drivers/hwmon/lis3lv02d.c

   1 /*
   2  *  lis3lv02d.c - ST LIS3LV02DL accelerometer driver
   3  *
   4  *  Copyright (C) 2007-2008 Yan Burman
   5  *  Copyright (C) 2008 Eric Piel
   6  *  Copyright (C) 2008 Pavel Machek
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/init.h>
  25 #include <linux/dmi.h>
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/input.h>
  31 #include <linux/kthread.h>
  32 #include <linux/semaphore.h>
  33 #include <linux/delay.h>
  34 #include <linux/wait.h>
  35 #include <linux/poll.h>
  36 #include <linux/freezer.h>
  37 #include <linux/uaccess.h>
  38 #include <acpi/acpi_drivers.h>
  39 #include <asm/atomic.h>
  40 #include "lis3lv02d.h"
  41
  42 #define DRIVER_NAME     "lis3lv02d"
  43
  44 /* joystick device poll interval in milliseconds */
  45 #define MDPS_POLL_INTERVAL 50
  46 /*
  47  * The sensor can also generate interrupts (DRDY) but it's pretty pointless
  48  * because their are generated even if the data do not change. So it's better
  49  * to keep the interrupt for the free-fall event. The values are updated at
  50  * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
  51  * some low processor, we poll the sensor only at 20Hz... enough for the
  52  * joystick.
  53  */
  54
  55 /* Maximum value our axis may get for the input device (signed 12 bits) */
  56 #define MDPS_MAX_VAL 2048
  57
  58 struct acpi_lis3lv02d adev;
  59 EXPORT_SYMBOL_GPL(adev);
  60
  61 static int lis3lv02d_add_fs(struct acpi_device *device);
  62
  63 static s16 lis3lv02d_read_16(acpi_handle handle, int reg)
  64 {
  65         u8 lo, hi;
  66
  67         adev.read(handle, reg, &lo);
  68         adev.read(handle, reg + 1, &hi);
  69         /* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
  70         return (s16)((hi << 8) | lo);
  71 }
  72
  73 /**
  74  * lis3lv02d_get_axis - For the given axis, give the value converted
  75  * @axis:      1,2,3 - can also be negative
  76  * @hw_values: raw values returned by the hardware
  77  *
  78  * Returns the converted value.
  79  */
  80 static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
  81 {
  82         if (axis > 0)
  83                 return hw_values[axis - 1];
  84         else
  85                 return -hw_values[-axis - 1];
  86 }
  87
  88 /**
  89  * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
  90  * @handle: the handle to the device
  91  * @x:      where to store the X axis value
  92  * @y:      where to store the Y axis value
  93  * @z:      where to store the Z axis value
  94  *
  95  * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
  96  */
  97 static void lis3lv02d_get_xyz(acpi_handle handle, int *x, int *y, int *z)
  98 {
  99         int position[3];
 100
 101         position[0] = lis3lv02d_read_16(handle, OUTX_L);
 102         position[1] = lis3lv02d_read_16(handle, OUTY_L);
 103         position[2] = lis3lv02d_read_16(handle, OUTZ_L);
 104
 105         *x = lis3lv02d_get_axis(adev.ac.x, position);
 106         *y = lis3lv02d_get_axis(adev.ac.y, position);
 107         *z = lis3lv02d_get_axis(adev.ac.z, position);
 108 }
 109
 110 void lis3lv02d_poweroff(acpi_handle handle)
 111 {
 112         adev.is_on = 0;
 113         /* disable X,Y,Z axis and power down */
 114         adev.write(handle, CTRL_REG1, 0x00);
 115 }
 116 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 117
 118 void lis3lv02d_poweron(acpi_handle handle)
 119 {
 120         u8 val;
 121
 122         adev.is_on = 1;
 123         adev.init(handle);
 124         adev.write(handle, FF_WU_CFG, 0);
 125         /*
 126          * BDU: LSB and MSB values are not updated until both have been read.
 127          *      So the value read will always be correct.
