diff options
Diffstat (limited to 'drivers/hwmon/lis3lv02d.c')
| -rw-r--r-- | drivers/hwmon/lis3lv02d.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c new file mode 100644 index 00000000000..219d2d0d5a6 --- /dev/null +++ b/drivers/hwmon/lis3lv02d.c @@ -0,0 +1,356 @@ +/* + * 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"); + |