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linux/drivers/hwmon/lis3lv02d.c

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/*
* lis3lv02d.c - ST LIS3LV02DL accelerometer driver
*
* Copyright (C) 2007-2008 Yan Burman
* Copyright (C) 2008 Eric Piel
* Copyright (C) 2008-2009 Pavel Machek
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/kthread.h>
#include <linux/semaphore.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <asm/atomic.h>
#include "lis3lv02d.h"
#define DRIVER_NAME "lis3lv02d"
/* joystick device poll interval in milliseconds */
#define MDPS_POLL_INTERVAL 50
/*
* The sensor can also generate interrupts (DRDY) but it's pretty pointless
* because their are generated even if the data do not change. So it's better
* to keep the interrupt for the free-fall event. The values are updated at
* 40Hz (at the lowest frequency), but as it can be pretty time consuming on
* some low processor, we poll the sensor only at 20Hz... enough for the
* joystick.
*/
struct lis3lv02d lis3_dev = {
.misc_wait = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
};
EXPORT_SYMBOL_GPL(lis3_dev);
static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
{
s8 lo;
if (lis3->read(lis3, reg, &lo) < 0)
return 0;
return lo;
}
static s16 lis3lv02d_read_16(struct lis3lv02d *lis3, int reg)
{
u8 lo, hi;
lis3->read(lis3, reg - 1, &lo);
lis3->read(lis3, reg, &hi);
/* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
return (s16)((hi << 8) | lo);
}
/**
* lis3lv02d_get_axis - For the given axis, give the value converted
* @axis: 1,2,3 - can also be negative
* @hw_values: raw values returned by the hardware
*
* Returns the converted value.
*/
static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
{
if (axis > 0)
return hw_values[axis - 1];
else
return -hw_values[-axis - 1];
}
/**
* lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
* @lis3: pointer to the device struct
* @x: where to store the X axis value
* @y: where to store the Y axis value
* @z: where to store the Z axis value
*
* Note that 40Hz input device can eat up about 10% CPU at 800MHZ
*/
static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
{
int position[3];
position[0] = lis3_dev.read_data(lis3, OUTX);
position[1] = lis3_dev.read_data(lis3, OUTY);
position[2] = lis3_dev.read_data(lis3, OUTZ);
*x = lis3lv02d_get_axis(lis3_dev.ac.x, position);
*y = lis3lv02d_get_axis(lis3_dev.ac.y, position);
*z = lis3lv02d_get_axis(lis3_dev.ac.z, position);
}
void lis3lv02d_poweroff(struct lis3lv02d *lis3)
{
lis3_dev.is_on = 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
void lis3lv02d_poweron(struct lis3lv02d *lis3)
{
lis3_dev.is_on = 1;
lis3_dev.init(lis3);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
/*
* To be called before starting to use the device. It makes sure that the
* device will always be on until a call to lis3lv02d_decrease_use(). Not to be
* used from interrupt context.
*/
static void lis3lv02d_increase_use(struct lis3lv02d *dev)
{
mutex_lock(&dev->lock);
dev->usage++;
if (dev->usage == 1) {
if (!dev->is_on)
lis3lv02d_poweron(dev);
}
mutex_unlock(&dev->lock);
}
/*
* To be called whenever a usage of the device is stopped.
* It will make sure to turn off the device when there is not usage.
*/
static void lis3lv02d_decrease_use(struct lis3lv02d *dev)
{
mutex_lock(&dev->lock);
dev->usage--;
if (dev->usage == 0)
lis3lv02d_poweroff(dev);
mutex_unlock(&dev->lock);
}
static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
{
/*
* Be careful: on some HP laptops the bios force DD when on battery and
* the lid is closed. This leads to interrupts as soon as a little move
* is done.
*/
atomic_inc(&lis3_dev.count);
wake_up_interruptible(&lis3_dev.misc_wait);
kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
return IRQ_HANDLED;
}
static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
{
int ret;
if (test_and_set_bit(0, &lis3_dev.misc_opened))
return -EBUSY; /* already open */
atomic_set(&lis3_dev.count, 0);
/*
* The sensor can generate interrupts for free-fall and direction
* detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
* the things simple and _fast_ we activate it only for free-fall, so
* no need to read register (very slow with ACPI). For the same reason,
* we forbid shared interrupts.
