diff options
Diffstat (limited to 'drivers/misc/mpu3050/timerirq.c')
-rw-r--r-- | drivers/misc/mpu3050/timerirq.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/misc/mpu3050/timerirq.c b/drivers/misc/mpu3050/timerirq.c new file mode 100644 index 000000000000..94dd095306a5 --- /dev/null +++ b/drivers/misc/mpu3050/timerirq.c @@ -0,0 +1,295 @@ +/* + $License: + Copyright (C) 2010 InvenSense Corporation, All Rights Reserved. + + 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 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. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + $ + */ +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/stat.h> +#include <linux/signal.h> +#include <linux/miscdevice.h> +#include <linux/i2c.h> +#include <linux/i2c-dev.h> +#include <linux/poll.h> + +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/timer.h> +#include <linux/slab.h> + +#include "mpu.h" +#include "mltypes.h" +#include "timerirq.h" + +/* function which gets timer data and sends it to TIMER */ +struct timerirq_data { + int pid; + int data_ready; + int run; + int timeout; + unsigned long period; + struct mpuirq_data data; + struct completion timer_done; + wait_queue_head_t timerirq_wait; + struct timer_list timer; + struct miscdevice *dev; +}; + +static struct miscdevice *timerirq_dev_data; + +static void timerirq_handler(unsigned long arg) +{ + struct timerirq_data *data = (struct timerirq_data *)arg; + struct timeval irqtime; + + /* dev_info(data->dev->this_device, + "%s, %ld\n", __func__, (unsigned long)data); */ + + data->data.interruptcount++; + + data->data_ready = 1; + + do_gettimeofday(&irqtime); + data->data.irqtime = (((long long) irqtime.tv_sec) << 32); + data->data.irqtime += irqtime.tv_usec; + data->data.data_type |= 1; + + wake_up_interruptible(&data->timerirq_wait); + + if (data->run) + mod_timer(&data->timer, + jiffies + msecs_to_jiffies(data->period)); + else + complete(&data->timer_done); +} + +static int start_timerirq(struct timerirq_data *data) +{ + dev_dbg(data->dev->this_device, + "%s current->pid %d\n", __func__, current->pid); + + /* Timer already running... success */ + if (data->run) + return 0; + + /* Don't allow a period of 0 since this would fire constantly */ + if (!data->period) + return -EINVAL; + + data->run = TRUE; + data->data_ready = FALSE; + + init_completion(&data->timer_done); + setup_timer(&data->timer, timerirq_handler, (unsigned long)data); + + return mod_timer(&data->timer, + jiffies + msecs_to_jiffies(data->period)); +} + +static int stop_timerirq(struct timerirq_data *data) +{ + dev_dbg(data->dev->this_device, + "%s current->pid %lx\n", __func__, (unsigned long)data); + + if (data->run) { + data->run = FALSE; + mod_timer(&data->timer, jiffies + 1); + wait_for_completion(&data->timer_done); + } + return 0; +} + +/* The following depends on patch fa1f68db6ca7ebb6fc4487ac215bffba06c01c28 + * drivers: misc: pass miscdevice pointer via file private data + */ +static int timerirq_open(struct inode *inode, struct file *file) +{ + /* Device node is availabe in the file->private_data, this is + * exactly what we want so we leave it there */ + struct miscdevice *dev_data = file->private_data; + struct timerirq_data *data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->dev = dev_data; + file->private_data = data; + data->pid = current->pid; + init_waitqueue_head(&data->timerirq_wait); + + dev_dbg(data->dev->this_device, + "%s current->pid %d\n", __func__, current->pid); + return 0; +} + +static int timerirq_release(struct inode *inode, struct file *file) +{ + struct timerirq_data *data = file->private_data; + dev_dbg(data->dev->this_device, "timerirq_release\n"); + if (data->run) + stop_timerirq(data); + kfree(data); + return 0; +} + +/* read function called when from /dev/timerirq is read */ +static ssize_t timerirq_read(struct file *file, + char *buf, size_t count, loff_t *ppos) +{ + int len, err; + struct timerirq_data *data = file->private_data; + + if (!data->data_ready) { + wait_event_interruptible_timeout(data->timerirq_wait, + data->data_ready, + data->timeout); + } + + if (data->data_ready && NULL != buf + && count >= sizeof(data->data)) { + err = copy_to_user(buf, &data->data, sizeof(data->data)); + data->data.data_type = 0; + } else { + return 0; + } + if (err != 0) { + dev_err(data->dev->this_device, + "Copy to user returned %d\n", err); + return -EFAULT; + } + data->data_ready = 0; + len = sizeof(data->data); + return len; +} + +unsigned int timerirq_poll(struct file *file, struct poll_table_struct *poll) +{ + int mask = 0; + struct timerirq_data *data = file->private_data; + + poll_wait(file, &data->timerirq_wait, poll); + if (data->data_ready) + mask |= POLLIN | POLLRDNORM; + return mask; +} + +/* ioctl - I/O control */ +static long timerirq_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + int retval = 0; + int tmp; + struct timerirq_data *data = file->private_data; + + dev_dbg(data->dev->this_device, + "%s current->pid %d, %d, %ld\n", + __func__, current->pid, cmd, arg); + + if (!data) + return -EFAULT; + + switch (cmd) { + case TIMERIRQ_SET_TIMEOUT: + data->timeout = arg; + break; + case TIMERIRQ_GET_INTERRUPT_CNT: + tmp = data->data.interruptcount - 1; + if (data->data.interruptcount > 1) + data->data.interruptcount = 1; + + if (copy_to_user((int *) arg, &tmp, sizeof(int))) + return -EFAULT; + break; + case TIMERIRQ_START: + data->period = arg; + retval = start_timerirq(data); + break; + case TIMERIRQ_STOP: + retval = stop_timerirq(data); + break; + default: + retval = -EINVAL; + } + return retval; +} + +/* define which file operations are supported */ +static const struct file_operations timerirq_fops = { + .owner = THIS_MODULE, + .read = timerirq_read, + .poll = timerirq_poll, + +#if HAVE_COMPAT_IOCTL + .compat_ioctl = timerirq_ioctl, +#endif +#if HAVE_UNLOCKED_IOCTL + .unlocked_ioctl = timerirq_ioctl, +#endif + .open = timerirq_open, + .release = timerirq_release, +}; + +static int __init timerirq_init(void) +{ + + int res; + static struct miscdevice *data; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + timerirq_dev_data = data; + data->minor = MISC_DYNAMIC_MINOR; + data->name = "timerirq"; + data->fops = &timerirq_fops; + + res = misc_register(data); + if (res < 0) { + dev_err(data->this_device, + "misc_register returned %d\n", + res); + return res; + } + + return res; +} +module_init(timerirq_init); + +static void __exit timerirq_exit(void) +{ + struct miscdevice *data = timerirq_dev_data; + + dev_info(data->this_device, "Unregistering %s\n", + data->name); + + misc_deregister(data); + kfree(data); + + timerirq_dev_data = NULL; +} +module_exit(timerirq_exit); + +MODULE_AUTHOR("Invensense Corporation"); +MODULE_DESCRIPTION("Timer IRQ device driver."); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("timerirq"); |