diff options
Diffstat (limited to 'drivers/staging/dream/smd/smd_tty.c')
| -rw-r--r-- | drivers/staging/dream/smd/smd_tty.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/staging/dream/smd/smd_tty.c b/drivers/staging/dream/smd/smd_tty.c new file mode 100644 index 0000000000000..2edd9d1ec2dc9 --- /dev/null +++ b/drivers/staging/dream/smd/smd_tty.c @@ -0,0 +1,213 @@ +/* arch/arm/mach-msm/smd_tty.c + * + * Copyright (C) 2007 Google, Inc. + * 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/wait.h> +#include <linux/wakelock.h> + +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/tty_flip.h> + +#include <mach/msm_smd.h> + +#define MAX_SMD_TTYS 32 + +static DEFINE_MUTEX(smd_tty_lock); + +struct smd_tty_info { + smd_channel_t *ch; + struct tty_struct *tty; + struct wake_lock wake_lock; + int open_count; +}; + +static struct smd_tty_info smd_tty[MAX_SMD_TTYS]; + + +static void smd_tty_notify(void *priv, unsigned event) +{ + unsigned char *ptr; + int avail; + struct smd_tty_info *info = priv; + struct tty_struct *tty = info->tty; + + if (!tty) + return; + + if (event != SMD_EVENT_DATA) + return; + + for (;;) { + if (test_bit(TTY_THROTTLED, &tty->flags)) break; + avail = smd_read_avail(info->ch); + if (avail == 0) break; + + avail = tty_prepare_flip_string(tty, &ptr, avail); + + 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 int smd_tty_open(struct tty_struct *tty, struct file *f) +{ + int res = 0; + int n = tty->index; + struct smd_tty_info *info; + const char *name; + + if (n == 0) { + name = "SMD_DS"; + } else if (n == 27) { + name = "SMD_GPSNMEA"; + } else { + return -ENODEV; + } + + info = smd_tty + n; + + mutex_lock(&smd_tty_lock); + wake_lock_init(&info->wake_lock, WAKE_LOCK_SUSPEND, name); + tty->driver_data = info; + + if (info->open_count++ == 0) { + info->tty = tty; + if (info->ch) { + smd_kick(info->ch); + } else { + res = smd_open(name, &info->ch, info, smd_tty_notify); + } + } + 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) { + info->tty = 0; + tty->driver_data = 0; + wake_lock_destroy(&info->wake_lock); + if (info->ch) { + smd_close(info->ch); + info->ch = 0; + } + } + 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 + */ + avail = smd_write_avail(info->ch); + 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; + smd_kick(info->ch); +} + +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, +}; + +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, 27, 0); + + return 0; +} + +module_init(smd_tty_init); |