diff options
Diffstat (limited to 'drivers/misc/inv_mpu/mpuirq.c')
| -rw-r--r-- | drivers/misc/inv_mpu/mpuirq.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/drivers/misc/inv_mpu/mpuirq.c b/drivers/misc/inv_mpu/mpuirq.c new file mode 100644 index 0000000..094712c --- /dev/null +++ b/drivers/misc/inv_mpu/mpuirq.c @@ -0,0 +1,253 @@ +/* + $License: + Copyright (C) 2011 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/irq.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/mpu.h> +#include "mpuirq.h" +#include "mldl_cfg.h" + +#define MPUIRQ_NAME "mpuirq" + +/* function which gets accel data and sends it to MPU */ + +DECLARE_WAIT_QUEUE_HEAD(mpuirq_wait); + +struct mpuirq_dev_data { + struct i2c_client *mpu_client; + struct miscdevice *dev; + int irq; + int pid; + int accel_divider; + int data_ready; + int timeout; +}; + +static struct mpuirq_dev_data mpuirq_dev_data; +static struct mpuirq_data mpuirq_data; +static char *interface = MPUIRQ_NAME; + +static int mpuirq_open(struct inode *inode, struct file *file) +{ + dev_dbg(mpuirq_dev_data.dev->this_device, + "%s current->pid %d\n", __func__, current->pid); + mpuirq_dev_data.pid = current->pid; + file->private_data = &mpuirq_dev_data; + return 0; +} + +/* close function - called when the "file" /dev/mpuirq is closed in userspace */ +static int mpuirq_release(struct inode *inode, struct file *file) +{ + dev_dbg(mpuirq_dev_data.dev->this_device, "mpuirq_release\n"); + return 0; +} + +/* read function called when from /dev/mpuirq is read */ +static ssize_t mpuirq_read(struct file *file, + char *buf, size_t count, loff_t *ppos) +{ + int len, err; + struct mpuirq_dev_data *p_mpuirq_dev_data = file->private_data; + + if (!mpuirq_dev_data.data_ready && + mpuirq_dev_data.timeout && (!(file->f_flags & O_NONBLOCK))) { + wait_event_interruptible_timeout(mpuirq_wait, + mpuirq_dev_data.data_ready, + mpuirq_dev_data.timeout); + } + + if (mpuirq_dev_data.data_ready && NULL != buf + && count >= sizeof(mpuirq_data)) { + err = copy_to_user(buf, &mpuirq_data, sizeof(mpuirq_data)); + mpuirq_data.data_type = 0; + } else { + return 0; + } + if (err != 0) { + dev_err(p_mpuirq_dev_data->dev->this_device, + "Copy to user returned %d\n", err); + return -EFAULT; + } + mpuirq_dev_data.data_ready = 0; + len = sizeof(mpuirq_data); + return len; +} + +unsigned int mpuirq_poll(struct file *file, struct poll_table_struct *poll) +{ + int mask = 0; + + poll_wait(file, &mpuirq_wait, poll); + if (mpuirq_dev_data.data_ready) + mask |= POLLIN | POLLRDNORM; + return mask; +} + +/* ioctl - I/O control */ +static long mpuirq_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int retval = 0; + int data; + + switch (cmd) { + case MPUIRQ_SET_TIMEOUT: + mpuirq_dev_data.timeout = arg; + break; + + case MPUIRQ_GET_INTERRUPT_CNT: + data = mpuirq_data.interruptcount - 1; + if (mpuirq_data.interruptcount > 1) + mpuirq_data.interruptcount = 1; + + if (copy_to_user((int *)arg, &data, sizeof(int))) + return -EFAULT; + break; + case MPUIRQ_GET_IRQ_TIME: + if (copy_to_user((int *)arg, &mpuirq_data.irqtime, + sizeof(mpuirq_data.irqtime))) + return -EFAULT; + mpuirq_data.irqtime = 0; + break; + case MPUIRQ_SET_FREQUENCY_DIVIDER: + mpuirq_dev_data.accel_divider = arg; + break; + default: + retval = -EINVAL; + } + return retval; +} + +static irqreturn_t mpuirq_handler(int irq, void *dev_id) +{ + static int mycount; + mycount++; + + mpuirq_data.interruptcount++; + + /* wake up (unblock) for reading data from userspace */ + /* and ignore first interrupt generated in module init */ + mpuirq_dev_data.data_ready = 1; + + mpuirq_data.irqtime = ktime_to_ns(ktime_get()); + mpuirq_data.data_type = MPUIRQ_DATA_TYPE_MPU_IRQ; + mpuirq_data.data = 0; + + wake_up_interruptible(&mpuirq_wait); + + return IRQ_HANDLED; + +} + +/* define which file operations are supported */ +const struct file_operations mpuirq_fops = { + .owner = THIS_MODULE, + .read = mpuirq_read, + .poll = mpuirq_poll, + + .unlocked_ioctl = mpuirq_ioctl, + .open = mpuirq_open, + .release = mpuirq_release, +}; + +static struct miscdevice mpuirq_device = { + .minor = MISC_DYNAMIC_MINOR, + .name = MPUIRQ_NAME, + .fops = &mpuirq_fops, +}; + +int mpuirq_init(struct i2c_client *mpu_client, struct mldl_cfg *mldl_cfg) +{ + + int res; + + mpuirq_dev_data.mpu_client = mpu_client; + + dev_info(&mpu_client->adapter->dev, + "Module Param interface = %s\n", interface); + + mpuirq_dev_data.irq = mpu_client->irq; + mpuirq_dev_data.pid = 0; + mpuirq_dev_data.accel_divider = -1; + mpuirq_dev_data.data_ready = 0; + mpuirq_dev_data.timeout = 0; + mpuirq_dev_data.dev = &mpuirq_device; + + if (mpuirq_dev_data.irq) { + unsigned long flags; + if (BIT_ACTL_LOW == ((mldl_cfg->pdata->int_config) & BIT_ACTL)) + flags = IRQF_TRIGGER_FALLING; + else + flags = IRQF_TRIGGER_RISING; + + res = + request_irq(mpuirq_dev_data.irq, mpuirq_handler, flags, + interface, &mpuirq_dev_data.irq); + if (res) { + dev_err(&mpu_client->adapter->dev, + "myirqtest: cannot register IRQ %d\n", + mpuirq_dev_data.irq); + } else { + res = misc_register(&mpuirq_device); + if (res < 0) { + dev_err(&mpu_client->adapter->dev, + "misc_register returned %d\n", res); + free_irq(mpuirq_dev_data.irq, + &mpuirq_dev_data.irq); + } + } + + } else { + res = 0; + } + + return res; +} + +void mpuirq_exit(void) +{ + if (mpuirq_dev_data.irq > 0) + free_irq(mpuirq_dev_data.irq, &mpuirq_dev_data.irq); + + dev_info(mpuirq_device.this_device, "Unregistering %s\n", MPUIRQ_NAME); + misc_deregister(&mpuirq_device); + + return; +} + +module_param(interface, charp, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(interface, "The Interface name"); |