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) 2008-2009 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 <linux/miscdevice.h>
  39 #include <acpi/acpi_drivers.h>
  40 #include <asm/atomic.h>
  41 #include "lis3lv02d.h"
  42
  43 #define DRIVER_NAME     "lis3lv02d"
  44
  45 /* joystick device poll interval in milliseconds */
  46 #define MDPS_POLL_INTERVAL 50
  47 /*
  48  * The sensor can also generate interrupts (DRDY) but it's pretty pointless
  49  * because their are generated even if the data do not change. So it's better
  50  * to keep the interrupt for the free-fall event. The values are updated at
  51  * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
  52  * some low processor, we poll the sensor only at 20Hz... enough for the
  53  * joystick.
  54  */
  55
  56 struct acpi_lis3lv02d adev = {
  57         .misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(adev.misc_wait),
  58 };
  59
  60 EXPORT_SYMBOL_GPL(adev);
  61
  62 static int lis3lv02d_add_fs(struct acpi_device *device);
  63
  64 /**
  65  * lis3lv02d_get_axis - For the given axis, give the value converted
  66  * @axis:      1,2,3 - can also be negative
  67  * @hw_values: raw values returned by the hardware
  68  *
  69  * Returns the converted value.
  70  */
  71 static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
  72 {
  73         if (axis > 0)
  74                 return hw_values[axis - 1];
  75         else
  76                 return -hw_values[-axis - 1];
  77 }
  78
  79 /**
  80  * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
  81  * @handle: the handle to the device
  82  * @x:      where to store the X axis value
  83  * @y:      where to store the Y axis value
  84  * @z:      where to store the Z axis value
  85  *
  86  * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
  87  */
  88 static void lis3lv02d_get_xyz(acpi_handle handle, int *x, int *y, int *z)
  89 {
  90         int position[3];
  91
  92         position[0] = adev.read_data(handle, OUTX);
  93         position[1] = adev.read_data(handle, OUTY);
  94         position[2] = adev.read_data(handle, OUTZ);
  95
  96         *x = lis3lv02d_get_axis(adev.ac.x, position);
  97         *y = lis3lv02d_get_axis(adev.ac.y, position);
  98         *z = lis3lv02d_get_axis(adev.ac.z, position);
  99 }
 100
 101 void lis3lv02d_poweroff(acpi_handle handle)
 102 {
 103         adev.is_on = 0;
 104 }
 105 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 106
 107 void lis3lv02d_poweron(acpi_handle handle)
 108 {
 109         adev.is_on = 1;
 110         adev.init(handle);
 111 }
 112 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 113
 114 /*
 115  * To be called before starting to use the device. It makes sure that the
 116  * device will always be on until a call to lis3lv02d_decrease_use(). Not to be
 117  * used from interrupt context.
 118  */
 119 static void lis3lv02d_increase_use(struct acpi_lis3lv02d *dev)
 120 {
 121         mutex_lock(&dev->lock);
 122         dev->usage++;
 123         if (dev->usage == 1) {
 124                 if (!dev->is_on)
 125                         lis3lv02d_poweron(dev->device->handle);
 126         }
 127         mutex_unlock(&dev->lock);
 128 }
 129
 130 /*
 131  * To be called whenever a usage of the device is stopped.
 132  * It will make sure to turn off the device when there is not usage.
 133  */
 134 static void lis3lv02d_decrease_use(struct acpi_lis3lv02d *dev)
 135 {
 136         mutex_lock(&dev->lock);
 137         dev->usage--;
 138         if (dev->usage == 0)
 139                 lis3lv02d_poweroff(dev->device->handle);
 140         mutex_unlock(&dev->lock);
 141 }
 142
 143 static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
 144 {
 145         /*
 146          * Be careful: on some HP laptops the bios force DD when on battery and
 147          * the lid is closed. This leads to interrupts as soon as a little move
 148          * is done.
 149          */
 150         atomic_inc(&adev.count);
 151
 152         wake_up_interruptible(&adev.misc_wait);
 153         kill_fasync(&adev.async_queue, SIGIO, POLL_IN);
 154         return IRQ_HANDLED;
 155 }
 156
 157 static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
 158 {
 159         int ret;
 160
 161         if (test_and_set_bit(0, &adev.misc_opened))
 162                 return -EBUSY; /* already open */
 163
 164         atomic_set(&adev.count, 0);
 165
 166         /*
 167          * The sensor can generate interrupts for free-fall and direction
 168          * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
 169          * the things simple and _fast_ we activate it only for free-fall, so
 170          * no need to read register (very slow with ACPI). For the same reason,
 171          * we forbid shared interrupts.
 172          *
 173          * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
 174          * io-apic is not configurable (and generates a warning) but I keep it
 175          * in case of support for other hardware.
