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 <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 struct lis3lv02d lis3_dev = {
  56         .misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
  57 };
  58
  59 EXPORT_SYMBOL_GPL(lis3_dev);
  60
  61 static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
  62 {
  63         s8 lo;
  64         if (lis3->read(lis3, reg, &lo) < 0)
  65                 return 0;
  66
  67         return lo;
  68 }
  69
  70 static s16 lis3lv02d_read_16(struct lis3lv02d *lis3, int reg)
  71 {
  72         u8 lo, hi;
  73
  74         lis3->read(lis3, reg - 1, &lo);
  75         lis3->read(lis3, reg, &hi);
  76         /* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
  77         return (s16)((hi << 8) | lo);
  78 }
  79
  80 /**
  81  * lis3lv02d_get_axis - For the given axis, give the value converted
  82  * @axis:      1,2,3 - can also be negative
  83  * @hw_values: raw values returned by the hardware
  84  *
  85  * Returns the converted value.
  86  */
  87 static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
  88 {
  89         if (axis > 0)
  90                 return hw_values[axis - 1];
  91         else
  92                 return -hw_values[-axis - 1];
  93 }
  94
  95 /**
  96  * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
  97  * @lis3: pointer to the device struct
  98  * @x:    where to store the X axis value
  99  * @y:    where to store the Y axis value
 100  * @z:    where to store the Z axis value
 101  *
 102  * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
 103  */
 104 static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
 105 {
 106         int position[3];
 107
 108         position[0] = lis3_dev.read_data(lis3, OUTX);
 109         position[1] = lis3_dev.read_data(lis3, OUTY);
 110         position[2] = lis3_dev.read_data(lis3, OUTZ);
 111
 112         *x = lis3lv02d_get_axis(lis3_dev.ac.x, position);
 113         *y = lis3lv02d_get_axis(lis3_dev.ac.y, position);
 114         *z = lis3lv02d_get_axis(lis3_dev.ac.z, position);
 115 }
 116
 117 void lis3lv02d_poweroff(struct lis3lv02d *lis3)
 118 {
 119         lis3_dev.is_on = 0;
 120 }
 121 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 122
 123 void lis3lv02d_poweron(struct lis3lv02d *lis3)
 124 {
 125         lis3_dev.is_on = 1;
 126         lis3_dev.init(lis3);
 127 }
 128 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 129
 130 /*
 131  * To be called before starting to use the device. It makes sure that the
 132  * device will always be on until a call to lis3lv02d_decrease_use(). Not to be
 133  * used from interrupt context.
 134  */
 135 static void lis3lv02d_increase_use(struct lis3lv02d *dev)
 136 {
 137         mutex_lock(&dev->lock);
 138         dev->usage++;
 139         if (dev->usage == 1) {
 140                 if (!dev->is_on)
 141                         lis3lv02d_poweron(dev);
 142         }
 143         mutex_unlock(&dev->lock);
 144 }
 145
 146 /*
 147  * To be called whenever a usage of the device is stopped.
 148  * It will make sure to turn off the device when there is not usage.
 149  */
 150 static void lis3lv02d_decrease_use(struct lis3lv02d *dev)
 151 {
 152         mutex_lock(&dev->lock);
 153         dev->usage--;
 154         if (dev->usage == 0)
 155                 lis3lv02d_poweroff(dev);
 156         mutex_unlock(&dev->lock);
 157 }
 158
 159 static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
 160 {
 161         /*
 162          * Be careful: on some HP laptops the bios force DD when on battery and
 163          * the lid is closed. This leads to interrupts as soon as a little move
 164          * is done.
