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: LSB and MSB values are not updated until both have been read.
 131          *      So the value read will always be correct.
 132          */
 133         lis3->read(lis3, CTRL_REG2, &reg);
 134         reg |= CTRL2_BDU;
 135         lis3->write(lis3, CTRL_REG2, reg);
 136 }
 137 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 138
 139
 140 static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
 141 {
 142         /*
 143          * Be careful: on some HP laptops the bios force DD when on battery and
 144          * the lid is closed. This leads to interrupts as soon as a little move
 145          * is done.
 146          */
 147         atomic_inc(&lis3_dev.count);
 148
 149         wake_up_interruptible(&lis3_dev.misc_wait);
 150         kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
 151         return IRQ_HANDLED;
 152 }
 153
 154 static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
 155 {
 156         int ret;
 157
 158         if (test_and_set_bit(0, &lis3_dev.misc_opened))
 159                 return -EBUSY; /* already open */
 160
 161         atomic_set(&lis3_dev.count, 0);
 162
 163         /*
 164          * The sensor can generate interrupts for free-fall and direction
 165          * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
 166          * the things simple and _fast_ we activate it only for free-fall, so
 167          * no need to read register (very slow with ACPI). For the same reason,
 168          * we forbid shared interrupts.
 169          *
 170          * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
 171          * io-apic is not configurable (and generates a warning) but I keep it
 172          * in case of support for other hardware.
 173          */
 174         ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
 175                           DRIVER_NAME, &lis3_dev);
 176
 177         if (ret) {
 178                 clear_bit(0, &lis3_dev.misc_opened);
 179                 printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
 180                 return -EBUSY;
 181         }
 182         return 0;
 183 }
 184
 185 static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
 186 {
 187         fasync_helper(-1, file, 0, &lis3_dev.async_queue);
 188         free_irq(lis3_dev.irq, &lis3_dev);
 189         clear_bit(0, &lis3_dev.misc_opened); /* release the device */
 190         return 0;
 191 }
 192
 193 static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
 194                                 size_t count, loff_t *pos)
 195 {
 196         DECLARE_WAITQUEUE(wait, current);
 197         u32 data;
 198         unsigned char byte_data;
 199         ssize_t retval = 1;
 200
 201         if (count < 1)
 202                 return -EINVAL;
 203
 204         add_wait_queue(&lis3_dev.misc_wait, &wait);
 205         while (true) {
 206                 set_current_state(TASK_INTERRUPTIBLE);
 207                 data = atomic_xchg(&lis3_dev.count, 0);
 208                 if (data)
 209                         break;
 210
 211                 if (file->f_flags & O_NONBLOCK) {
 212                         retval = -EAGAIN;
 213                         goto out;
 214                 }
 215
 216                 if (signal_pending(current)) {
 217                         retval = -ERESTARTSYS;
 218                         goto out;
 219                 }
 220
 221                 schedule();
 222         }
 223
 224         if (data < 255)
 225                 byte_data = data;
 226         else
 227                 byte_data = 255;
 228
 229         /* make sure we are not going into copy_to_user() with
 230          * TASK_INTERRUPTIBLE state */
 231         set_current_state(TASK_RUNNING);
 232         if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
 233                 retval = -EFAULT;
 234
 235 out:
 236         __set_current_state(TASK_RUNNING);
 237         remove_wait_queue(&lis3_dev.misc_wait, &wait);
 238
 239         return retval;
 240 }
 241
 242 static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
 243 {
 244         poll_wait(file, &lis3_dev.misc_wait, wait);
 245         if (atomic_read(&lis3_dev.count))
 246                 return POLLIN | POLLRDNORM;
 247         return 0;
 248 }
 249
 250 static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
