| /* arch/arm/mach-msm/smd_tty.c |
| * |
| * Copyright (C) 2007 Google, Inc. |
| * Copyright (c) 2009-2013, The Linux Foundation. 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/subsystem_restart.h> |
| #include <mach/socinfo.h> |
| |
| #include "smd_private.h" |
| |
| #define MAX_SMD_TTYS 37 |
| #define MAX_TTY_BUF_SIZE 2048 |
| #define MAX_RA_WAKE_LOCK_NAME_LEN 32 |
| |
| 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; |
| spinlock_t ra_lock; /* Read Available Lock*/ |
| char ra_wake_lock_name[MAX_RA_WAKE_LOCK_NAME_LEN]; |
| struct wake_lock ra_wake_lock; /* Read Available Wakelock */ |
| 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}, |
| {5, "APPS_RIVA_ANT_CMD", NULL, SMD_APPS_WCNSS}, |
| {6, "APPS_RIVA_ANT_DATA", NULL, SMD_APPS_WCNSS}, |
| {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; |
| unsigned long flags; |
| |
| 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; |
| spin_lock_irqsave(&info->ra_lock, flags); |
| avail = smd_read_avail(info->ch); |
| if (avail == 0) { |
| wake_unlock(&info->ra_wake_lock); |
| spin_unlock_irqrestore(&info->ra_lock, flags); |
| break; |
| } |
| spin_unlock_irqrestore(&info->ra_lock, flags); |
| |
| if (avail > MAX_TTY_BUF_SIZE) |
| avail = MAX_TTY_BUF_SIZE; |
| |
| avail = tty_prepare_flip_string(tty, &ptr, avail); |
| if (avail <= 0) { |
| mod_timer(&info->buf_req_timer, |
| jiffies + msecs_to_jiffies(30)); |
| 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); |
| } |
| spin_lock_irqsave(&info->ra_lock, flags); |
| if (smd_read_avail(info->ch)) { |
| wake_lock(&info->ra_wake_lock); |
| tasklet_hi_schedule(&info->tty_tsklt); |
| } |
| spin_unlock_irqrestore(&info->ra_lock, flags); |
| 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; |
| const 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) { |
| peripheral = smd_edge_to_subsystem(smd_tty[n].smd->edge); |
| if (peripheral) { |
| info->pil = subsystem_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); |
| scnprintf(info->ra_wake_lock_name, |
| MAX_RA_WAKE_LOCK_NAME_LEN, |
| "SMD_TTY_%s_RA", smd_tty[n].smd->port_name); |
| wake_lock_init(&info->ra_wake_lock, WAKE_LOCK_SUSPEND, |
| info->ra_wake_lock_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) |
| subsystem_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); |
| wake_lock_destroy(&info->ra_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; |
| subsystem_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 (pdev->id == smd_configs[n].edge && |
| !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); |
| spin_lock_init(&smd_tty[idx].ra_lock); |
| smd_tty[idx].is_open = 0; |
| setup_timer(&smd_tty[idx].buf_req_timer, buf_req_retry, |
| (unsigned long)&smd_tty[idx]); |
| 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); |