for
+ * writing.
+ */
+static int
+mux_write_room(struct tty_struct *tty)
+{
+	int room = mux_chars_in_buffer(tty);
+	if(room > MUX_FIFO_SIZE)
+		return 0;
+
+	return MUX_FIFO_SIZE - room;
+}
+
+/**
+ * mux_write - Write chars to the mux fifo.
+ * @tty: Ptr to the tty structure.
+ * @from_user: Is the buffer from user space?
+ * @buf: The buffer to write to the mux fifo.
+ * @count: The number of chars to write to the mux fifo.
+ *
+ * This function writes the data from buf to the mux fifo.
+ * [Note: we need the mux_flush_buffer() at the end of the 
+ * function, otherwise the system will wait for LONG_MAX
+ * if the fifo is not empty when the TCSETSW ioctl is called.]
+ */
+static int
+mux_write(struct tty_struct *tty, int from_user,
+	  const unsigned char *buf, int count)
+{
+	int size, len, ret = count;
+	char buffer[MUX_FIFO_SIZE], *buf_p;
+	unsigned long iomem_base = 
+		(unsigned long)((struct async_struct *)tty->driver_data)->iomem_base;
+
+	while (count) {
+		size = mux_write_room(tty);
+		len = (size < count) ? size : count;
+
+		if (from_user) {
+			copy_from_user(buffer, buf, len);
+			buf_p = buffer;
+		} else {
+			buf_p = (char *)buf;
+		}
+
+		count -= len;
+		buf += len;
+
+		if(size < MUX_MIN_FREE_SIZE)
+			mux_flush_buffer(tty);
+
+		while(len--) {
+			__raw_writel(*buf_p++, iomem_base + IO_DATA_REG_OFFSET);
+		}
+	}
+
+	mux_flush_buffer(tty);
+	return ret;
+}
+
+/**
+ * mux_break - Turn break handling on or off.
+ * @tty: Ptr to the tty structure.
+ * @break_state: break value.
+ *
+ * This function must be defined because the send_break() in
+ * drivers/char/tty_io.c requires it.  Currently the Serial Mux
+ * does nothing when this function is called.
+ */
+static void
+mux_break(struct tty_struct *tty, int break_state)
+{
+}
+
+/**
+ * get_serial_info - Return the serial structure to userspace.
+ * @info: Ptr to the async structure.
+ * @retinfo: Ptr to the users space buffer.
+ *
+ * Fill in this serial structure and return it to userspace.
+ */
+static int
+get_serial_info(struct async_struct *info,
+		struct serial_struct *retinfo)
+{
+	struct serial_struct tmp;
+
+	if (!retinfo)
+		return -EFAULT;
+
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.line = info->line;
+	tmp.port = info->line;
+	tmp.flags = info->flags;
+	tmp.close_delay = info->close_delay;
+	return copy_to_user(retinfo, &tmp, sizeof(*retinfo)) ? -EFAULT : 0;
+}
+
+/**
+ * get_modem_info - Return the modem control and status signals to userspace.
+ * @info: Ptr to the async structure.
+ * @value: The return buffer.
+ *
+ * The Serial MUX driver always returns these values to userspace:
+ *      Data Terminal Ready, Carrier Detect, Clear To Send,
+ *      Request To Send.
+ *
+ */
+static int 
+get_modem_info(struct async_struct *info, unsigned int *value)
+{
+	unsigned int result = TIOCM_DTR|TIOCM_CAR|TIOCM_CTS|TIOCM_RTS;
+	return copy_to_user(value, &result, sizeof(int)) ? -EFAULT : 0;
+}
+
+/**
+ * get_lsr_info - Return line status register info to userspace.
+ * @info: Ptr to the async structure.
+ * @value: The return buffer.
+ *
+ * The Serial MUX driver always returns empty transmitter to userspace.
+ */
+static int 
+get_lsr_info(struct async_struct *info, unsigned int *value)
+{
+	unsigned int result = TIOCSER_TEMT;
+	return copy_to_user(value, &result, sizeof(int)) ? -EFAULT : 0;
+}
+
+/**
+ * mux_ioctl - Handle driver specific ioctl commands.
+ * @tty: Ptr to the tty structure.
+ * @file: Unused.
+ * @cmd: The ioctl number.
+ * @arg: The ioctl argument.
+ *
+ * This function handles ioctls specific to the Serial MUX driver,
+ * or ioctls that need driver specific information.