 165          */
 166         atomic_inc(&lis3_dev.count);
 167
 168         wake_up_interruptible(&lis3_dev.misc_wait);
 169         kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
 170         return IRQ_HANDLED;
 171 }
 172
 173 static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
 174 {
 175         int ret;
 176
 177         if (test_and_set_bit(0, &lis3_dev.misc_opened))
 178                 return -EBUSY; /* already open */
 179
 180         atomic_set(&lis3_dev.count, 0);
 181
 182         /*
 183          * The sensor can generate interrupts for free-fall and direction
 184          * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
 185          * the things simple and _fast_ we activate it only for free-fall, so
 186          * no need to read register (very slow with ACPI). For the same reason,
 187          * we forbid shared interrupts.
 188          *
 189          * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
 190          * io-apic is not configurable (and generates a warning) but I keep it
 191          * in case of support for other hardware.
 192          */
 193         ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
 194                           DRIVER_NAME, &lis3_dev);
 195
 196         if (ret) {
 197                 clear_bit(0, &lis3_dev.misc_opened);
 198                 printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
 199                 return -EBUSY;
 200         }
 201         lis3lv02d_increase_use(&lis3_dev);
 202         printk("lis3: registered interrupt %d\n", lis3_dev.irq);
 203         return 0;
 204 }
 205
 206 static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
 207 {
 208         fasync_helper(-1, file, 0, &lis3_dev.async_queue);
 209         lis3lv02d_decrease_use(&lis3_dev);
 210         free_irq(lis3_dev.irq, &lis3_dev);
 211         clear_bit(0, &lis3_dev.misc_opened); /* release the device */
 212         return 0;
 213 }
 214
 215 static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
 216                                 size_t count, loff_t *pos)
 217 {
 218         DECLARE_WAITQUEUE(wait, current);
 219         u32 data;
 220         unsigned char byte_data;
 221         ssize_t retval = 1;
 222
 223         if (count < 1)
 224                 return -EINVAL;
 225
 226         add_wait_queue(&lis3_dev.misc_wait, &wait);
 227         while (true) {
 228                 set_current_state(TASK_INTERRUPTIBLE);
 229                 data = atomic_xchg(&lis3_dev.count, 0);
 230                 if (data)
 231                         break;
 232
 233                 if (file->f_flags & O_NONBLOCK) {
 234                         retval = -EAGAIN;
 235                         goto out;
 236                 }
 237
 238                 if (signal_pending(current)) {
 239                         retval = -ERESTARTSYS;
 240                         goto out;
 241                 }
 242
 243                 schedule();
 244         }
 245
 246         if (data < 255)
 247                 byte_data = data;
 248         else
 249                 byte_data = 255;
 250
 251         /* make sure we are not going into copy_to_user() with
 252          * TASK_INTERRUPTIBLE state */
 253         set_current_state(TASK_RUNNING);
 254         if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
 255                 retval = -EFAULT;
 256
 257 out:
 258         __set_current_state(TASK_RUNNING);
 259         remove_wait_queue(&lis3_dev.misc_wait, &wait);
 260
 261         return retval;
 262 }
 263
 264 static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
 265 {
 266         poll_wait(file, &lis3_dev.misc_wait, wait);
 267         if (atomic_read(&lis3_dev.count))
 268                 return POLLIN | POLLRDNORM;
 269         return 0;
 270 }
 271
 272 static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
 273 {
 274         return fasync_helper(fd, file, on, &lis3_dev.async_queue);
 275 }
 276
 277 static const struct file_operations lis3lv02d_misc_fops = {
 278         .owner   = THIS_MODULE,
 279         .llseek  = no_llseek,
 280         .read    = lis3lv02d_misc_read,
 281         .open    = lis3lv02d_misc_open,
 282         .release = lis3lv02d_misc_release,
 283         .poll    = lis3lv02d_misc_poll,