 176          */
 177         ret = request_irq(adev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
 178                           DRIVER_NAME, &adev);
 179
 180         if (ret) {
 181                 clear_bit(0, &adev.misc_opened);
 182                 printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", adev.irq);
 183                 return -EBUSY;
 184         }
 185         lis3lv02d_increase_use(&adev);
 186         printk("lis3: registered interrupt %d\n", adev.irq);
 187         return 0;
 188 }
 189
 190 static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
 191 {
 192         fasync_helper(-1, file, 0, &adev.async_queue);
 193         lis3lv02d_decrease_use(&adev);
 194         free_irq(adev.irq, &adev);
 195         clear_bit(0, &adev.misc_opened); /* release the device */
 196         return 0;
 197 }
 198
 199 static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
 200                                 size_t count, loff_t *pos)
 201 {
 202         DECLARE_WAITQUEUE(wait, current);
 203         u32 data;
 204         unsigned char byte_data;
 205         ssize_t retval = 1;
 206
 207         if (count < 1)
 208                 return -EINVAL;
 209
 210         add_wait_queue(&adev.misc_wait, &wait);
 211         while (true) {
 212                 set_current_state(TASK_INTERRUPTIBLE);
 213                 data = atomic_xchg(&adev.count, 0);
 214                 if (data)
 215                         break;
 216
 217                 if (file->f_flags & O_NONBLOCK) {
 218                         retval = -EAGAIN;
 219                         goto out;
 220                 }
 221
 222                 if (signal_pending(current)) {
 223                         retval = -ERESTARTSYS;
 224                         goto out;
 225                 }
 226
 227                 schedule();
 228         }
 229
 230         if (data < 255)
 231                 byte_data = data;
 232         else
 233                 byte_data = 255;
 234
 235         /* make sure we are not going into copy_to_user() with
 236          * TASK_INTERRUPTIBLE state */
 237         set_current_state(TASK_RUNNING);
 238         if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
 239                 retval = -EFAULT;
 240
 241 out:
 242         __set_current_state(TASK_RUNNING);
 243         remove_wait_queue(&adev.misc_wait, &wait);
 244
 245         return retval;
 246 }
 247
 248 static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
 249 {
 250         poll_wait(file, &adev.misc_wait, wait);
 251         if (atomic_read(&adev.count))
 252                 return POLLIN | POLLRDNORM;
 253         return 0;
 254 }
 255
 256 static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
 257 {
 258         return fasync_helper(fd, file, on, &adev.async_queue);
 259 }
 260
 261 static const struct file_operations lis3lv02d_misc_fops = {
 262         .owner   = THIS_MODULE,
 263         .llseek  = no_llseek,
 264         .read    = lis3lv02d_misc_read,
 265         .open    = lis3lv02d_misc_open,
 266         .release = lis3lv02d_misc_release,
 267         .poll    = lis3lv02d_misc_poll,
 268         .fasync  = lis3lv02d_misc_fasync,
 269 };
 270
 271 static struct miscdevice lis3lv02d_misc_device = {
 272         .minor   = MISC_DYNAMIC_MINOR,
 273         .name    = "freefall",
 274         .fops    = &lis3lv02d_misc_fops,
 275 };
 276
 277 /**
 278  * lis3lv02d_joystick_kthread - Kthread polling function
 279  * @data: unused - here to conform to threadfn prototype
 280  */
 281 static int lis3lv02d_joystick_kthread(void *data)
 282 {
 283         int x, y, z;
 284
 285         while (!kthread_should_stop()) {
 286                 lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
 287                 input_report_abs(adev.idev, ABS_X, x - adev.xcalib);
 288                 input_report_abs(adev.idev, ABS_Y, y - adev.ycalib);
 289                 input_report_abs(adev.idev, ABS_Z, z - adev.zcalib);
 290
 291                 input_sync(adev.idev);
 292
 293                 try_to_freeze();
 294                 msleep_interruptible(MDPS_POLL_INTERVAL);
 295         }
 296
 297         return 0;
 298 }
 299
 300 static int lis3lv02d_joystick_open(struct input_dev *input)
 301 {
 302         lis3lv02d_increase_use(&adev);
 303         adev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
 304         if (IS_ERR(adev.kthread)) {
 305                 lis3lv02d_decrease_use(&adev);
 306                 return PTR_ERR(adev.kthread);
 307         }
 308
 309         return 0;
 310 }
 311
 312 static void lis3lv02d_joystick_close(struct input_dev *input)
 313 {
 314         kthread_stop(adev.kthread);
 315         lis3lv02d_decrease_use(&adev);
 316 }
 317
 318 static inline void lis3lv02d_calibrate_joystick(void)
 319 {
 320         lis3lv02d_get_xyz(adev.device->handle, &adev.xcalib, &adev.ycalib, &adev.zcalib);
 321 }
 322
 323 int lis3lv02d_joystick_enable(void)
 324 {
 325         int err;
 326
 327         if (adev.idev)
 328                 return -EINVAL;
 329
 330         adev.idev = input_allocate_device();
 331         if (!adev.idev)
 332                 return -ENOMEM;
 333
 334         lis3lv02d_calibrate_joystick();
 335
 336         adev.idev->name       = "ST LIS3LV02DL Accelerometer";
 337         adev.idev->phys       = DRIVER_NAME "/input0";
 338         adev.idev->id.bustype = BUS_HOST;
 339         adev.idev->id.vendor  = 0;
 340         adev.idev->dev.parent = &adev.pdev->dev;
 341         adev.idev->open       = lis3lv02d_joystick_open;
 342         adev.idev->close      = lis3lv02d_joystick_close;
 343
 344         set_bit(EV_ABS, adev.idev->evbit);
 345         input_set_abs_params(adev.idev, ABS_X, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
 346         input_set_abs_params(adev.idev, ABS_Y, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
 347         input_set_abs_params(adev.idev, ABS_Z, -adev.mdps_max_val, adev.mdps_max_val, 3, 3);
 348
 349         err = input_register_device(adev.idev);
 350         if (err) {
 351                 input_free_device(adev.idev);
 352                 adev.idev = NULL;
 353         }
 354
 355         return err;
 356 }
 357 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
 358
 359 void lis3lv02d_joystick_disable(void)
 360 {
 361         if (!adev.idev)
 362                 return;
 363
 364         misc_deregister(&lis3lv02d_misc_device);
 365         input_unregister_device(adev.idev);
 366         adev.idev = NULL;
 367 }
 368 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
 369
 370 /*
 371  * Initialise the accelerometer and the various subsystems.