+ *
+ */
+static int
+mux_ioctl(struct tty_struct *tty, struct file *file,
+	  unsigned int cmd, unsigned long arg)
+{
+	struct async_struct *info = (struct async_struct *) tty->driver_data;
+
+	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
+	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
+	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
+		if (tty->flags & (1 << TTY_IO_ERROR))
+			return -EIO;
+	}
+
+	switch (cmd) {
+	case TIOCMGET:
+		return get_modem_info(info, (unsigned int *) arg);
+
+	case TIOCMBIS:
+	case TIOCMBIC:
+	case TIOCMSET:
+		return 0;
+
+	case TIOCGSERIAL:
+		return get_serial_info(info, (struct serial_struct *) arg);
+
+	case TIOCSSERIAL:
+		return 0;
+
+	case TIOCSERCONFIG:
+		return 0;
+
+	case TIOCSERGETLSR:
+		return get_lsr_info(info, (unsigned int *) arg);
+
+	case TIOCSERGSTRUCT:
+		if (copy_to_user((struct async_struct *) arg,
+				 info, sizeof (struct async_struct)))
+			return -EFAULT;
+		return 0;
+
+	case TIOCMIWAIT:
+		return 0;
+
+	case TIOCGICOUNT:
+		return 0;
+
+	case TIOCSERGWILD:
+	case TIOCSERSWILD:
+		/* "setserial -W" is called in Debian boot */
+		printk("TIOCSER?WILD ioctl obsolete, ignored.\n");
+		return 0;
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+/**
+ * mux_close - Close the serial mux driver.
+ * @tty: Ptr to the tty structure.
+ * @filp: Unused.
+ * 
+ * This routine is called when the serial port gets closed.  First, we
+ * wait for the last remaining data to be sent.  Then, we unlink its
+ * async structure from the interrupt chain if necessary, and we free
+ * that IRQ if nothing is left in the chain.
+ */
+static void
+mux_close(struct tty_struct *tty, struct file *filp)
+{
+	struct async_struct *info = (struct async_struct *) tty->driver_data;
+
+	mux_drv_refcount--;
+	if (mux_drv_refcount > 0)
+		return;
+
+	info->flags |= ASYNC_CLOSING;
+
+	/*
+	 * Save the termios structure, since this port may have
+	 * separate termios for callout and dialin.
+	 */
+	if (info->flags & ASYNC_NORMAL_ACTIVE)
+		info->state->normal_termios = *tty->termios;
+	if (info->flags & ASYNC_CALLOUT_ACTIVE)
+		info->state->callout_termios = *tty->termios;
+
+	/*
+	 * At this point we stop accepting input.  To do this, we
+	 * disable the receive line status interrupts, and tell the
+	 * interrupt driver to stop checking the data ready bit in the
+	 * line status register.
+	 */
+
+	/* XXX CP: make mask for receive !!! */
+
+	if (tty->driver.flush_buffer)
+		tty->driver.flush_buffer(tty);
+	if (tty->ldisc.flush_buffer)
+		tty->ldisc.flush_buffer(tty);
+	tty->closing = 0;
+	info->event = 0;
+	info->tty = 0;
+	mux_drv_info = NULL;
+	if (info->blocked_open) {
+		if (info->close_delay) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(info->close_delay);
+		}
+		wake_up_interruptible(&info->open_wait);
+	}
+	info->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CALLOUT_ACTIVE |
+			 ASYNC_CLOSING);
+	wake_up_interruptible(&info->close_wait);
+	MOD_DEC_USE_COUNT;
+}
+
+/**
+ * get_async_struct - Get the async structure.
+ * @line: Minor number of the tty device.
+ * @ret_info: Ptr to the newly allocated async structure.
+ *
+ * Allocate and return an async structure for the specified
+ * tty device line.
+ */
+static int
+get_async_struct(int line, struct async_struct **ret_info)
+{
+	struct async_struct *info;
+
+	info = kmalloc(sizeof (struct async_struct), GFP_KERNEL);
+	if (!info) {
+		return -ENOMEM;
+	}
+	memset(info, 0, sizeof (struct async_struct));
+	init_waitqueue_head(&info->open_wait);
+	init_waitqueue_head(&info->close_wait);
+	init_waitqueue_head(&info->delta_msr_wait);
+	info->magic = SERIAL_MAGIC;
+	info->port = 0;
+	info->flags = 0;
+	info->io_type = 0;
+	info->iomem_base = (void *)(hpa + MUX_OFFSET);
+	info->iomem_reg_shift = 0;
+	info->xmit_fifo_size = MUX_FIFO_SIZE;
+	info->line = line;
+	info->tqueue.routine = NULL;
+	info->tqueue.data = info;
+	info->state = NULL;
+	*ret_info = info;
+	return 0;
+}
+
+/**
+ * mux_open - Open the serial mux driver.
+ * @tty: Ptr to the tty structure.
+ * @filp: Unused.
