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-polldev.h>
  31 #include <linux/delay.h>
  32 #include <linux/wait.h>
  33 #include <linux/poll.h>
  34 #include <linux/freezer.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/miscdevice.h>
  37 #include <asm/atomic.h>
  38 #include "lis3lv02d.h"
  39
  40 #define DRIVER_NAME     "lis3lv02d"
  41
  42 /* joystick device poll interval in milliseconds */
  43 #define MDPS_POLL_INTERVAL 50
  44 /*
  45  * The sensor can also generate interrupts (DRDY) but it's pretty pointless
  46  * because their are generated even if the data do not change. So it's better
  47  * to keep the interrupt for the free-fall event. The values are updated at
  48  * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
  49  * some low processor, we poll the sensor only at 20Hz... enough for the
  50  * joystick.
  51  */
  52
  53 struct lis3lv02d lis3_dev = {
  54         .misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
  55 };
  56
  57 EXPORT_SYMBOL_GPL(lis3_dev);
  58
  59 static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
  60 {
  61         s8 lo;
  62         if (lis3->read(lis3, reg, &lo) < 0)
  63                 return 0;
  64
  65         return lo;
  66 }
  67
  68 static s16 lis3lv02d_read_16(struct lis3lv02d *lis3, int reg)
  69 {
  70         u8 lo, hi;
  71
  72         lis3->read(lis3, reg - 1, &lo);
  73         lis3->read(lis3, reg, &hi);
  74         /* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
  75         return (s16)((hi << 8) | lo);
  76 }
  77
  78 /**
  79  * lis3lv02d_get_axis - For the given axis, give the value converted
  80  * @axis:      1,2,3 - can also be negative
  81  * @hw_values: raw values returned by the hardware
  82  *
  83  * Returns the converted value.
  84  */
  85 static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
  86 {
  87         if (axis > 0)
  88                 return hw_values[axis - 1];
  89         else
  90                 return -hw_values[-axis - 1];
  91 }
  92
  93 /**
  94  * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
  95  * @lis3: pointer to the device struct
  96  * @x:    where to store the X axis value
  97  * @y:    where to store the Y axis value
  98  * @z:    where to store the Z axis value
  99  *
 100  * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
 101  */
 102 static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
 103 {
 104         int position[3];
 105
 106         position[0] = lis3->read_data(lis3, OUTX);
 107         position[1] = lis3->read_data(lis3, OUTY);
 108         position[2] = lis3->read_data(lis3, OUTZ);
 109
 110         *x = lis3lv02d_get_axis(lis3->ac.x, position);
 111         *y = lis3lv02d_get_axis(lis3->ac.y, position);
 112         *z = lis3lv02d_get_axis(lis3->ac.z, position);
 113 }
 114
 115 void lis3lv02d_poweroff(struct lis3lv02d *lis3)
 116 {
 117         /* disable X,Y,Z axis and power down */
 118         lis3->write(lis3, CTRL_REG1, 0x00);
 119 }
 120 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 121
 122 void lis3lv02d_poweron(struct lis3lv02d *lis3)
 123 {
 124         u8 reg;
 125
 126         lis3->init(lis3);
 127
 128         /*
 129          * Common configuration
 130          * BDU: (12 bits sensors only) LSB and MSB values are not updated until
 131          *      both have been read. So the value read will always be correct.
 132          */
 133         if (lis3->whoami == LIS_DOUBLE_ID) {
 134                 lis3->read(lis3, CTRL_REG2, &reg);
 135                 reg |= CTRL2_BDU;
 136                 lis3->write(lis3, CTRL_REG2, reg);
 137         }
 138 }
 139 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 140
 141
 142 static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
 143 {
 144         /*
 145          * Be careful: on some HP laptops the bios force DD when on battery and
 146          * the lid is closed. This leads to interrupts as soon as a little move
 147          * is done.
