Initial Contribution

msm-2.6.38: tag AU_LINUX_ANDROID_GINGERBREAD.02.03.04.00.142

Signed-off-by: Bryan Huntsman <bryanh@codeaurora.org>
diff --git a/arch/arm/mach-msm/smd_tty.c b/arch/arm/mach-msm/smd_tty.c
new file mode 100644
index 0000000..a8a504f
--- /dev/null
+++ b/arch/arm/mach-msm/smd_tty.c
@@ -0,0 +1,590 @@
+/* arch/arm/mach-msm/smd_tty.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
+ * Author: Brian Swetland <swetland@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/wakelock.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+
+#include <mach/msm_smd.h>
+#include <mach/peripheral-loader.h>
+
+#include "smd_private.h"
+
+#define MAX_SMD_TTYS 37
+#define MAX_TTY_BUF_SIZE 2048
+
+static DEFINE_MUTEX(smd_tty_lock);
+
+static uint smd_tty_modem_wait;
+module_param_named(modem_wait, smd_tty_modem_wait,
+			uint, S_IRUGO | S_IWUSR | S_IWGRP);
+
+struct smd_tty_info {
+	smd_channel_t *ch;
+	struct tty_struct *tty;
+	struct wake_lock wake_lock;
+	int open_count;
+	struct tasklet_struct tty_tsklt;
+	struct timer_list buf_req_timer;
+	struct completion ch_allocated;
+	struct platform_driver driver;
+	void *pil;
+	int in_reset;
+	int in_reset_updated;
+	spinlock_t reset_lock;
+};
+
+#define LOOPBACK_IDX 36
+static char *smd_ch_name[] = {
+	[0] = "DS",
+	[1] = "APPS_FM",
+	[2] = "APPS_RIVA_BT_ACL",
+	[3] = "APPS_RIVA_BT_CMD",
+	[7] = "DATA1",
+	[21] = "DATA21",
+	[27] = "GPSNMEA",
+	[36] = "LOOPBACK",
+};
+
+static uint32_t smd_ch_edge[] = {
+	[0] = SMD_APPS_MODEM,
+	[1] = SMD_APPS_WCNSS,
+	[2] = SMD_APPS_WCNSS,
+	[3] = SMD_APPS_WCNSS,
+	[7] = SMD_APPS_MODEM,
+	[21] = SMD_APPS_MODEM,
+	[27] = SMD_APPS_MODEM,
+	[36] = SMD_APPS_MODEM,
+};
+
+
+static struct delayed_work loopback_work;
+static struct smd_tty_info smd_tty[MAX_SMD_TTYS];
+
+static int is_in_reset(struct smd_tty_info *info)
+{
+	return info->in_reset;
+}
+
+static void buf_req_retry(unsigned long param)
+{
+	struct smd_tty_info *info = (struct smd_tty_info *)param;
+	tasklet_hi_schedule(&info->tty_tsklt);
+}
+
+static void smd_tty_read(unsigned long param)
+{
+	unsigned char *ptr;
+	int avail;
+	struct smd_tty_info *info = (struct smd_tty_info *)param;
+	struct tty_struct *tty = info->tty;
+
+	if (!tty)
+		return;
+
+	for (;;) {
+		if (is_in_reset(info)) {
+			/* signal TTY clients using TTY_BREAK */
+			tty_insert_flip_char(tty, 0x00, TTY_BREAK);
+			tty_flip_buffer_push(tty);
+			break;
+		}
+
+		if (test_bit(TTY_THROTTLED, &tty->flags)) break;
+		avail = smd_read_avail(info->ch);
+		if (avail == 0)
+			break;
+
+		if (avail > MAX_TTY_BUF_SIZE)
+			avail = MAX_TTY_BUF_SIZE;
+
+		avail = tty_prepare_flip_string(tty, &ptr, avail);
+		if (avail <= 0) {
+			if (!timer_pending(&info->buf_req_timer)) {
+				init_timer(&info->buf_req_timer);
+				info->buf_req_timer.expires = jiffies +
+							((30 * HZ)/1000);
+				info->buf_req_timer.function = buf_req_retry;
+				info->buf_req_timer.data = param;
+				add_timer(&info->buf_req_timer);
+			}
+			return;
+		}
+
+		if (smd_read(info->ch, ptr, avail) != avail) {
+			/* shouldn't be possible since we're in interrupt
+			** context here and nobody else could 'steal' our
+			** characters.
