path: root/drivers/misc/lis3lv02d/lis3lv02d.c

/*
 *  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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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-polldev.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/pm_runtime.h>
#include <linux/atomic.h>
#include "lis3lv02d.h"

#define DRIVER_NAME     "lis3lv02d"

/* joystick device poll interval in milliseconds */
#define MDPS_POLL_INTERVAL 50
#define MDPS_POLL_MIN	   0
#define MDPS_POLL_MAX	   2000

#define LIS3_SYSFS_POWERDOWN_DELAY 5000 /* In milliseconds */

#define SELFTEST_OK	       0
#define SELFTEST_FAIL	       -1
#define SELFTEST_IRQ	       -2

#define IRQ_LINE0	       0
#define IRQ_LINE1	       1

/*
 * The sensor can also generate interrupts (DRDY) but it's pretty pointless
 * because they 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.
 */

#define LIS3_PWRON_DELAY_WAI_12B	(5000)
#define LIS3_PWRON_DELAY_WAI_8B		(3000)

/*
 * LIS3LV02D spec says 1024 LSBs corresponds 1 G -> 1LSB is 1000/1024 mG
 * LIS302D spec says: 18 mG / digit
 * LIS3_ACCURACY is used to increase accuracy of the intermediate
 * calculation results.
 */
#define LIS3_ACCURACY			1024
/* Sensitivity values for -2G +2G scale */
#define LIS3_SENSITIVITY_12B		((LIS3_ACCURACY * 1000) / 1024)
#define LIS3_SENSITIVITY_8B		(18 * LIS3_ACCURACY)

#define LIS3_DEFAULT_FUZZ_12B		3
#define LIS3_DEFAULT_FLAT_12B		3
#define LIS3_DEFAULT_FUZZ_8B		1
#define LIS3_DEFAULT_FLAT_8B		1

struct lis3lv02d lis3_dev = {
	.misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
};
EXPORT_SYMBOL_GPL(lis3_dev);

/* just like param_set_int() but does sanity-check so that it won't point
 * over the axis array size
 */
static int param_set_axis(const char *val, const struct kernel_param *kp)
{
	int ret = param_set_int(val, kp);
	if (!ret) {
		int val = *(int *)kp->arg;
		if (val < 0)
			val = -val;
		if (!val || val > 3)
			return -EINVAL;
	}
	return ret;
}

static struct kernel_param_ops param_ops_axis = {
	.set = param_set_axis,
	.get = param_get_int,
};

module_param_array_named(axes, lis3_dev.ac.as_array, axis, NULL, 0644);
MODULE_PARM_DESC(axes, "Axis-mapping for x,y,z directions");

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_12(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];
	int i;

	if (lis3->blkread) {
		if (lis3->whoami == WAI_12B) {
			u16 data[3];
			lis3->blkread(lis3, OUTX_L, 6, (u8 *)data);
			for (i = 0; i < 3; i++)
				position[i] = (s16)le16_to_cpu(data[i]);
		} else {
			u8 data[5];
			/* Data: x, dummy, y, dummy, z */
			lis3->blkread(lis3, OUTX, 5, data);