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/* arch/arm/mach-msm/smd_tty.c
*
* Copyright (C) 2007 Google, Inc.
* Copyright (c) 2009-2012, 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 <mach/socinfo.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;
int is_open;
wait_queue_head_t ch_opened_wait_queue;
spinlock_t reset_lock;
struct smd_config *smd;
};
/**
* SMD port configuration.
*
* @tty_dev_index Index into smd_tty[]
* @port_name Name of the SMD port
* @dev_name Name of the TTY Device (if NULL, @port_name is used)
* @edge SMD edge
*/
struct smd_config {
uint32_t tty_dev_index;
const char *port_name;
const char *dev_name;
uint32_t edge;
};
static struct smd_config smd_configs[] = {
{0, "DS", NULL, SMD_APPS_MODEM},
{1, "APPS_FM", NULL, SMD_APPS_WCNSS},
{2, "APPS_RIVA_BT_ACL", NULL, SMD_APPS_WCNSS},
{3, "APPS_RIVA_BT_CMD", NULL, SMD_APPS_WCNSS},
{4, "MBALBRIDGE", NULL, SMD_APPS_MODEM},
{7, "DATA1", NULL, SMD_APPS_MODEM},
{11, "DATA11", NULL, SMD_APPS_MODEM},
{21, "DATA21", NULL, SMD_APPS_MODEM},
{27, "GPSNMEA", NULL, SMD_APPS_MODEM},
{36, "LOOPBACK", "LOOPBACK_TTY", SMD_APPS_MODEM},
};
#define DS_IDX 0
#define LOOPBACK_IDX 36
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;
unsigned long flags;
spin_lock_irqsave(&info->reset_lock, flags);
if (info->is_open) {
spin_unlock_irqrestore(&info->reset_lock, flags);
tasklet_hi_schedule(&info->tty_tsklt);
return;
}
spin_unlock_irqrestore(&info->reset_lock, flags);
}
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:
spin_lock_irqsave(&info->reset_lock, flags);
if (!info->is_open) {
spin_unlock_irqrestore(&info->reset_lock, flags);
break;
}
spin_unlock_irqrestore(&info->reset_lock, flags);
/* 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;
info->is_open = 1;
wake_up_interruptible(&info->ch_opened_wait_queue);
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;
info->is_open = 0;
wake_up_interruptible(&info->ch_opened_wait_queue);
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;
unsigned int n = tty->index;
struct smd_tty_info *info;
char *peripheral = NULL;
if (n >= MAX_SMD_TTYS || !smd_tty[n].smd)
return -ENODEV;
info = smd_tty + n;
mutex_lock(&smd_tty_lock);
tty->driver_data = info;
if (info->open_count++ == 0) {
if (smd_tty[n].smd->edge == SMD_APPS_MODEM)
peripheral = "modem";
if (peripheral) {
info->pil = pil_get(peripheral);
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 == LOOPBACK_IDX) {
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_tty[n].smd->port_name);
if (!info->ch) {
res = smd_named_open_on_edge(smd_tty[n].smd->port_name,
smd_tty[n].smd->edge,
&info->ch, info,
smd_tty_notify);
if (res < 0) {
pr_err("%s: %s open failed %d\n", __func__,
smd_tty[n].smd->port_name, res);
goto release_pil;
}
res = wait_event_interruptible_timeout(
info->ch_opened_wait_queue,
info->is_open, (2 * HZ));
if (res == 0)
res = -ETIMEDOUT;
if (res < 0) {
pr_err("%s: wait for %s smd_open failed %d\n",
__func__, smd_tty[n].smd->port_name,
res);
goto release_pil;
}
res = 0;
}
}
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;
unsigned long flags;
if (info == 0)
return;
mutex_lock(&smd_tty_lock);
if (--info->open_count == 0) {
spin_lock_irqsave(&info->reset_lock, flags);
info->is_open = 0;
spin_unlock_irqrestore(&info->reset_lock, flags);
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;
unsigned long flags;
spin_lock_irqsave(&info->reset_lock, flags);
if (info->is_open) {
spin_unlock_irqrestore(&info->reset_lock, flags);
tasklet_hi_schedule(&info->tty_tsklt);
return;
}
spin_unlock_irqrestore(&info->reset_lock, flags);
}
/*
* 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)
{
int n;
int idx;
for (n = 0; n < ARRAY_SIZE(smd_configs); ++n) {
idx = smd_configs[n].tty_dev_index;
if (!smd_configs[n].dev_name)
continue;
if (!strncmp(pdev->name, smd_configs[n].dev_name,
SMD_MAX_CH_NAME_LEN)) {
complete_all(&smd_tty[idx].ch_allocated);
return 0;
}
}
pr_err("%s: unknown device '%s'\n", __func__, pdev->name);
return -ENODEV;
}
static struct tty_driver *smd_tty_driver;
static int __init smd_tty_init(void)
{
int ret;
int n;
int idx;
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) {
put_tty_driver(smd_tty_driver);
pr_err("%s: driver registration failed %d\n", __func__, ret);
return ret;
}
for (n = 0; n < ARRAY_SIZE(smd_configs); ++n) {
idx = smd_configs[n].tty_dev_index;
if (smd_configs[n].dev_name == NULL)
smd_configs[n].dev_name = smd_configs[n].port_name;
if (idx == DS_IDX) {
/*
* DS port uses the kernel API starting with
* 8660 Fusion. Only register the userspace
* platform device for older targets.
*/
int legacy_ds = 0;
legacy_ds |= cpu_is_msm7x01() || cpu_is_msm7x25();
legacy_ds |= cpu_is_msm7x27() || cpu_is_msm7x30();
legacy_ds |= cpu_is_qsd8x50() || cpu_is_msm8x55();
/*
* use legacy mode for 8660 Standalone (subtype 0)
*/
legacy_ds |= cpu_is_msm8x60() &&
(socinfo_get_platform_subtype() == 0x0);
if (!legacy_ds)
continue;
}
tty_register_device(smd_tty_driver, idx, 0);
init_completion(&smd_tty[idx].ch_allocated);
/* register platform device */
smd_tty[idx].driver.probe = smd_tty_dummy_probe;
smd_tty[idx].driver.driver.name = smd_configs[n].dev_name;
smd_tty[idx].driver.driver.owner = THIS_MODULE;
spin_lock_init(&smd_tty[idx].reset_lock);
smd_tty[idx].is_open = 0;
init_waitqueue_head(&smd_tty[idx].ch_opened_wait_queue);
ret = platform_driver_register(&smd_tty[idx].driver);
if (ret) {
pr_err("%s: init failed %d (%d)\n", __func__, idx, ret);
smd_tty[idx].driver.probe = NULL;
goto out;
}
smd_tty[idx].smd = &smd_configs[n];
}
INIT_DELAYED_WORK(&loopback_work, loopback_probe_worker);
return 0;
out:
/* unregister platform devices */
for (n = 0; n < ARRAY_SIZE(smd_configs); ++n) {
idx = smd_configs[n].tty_dev_index;
if (smd_tty[idx].driver.probe) {
platform_driver_unregister(&smd_tty[idx].driver);
tty_unregister_device(smd_tty_driver, idx);
}
}
tty_unregister_driver(smd_tty_driver);
put_tty_driver(smd_tty_driver);
return ret;
}
module_init(smd_tty_init);