linux/drivers/hwmon/lis3lv02d.c
Samu Onkalo 32496c76b7 lis3: scale output values to mg
Report output values as 1/1000 of earth gravity.

Output values from lis3 can be read from sysfs position entry and from
input device.  Input device can be accessed as event device and as
joystick device.  Joystick device can be in two modes.  Meaning of the
output values varies from case to case depending on the chip type and
configuration (scale).  Only joystick interface in JS_CORR_BROKEN mode
returned somehow similar output values in different configurations.
Joystick device is in that state by default in case of lis3.

Position sysfs entry, input event device and raw joystick device have been
little bit broken since meaning of the output values has been varied
between 12 and 8 bit devices.  Applications which relayed on those methods
failed if the chip is different than the expected one.

This patch converts output values to mean similar thing in different
configurations.  Both 8 and 12 bit devices reports now same acceleration
values.  If somebody implements full scale support to the driver, output
values will still mean the same.  Scaling factor and input device range
must be updated in that case.

Joystick interface in JS_CORR_BROKEN mode is not touched by this patch.
All other interfaces have different scale after this change.  For 12 bit
device scaling factor is 0.977 which keeps scaled and unscaled values are
quite close to each others.  For 8 bit device, scaled values are 18 times
bigger than unscaled values.

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:36 -08:00

611 lines
16 KiB
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
*/
#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/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 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 3
#define LIS3_DEFAULT_FLAT 3
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_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;
mutex_lock(&lis3->mutex);
position[0] = lis3->read_data(lis3, OUTX);
position[1] = lis3->read_data(lis3, OUTY);
position[2] = lis3->read_data(lis3, OUTZ);
mutex_unlock(&lis3->mutex);
for (i = 0; i < 3; i++)
position[i] = (position[i] * lis3->scale) / LIS3_ACCURACY;
*x = lis3lv02d_get_axis(lis3->ac.x, position);
*y = lis3lv02d_get_axis(lis3->ac.y, position);
*z = lis3lv02d_get_axis(lis3->ac.z, position);
}
/* conversion btw sampling rate and the register values */
static int lis3_12_rates[4] = {40, 160, 640, 2560};
static int lis3_8_rates[2] = {100, 400};
/* ODR is Output Data Rate */
static int lis3lv02d_get_odr(void)
{
u8 ctrl;
int shift;
lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
ctrl &= lis3_dev.odr_mask;
shift = ffs(lis3_dev.odr_mask) - 1;
return lis3_dev.odrs[(ctrl >> shift)];
}
static int lis3lv02d_set_odr(int rate)
{
u8 ctrl;
int i, len, shift;
lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
ctrl &= ~lis3_dev.odr_mask;
len = 1 << hweight_long(lis3_dev.odr_mask); /* # of possible values */
shift = ffs(lis3_dev.odr_mask) - 1;
for (i = 0; i < len; i++)
if (lis3_dev.odrs[i] == rate) {
lis3_dev.write(&lis3_dev, CTRL_REG1,
ctrl | (i << shift));
return 0;
}
return -EINVAL;
}
static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
{
u8 reg;
s16 x, y, z;
u8 selftest;
int ret;
mutex_lock(&lis3->mutex);
if (lis3_dev.whoami == WAI_12B)
selftest = CTRL1_ST;
else
selftest = CTRL1_STP;
lis3->read(lis3, CTRL_REG1, &reg);
lis3->write(lis3, CTRL_REG1, (reg | selftest));
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
/* Read directly to avoid axis remap */
x = lis3->read_data(lis3, OUTX);
y = lis3->read_data(lis3, OUTY);
z = lis3->read_data(lis3, OUTZ);
/* back to normal settings */
lis3->write(lis3, CTRL_REG1, reg);
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
results[0] = x - lis3->read_data(lis3, OUTX);
results[1] = y - lis3->read_data(lis3, OUTY);
results[2] = z - lis3->read_data(lis3, OUTZ);
ret = 0;
if (lis3->pdata) {
int i;
for (i = 0; i < 3; i++) {
/* Check against selftest acceptance limits */
if ((results[i] < lis3->pdata->st_min_limits[i]) ||
(results[i] > lis3->pdata->st_max_limits[i])) {
ret = -EIO;
goto fail;
}
}
}
/* test passed */
fail:
mutex_unlock(&lis3->mutex);
return ret;
}
void lis3lv02d_poweroff(struct lis3lv02d *lis3)
{
/* disable X,Y,Z axis and power down */
lis3->write(lis3, CTRL_REG1, 0x00);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
void lis3lv02d_poweron(struct lis3lv02d *lis3)
{
u8 reg;
lis3->init(lis3);
/* LIS3 power on delay is quite long */
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
/*
* Common configuration
* BDU: (12 bits sensors only) LSB and MSB values are not updated until
* both have been read. So the value read will always be correct.
*/
if (lis3->whoami == WAI_12B) {
lis3->read(lis3, CTRL_REG2, &reg);
reg |= CTRL2_BDU;
lis3->write(lis3, CTRL_REG2, reg);
}
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
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;
}
return 0;
}
static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
{
fasync_helper(-1, file, 0, &lis3_dev.async_queue);
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,
};
static void lis3lv02d_joystick_poll(struct input_polled_dev *pidev)
{
int x, y, z;
lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
