Linux 2.6.34-rc3

[pohmelfs.git] / drivers / hwmon / lis3lv02d.c

/*
 *  lis3lv02d.c - ST LIS3LV02DL accelerometer driver
 *
 *  Copyright (C) 2007-2008 Yan Burman
 *  Copyright (C) 2008 Eric Piel
 *  Copyright (C) 2008-2009 Pavel Machek
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/input-polldev.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <asm/atomic.h>
#include "lis3lv02d.h"

#define DRIVER_NAME     "lis3lv02d"

/* joystick device poll interval in milliseconds */
#define MDPS_POLL_INTERVAL 50
/*
 * The sensor can also generate interrupts (DRDY) but it's pretty pointless
 * because they are generated even if the data do not change. So it's better
 * to keep the interrupt for the free-fall event. The values are updated at
 * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
 * some low processor, we poll the sensor only at 20Hz... enough for the
 * joystick.
 */

#define LIS3_PWRON_DELAY_WAI_12B        (5000)
#define LIS3_PWRON_DELAY_WAI_8B         (3000)

/*
 * LIS3LV02D spec says 1024 LSBs corresponds 1 G -> 1LSB is 1000/1024 mG
 * LIS302D spec says: 18 mG / digit
 * LIS3_ACCURACY is used to increase accuracy of the intermediate
 * calculation results.
 */
#define LIS3_ACCURACY                   1024
/* Sensitivity values for -2G +2G scale */
#define LIS3_SENSITIVITY_12B            ((LIS3_ACCURACY * 1000) / 1024)
#define LIS3_SENSITIVITY_8B             (18 * LIS3_ACCURACY)

#define LIS3_DEFAULT_FUZZ               3
#define LIS3_DEFAULT_FLAT               3

struct lis3lv02d lis3_dev = {
        .misc_wait   = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
};

EXPORT_SYMBOL_GPL(lis3_dev);

static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
{
        s8 lo;
        if (lis3->read(lis3, reg, &lo) < 0)
                return 0;

        return lo;
}

static s16 lis3lv02d_read_12(struct lis3lv02d *lis3, int reg)
{
        u8 lo, hi;

        lis3->read(lis3, reg - 1, &lo);
        lis3->read(lis3, reg, &hi);
        /* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
        return (s16)((hi << 8) | lo);
}

/**
 * lis3lv02d_get_axis - For the given axis, give the value converted
 * @axis:      1,2,3 - can also be negative
 * @hw_values: raw values returned by the hardware
 *
 * Returns the converted value.
 */
static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
{
        if (axis > 0)
                return hw_values[axis - 1];
        else
                return -hw_values[-axis - 1];
}

/**
 * lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
 * @lis3: pointer to the device struct
 * @x:    where to store the X axis value
 * @y:    where to store the Y axis value
 * @z:    where to store the Z axis value
 *
 * Note that 40Hz input device can eat up about 10% CPU at 800MHZ
 */
static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
{
        int position[3];
        int i;

        mutex_lock(&lis3->mutex);
        position[0] = lis3->read_data(lis3, OUTX);
        position[1] = lis3->read_data(lis3, OUTY);
        position[2] = lis3->read_data(lis3, OUTZ);
        mutex_unlock(&lis3->mutex);

        for (i = 0; i < 3; i++)
                position[i] = (position[i] * lis3->scale) / LIS3_ACCURACY;

        *x = lis3lv02d_get_axis(lis3->ac.x, position);
        *y = lis3lv02d_get_axis(lis3->ac.y, position);
        *z = lis3lv02d_get_axis(lis3->ac.z, position);
}

/* conversion btw sampling rate and the register values */
static int lis3_12_rates[4] = {40, 160, 640, 2560};
static int lis3_8_rates[2] = {100, 400};

/* ODR is Output Data Rate */
static int lis3lv02d_get_odr(void)
{
        u8 ctrl;
        int shift;

        lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
        ctrl &= lis3_dev.odr_mask;
        shift = ffs(lis3_dev.odr_mask) - 1;
        return lis3_dev.odrs[(ctrl >> shift)];
}

static int lis3lv02d_set_odr(int rate)
{
        u8 ctrl;
        int i, len, shift;

        lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
        ctrl &= ~lis3_dev.odr_mask;
        len = 1 << hweight_long(lis3_dev.odr_mask); /* # of possible values */
        shift = ffs(lis3_dev.odr_mask) - 1;

        for (i = 0; i < len; i++)
                if (lis3_dev.odrs[i] == rate) {
                        lis3_dev.write(&lis3_dev, CTRL_REG1,
                                        ctrl | (i << shift));
                        return 0;
                }
        return -EINVAL;
}

static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
{
        u8 reg;
        s16 x, y, z;
        u8 selftest;
        int ret;

        mutex_lock(&lis3->mutex);
        if (lis3_dev.whoami == WAI_12B)
                selftest = CTRL1_ST;
        else
                selftest = CTRL1_STP;

        lis3->read(lis3, CTRL_REG1, &reg);
        lis3->write(lis3, CTRL_REG1, (reg | selftest));
        msleep(lis3->pwron_delay / lis3lv02d_get_odr());

