linux/drivers/hwmon/lis3lv02d.c
Giuseppe Bilotta 137bad3234 lis3lv02d: support both one- and two-byte sensors
Sensors responding with 0x3B to WHO_AM_I only have one data register per
direction, thus returning a signed byte from the position which is
occupied by the MSB in sensors responding with 0x3A.

Since multiple sensors share the reply to WHO_AM_I, we rename the defines
to better indicate what they identify (family of single and double
precision sensors).

We support both kind of sensors by checking for the sensor type on init
and defining appropriate data-access routines and sensor limits (for the
joystick) depending on what we find.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Acked-by: Eric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:54 -08:00

482 lines
13 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.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 <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.
*/
struct acpi_lis3lv02d adev = {
.misc_wait = __WAIT_QUEUE_HEAD_INITIALIZER(adev.misc_wait),
};
EXPORT_SYMBOL_GPL(adev);
static int lis3lv02d_add_fs(struct acpi_device *device);
/**
* 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] = adev.read_data(handle, OUTX);
position[1] = adev.read_data(handle, OUTY);
position[2] = adev.read_data(handle, OUTZ);
*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;
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
void lis3lv02d_poweron(acpi_handle handle)
{
adev.is_on = 1;
adev.init(handle);
}
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);
}
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(&adev.count);
wake_up_interruptible(&adev.misc_wait);
kill_fasync(&adev.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, &adev.misc_opened))
return -EBUSY; /* already open */
atomic_set(&adev.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(adev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
DRIVER_NAME, &adev);
if (ret) {
clear_bit(0, &adev.misc_opened);
printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", adev.irq);
return -EBUSY;
}
lis3lv02d_increase_use(&adev);
printk("lis3: registered interrupt %d\n", adev.irq);
return 0;
}
static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
{
fasync_helper(-1, file, 0, &adev.async_queue);
lis3lv02d_decrease_use(&adev);
free_irq(adev.irq, &adev);
clear_bit(0, &adev.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(&adev.misc_wait, &wait);
while (true) {
set_current_state(TASK_INTERRUPTIBLE);
data = atomic_xchg(&adev.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(&adev.misc_wait, &wait);
return retval;
}
static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
{
poll_wait(file, &adev.misc_wait, wait);
if (atomic_read(&adev.count))
return POLLIN | POLLRDNORM;
return 0;
}
static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
{
return fasync_helper(fd, file, on, &adev.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(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, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
input_set_abs_params(adev.idev, ABS_Y, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
input_set_abs_params(adev.idev, ABS_Z, -adev.mdps_max_val, adev.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;
misc_deregister(&lis3lv02d_misc_device);
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");
printk("lis3_init_device: irq %d\n", dev->irq);
/* if we did not get an IRQ from ACPI - we have nothing more to do */
if (!dev->irq) {
printk(KERN_ERR DRIVER_NAME
": No IRQ in ACPI. 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);
/* 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, Eric Piel, Pavel Machek");
MODULE_LICENSE("GPL");