input_report_abs(pidev->input, ABS_X, x);
input_report_abs(pidev->input, ABS_Y, y);
input_report_abs(pidev->input, ABS_Z, z);
input_sync(pidev->input);
}
int lis3lv02d_joystick_enable(void)
{
struct input_dev *input_dev;
int err;
int max_val, fuzz, flat;
if (lis3_dev.idev)
return -EINVAL;
lis3_dev.idev = input_allocate_polled_device();
if (!lis3_dev.idev)
return -ENOMEM;
lis3_dev.idev->poll = lis3lv02d_joystick_poll;
lis3_dev.idev->poll_interval = MDPS_POLL_INTERVAL;
input_dev = lis3_dev.idev->input;
input_dev->name = "ST LIS3LV02DL Accelerometer";
input_dev->phys = DRIVER_NAME "/input0";
input_dev->id.bustype = BUS_HOST;
input_dev->id.vendor = 0;
input_dev->dev.parent = &lis3_dev.pdev->dev;
set_bit(EV_ABS, input_dev->evbit);
max_val = (lis3_dev.mdps_max_val * lis3_dev.scale) / LIS3_ACCURACY;
fuzz = (LIS3_DEFAULT_FUZZ * lis3_dev.scale) / LIS3_ACCURACY;
flat = (LIS3_DEFAULT_FLAT * lis3_dev.scale) / LIS3_ACCURACY;
input_set_abs_params(input_dev, ABS_X, -max_val, max_val, fuzz, flat);
input_set_abs_params(input_dev, ABS_Y, -max_val, max_val, fuzz, flat);
input_set_abs_params(input_dev, ABS_Z, -max_val, max_val, fuzz, flat);
err = input_register_polled_device(lis3_dev.idev);
if (err) {
input_free_polled_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;
if (lis3_dev.irq)
misc_deregister(&lis3lv02d_misc_device);
input_unregister_polled_device(lis3_dev.idev);
input_free_polled_device(lis3_dev.idev);
lis3_dev.idev = NULL;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
/* Sysfs stuff */
static ssize_t lis3lv02d_selftest_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int result;
s16 values[3];
result = lis3lv02d_selftest(&lis3_dev, values);
return sprintf(buf, "%s %d %d %d\n", result == 0 ? "OK" : "FAIL",
values[0], values[1], values[2]);
}
static ssize_t lis3lv02d_position_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int x, y, z;
lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
}
static ssize_t lis3lv02d_rate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", lis3lv02d_get_odr());
}
static ssize_t lis3lv02d_rate_set(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
unsigned long rate;
if (strict_strtoul(buf, 0, &rate))
return -EINVAL;
if (lis3lv02d_set_odr(rate))
return -EINVAL;
return count;
}
static DEVICE_ATTR(selftest, S_IRUSR, lis3lv02d_selftest_show, NULL);
static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
static DEVICE_ATTR(rate, S_IRUGO | S_IWUSR, lis3lv02d_rate_show,
lis3lv02d_rate_set);
static struct attribute *lis3lv02d_attributes[] = {
&dev_attr_selftest.attr,
&dev_attr_position.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->pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
if (IS_ERR(lis3->pdev))
return PTR_ERR(lis3->pdev);
return sysfs_create_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
}
int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
{
sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
platform_device_unregister(lis3->pdev);
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
/*
* Initialise the accelerometer and the various subsystems.
* Should be rather independent of the bus system.
*/
int lis3lv02d_init_device(struct lis3lv02d *dev)
{
dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
switch (dev->whoami) {
case WAI_12B:
printk(KERN_INFO DRIVER_NAME ": 12 bits sensor found\n");
dev->read_data = lis3lv02d_read_12;
dev->mdps_max_val = 2048;
dev->pwron_delay = LIS3_PWRON_DELAY_WAI_12B;
dev->odrs = lis3_12_rates;
dev->odr_mask = CTRL1_DF0 | CTRL1_DF1;
dev->scale = LIS3_SENSITIVITY_12B;
break;
case WAI_8B:
printk(KERN_INFO DRIVER_NAME ": 8 bits sensor found\n");
dev->read_data = lis3lv02d_read_8;
dev->mdps_max_val = 128;
dev->pwron_delay = LIS3_PWRON_DELAY_WAI_8B;
dev->odrs = lis3_8_rates;
dev->odr_mask = CTRL1_DR;
dev->scale = LIS3_SENSITIVITY_8B;
break;
default:
printk(KERN_ERR DRIVER_NAME
": unknown sensor type 0x%X\n", dev->whoami);
return -EINVAL;
}
mutex_init(&dev->mutex);
lis3lv02d_add_fs(dev);
lis3lv02d_poweron(dev);
if (lis3lv02d_joystick_enable())
printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
/* passing in platform specific data is purely optional and only
* used by the SPI transport layer at the moment */
if (dev->pdata) {
struct lis3lv02d_platform_data *p = dev->pdata;
if (p->click_flags && (dev->whoami == WAI_8B)) {
dev->write(dev, CLICK_CFG, p->click_flags);
dev->write(dev, CLICK_TIMELIMIT, p->click_time_limit);
dev->write(dev, CLICK_LATENCY, p->click_latency);
dev->write(dev, CLICK_WINDOW, p->click_window);
dev->write(dev, CLICK_THSZ, p->click_thresh_z & 0xf);
dev->write(dev, CLICK_THSY_X,
(p->click_thresh_x & 0xf) |
(p->click_thresh_y << 4));
}
if (p->wakeup_flags && (dev->whoami == WAI_8B)) {
dev->write(dev, FF_WU_CFG_1, p->wakeup_flags);
dev->write(dev, FF_WU_THS_1, p->wakeup_thresh & 0x7f);
/* default to 2.5ms for now */
dev->write(dev, FF_WU_DURATION_1, 1);
/* enable high pass filter for both free-fall units */
dev->write(dev, CTRL_REG2, HP_FF_WU1 | HP_FF_WU2);
}
if (p->irq_cfg)
dev->write(dev, CTRL_REG3, p->irq_cfg);
}
/* 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;
}
if (misc_register(&lis3lv02d_misc_device))
printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
out:
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");