 148          */
 149         atomic_inc(&lis3_dev.count);
 150
 151         wake_up_interruptible(&lis3_dev.misc_wait);
 152         kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
 153         return IRQ_HANDLED;
 154 }
 155
 156 static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
 157 {
 158         int ret;
 159
 160         if (test_and_set_bit(0, &lis3_dev.misc_opened))
 161                 return -EBUSY; /* already open */
 162
 163         atomic_set(&lis3_dev.count, 0);
 164
 165         /*
 166          * The sensor can generate interrupts for free-fall and direction
 167          * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
 168          * the things simple and _fast_ we activate it only for free-fall, so
 169          * no need to read register (very slow with ACPI). For the same reason,
 170          * we forbid shared interrupts.
 171          *
 172          * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
 173          * io-apic is not configurable (and generates a warning) but I keep it
 174          * in case of support for other hardware.
 175          */
 176         ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
 177                           DRIVER_NAME, &lis3_dev);
 178
 179         if (ret) {
 180                 clear_bit(0, &lis3_dev.misc_opened);
 181                 printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
 182                 return -EBUSY;
 183         }
 184         return 0;
 185 }
 186
 187 static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
 188 {
 189         fasync_helper(-1, file, 0, &lis3_dev.async_queue);
 190         free_irq(lis3_dev.irq, &lis3_dev);
 191         clear_bit(0, &lis3_dev.misc_opened); /* release the device */
 192         return 0;
 193 }
 194
 195 static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
 196                                 size_t count, loff_t *pos)
 197 {
 198         DECLARE_WAITQUEUE(wait, current);
 199         u32 data;
 200         unsigned char byte_data;
 201         ssize_t retval = 1;
 202
 203         if (count < 1)
 204                 return -EINVAL;
 205
 206         add_wait_queue(&lis3_dev.misc_wait, &wait);
 207         while (true) {
 208                 set_current_state(TASK_INTERRUPTIBLE);
 209                 data = atomic_xchg(&lis3_dev.count, 0);
 210                 if (data)
 211                         break;
 212
 213                 if (file->f_flags & O_NONBLOCK) {
 214                         retval = -EAGAIN;
 215                         goto out;
 216                 }
 217
 218                 if (signal_pending(current)) {
 219                         retval = -ERESTARTSYS;
 220                         goto out;
 221                 }
 222
 223                 schedule();
 224         }
 225
 226         if (data < 255)
 227                 byte_data = data;
 228         else
 229                 byte_data = 255;
 230
 231         /* make sure we are not going into copy_to_user() with
 232          * TASK_INTERRUPTIBLE state */
 233         set_current_state(TASK_RUNNING);
 234         if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
 235                 retval = -EFAULT;
 236
 237 out:
 238         __set_current_state(TASK_RUNNING);
 239         remove_wait_queue(&lis3_dev.misc_wait, &wait);
 240
 241         return retval;
 242 }
 243
 244 static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
 245 {
 246         poll_wait(file, &lis3_dev.misc_wait, wait);
 247         if (atomic_read(&lis3_dev.count))
 248                 return POLLIN | POLLRDNORM;
 249         return 0;
 250 }
 251
 252 static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
 253 {
 254         return fasync_helper(fd, file, on, &lis3_dev.async_queue);
 255 }
 256
 257 static const struct file_operations lis3lv02d_misc_fops = {
 258         .owner   = THIS_MODULE,
 259         .llseek  = no_llseek,
 260         .read    = lis3lv02d_misc_read,
 261         .open    = lis3lv02d_misc_open,
 262         .release = lis3lv02d_misc_release,
 263         .poll    = lis3lv02d_misc_poll,
 264         .fasync  = lis3lv02d_misc_fasync,
 265 };
 266
 267 static struct miscdevice lis3lv02d_misc_device = {
 268         .minor   = MISC_DYNAMIC_MINOR,
 269         .name    = "freefall",
 270         .fops    = &lis3lv02d_misc_fops,
 271 };
 272
 273 static void lis3lv02d_joystick_poll(struct input_polled_dev *pidev)
 274 {
 275         int x, y, z;
 276
 277         lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
 278         input_report_abs(pidev->input, ABS_X, x - lis3_dev.xcalib);
 279         input_report_abs(pidev->input, ABS_Y, y - lis3_dev.ycalib);
 280         input_report_abs(pidev->input, ABS_Z, z - lis3_dev.zcalib);
 281 }
 282
 283
 284 static inline void lis3lv02d_calibrate_joystick(void)
 285 {