 251 {
 252         return fasync_helper(fd, file, on, &lis3_dev.async_queue);
 253 }
 254
 255 static const struct file_operations lis3lv02d_misc_fops = {
 256         .owner   = THIS_MODULE,
 257         .llseek  = no_llseek,
 258         .read    = lis3lv02d_misc_read,
 259         .open    = lis3lv02d_misc_open,
 260         .release = lis3lv02d_misc_release,
 261         .poll    = lis3lv02d_misc_poll,
 262         .fasync  = lis3lv02d_misc_fasync,
 263 };
 264
 265 static struct miscdevice lis3lv02d_misc_device = {
 266         .minor   = MISC_DYNAMIC_MINOR,
 267         .name    = "freefall",
 268         .fops    = &lis3lv02d_misc_fops,
 269 };
 270
 271 static void lis3lv02d_joystick_poll(struct input_polled_dev *pidev)
 272 {
 273         int x, y, z;
 274
 275         lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
 276         input_report_abs(pidev->input, ABS_X, x - lis3_dev.xcalib);
 277         input_report_abs(pidev->input, ABS_Y, y - lis3_dev.ycalib);
 278         input_report_abs(pidev->input, ABS_Z, z - lis3_dev.zcalib);
 279 }
 280
 281
 282 static inline void lis3lv02d_calibrate_joystick(void)
 283 {
 284         lis3lv02d_get_xyz(&lis3_dev,
 285                 &lis3_dev.xcalib, &lis3_dev.ycalib, &lis3_dev.zcalib);
 286 }
 287
 288 int lis3lv02d_joystick_enable(void)
 289 {
 290         struct input_dev *input_dev;
 291         int err;
 292
 293         if (lis3_dev.idev)
 294                 return -EINVAL;
 295
 296         lis3_dev.idev = input_allocate_polled_device();
 297         if (!lis3_dev.idev)
 298                 return -ENOMEM;
 299
 300         lis3_dev.idev->poll = lis3lv02d_joystick_poll;
 301         lis3_dev.idev->poll_interval = MDPS_POLL_INTERVAL;
 302         input_dev = lis3_dev.idev->input;
 303
 304         lis3lv02d_calibrate_joystick();
 305
 306         input_dev->name       = "ST LIS3LV02DL Accelerometer";
 307         input_dev->phys       = DRIVER_NAME "/input0";
 308         input_dev->id.bustype = BUS_HOST;
 309         input_dev->id.vendor  = 0;
 310         input_dev->dev.parent = &lis3_dev.pdev->dev;
 311
 312         set_bit(EV_ABS, input_dev->evbit);
 313         input_set_abs_params(input_dev, ABS_X, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 314         input_set_abs_params(input_dev, ABS_Y, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 315         input_set_abs_params(input_dev, ABS_Z, -lis3_dev.mdps_max_val, lis3_dev.mdps_max_val, 3, 3);
 316
 317         err = input_register_polled_device(lis3_dev.idev);
 318         if (err) {
 319                 input_free_polled_device(lis3_dev.idev);
 320                 lis3_dev.idev = NULL;
 321         }
 322
 323         return err;
 324 }
 325 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
 326
 327 void lis3lv02d_joystick_disable(void)
 328 {
 329         if (!lis3_dev.idev)
 330                 return;
 331
 332         if (lis3_dev.irq)
 333                 misc_deregister(&lis3lv02d_misc_device);
 334         input_unregister_polled_device(lis3_dev.idev);
 335         lis3_dev.idev = NULL;
 336 }
 337 EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
 338
 339 /* Sysfs stuff */
 340 static ssize_t lis3lv02d_position_show(struct device *dev,
 341                                 struct device_attribute *attr, char *buf)
 342 {
 343         int x, y, z;
 344
 345         lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
 346         return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
 347 }
 348
 349 static ssize_t lis3lv02d_calibrate_show(struct device *dev,
 350                                 struct device_attribute *attr, char *buf)
 351 {
 352         return sprintf(buf, "(%d,%d,%d)\n", lis3_dev.xcalib, lis3_dev.ycalib, lis3_dev.zcalib);
 353 }
 354
 355 static ssize_t lis3lv02d_calibrate_store(struct device *dev,
 356                                 struct device_attribute *attr,
 357                                 const char *buf, size_t count)
 358 {
 359         lis3lv02d_calibrate_joystick();
 360         return count;
 361 }
 362
 363 /* conversion btw sampling rate and the register values */
 364 static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
 365 static ssize_t lis3lv02d_rate_show(struct device *dev,
 366                         struct device_attribute *attr, char *buf)
 367 {
 368         u8 ctrl;