        /* Read directly to avoid axis remap */
        x = lis3->read_data(lis3, OUTX);
        y = lis3->read_data(lis3, OUTY);
        z = lis3->read_data(lis3, OUTZ);

        /* back to normal settings */
        lis3->write(lis3, CTRL_REG1, reg);
        msleep(lis3->pwron_delay / lis3lv02d_get_odr());

        results[0] = x - lis3->read_data(lis3, OUTX);
        results[1] = y - lis3->read_data(lis3, OUTY);
        results[2] = z - lis3->read_data(lis3, OUTZ);

        ret = 0;
        if (lis3->pdata) {
                int i;
                for (i = 0; i < 3; i++) {
                        /* Check against selftest acceptance limits */
                        if ((results[i] < lis3->pdata->st_min_limits[i]) ||
                            (results[i] > lis3->pdata->st_max_limits[i])) {
                                ret = -EIO;
                                goto fail;
                        }
                }
        }

        /* test passed */
fail:
        mutex_unlock(&lis3->mutex);
        return ret;
}

void lis3lv02d_poweroff(struct lis3lv02d *lis3)
{
        /* disable X,Y,Z axis and power down */
        lis3->write(lis3, CTRL_REG1, 0x00);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);

void lis3lv02d_poweron(struct lis3lv02d *lis3)
{
        u8 reg;

        lis3->init(lis3);

        /* LIS3 power on delay is quite long */
        msleep(lis3->pwron_delay / lis3lv02d_get_odr());

        /*
         * Common configuration
         * BDU: (12 bits sensors only) LSB and MSB values are not updated until
         *      both have been read. So the value read will always be correct.
         */
        if (lis3->whoami ==  WAI_12B) {
                lis3->read(lis3, CTRL_REG2, &reg);
                reg |= CTRL2_BDU;
                lis3->write(lis3, CTRL_REG2, reg);
        }
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweron);


static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
{
        /*
         * Be careful: on some HP laptops the bios force DD when on battery and
         * the lid is closed. This leads to interrupts as soon as a little move
         * is done.
         */
        atomic_inc(&lis3_dev.count);

        wake_up_interruptible(&lis3_dev.misc_wait);
        kill_fasync(&lis3_dev.async_queue, SIGIO, POLL_IN);
        return IRQ_HANDLED;
}

static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
{
        int ret;

        if (test_and_set_bit(0, &lis3_dev.misc_opened))
                return -EBUSY; /* already open */

        atomic_set(&lis3_dev.count, 0);

        /*
         * The sensor can generate interrupts for free-fall and direction
         * detection (distinguishable with FF_WU_SRC and DD_SRC) but to keep
         * the things simple and _fast_ we activate it only for free-fall, so
         * no need to read register (very slow with ACPI). For the same reason,
         * we forbid shared interrupts.
         *
         * IRQF_TRIGGER_RISING seems pointless on HP laptops because the
         * io-apic is not configurable (and generates a warning) but I keep it
         * in case of support for other hardware.
         */
        ret = request_irq(lis3_dev.irq, lis302dl_interrupt, IRQF_TRIGGER_RISING,
                          DRIVER_NAME, &lis3_dev);

        if (ret) {
                clear_bit(0, &lis3_dev.misc_opened);
                printk(KERN_ERR DRIVER_NAME ": IRQ%d allocation failed\n", lis3_dev.irq);
                return -EBUSY;
        }
        return 0;
}

static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
{
        fasync_helper(-1, file, 0, &lis3_dev.async_queue);
        free_irq(lis3_dev.irq, &lis3_dev);
        clear_bit(0, &lis3_dev.misc_opened); /* release the device */
        return 0;
}

static ssize_t lis3lv02d_misc_read(struct file *file, char __user *buf,
                                size_t count, loff_t *pos)
{
        DECLARE_WAITQUEUE(wait, current);
        u32 data;
        unsigned char byte_data;
        ssize_t retval = 1;

        if (count < 1)
                return -EINVAL;

        add_wait_queue(&lis3_dev.misc_wait, &wait);
        while (true) {
                set_current_state(TASK_INTERRUPTIBLE);
                data = atomic_xchg(&lis3_dev.count, 0);
                if (data)
                        break;

                if (file->f_flags & O_NONBLOCK) {
                        retval = -EAGAIN;
                        goto out;
                }

                if (signal_pending(current)) {
                        retval = -ERESTARTSYS;
                        goto out;
                }

                schedule();
        }

        if (data < 255)
                byte_data = data;
        else
                byte_data = 255;