 128          * IEN: Interrupt for free-fall and DD, not for data-ready.
 129          */
 130         adev.read(handle, CTRL_REG2, &val);
 131         val |= CTRL2_BDU | CTRL2_IEN;
 132         adev.write(handle, CTRL_REG2, val);
 133 }
 134 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 135
 136 /*
 137  * To be called before starting to use the device. It makes sure that the
 138  * device will always be on until a call to lis3lv02d_decrease_use(). Not to be
 139  * used from interrupt context.
 140  */
 141 static void lis3lv02d_increase_use(struct acpi_lis3lv02d *dev)
 142 {
 143         mutex_lock(&dev->lock);
 144         dev->usage++;
 145         if (dev->usage == 1) {
 146                 if (!dev->is_on)
 147                         lis3lv02d_poweron(dev->device->handle);
 148         }
 149         mutex_unlock(&dev->lock);
 150 }
 151
 152 /*
 153  * To be called whenever a usage of the device is stopped.
 154  * It will make sure to turn off the device when there is not usage.
 155  */
 156 static void lis3lv02d_decrease_use(struct acpi_lis3lv02d *dev)
 157 {
 158         mutex_lock(&dev->lock);
 159         dev->usage--;
 160         if (dev->usage == 0)
 161                 lis3lv02d_poweroff(dev->device->handle);
 162         mutex_unlock(&dev->lock);
 163 }
 164
 165 /**
 166  * lis3lv02d_joystick_kthread - Kthread polling function
 167  * @data: unused - here to conform to threadfn prototype
 168  */
 169 static int lis3lv02d_joystick_kthread(void *data)
 170 {
 171         int x, y, z;
 172
 173         while (!kthread_should_stop()) {
 174                 lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
 175                 input_report_abs(adev.idev, ABS_X, x - adev.xcalib);
 176                 input_report_abs(adev.idev, ABS_Y, y - adev.ycalib);
 177                 input_report_abs(adev.idev, ABS_Z, z - adev.zcalib);
 178
 179                 input_sync(adev.idev);
 180
 181                 try_to_freeze();
 182                 msleep_interruptible(MDPS_POLL_INTERVAL);
 183         }
 184
 185         return 0;
 186 }
 187
 188 static int lis3lv02d_joystick_open(struct input_dev *input)
 189 {
 190         lis3lv02d_increase_use(&adev);
 191         adev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
 192         if (IS_ERR(adev.kthread)) {
 193                 lis3lv02d_decrease_use(&adev);
 194                 return PTR_ERR(adev.kthread);
 195         }
 196
 197         return 0;
 198 }
 199
 200 static void lis3lv02d_joystick_close(struct input_dev *input)
 201 {
 202         kthread_stop(adev.kthread);
 203         lis3lv02d_decrease_use(&adev);
 204 }
 205
 206
 207 static inline void lis3lv02d_calibrate_joystick(void)
 208 {
 209         lis3lv02d_get_xyz(adev.device->handle, &adev.xcalib, &adev.ycalib, &adev.zcalib);
 210 }
 211
 212 int lis3lv02d_joystick_enable(void)
 213 {
 214         int err;
 215
 216         if (adev.idev)
 217                 return -EINVAL;
 218
 219         adev.idev = input_allocate_device();
 220         if (!adev.idev)
 221                 return -ENOMEM;
 222
 223         lis3lv02d_calibrate_joystick();
 224
 225         adev.idev->name       = "ST LIS3LV02DL Accelerometer";
 226         adev.idev->phys       = DRIVER_NAME "/input0";
 227         adev.idev->id.bustype = BUS_HOST;
 228         adev.idev->id.vendor  = 0;
 229         adev.idev->dev.parent = &adev.pdev->dev;
 230         adev.idev->open       = lis3lv02d_joystick_open;
 231         adev.idev->close      = lis3lv02d_joystick_close;
 232
 233         set_bit(EV_ABS, adev.idev->evbit);
 234         input_set_abs_params(adev.idev, ABS_X, -MDPS_MAX_VAL, MDPS_MAX_VAL, 3, 3);
 235         input_set_abs_params(adev.idev, ABS_Y, -MDPS_MAX_VAL, MDPS_MAX_VAL, 3, 3);
 236         input_set_abs_params(adev.idev, ABS_Z, -MDPS_MAX_VAL, MDPS_MAX_VAL, 3, 3);
 237
 238         err = input_register_device(adev.idev);
 239         if (err) {
 240                 input_free_device(adev.idev);
 241                 adev.idev = NULL;
 242         }
 243
 244         return err;
 245 }
 246 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
 247
 248 void lis3lv02d_joystick_disable(void)
 249 {
 250         if (!adev.idev)
 251                 return;
 252
 253         input_unregister_device(adev.idev);
 254         adev.idev = NULL;
 255 }
 256 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
 257
 258 /*
 259  * Initialise the accelerometer and the various subsystems.