+			*/
+			printk(KERN_ERR "OOPS - smd_tty_buffer mismatch?!");
+		}
+
+		wake_lock_timeout(&info->wake_lock, HZ / 2);
+		tty_flip_buffer_push(tty);
+	}
+
+	/* XXX only when writable and necessary */
+	tty_wakeup(tty);
+}
+
+static void smd_tty_notify(void *priv, unsigned event)
+{
+	struct smd_tty_info *info = priv;
+	unsigned long flags;
+
+	switch (event) {
+	case SMD_EVENT_DATA:
+		/* There may be clients (tty framework) that are blocked
+		 * waiting for space to write data, so if a possible read
+		 * interrupt came in wake anyone waiting and disable the
+		 * interrupts
+		 */
+		if (smd_write_avail(info->ch)) {
+			smd_disable_read_intr(info->ch);
+			if (info->tty)
+				wake_up_interruptible(&info->tty->write_wait);
+		}
+		tasklet_hi_schedule(&info->tty_tsklt);
+		break;
+
+	case SMD_EVENT_OPEN:
+		spin_lock_irqsave(&info->reset_lock, flags);
+		info->in_reset = 0;
+		info->in_reset_updated = 1;
+		spin_unlock_irqrestore(&info->reset_lock, flags);
+		break;
+
+	case SMD_EVENT_CLOSE:
+		spin_lock_irqsave(&info->reset_lock, flags);
+		info->in_reset = 1;
+		info->in_reset_updated = 1;
+		spin_unlock_irqrestore(&info->reset_lock, flags);
+		/* schedule task to send TTY_BREAK */
+		tasklet_hi_schedule(&info->tty_tsklt);
+
+		if (info->tty->index == LOOPBACK_IDX)
+			schedule_delayed_work(&loopback_work,
+					msecs_to_jiffies(1000));
+		break;
+	}
+}
+
+static uint32_t is_modem_smsm_inited(void)
+{
+	uint32_t modem_state;
+	uint32_t ready_state = (SMSM_INIT | SMSM_SMDINIT);
+
+	modem_state = smsm_get_state(SMSM_MODEM_STATE);
+	return (modem_state & ready_state) == ready_state;
+}
+
+static int smd_tty_open(struct tty_struct *tty, struct file *f)
+{
+	int res = 0;
+	int n = tty->index;
+	struct smd_tty_info *info;
+	char *peripheral = NULL;
+
+
+	if (!smd_ch_name[n])
+		return -ENODEV;
+
+	info = smd_tty + n;
+
+	mutex_lock(&smd_tty_lock);
+	tty->driver_data = info;
+
+	if (info->open_count++ == 0) {
+		if (smd_ch_edge[n] == SMD_APPS_MODEM)
+			peripheral = "modem";
+
+		if (peripheral) {
+			info->pil = pil_get("modem");
+			if (IS_ERR(info->pil)) {
+				res = PTR_ERR(info->pil);
+				goto out;
+			}
+
+			/* Wait for the modem SMSM to be inited for the SMD
+			 * Loopback channel to be allocated at the modem. Since
+			 * the wait need to be done atmost once, using msleep
+			 * doesn't degrade the performance.
+			 */
+			if (n == 36) {
+				if (!is_modem_smsm_inited())
+					msleep(5000);
+				smsm_change_state(SMSM_APPS_STATE,
+					0, SMSM_SMD_LOOPBACK);
+				msleep(100);
+			}
+
+
+			/*
+			 * Wait for a channel to be allocated so we know
+			 * the modem is ready enough.