 284         .fasync  = lis3lv02d_misc_fasync,
 285 };
 286
 287 static struct miscdevice lis3lv02d_misc_device = {
 288         .minor   = MISC_DYNAMIC_MINOR,
 289         .name    = "freefall",
 290         .fops    = &lis3lv02d_misc_fops,
 291 };
 292
 293 /**
 294  * lis3lv02d_joystick_kthread - Kthread polling function
 295  * @data: unused - here to conform to threadfn prototype
 296  */
 297 static int lis3lv02d_joystick_kthread(void *data)
 298 {
 299         int x, y, z;
 300
 301         while (!kthread_should_stop()) {
 302                 lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
 303                 input_report_abs(lis3_dev.idev, ABS_X, x - lis3_dev.xcalib);
 304                 input_report_abs(lis3_dev.idev, ABS_Y, y - lis3_dev.ycalib);
 305                 input_report_abs(lis3_dev.idev, ABS_Z, z - lis3_dev.zcalib);
 306
 307                 input_sync(lis3_dev.idev);
 308
 309                 try_to_freeze();
 310                 msleep_interruptible(MDPS_POLL_INTERVAL);
 311         }
 312
 313         return 0;
 314 }
 315
 316 static int lis3lv02d_joystick_open(struct input_dev *input)
 317 {
 318         lis3lv02d_increase_use(&lis3_dev);
 319         lis3_dev.kthread = kthread_run(lis3lv02d_joystick_kthread, NULL, "klis3lv02d");
 320         if (IS_ERR(lis3_dev.kthread)) {
 321                 lis3lv02d_decrease_use(&lis3_dev);
 322                 return PTR_ERR(lis3_dev.kthread);
 323         }
 324
 325         return 0;
 326 }
 327
 328 static void lis3lv02d_joystick_close(struct input_dev *input)
 329 {
 330         kthread_stop(lis3_dev.kthread);
 331         lis3lv02d_decrease_use(&lis3_dev);
 332 }
 333
 334 static inline void lis3lv02d_calibrate_joystick(void)
 335 {
 336         lis3lv02d_get_xyz(&lis3_dev,
 337                 &lis3_dev.xcalib, &lis3_dev.ycalib, &lis3_dev.zcalib);
 338 }
 339
 340 int lis3lv02d_joystick_enable(void)
 341 {
 342         int err;
 343
 344         if (lis3_dev.idev)
 345                 return -EINVAL;
 346
 347         lis3_dev.idev = input_allocate_device();
 348         if (!lis3_dev.idev)
 349                 return -ENOMEM;
 350
 351         lis3lv02d_calibrate_joystick();
 352
 353         lis3_dev.idev->name       = "ST LIS3LV02DL Accelerometer";
 354         lis3_dev.idev->phys       = DRIVER_NAME "/input0";
 355         lis3_dev.idev->id.bustype = BUS_HOST;
 356         lis3_dev.idev->id.vendor  = 0;
 357         lis3_dev.idev->dev.parent = &lis3_dev.pdev->dev;
 358         lis3_dev.idev->open       = lis3lv02d_joystick_open;
 359         lis3_dev.idev->close      = lis3lv02d_joystick_close;
 360
 361         set_bit(EV_ABS, lis3_dev.idev->evbit);
 362         input_set_abs_params(lis3_dev.idev, ABS_X, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 363         input_set_abs_params(lis3_dev.idev, ABS_Y, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 364         input_set_abs_params(lis3_dev.idev, ABS_Z, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 365
 366         err = input_register_device(lis3_dev.idev);
 367         if (err) {
 368                 input_free_device(lis3_dev.idev);
 369                 lis3_dev.idev = NULL;
 370         }
 371
 372         return err;
 373 }
 374 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
 375
 376 void lis3lv02d_joystick_disable(void)
 377 {
 378         if (!lis3_dev.idev)
 379                 return;
 380
 381         misc_deregister(&lis3lv02d_misc_device);
 382         input_unregister_device(lis3_dev.idev);
 383         lis3_dev.idev = NULL;
 384 }
 385 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
 386
 387 /* Sysfs stuff */
 388 static ssize_t lis3lv02d_position_show(struct device *dev,
 389                                 struct device_attribute *attr, char *buf)
 390 {
 391         int x, y, z;
 392
 393         lis3lv02d_increase_use(&lis3_dev);
 394         lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
 395         lis3lv02d_decrease_use(&lis3_dev);
 396         return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
 397 }
 398
 399 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
 400                                 struct device_attribute *attr, char *buf)
 401 {
 402         return sprintf(buf, "(%d,%d,%d)\n", lis3_dev.xcalib, lis3_dev.ycalib, lis3_dev.zcalib);