 260  * Should be rather independant of the bus system.
 261  */
 262 int lis3lv02d_init_device(struct acpi_lis3lv02d *dev)
 263 {
 264         mutex_init(&dev->lock);
 265         lis3lv02d_add_fs(dev->device);
 266         lis3lv02d_increase_use(dev);
 267
 268         if (lis3lv02d_joystick_enable())
 269                 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
 270
 271         lis3lv02d_decrease_use(dev);
 272         return 0;
 273 }
 274 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
 275
 276 /* Sysfs stuff */
 277 static ssize_t lis3lv02d_position_show(struct device *dev,
 278                                 struct device_attribute *attr, char *buf)
 279 {
 280         int x, y, z;
 281
 282         lis3lv02d_increase_use(&adev);
 283         lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
 284         lis3lv02d_decrease_use(&adev);
 285         return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
 286 }
 287
 288 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
 289                                 struct device_attribute *attr, char *buf)
 290 {
 291         return sprintf(buf, "(%d,%d,%d)\n", adev.xcalib, adev.ycalib, adev.zcalib);
 292 }
 293
 294 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
 295                                 struct device_attribute *attr,
 296                                 const char *buf, size_t count)
 297 {
 298         lis3lv02d_increase_use(&adev);
 299         lis3lv02d_calibrate_joystick();
 300         lis3lv02d_decrease_use(&adev);
 301         return count;
 302 }
 303
 304 /* conversion btw sampling rate and the register values */
 305 static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
 306 static ssize_t lis3lv02d_rate_show(struct device *dev,
 307                         struct device_attribute *attr, char *buf)
 308 {
 309         u8 ctrl;
 310         int val;
 311
 312         lis3lv02d_increase_use(&adev);
 313         adev.read(adev.device->handle, CTRL_REG1, &ctrl);
 314         lis3lv02d_decrease_use(&adev);
 315         val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
 316         return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
 317 }
 318
 319 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
 320 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
 321         lis3lv02d_calibrate_store);
 322 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
 323
 324 static struct attribute *lis3lv02d_attributes[] = {
 325         &dev_attr_position.attr,
 326         &dev_attr_calibrate.attr,
 327         &dev_attr_rate.attr,
 328         NULL
 329 };
 330
 331 static struct attribute_group lis3lv02d_attribute_group = {
 332         .attrs = lis3lv02d_attributes
 333 };
 334
 335
 336 static int lis3lv02d_add_fs(struct acpi_device *device)
 337 {
 338         adev.pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 339         if (IS_ERR(adev.pdev))
 340                 return PTR_ERR(adev.pdev);
 341
 342         return sysfs_create_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
 343 }
 344
 345 int lis3lv02d_remove_fs(void)
 346 {
 347         sysfs_remove_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
 348         platform_device_unregister(adev.pdev);
 349         return 0;
 350 }
 351 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 352
 353 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
 354 MODULE_AUTHOR("Yan Burman and Eric Piel");
 355 MODULE_LICENSE("GPL");
 356