+			 */
+			if (smd_tty_modem_wait) {
+				res = wait_for_completion_interruptible_timeout(
+					&info->ch_allocated,
+					msecs_to_jiffies(smd_tty_modem_wait *
+									1000));
+
+				if (res == 0) {
+					pr_err("Timed out waiting for SMD"
+								" channel\n");
+					res = -ETIMEDOUT;
+					goto release_pil;
+				} else if (res < 0) {
+					pr_err("Error waiting for SMD channel:"
+									" %d\n",
+						res);
+					goto release_pil;
+				}
+
+				res = 0;
+			}
+		}
+
+
+		info->tty = tty;
+		tasklet_init(&info->tty_tsklt, smd_tty_read,
+			     (unsigned long)info);
+		wake_lock_init(&info->wake_lock, WAKE_LOCK_SUSPEND,
+				smd_ch_name[n]);
+		if (!info->ch) {
+			res = smd_named_open_on_edge(smd_ch_name[n],
+							smd_ch_edge[n],
+							&info->ch, info,
+							smd_tty_notify);
+		}
+	}
+
+release_pil:
+	if (res < 0)
+		pil_put(info->pil);
+	else
+		smd_disable_read_intr(info->ch);
+out:
+	mutex_unlock(&smd_tty_lock);
+
+	return res;
+}
+
+static void smd_tty_close(struct tty_struct *tty, struct file *f)
+{
+	struct smd_tty_info *info = tty->driver_data;
+
+	if (info == 0)
+		return;
+
+	mutex_lock(&smd_tty_lock);
+	if (--info->open_count == 0) {
+		if (info->tty) {
+			tasklet_kill(&info->tty_tsklt);
+			wake_lock_destroy(&info->wake_lock);
+			info->tty = 0;
+		}
+		tty->driver_data = 0;
+		del_timer(&info->buf_req_timer);
+		if (info->ch) {
+			smd_close(info->ch);
+			info->ch = 0;
+			pil_put(info->pil);
+		}
+	}
+	mutex_unlock(&smd_tty_lock);
+}
+
+static int smd_tty_write(struct tty_struct *tty, const unsigned char *buf, int len)
+{
+	struct smd_tty_info *info = tty->driver_data;
+	int avail;
+
+	/* if we're writing to a packet channel we will
+	** never be able to write more data than there
+	** is currently space for
+	*/
+	if (is_in_reset(info))
+		return -ENETRESET;
+
+	avail = smd_write_avail(info->ch);
+	/* if no space, we'll have to setup a notification later to wake up the
+	 * tty framework when space becomes avaliable
+	 */
+	if (!avail) {
+		smd_enable_read_intr(info->ch);
+		return 0;
+	}
+	if (len > avail)
+		len = avail;
+
+	return smd_write(info->ch, buf, len);
+}
+
+static int smd_tty_write_room(struct tty_struct *tty)
+{
+	struct smd_tty_info *info = tty->driver_data;
+	return smd_write_avail(info->ch);
+}
+
+static int smd_tty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct smd_tty_info *info = tty->driver_data;
+	return smd_read_avail(info->ch);
+}
+
+static void smd_tty_unthrottle(struct tty_struct *tty)
+{
+	struct smd_tty_info *info = tty->driver_data;
+	tasklet_hi_schedule(&info->tty_tsklt);
+	return;
+}
+
+/*
+ * Returns the current TIOCM status bits including:
+ *      SMD Signals (DTR/DSR, CTS/RTS, CD, RI)
+ *      TIOCM_OUT1 - reset state (1=in reset)
+ *      TIOCM_OUT2 - reset state updated (1=updated)
+ */
+static int smd_tty_tiocmget(struct tty_struct *tty)
+{
+	struct smd_tty_info *info = tty->driver_data;
+	unsigned long flags;
+	int tiocm;
+
+	tiocm = smd_tiocmget(info->ch);
+
+	spin_lock_irqsave(&info->reset_lock, flags);
+	tiocm |= (info->in_reset ? TIOCM_OUT1 : 0);
+	if (info->in_reset_updated) {
+		tiocm |= TIOCM_OUT2;
+		info->in_reset_updated = 0;
+	}
+	spin_unlock_irqrestore(&info->reset_lock, flags);
+
+	return tiocm;
+}
+
+static int smd_tty_tiocmset(struct tty_struct *tty,
+				unsigned int set, unsigned int clear)
+{
+	struct smd_tty_info *info = tty->driver_data;
+