 403 }
 404
 405 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
 406                                 struct device_attribute *attr,
 407                                 const char *buf, size_t count)
 408 {
 409         lis3lv02d_increase_use(&lis3_dev);
 410         lis3lv02d_calibrate_joystick();
 411         lis3lv02d_decrease_use(&lis3_dev);
 412         return count;
 413 }
 414
 415 /* conversion btw sampling rate and the register values */
 416 static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
 417 static ssize_t lis3lv02d_rate_show(struct device *dev,
 418                         struct device_attribute *attr, char *buf)
 419 {
 420         u8 ctrl;
 421         int val;
 422
 423         lis3lv02d_increase_use(&lis3_dev);
 424         lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
 425         lis3lv02d_decrease_use(&lis3_dev);
 426         val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
 427         return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
 428 }
 429
 430 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
 431 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
 432         lis3lv02d_calibrate_store);
 433 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
 434
 435 static struct attribute *lis3lv02d_attributes[] = {
 436         &dev_attr_position.attr,
 437         &dev_attr_calibrate.attr,
 438         &dev_attr_rate.attr,
 439         NULL
 440 };
 441
 442 static struct attribute_group lis3lv02d_attribute_group = {
 443         .attrs = lis3lv02d_attributes
 444 };
 445
 446
 447 static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
 448 {
 449         lis3_dev.pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 450         if (IS_ERR(lis3_dev.pdev))
 451                 return PTR_ERR(lis3_dev.pdev);
 452
 453         return sysfs_create_group(&lis3_dev.pdev->dev.kobj, &lis3lv02d_attribute_group);
 454 }
 455
 456 int lis3lv02d_remove_fs(void)
 457 {
 458         sysfs_remove_group(&lis3_dev.pdev->dev.kobj, &lis3lv02d_attribute_group);
 459         platform_device_unregister(lis3_dev.pdev);
 460         return 0;
 461 }
 462 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 463
 464 /*
 465  * Initialise the accelerometer and the various subsystems.
 466  * Should be rather independant of the bus system.
 467  */
 468 int lis3lv02d_init_device(struct lis3lv02d *dev)
 469 {
 470         dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
 471
 472         switch (dev->whoami) {
 473         case LIS_DOUBLE_ID:
 474                 printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
 475                 dev->read_data = lis3lv02d_read_16;
 476                 dev->mdps_max_val = 2048;
 477                 break;
 478         case LIS_SINGLE_ID:
 479                 printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
 480                 dev->read_data = lis3lv02d_read_8;
 481                 dev->mdps_max_val = 128;
 482                 break;
 483         default:
 484                 printk(KERN_ERR DRIVER_NAME
 485                         ": unknown sensor type 0x%X\n", lis3_dev.whoami);
 486                 return -EINVAL;
 487         }
 488
 489         mutex_init(&dev->lock);
 490         lis3lv02d_add_fs(dev);
 491         lis3lv02d_increase_use(dev);
 492
 493         if (lis3lv02d_joystick_enable())
 494                 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
 495
 496         printk("lis3_init_device: irq %d\n", dev->irq);
 497
 498         /* bail if we did not get an IRQ from the bus layer */
 499         if (!dev->irq) {
 500                 printk(KERN_ERR DRIVER_NAME
 501                         ": No IRQ. Disabling /dev/freefall\n");
 502                 goto out;
 503         }
 504
 505         printk("lis3: registering device\n");
 506         if (misc_register(&lis3lv02d_misc_device))
 507                 printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
 508 out:
 509         lis3lv02d_decrease_use(dev);
 510         return 0;
 511 }
 512 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
 513
 514 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
 515 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 516 MODULE_LICENSE("GPL");
 517