*
* IRQF_TRIGGER_RISING seems pointless on HP laptops because the
* io-apic is not configurable (and generates a warning) but I keep it
* in case of support for other hardware.
*/
ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
DRIVER_NAME, &lis3_dev);
if (ret) {
clear_bit(0, &lis3_dev.misc_opened);
printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
return -EBUSY;
}
lis3lv02d_increase_use(&lis3_dev);
printk("lis3: registered interrupt %d\n", lis3_dev.irq);
return 0;
}
static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
{
fasync_helper(-1, file, 0, &lis3_dev.async_queue);
lis3lv02d_decrease_use(&lis3_dev);
free_irq(lis3_dev.irq, &lis3_dev);
clear_bit(0, &lis3_dev.misc_opened); /* release the device */
return 0;
}
static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
size_t count, loff_t *pos)
{
DECLARE_WAITQUEUE(wait, current);
u32 data;
unsigned char byte_data;
ssize_t retval = 1;
if (count < 1)
return -EINVAL;
add_wait_queue(&lis3_dev.misc_wait, &wait);
while (true) {
set_current_state(TASK_INTERRUPTIBLE);
data = atomic_xchg(&lis3_dev.count, 0);
if (data)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
goto out;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
goto out;
}
schedule();
}
if (data < 255)
byte_data = data;
else
byte_data = 255;
/* make sure we are not going into copy_to_user() with
* TASK_INTERRUPTIBLE state */
set_current_state(TASK_RUNNING);
if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
retval = -EFAULT;
out:
__set_current_state(TASK_RUNNING);
remove_wait_queue(&lis3_dev.misc_wait, &wait);
return retval;
}
static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
{
poll_wait(file, &lis3_dev.misc_wait, wait);
if (atomic_read(&lis3_dev.count))
return POLLIN | POLLRDNORM;
return 0;
}
static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
{
return fasync_helper(fd, file, on, &lis3_dev.async_queue);
}
static const struct file_operations lis3lv02d_misc_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = lis3lv02d_misc_read,
.open = lis3lv02d_misc_open,
.release = lis3lv02d_misc_release,
.poll = lis3lv02d_misc_poll,
.fasync = lis3lv02d_misc_fasync,
};
static struct miscdevice lis3lv02d_misc_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "freefall",
.fops = &lis3lv02d_misc_fops,
};
/**
* lis3lv02d_joystick_kthread - Kthread polling function
* @data: unused - here to conform to threadfn prototype
*/
static int lis3lv02d_joystick_kthread(void *data)
{
int x, y, z;
while (!kthread_should_stop()) {
lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
input_report_abs(lis3_dev.idev, ABS_X, x - lis3_dev.xcalib);
input_report_abs(lis3_dev.idev, ABS_Y, y - lis3_dev.ycalib);
input_report_abs(lis3_dev.idev, ABS_Z, z - lis3_dev.zcalib);
input_sync(lis3_dev.idev);
try_to_freeze();
msleep_interruptible(MDPS_POLL_INTERVAL);
}
return 0;
}
static int lis3lv02d_joystick_open(struct input_dev *input)
{
lis3lv02d_increase_use(&lis3_dev);
lis3_dev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
if (IS_ERR(lis3_dev.kthread)) {
lis3lv02d_decrease_use(&lis3_dev);
return PTR_ERR(lis3_dev.kthread);
}
return 0;
}
static void lis3lv02d_joystick_close(struct input_dev *input)
{
kthread_stop(lis3_dev.kthread);
lis3lv02d_decrease_use(&lis3_dev);
}
static inline void lis3lv02d_calibrate_joystick(void)
{
lis3lv02d_get_xyz(&lis3_dev,
&lis3_dev.xcalib, &lis3_dev.ycalib, &lis3_dev.zcalib);
}
int lis3lv02d_joystick_enable(void)
{
int err;
if (lis3_dev.idev)
return -EINVAL;
lis3_dev.idev = input_allocate_device();
if (!lis3_dev.idev)
return -ENOMEM;
lis3lv02d_calibrate_joystick();
lis3_dev.idev->name = "ST LIS3LV02DL Accelerometer";
lis3_dev.idev->phys = DRIVER_NAME "/input0";
lis3_dev.idev->id.bustype = BUS_HOST;
lis3_dev.idev->id.vendor = 0;
lis3_dev.idev->dev.parent = &lis3_dev.pdev->dev;
lis3_dev.idev->open = lis3lv02d_joystick_open;
lis3_dev.idev->close = lis3lv02d_joystick_close;
set_bit(EV_ABS, lis3_dev.idev->evbit);