+	if (info->in_reset)
+		return -ENETRESET;
+
+	return smd_tiocmset(info->ch, set, clear);
+}
+
+static void loopback_probe_worker(struct work_struct *work)
+{
+	/* wait for modem to restart before requesting loopback server */
+	if (!is_modem_smsm_inited())
+		schedule_delayed_work(&loopback_work, msecs_to_jiffies(1000));
+	else
+		smsm_change_state(SMSM_APPS_STATE,
+			  0, SMSM_SMD_LOOPBACK);
+}
+
+static struct tty_operations smd_tty_ops = {
+	.open = smd_tty_open,
+	.close = smd_tty_close,
+	.write = smd_tty_write,
+	.write_room = smd_tty_write_room,
+	.chars_in_buffer = smd_tty_chars_in_buffer,
+	.unthrottle = smd_tty_unthrottle,
+	.tiocmget = smd_tty_tiocmget,
+	.tiocmset = smd_tty_tiocmset,
+};
+
+static int smd_tty_dummy_probe(struct platform_device *pdev)
+{
+	if (!strncmp(pdev->name, smd_ch_name[0],
+				strnlen(smd_ch_name[0], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[0].ch_allocated);
+	else if (!strncmp(pdev->name, smd_ch_name[1],
+				strnlen(smd_ch_name[1], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[1].ch_allocated);
+	else if (!strncmp(pdev->name, smd_ch_name[2],
+				strnlen(smd_ch_name[2], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[2].ch_allocated);
+	else if (!strncmp(pdev->name, smd_ch_name[3],
+				strnlen(smd_ch_name[3], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[3].ch_allocated);
+	else if (!strncmp(pdev->name, smd_ch_name[7],
+				strnlen(smd_ch_name[7], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[7].ch_allocated);
+	else if (!strncmp(pdev->name, smd_ch_name[21],
+				strnlen(smd_ch_name[21], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[21].ch_allocated);
+	else if (!strncmp(pdev->name, smd_ch_name[27],
+				strnlen(smd_ch_name[27], SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[27].ch_allocated);
+	else if (!strncmp(pdev->name, "LOOPBACK_TTY",
+				strnlen("LOOPBACK_TTY", SMD_MAX_CH_NAME_LEN)))
+		complete_all(&smd_tty[36].ch_allocated);
+
+	return 0;
+}
+
+static struct tty_driver *smd_tty_driver;
+
+static int __init smd_tty_init(void)
+{
+	int ret;
+
+	smd_tty_driver = alloc_tty_driver(MAX_SMD_TTYS);
+	if (smd_tty_driver == 0)
+		return -ENOMEM;
+
+	smd_tty_driver->owner = THIS_MODULE;
+	smd_tty_driver->driver_name = "smd_tty_driver";
+	smd_tty_driver->name = "smd";
+	smd_tty_driver->major = 0;
+	smd_tty_driver->minor_start = 0;
+	smd_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	smd_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+	smd_tty_driver->init_termios = tty_std_termios;
+	smd_tty_driver->init_termios.c_iflag = 0;
+	smd_tty_driver->init_termios.c_oflag = 0;
+	smd_tty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	smd_tty_driver->init_termios.c_lflag = 0;
+	smd_tty_driver->flags = TTY_DRIVER_RESET_TERMIOS |
+		TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+	tty_set_operations(smd_tty_driver, &smd_tty_ops);
+
+	ret = tty_register_driver(smd_tty_driver);
+	if (ret) return ret;
+
+	/* this should be dynamic */
+	tty_register_device(smd_tty_driver, 0, 0);
+	tty_register_device(smd_tty_driver, 1, 0);
+	tty_register_device(smd_tty_driver, 2, 0);
+	tty_register_device(smd_tty_driver, 3, 0);
+	tty_register_device(smd_tty_driver, 7, 0);
+	tty_register_device(smd_tty_driver, 21, 0);
+	tty_register_device(smd_tty_driver, 27, 0);
+	tty_register_device(smd_tty_driver, 36, 0);
+
+	init_completion(&smd_tty[0].ch_allocated);