 286         lis3lv02d_get_xyz(&lis3_dev,
 287                 &lis3_dev.xcalib, &lis3_dev.ycalib, &lis3_dev.zcalib);
 288 }
 289
 290 int lis3lv02d_joystick_enable(void)
 291 {
 292         struct input_dev *input_dev;
 293         int err;
 294
 295         if (lis3_dev.idev)
 296                 return -EINVAL;
 297
 298         lis3_dev.idev = input_allocate_polled_device();
 299         if (!lis3_dev.idev)
 300                 return -ENOMEM;
 301
 302         lis3_dev.idev->poll = lis3lv02d_joystick_poll;
 303         lis3_dev.idev->poll_interval = MDPS_POLL_INTERVAL;
 304         input_dev = lis3_dev.idev->input;
 305
 306         lis3lv02d_calibrate_joystick();
 307
 308         input_dev->name       = "ST LIS3LV02DL Accelerometer";
 309         input_dev->phys       = DRIVER_NAME "/input0";
 310         input_dev->id.bustype = BUS_HOST;
 311         input_dev->id.vendor  = 0;
 312         input_dev->dev.parent = &lis3_dev.pdev->dev;
 313
 314         set_bit(EV_ABS, input_dev->evbit);
 315         input_set_abs_params(input_dev, ABS_X, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 316         input_set_abs_params(input_dev, ABS_Y, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 317         input_set_abs_params(input_dev, ABS_Z, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 318
 319         err = input_register_polled_device(lis3_dev.idev);
 320         if (err) {
 321                 input_free_polled_device(lis3_dev.idev);
 322                 lis3_dev.idev = NULL;
 323         }
 324
 325         return err;
 326 }
 327 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
 328
 329 void lis3lv02d_joystick_disable(void)
 330 {
 331         if (!lis3_dev.idev)
 332                 return;
 333
 334         if (lis3_dev.irq)
 335                 misc_deregister(&lis3lv02d_misc_device);
 336         input_unregister_polled_device(lis3_dev.idev);
 337         lis3_dev.idev = NULL;
 338 }
 339 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
 340
 341 /* Sysfs stuff */
 342 static ssize_t lis3lv02d_position_show(struct device *dev,
 343                                 struct device_attribute *attr, char *buf)
 344 {
 345         int x, y, z;
 346
 347         lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
 348         return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
 349 }
 350
 351 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
 352                                 struct device_attribute *attr, char *buf)
 353 {
 354         return sprintf(buf, "(%d,%d,%d)\n", lis3_dev.xcalib, lis3_dev.ycalib, lis3_dev.zcalib);
 355 }
 356
 357 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
 358                                 struct device_attribute *attr,
 359                                 const char *buf, size_t count)
 360 {
 361         lis3lv02d_calibrate_joystick();
 362         return count;
 363 }
 364
 365 /* conversion btw sampling rate and the register values */
 366 static int lis3_12_rates[4] = {40, 160, 640, 2560};
 367 static int lis3_8_rates[2] = {100, 400};
 368 static ssize_t lis3lv02d_rate_show(struct device *dev,
 369                         struct device_attribute *attr, char *buf)
 370 {
 371         u8 ctrl;
 372         int val;
 373
 374         lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
 375
 376         if (lis3_dev.whoami == LIS_DOUBLE_ID)
 377                 val = lis3_12_rates[(ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4];
 378         else
 379                 val = lis3_8_rates[(ctrl & CTRL1_DR) >> 7];
 380
 381         return sprintf(buf, "%d\n", val);
 382 }
 383
 384 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
 385 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
 386         lis3lv02d_calibrate_store);
 387 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
 388
 389 static struct attribute *lis3lv02d_attributes[] = {
 390         &dev_attr_position.attr,
 391         &dev_attr_calibrate.attr,
 392         &dev_attr_rate.attr,
 393         NULL
 394 };
 395
 396 static struct attribute_group lis3lv02d_attribute_group = {
 397         .attrs = lis3lv02d_attributes
 398 };
 399
 400
 401 static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
 402 {
 403         lis3->pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 404         if (IS_ERR(lis3->pdev))
 405                 return PTR_ERR(lis3->pdev);
 406
 407         return sysfs_create_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
 408 }
 409
 410 int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
 411 {
 412         sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
 413         platform_device_unregister(lis3->pdev);
 414         return 0;
 415 }
 416 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 417
 418 /*
 419  * Initialise the accelerometer and the various subsystems.
