LXR linux/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
  53struct lis3lv02d lis3_dev = {
  54        .misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
  55};
  56
  57EXPORT_SYMBOL_GPL(lis3_dev);
  58
  59static 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
  68static 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 */
  85static 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 */
 102static 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
 115void lis3lv02d_poweroff(struct lis3lv02d *lis3)
 116{
 117        /* disable X,Y,Z axis and power down */
 118        lis3->write(lis3, CTRL_REG1, 0x00);
 119}
 120EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 121
 122void 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}
 137EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 138
 139
 140static 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
 154static 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
 185static 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
 193static 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
 235out:
 236        __set_current_state(TASK_RUNNING);
 237        remove_wait_queue(&lis3_dev.misc_wait, &wait);
 238
 239        return retval;
 240}
 241
 242static 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
 250static 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
 255static 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
 265static struct miscdevice lis3lv02d_misc_device = {
 266        .minor   = MISC_DYNAMIC_MINOR,
 267        .name    = "freefall",
 268        .fops    = &lis3lv02d_misc_fops,
 269};
 270
 271static 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
 282static 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
 288int 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}
 325EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);
 326
 327void 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}
 337EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);
 338
 339/* Sysfs stuff */
 340static 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
 349static 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
 355static 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 */
 364static int lis3lv02dl_df_val[4] = {40, 160, 640, 2560};
 365static 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
 376static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
 377static DEVICE_ATTR(calibrate, S_IRUGO|S_IWUSR, lis3lv02d_calibrate_show,
 378        lis3lv02d_calibrate_store);
 379static DEVICE_ATTR(rate, S_IRUGO, lis3lv02d_rate_show, NULL);
 380
 381static struct attribute *lis3lv02d_attributes[] = {
 382        &dev_attr_position.attr,
 383        &dev_attr_calibrate.attr,
 384        &dev_attr_rate.attr,
 385        NULL
 386};
 387
 388static struct attribute_group lis3lv02d_attribute_group = {
 389        .attrs = lis3lv02d_attributes
 390};
 391
 392
 393static 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
 402int 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}
 408EXPORT_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 */
 414int 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->wakeup_flags && (dev->whoami == LIS_SINGLE_ID)) {
 458                        dev->write(dev, FF_WU_CFG_1, p->wakeup_flags);
 459                        dev->write(dev, FF_WU_THS_1, p->wakeup_thresh & 0x7f);
 460                        /* default to 2.5ms for now */
 461                        dev->write(dev, FF_WU_DURATION_1, 1);
 462                        /* enable high pass filter for both free-fall units */
 463                        dev->write(dev, CTRL_REG2, HP_FF_WU1 | HP_FF_WU2);
 464                }
 465
 466                if (p->irq_cfg)
 467                        dev->write(dev, CTRL_REG3, p->irq_cfg);
 468        }
 469
 470        /* bail if we did not get an IRQ from the bus layer */
 471        if (!dev->irq) {
 472                printk(KERN_ERR DRIVER_NAME
 473                        ": No IRQ. Disabling /dev/freefall\n");
 474                goto out;
 475        }
 476
 477        if (misc_register(&lis3lv02d_misc_device))
 478                printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
 479out:
 480        return 0;
 481}
 482EXPORT_SYMBOL_GPL(lis3lv02d_init_device);
 483
 484MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
 485MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
 486MODULE_LICENSE("GPL");
 487
 488