 369         int val;
 370
 371         lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
 372         val = (ctrl & (CTRL1_DF0 | CTRL1_DF1)) >> 4;
 373         return sprintf(buf, "%d\n", lis3lv02dl_df_val[val]);
 374 }
 375
 376 static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
 377 static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
 378         lis3lv02d_calibrate_store);
 379 static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
 380
 381 static struct attribute *lis3lv02d_attributes[] = {
 382         &dev_attr_position.attr,
 383         &dev_attr_calibrate.attr,
 384         &dev_attr_rate.attr,
 385         NULL
 386 };
 387
 388 static struct attribute_group lis3lv02d_attribute_group = {
 389         .attrs = lis3lv02d_attributes
 390 };
 391
 392
 393 static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
 394 {
 395         lis3->pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 396         if (IS_ERR(lis3->pdev))
 397                 return PTR_ERR(lis3->pdev);
 398
 399         return sysfs_create_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
 400 }
 401
 402 int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
 403 {
 404         sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
 405         platform_device_unregister(lis3->pdev);
 406         return 0;
 407 }
 408 EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 409
 410 /*
 411  * Initialise the accelerometer and the various subsystems.
 412  * Should be rather independant of the bus system.
 413  */
 414 int lis3lv02d_init_device(struct lis3lv02d *dev)
 415 {
 416         dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
 417
 418         switch (dev->whoami) {
 419         case LIS_DOUBLE_ID:
 420                 printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
 421                 dev->read_data = lis3lv02d_read_16;
 422                 dev->mdps_max_val = 2048;
 423                 break;
 424         case LIS_SINGLE_ID:
 425                 printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
 426                 dev->read_data = lis3lv02d_read_8;
 427                 dev->mdps_max_val = 128;
 428                 break;
 429         default:
 430                 printk(KERN_ERR DRIVER_NAME
 431                         ": unknown sensor type 0x%X\n", dev->whoami);
 432                 return -EINVAL;
 433         }
 434
 435         lis3lv02d_add_fs(dev);
 436         lis3lv02d_poweron(dev);
 437
 438         if (lis3lv02d_joystick_enable())
 439                 printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");
 440
 441         /* passing in platform specific data is purely optional and only
 442          * used by the SPI transport layer at the moment */
 443         if (dev->pdata) {
 444                 struct lis3lv02d_platform_data *p = dev->pdata;
 445
 446                 if (p->click_flags && (dev->whoami == LIS_SINGLE_ID)) {
 447                         dev->write(dev, CLICK_CFG, p->click_flags);
 448                         dev->write(dev, CLICK_TIMELIMIT, p->click_time_limit);
 449                         dev->write(dev, CLICK_LATENCY, p->click_latency);
 450                         dev->write(dev, CLICK_WINDOW, p->click_window);
 451                         dev->write(dev, CLICK_THSZ, p->click_thresh_z & 0xf);
 452                         dev->write(dev, CLICK_THSY_X,
 453                                         (p->click_thresh_x & 0xf) |
 454                                         (p->click_thresh_y << 4));
 455                 }
 456
 457                 if (p->irq_cfg)
 458                         dev->write(dev, CTRL_REG3, p->irq_cfg);
 459         }
 460
 461         /* bail if we did not get an IRQ from the bus layer */
 462         if (!dev->irq) {
 463                 printk(KERN_ERR DRIVER_NAME
 464                         ": No IRQ. Disabling /dev/freefall\n");
 465                 goto out;
 466         }
 467
 468         if (misc_register(&lis3lv02d_misc_device))
 469                 printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
 470 out:
 471         return 0;
 472 }
 473 EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
 474
 475 MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
 476 MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 477 MODULE_LICENSE("GPL");
 478