 372  * Should be rather independant of the bus system.
 373  */
 374 int lis3lv02d_init_device(struct acpi_lis3lv02d *dev)
 375 {
 376         mutex_init(&dev->lock);
 377         lis3lv02d_add_fs(dev->device);
 378         lis3lv02d_increase_use(dev);
 379
 380         if (lis3lv02d_joystick_enable())
 381                 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
 382
 383         printk("lis3_init_device: irq %d\n", dev->irq);
 384
 385         /* if we did not get an IRQ from ACPI - we have nothing more to do */
 386         if (!dev->irq) {
 387                 printk(KERN_ERR DRIVER_NAME
 388                         ": No IRQ in ACPI. Disabling /dev/freefall\n");
 389                 goto out;
 390         }
 391
 392         printk("lis3: registering device\n");
 393         if (misc_register(&lis3lv02d_misc_device))
 394                 printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
 395 out:
 396         lis3lv02d_decrease_use(dev);
 397         return 0;
 398 }
 399 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
 400
 401 /* Sysfs stuff */
 402 static ssize_t lis3lv02d_position_show(struct device *dev,
 403                                 struct device_attribute *attr, char *buf)
 404 {
 405         int x, y, z;
 406
 407         lis3lv02d_increase_use(&adev);
 408         lis3lv02d_get_xyz(adev.device->handle, &x, &y, &z);
 409         lis3lv02d_decrease_use(&adev);
 410         return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
 411 }
 412
 413 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
 414                                 struct device_attribute *attr, char *buf)
 415 {
 416         return sprintf(buf, "(%d,%d,%d)\n", adev.xcalib, adev.ycalib, adev.zcalib);
 417 }
 418
 419 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
 420                                 struct device_attribute *attr,
 421                                 const char *buf, size_t count)
 422 {
 423         lis3lv02d_increase_use(&adev);
 424         lis3lv02d_calibrate_joystick();
 425         lis3lv02d_decrease_use(&adev);
 426         return count;
 427 }
 428
 429 /* conversion btw sampling rate and the register values */
 430 static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
 431 static ssize_t lis3lv02d_rate_show(struct device *dev,
 432                         struct device_attribute *attr, char *buf)
 433 {
 434         u8 ctrl;
 435         int val;
 436
 437         lis3lv02d_increase_use(&adev);
 438         adev.read(adev.device->handle, CTRL_REG1, &ctrl);
 439         lis3lv02d_decrease_use(&adev);
 440         val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
 441         return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
 442 }
 443
 444 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
 445 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
 446         lis3lv02d_calibrate_store);
 447 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
 448
 449 static struct attribute *lis3lv02d_attributes[] = {
 450         &dev_attr_position.attr,
 451         &dev_attr_calibrate.attr,
 452         &dev_attr_rate.attr,
 453         NULL
 454 };
 455
 456 static struct attribute_group lis3lv02d_attribute_group = {
 457         .attrs = lis3lv02d_attributes
 458 };
 459
 460
 461 static int lis3lv02d_add_fs(struct acpi_device *device)
 462 {
 463         adev.pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 464         if (IS_ERR(adev.pdev))
 465                 return PTR_ERR(adev.pdev);
 466
 467         return sysfs_create_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
 468 }
 469
 470 int lis3lv02d_remove_fs(void)
 471 {
 472         sysfs_remove_group(&adev.pdev->dev.kobj, &lis3lv02d_attribute_group);
 473         platform_device_unregister(adev.pdev);
 474         return 0;
 475 }
 476 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 477
 478 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
 479 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 480 MODULE_LICENSE("GPL");
 481