+	init_completion(&smd_tty[1].ch_allocated);
+	init_completion(&smd_tty[2].ch_allocated);
+	init_completion(&smd_tty[3].ch_allocated);
+	init_completion(&smd_tty[7].ch_allocated);
+	init_completion(&smd_tty[21].ch_allocated);
+	init_completion(&smd_tty[27].ch_allocated);
+	init_completion(&smd_tty[36].ch_allocated);
+
+	smd_tty[0].driver.probe = smd_tty_dummy_probe;
+	smd_tty[0].driver.driver.name = smd_ch_name[0];
+	smd_tty[0].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[0].reset_lock);
+	ret = platform_driver_register(&smd_tty[0].driver);
+	if (ret)
+		goto out;
+	smd_tty[1].driver.probe = smd_tty_dummy_probe;
+	smd_tty[1].driver.driver.name = smd_ch_name[1];
+	smd_tty[1].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[1].reset_lock);
+	ret = platform_driver_register(&smd_tty[1].driver);
+	if (ret)
+		goto unreg0;
+	smd_tty[2].driver.probe = smd_tty_dummy_probe;
+	smd_tty[2].driver.driver.name = smd_ch_name[2];
+	smd_tty[2].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[2].reset_lock);
+	ret = platform_driver_register(&smd_tty[2].driver);
+	if (ret)
+		goto unreg1;
+	smd_tty[3].driver.probe = smd_tty_dummy_probe;
+	smd_tty[3].driver.driver.name = smd_ch_name[3];
+	smd_tty[3].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[3].reset_lock);
+	ret = platform_driver_register(&smd_tty[3].driver);
+	if (ret)
+		goto unreg2;
+	smd_tty[7].driver.probe = smd_tty_dummy_probe;
+	smd_tty[7].driver.driver.name = smd_ch_name[7];
+	smd_tty[7].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[7].reset_lock);
+	ret = platform_driver_register(&smd_tty[7].driver);
+	if (ret)
+		goto unreg3;
+	smd_tty[21].driver.probe = smd_tty_dummy_probe;
+	smd_tty[21].driver.driver.name = smd_ch_name[21];
+	smd_tty[21].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[21].reset_lock);
+	ret = platform_driver_register(&smd_tty[21].driver);
+	if (ret)
+		goto unreg7;
+	smd_tty[27].driver.probe = smd_tty_dummy_probe;
+	smd_tty[27].driver.driver.name = smd_ch_name[27];
+	smd_tty[27].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[27].reset_lock);
+	ret = platform_driver_register(&smd_tty[27].driver);
+	if (ret)
+		goto unreg21;
+	smd_tty[36].driver.probe = smd_tty_dummy_probe;
+	smd_tty[36].driver.driver.name = "LOOPBACK_TTY";
+	smd_tty[36].driver.driver.owner = THIS_MODULE;
+	spin_lock_init(&smd_tty[36].reset_lock);
+	INIT_DELAYED_WORK(&loopback_work, loopback_probe_worker);
+	ret = platform_driver_register(&smd_tty[36].driver);
+	if (ret)
+		goto unreg27;
+
+	return 0;
+
+unreg27:
+	platform_driver_unregister(&smd_tty[27].driver);
+unreg21:
+	platform_driver_unregister(&smd_tty[21].driver);
+unreg7:
+	platform_driver_unregister(&smd_tty[7].driver);
+unreg3:
+	platform_driver_unregister(&smd_tty[3].driver);
+unreg2:
+	platform_driver_unregister(&smd_tty[2].driver);
+unreg1:
+	platform_driver_unregister(&smd_tty[1].driver);
+unreg0:
+	platform_driver_unregister(&smd_tty[0].driver);
+out:
+	tty_unregister_device(smd_tty_driver, 0);
+	tty_unregister_device(smd_tty_driver, 1);
+	tty_unregister_device(smd_tty_driver, 2);
+	tty_unregister_device(smd_tty_driver, 3);
+	tty_unregister_device(smd_tty_driver, 7);
+	tty_unregister_device(smd_tty_driver, 21);
+	tty_unregister_device(smd_tty_driver, 27);
+	tty_unregister_device(smd_tty_driver, 36);
+	tty_unregister_driver(smd_tty_driver);
+	put_tty_driver(smd_tty_driver);
+	return ret;
+}
+
+module_init(smd_tty_init);