input_set_abs_params(lis3_dev.idev, ABS_X, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
input_set_abs_params(lis3_dev.idev, ABS_Y, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
input_set_abs_params(lis3_dev.idev, ABS_Z, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
err = input_register_device(lis3_dev.idev);
if (err) {
input_free_device(lis3_dev.idev);
lis3_dev.idev = NULL;
}
return err;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
void lis3lv02d_joystick_disable(void)
{
if (!lis3_dev.idev)
return;
misc_deregister(&lis3lv02d_misc_device);
input_unregister_device(lis3_dev.idev);
lis3_dev.idev = NULL;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
/* Sysfs stuff */
static ssize_t lis3lv02d_position_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int x, y, z;
lis3lv02d_increase_use(&lis3_dev);
lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
lis3lv02d_decrease_use(&lis3_dev);
return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
}
static ssize_t lis3lv02d_calibrate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "(%d,%d,%d)\n", lis3_dev.xcalib, lis3_dev.ycalib, lis3_dev.zcalib);
}
static ssize_t lis3lv02d_calibrate_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
lis3lv02d_increase_use(&lis3_dev);
lis3lv02d_calibrate_joystick();
lis3lv02d_decrease_use(&lis3_dev);
return count;
}
/* conversion btw sampling rate and the register values */
static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
static ssize_t lis3lv02d_rate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
u8 ctrl;
int val;
lis3lv02d_increase_use(&lis3_dev);
lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
lis3lv02d_decrease_use(&lis3_dev);
val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
}
static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
lis3lv02d_calibrate_store);
static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
static struct attribute *lis3lv02d_attributes[] = {
&dev_attr_position.attr,
&dev_attr_calibrate.attr,
&dev_attr_rate.attr,
NULL
};
static struct attribute_group lis3lv02d_attribute_group = {
.attrs = lis3lv02d_attributes
};
static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
{
lis3_dev.pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
if (IS_ERR(lis3_dev.pdev))
return PTR_ERR(lis3_dev.pdev);
return sysfs_create_group(&lis3_dev.pdev->dev.kobj, &lis3lv02d_attribute_group);
}
int lis3lv02d_remove_fs(void)
{
sysfs_remove_group(&lis3_dev.pdev->dev.kobj, &lis3lv02d_attribute_group);
platform_device_unregister(lis3_dev.pdev);
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
/*
* Initialise the accelerometer and the various subsystems.
* Should be rather independant of the bus system.
*/
int lis3lv02d_init_device(struct lis3lv02d *dev)
{
dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
switch (dev->whoami) {
case LIS_DOUBLE_ID:
printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
dev->read_data = lis3lv02d_read_16;
dev->mdps_max_val = 2048;
break;
case LIS_SINGLE_ID:
printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
dev->read_data = lis3lv02d_read_8;
dev->mdps_max_val = 128;
break;
default:
printk(KERN_ERR DRIVER_NAME
": unknown sensor type 0x%X\n", lis3_dev.whoami);
return -EINVAL;
}
mutex_init(&dev->lock);
lis3lv02d_add_fs(dev);
lis3lv02d_increase_use(dev);
if (lis3lv02d_joystick_enable())
printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
printk("lis3_init_device: irq %d\n", dev->irq);
/* bail if we did not get an IRQ from the bus layer */
if (!dev->irq) {
printk(KERN_ERR DRIVER_NAME
": No IRQ. Disabling /dev/freefall\n");
goto out;
}
printk("lis3: registering device\n");
if (misc_register(&lis3lv02d_misc_device))
printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
out:
lis3lv02d_decrease_use(dev);
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
MODULE_LICENSE("GPL");
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