 420  * Should be rather independant of the bus system.
 421  */
 422 int lis3lv02d_init_device(struct lis3lv02d *dev)
 423 {
 424         dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
 425
 426         switch (dev->whoami) {
 427         case LIS_DOUBLE_ID:
 428                 printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
 429                 dev->read_data = lis3lv02d_read_16;
 430                 dev->mdps_max_val = 2048;
 431                 break;
 432         case LIS_SINGLE_ID:
 433                 printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
 434                 dev->read_data = lis3lv02d_read_8;
 435                 dev->mdps_max_val = 128;
 436                 break;
 437         default:
 438                 printk(KERN_ERR DRIVER_NAME
 439                         ": unknown sensor type 0x%X\n", dev->whoami);
 440                 return -EINVAL;
 441         }
 442
 443         lis3lv02d_add_fs(dev);
 444         lis3lv02d_poweron(dev);
 445
 446         if (lis3lv02d_joystick_enable())
 447                 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
 448
 449         /* passing in platform specific data is purely optional and only
 450          * used by the SPI transport layer at the moment */
 451         if (dev->pdata) {
 452                 struct lis3lv02d_platform_data *p = dev->pdata;
 453
 454                 if (p->click_flags && (dev->whoami == LIS_SINGLE_ID)) {
 455                         dev->write(dev, CLICK_CFG, p->click_flags);
 456                         dev->write(dev, CLICK_TIMELIMIT, p->click_time_limit);
 457                         dev->write(dev, CLICK_LATENCY, p->click_latency);
 458                         dev->write(dev, CLICK_WINDOW, p->click_window);
 459                         dev->write(dev, CLICK_THSZ, p->click_thresh_z & 0xf);
 460                         dev->write(dev, CLICK_THSY_X,
 461                                         (p->click_thresh_x & 0xf) |
 462                                         (p->click_thresh_y << 4));
 463                 }
 464
 465                 if (p->wakeup_flags && (dev->whoami == LIS_SINGLE_ID)) {
 466                         dev->write(dev, FF_WU_CFG_1, p->wakeup_flags);
 467                         dev->write(dev, FF_WU_THS_1, p->wakeup_thresh & 0x7f);
 468                         /* default to 2.5ms for now */
 469                         dev->write(dev, FF_WU_DURATION_1, 1);
 470                         /* enable high pass filter for both free-fall units */
 471                         dev->write(dev, CTRL_REG2, HP_FF_WU1 | HP_FF_WU2);
 472                 }
 473
 474                 if (p->irq_cfg)
 475                         dev->write(dev, CTRL_REG3, p->irq_cfg);
 476         }
 477
 478         /* bail if we did not get an IRQ from the bus layer */
 479         if (!dev->irq) {
 480                 printk(KERN_ERR DRIVER_NAME
 481                         ": No IRQ. Disabling /dev/freefall\n");
 482                 goto out;
 483         }
 484
 485         if (misc_register(&lis3lv02d_misc_device))
 486                 printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
 487 out:
 488         return 0;
 489 }
 490 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
 491
 492 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
 493 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 494 MODULE_LICENSE("GPL");
 495