        /* make sure we are not going into copy_to_user() with
         * TASK_INTERRUPTIBLE state */
        set_current_state(TASK_RUNNING);
        if (copy_to_user(buf, &byte_data, sizeof(byte_data)))
                retval = -EFAULT;

out:
        __set_current_state(TASK_RUNNING);
        remove_wait_queue(&lis3_dev.misc_wait, &wait);

        return retval;
}

static unsigned int lis3lv02d_misc_poll(struct file *file, poll_table *wait)
{
        poll_wait(file, &lis3_dev.misc_wait, wait);
        if (atomic_read(&lis3_dev.count))
                return POLLIN | POLLRDNORM;
        return 0;
}

static int lis3lv02d_misc_fasync(int fd, struct file *file, int on)
{
        return fasync_helper(fd, file, on, &lis3_dev.async_queue);
}

static const struct file_operations lis3lv02d_misc_fops = {
        .owner   = THIS_MODULE,
        .llseek  = no_llseek,
        .read    = lis3lv02d_misc_read,
        .open    = lis3lv02d_misc_open,
        .release = lis3lv02d_misc_release,
        .poll    = lis3lv02d_misc_poll,
        .fasync  = lis3lv02d_misc_fasync,
};

static struct miscdevice lis3lv02d_misc_device = {
        .minor   = MISC_DYNAMIC_MINOR,
        .name    = "freefall",
        .fops    = &lis3lv02d_misc_fops,
};

static void lis3lv02d_joystick_poll(struct input_polled_dev *pidev)
{
        int x, y, z;

        lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
        input_report_abs(pidev->input, ABS_X, x);
        input_report_abs(pidev->input, ABS_Y, y);
        input_report_abs(pidev->input, ABS_Z, z);
        input_sync(pidev->input);
}

int lis3lv02d_joystick_enable(void)
{
        struct input_dev *input_dev;
        int err;
        int max_val, fuzz, flat;

        if (lis3_dev.idev)
                return -EINVAL;

        lis3_dev.idev = input_allocate_polled_device();
        if (!lis3_dev.idev)
                return -ENOMEM;

        lis3_dev.idev->poll = lis3lv02d_joystick_poll;
        lis3_dev.idev->poll_interval = MDPS_POLL_INTERVAL;
        input_dev = lis3_dev.idev->input;

        input_dev->name       = "ST LIS3LV02DL Accelerometer";
        input_dev->phys       = DRIVER_NAME "/input0";
        input_dev->id.bustype = BUS_HOST;
        input_dev->id.vendor  = 0;
        input_dev->dev.parent = &lis3_dev.pdev->dev;

        set_bit(EV_ABS, input_dev->evbit);
        max_val = (lis3_dev.mdps_max_val * lis3_dev.scale) / LIS3_ACCURACY;
        fuzz = (LIS3_DEFAULT_FUZZ * lis3_dev.scale) / LIS3_ACCURACY;
        flat = (LIS3_DEFAULT_FLAT * lis3_dev.scale) / LIS3_ACCURACY;
        input_set_abs_params(input_dev, ABS_X, -max_val, max_val, fuzz, flat);
        input_set_abs_params(input_dev, ABS_Y, -max_val, max_val, fuzz, flat);
        input_set_abs_params(input_dev, ABS_Z, -max_val, max_val, fuzz, flat);

        err = input_register_polled_device(lis3_dev.idev);
        if (err) {
                input_free_polled_device(lis3_dev.idev);
                lis3_dev.idev = NULL;
        }

        return err;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_enable);

void lis3lv02d_joystick_disable(void)
{
        if (!lis3_dev.idev)
                return;

        if (lis3_dev.irq)
                misc_deregister(&lis3lv02d_misc_device);
        input_unregister_polled_device(lis3_dev.idev);
        input_free_polled_device(lis3_dev.idev);
        lis3_dev.idev = NULL;
}
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);