+ *
+ * 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
+mux_open(struct tty_struct *tty, struct file *filp)
+{
+	struct async_struct *info;
+	int retval, line;
+
+	MOD_INC_USE_COUNT;
+	line = MINOR(tty->device) - tty->driver.minor_start;
+	if ((line < 0) || (line >= NR_PORTS)) {
+		MOD_DEC_USE_COUNT;
+		return -ENODEV;
+	}
+	retval = get_async_struct(line, &info);
+	if (retval) {
+		MOD_DEC_USE_COUNT;
+		return retval;
+	}
+
+	tty->driver_data = info;
+	info->tty = tty;
+	mux_drv_info = info;
+	info->tty->low_latency = 0;
+	info->session = current->session;
+	info->pgrp = current->pgrp;
+	mux_drv_refcount++;
+	return 0;
+}
+
+/**
+ * mux_probe - Determine if the Serial Mux should claim this device.
+ * @dev: The parisc device.
+ *
+ * Deterimine if the Sserial Mux should claim this chip (return 0)
+ * or not (return 1).
+ */
+static int __init 
+mux_probe(struct parisc_device *dev)
+{
+	if(hpa) {
+		printk(KERN_INFO "Serial MUX driver already registered, skipping additonal MUXes for now.\n");
+		return 1;
+	}
+
+	init_timer(&mux_drv_timer);
+	mux_drv_timer.function = mux_drv_poll;
+	mod_timer(&mux_drv_timer, jiffies + MUX_POLL_DELAY);
+
+	hpa = dev->hpa;
+	printk(KERN_INFO "Serial MUX driver version %s at 0x%lx\n",
+	       mux_drv_version, hpa);
+
+	/* Initialize the tty_driver structure */
+
+	memset(&mux_drv_driver, 0, sizeof (struct tty_driver));
+	mux_drv_driver.magic = TTY_DRIVER_MAGIC;
+	mux_drv_driver.driver_name = "Serial MUX driver";
+#ifdef CONFIG_DEVFS_FS
+	mux_drv_driver.name = "ttb/%d";
+#else
+	mux_drv_driver.name = "ttyB";
+#endif
+	mux_drv_driver.major = MUX_MAJOR;
+	mux_drv_driver.minor_start = 0;
+	mux_drv_driver.num = NR_PORTS;
+	mux_drv_driver.type = TTY_DRIVER_TYPE_SERIAL;
+	mux_drv_driver.subtype = SERIAL_TYPE_NORMAL;
+	mux_drv_driver.init_termios = tty_std_termios;
+	mux_drv_driver.init_termios.c_cflag =
+	    B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	mux_drv_driver.flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
+	mux_drv_driver.refcount = &mux_drv_refcount;
+	mux_drv_driver.table = mux_drv_table;
+	mux_drv_driver.termios = mux_drv_termios;
+	mux_drv_driver.termios_locked = mux_drv_termios_locked;
+
+	mux_drv_driver.open = mux_open;
+	mux_drv_driver.close = mux_close;
+	mux_drv_driver.write = mux_write;
+	mux_drv_driver.put_char = NULL;
+	mux_drv_driver.flush_chars = NULL;
+	mux_drv_driver.write_room = mux_write_room;
+	mux_drv_driver.chars_in_buffer = mux_chars_in_buffer;
+	mux_drv_driver.flush_buffer = mux_flush_buffer;
+	mux_drv_driver.ioctl = mux_ioctl;
+	mux_drv_driver.throttle = NULL;
+	mux_drv_driver.unthrottle = NULL;
+	mux_drv_driver.set_termios = NULL;
+	mux_drv_driver.stop = NULL;
+	mux_drv_driver.start = NULL;
+	mux_drv_driver.hangup = NULL;
+	mux_drv_driver.break_ctl = mux_break;
+	mux_drv_driver.send_xchar = NULL;
+	mux_drv_driver.wait_until_sent = NULL;
+	mux_drv_driver.read_proc = NULL;
+
+	if (tty_register_driver(&mux_drv_driver))
+		panic("Could not register the serial MUX driver\n");
+
+	return 0;
+}
+
+static struct parisc_device_id mux_tbl[] = {
+	{ HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(parisc, mux_tbl);
+
+static struct parisc_driver mux_driver = {
+	name:		"Serial MUX driver",
+	id_table:	mux_tbl,
+	probe:		mux_probe,
+};
+
+/**
+ * mux_init - Serial MUX initalization procedure.
+ *
+ * Register the Serial MUX driver.
+ */
+static int __init mux_init(void) 
+{
+	return register_parisc_driver(&mux_driver);
+}
+
+/**
+ * mux_exit - Serial MUX cleanup procedure.
+ *
+ * Unregister the Serial MUX driver from the tty layer.
+ */
+static void __exit mux_exit(void)
+{
+	int status = tty_unregister_driver(&mux_drv_driver);
+	if(status) {
+		printk("MUX: failed to unregister the Serial MUX driver (%d)\n", status);
+	}
+}
+
+module_init(mux_init);
+module_exit(mux_exit);
+MODULE_DESCRIPTION("Serial MUX driver");
+MODULE_AUTHOR("Ryan Bradetich");
+MODULE_LICENSE("GPL");
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