/*
* lis3lv02d.c - ST LIS3LV02DL accelerometer driver
*
* Copyright (C) 2007-2008 Yan Burman
* Copyright (C) 2008 Eric Piel
* Copyright (C) 2008 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 <acpi/acpi_drivers.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.
*/
/* Maximum value our axis may get for the input device (signed 12 bits) */
#define MDPS_MAX_VAL 2048
struct acpi_lis3lv02d adev;
EXPORT_SYMBOL_GPL(adev);
static int lis3lv02d_add_fs(struct acpi_device *device);
static s16 lis3lv02d_read_16(acpi_handle handle, int reg)
{
u8 lo, hi;
adev.read(handle, reg, &lo);
adev.read(handle, reg + 1, &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
* @handle: the handle to the device
* @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(acpi_handle handle, int *x, int *y, int *z)
{
int position[3];
position[0] = lis3lv02d_read_16(handle, OUTX_L);
position[1] = lis3lv02d_read_16(handle, OUTY_L);
position[2] = lis3lv02d_read_16(handle, OUTZ_L);
*x = lis3lv02d_get_axis(adev.ac.x, position);
*y = lis3lv02d_get_axis(adev.ac.y, position);
*z = lis3lv02d_get_axis(adev.ac.z, position);
}
void lis3lv02d_poweroff(acpi_handle handle)
{
adev.is_on = 0;
/* disable X,Y,Z axis and power down */
adev.write(handle, CTRL_REG1, 0x00);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
void lis3lv02d_poweron(acpi_handle handle)
{
u8 val;
adev.is_on = 1;
adev.init(handle);
adev.write(handle, FF_WU_CFG, 0);
/*
* BDU: LSB and MSB values are not updated until both have been read.
* So the value read will always be correct.
* IEN: Interrupt for free-fall and DD, not for data-ready.
*/
adev.read(handle, CTRL_REG2, &val);
val |= CTRL2_BDU | CTRL2_IEN;
adev.write(handle, CTRL_REG2, val);
}
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 acpi_lis3lv02d *dev)
{
mutex_lock(&dev->lock);
dev->usage++;
if (dev->usage == 1) {
if (!dev->is_on)
lis3lv02d_poweron(dev->device->handle);
}
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 acpi_lis3lv02d *dev)
{
mutex_lock(&dev->lock);
dev->usage--;
if (dev->usage == 0)
lis3lv02d_poweroff(dev->device->handle);
mutex_unlock(&dev->lock);
}
/**
* 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(adev.device->handle, &x, &y, &z);
input_report_abs(adev.idev, ABS_X, x - adev.xcalib);
input_report_abs(adev.idev, ABS_Y, y - adev.ycalib);
input_report_abs(adev.idev, ABS_Z, z - adev.zcalib);
input_sync(adev.idev);
try_to_freeze();
msleep_interruptible(MDPS_POLL_INTERVAL);
}
return 0;
}
static int lis3lv02d_joystick_open(struct input_dev *input)
{
lis3lv02d_increase_use(&adev);
adev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
if (IS_ERR(adev.kthread)) {
lis3lv02d_decrease_use(&adev);
return PTR_ERR(adev.kthread);
}
return 0;
}
static void lis3lv02d_joystick_close(struct input_dev *input)
{
kthread_stop(adev.kthread);
lis3lv02d_decrease_use(&adev);
}
static inline void lis3lv02d_calibrate_joystick(void)
{
lis3lv02d_get_xyz(adev.device->handle, &adev.xcalib, &adev.ycalib, &adev.zcalib);
}
int lis3lv02d_joystick_enable(void)
{
int err;
if (adev.idev)
return -EINVAL;
adev.idev = input_allocate_device();
if (!adev.idev)
return -ENOMEM;
lis3lv02d_calibrate_joystick();
adev.idev->name = "ST LIS3LV02DL Accelerometer";
adev.idev->phys = DRIVER_NAME "/input0";
adev.idev->id.bustype = BUS_HOST;
adev.idev->id.vendor = 0;
adev.idev->dev.parent = &adev.pdev->dev;
adev.idev->open = lis3lv02d_joystick_open;
adev.idev->close = lis3lv02d_joystick_close;
set_bit(EV_ABS, adev.idev->evbit);
input_set_abs_params(adev.idev, ABS_X, -MDPS_MAX_VAL, MDPS_MAX_VAL, 3, 3);
input_set_abs_params(adev.idev, ABS_Y, -MDPS_MAX_VAL, MDPS_MAX_VAL, 3, 3);
input_set_abs_params(adev.idev, ABS_Z, -MDPS_MAX_VAL, MDPS_MAX_VAL, 3, 3);
err = input_register_device(adev.idev);
if (err) {
input_free_device(adev.idev);
adev.idev = NULL;
}
return err;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
void lis3lv02d_joystick_disable(void)
{
if (!adev.idev)
return;
input_unregister_device(adev.idev);
adev.idev = NULL;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
/*
* Initialise the accelerometer and the various subsystems.
* Should be rather independant of the bus system.
*/
int lis3lv02d_init_device(struct acpi_lis3lv02d *dev)
{
mutex_init(&dev->lock);
lis3lv02d_add_fs(dev->device);
lis3lv02d_increase_use(dev);
if (lis3lv02d_joystick_enable())
printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
lis3lv02d_decrease_use(dev);
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
/* Sysfs stuff */
static ssize_t lis3lv02d_position_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int x, y, z;
lis3lv02d_increase_use(&adev);
lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
lis3lv02d_decrease_use(&adev);
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", adev.xcalib, adev.ycalib, adev.zcalib);
}
static ssize_t lis3lv02d_calibrate_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
lis3lv02d_increase_use(&adev);
lis3lv02d_calibrate_joystick();
lis3lv02d_decrease_use(&adev);
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(&adev);
adev.read(adev.device->handle, CTRL_REG1, &ctrl);
lis3lv02d_decrease_use(&adev);
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 acpi_device *device)
{
adev.pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
if (IS_ERR(adev.pdev))
return PTR_ERR(adev.pdev);
return sysfs_create_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
}
int lis3lv02d_remove_fs(void)
{
sysfs_remove_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
platform_device_unregister(adev.pdev);
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
MODULE_AUTHOR("Yan Burman and Eric Piel");
MODULE_LICENSE("GPL");