/* Sysfs stuff */
static ssize_t lis3lv02d_selftest_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        int result;
        s16 values[3];

        result = lis3lv02d_selftest(&lis3_dev, values);
        return sprintf(buf, "%s %d %d %d\n", result == 0 ? "OK" : "FAIL",
                values[0], values[1], values[2]);
}

static ssize_t lis3lv02d_position_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        int x, y, z;

        lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
        return sprintf(buf, "(%d,%d,%d)\n", x, y, z);
}

static ssize_t lis3lv02d_rate_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%d\n", lis3lv02d_get_odr());
}

static ssize_t lis3lv02d_rate_set(struct device *dev,
                                struct device_attribute *attr, const char *buf,
                                size_t count)
{
        unsigned long rate;

        if (strict_strtoul(buf, 0, &rate))
                return -EINVAL;

        if (lis3lv02d_set_odr(rate))
                return -EINVAL;

        return count;
}

static DEVICE_ATTR(selftest, S_IRUSR, lis3lv02d_selftest_show, NULL);
static DEVICE_ATTR(position, S_IRUGO, lis3lv02d_position_show, NULL);
static DEVICE_ATTR(rate, S_IRUGO | S_IWUSR, lis3lv02d_rate_show,
                                            lis3lv02d_rate_set);

static struct attribute *lis3lv02d_attributes[] = {
        &dev_attr_selftest.attr,
        &dev_attr_position.attr,
        &dev_attr_rate.attr,
        NULL
};

static struct attribute_group lis3lv02d_attribute_group = {
        .attrs = lis3lv02d_attributes
};


static int lis3lv02d_add_fs(struct lis3lv02d *lis3)
{
        lis3->pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
        if (IS_ERR(lis3->pdev))
                return PTR_ERR(lis3->pdev);

        return sysfs_create_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
}

int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
{
        sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
        platform_device_unregister(lis3->pdev);
        return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);

/*
 * Initialise the accelerometer and the various subsystems.
 * Should be rather independent of the bus system.
 */
int lis3lv02d_init_device(struct lis3lv02d *dev)
{
        dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);

        switch (dev->whoami) {
        case WAI_12B:
                printk(KERN_INFO DRIVER_NAME ": 12 bits sensor found\n");
                dev->read_data = lis3lv02d_read_12;
                dev->mdps_max_val = 2048;
                dev->pwron_delay = LIS3_PWRON_DELAY_WAI_12B;
                dev->odrs = lis3_12_rates;
                dev->odr_mask = CTRL1_DF0 | CTRL1_DF1;
                dev->scale = LIS3_SENSITIVITY_12B;
                break;
        case WAI_8B:
                printk(KERN_INFO DRIVER_NAME ": 8 bits sensor found\n");
                dev->read_data = lis3lv02d_read_8;
                dev->mdps_max_val = 128;
                dev->pwron_delay = LIS3_PWRON_DELAY_WAI_8B;
                dev->odrs = lis3_8_rates;
                dev->odr_mask = CTRL1_DR;
                dev->scale = LIS3_SENSITIVITY_8B;
                break;
        default:
                printk(KERN_ERR DRIVER_NAME
                        ": unknown sensor type 0x%X\n", dev->whoami);
                return -EINVAL;
        }

        mutex_init(&dev->mutex);

        lis3lv02d_add_fs(dev);
        lis3lv02d_poweron(dev);

        if (lis3lv02d_joystick_enable())
                printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");

        /* passing in platform specific data is purely optional and only
         * used by the SPI transport layer at the moment */
        if (dev->pdata) {
                struct lis3lv02d_platform_data *p = dev->pdata;

                if (p->click_flags && (dev->whoami == WAI_8B)) {
                        dev->write(dev, CLICK_CFG, p->click_flags);
                        dev->write(dev, CLICK_TIMELIMIT, p->click_time_limit);
                        dev->write(dev, CLICK_LATENCY, p->click_latency);
                        dev->write(dev, CLICK_WINDOW, p->click_window);
                        dev->write(dev, CLICK_THSZ, p->click_thresh_z & 0xf);
                        dev->write(dev, CLICK_THSY_X,
                                        (p->click_thresh_x & 0xf) |
                                        (p->click_thresh_y << 4));
                }

                if (p->wakeup_flags && (dev->whoami == WAI_8B)) {
                        dev->write(dev, FF_WU_CFG_1, p->wakeup_flags);
                        dev->write(dev, FF_WU_THS_1, p->wakeup_thresh & 0x7f);
                        /* default to 2.5ms for now */
                        dev->write(dev, FF_WU_DURATION_1, 1);
                        /* enable high pass filter for both free-fall units */
                        dev->write(dev, CTRL_REG2, HP_FF_WU1 | HP_FF_WU2);
                }

                if (p->irq_cfg)
                        dev->write(dev, CTRL_REG3, p->irq_cfg);
        }

        /* bail if we did not get an IRQ from the bus layer */
        if (!dev->irq) {
                printk(KERN_ERR DRIVER_NAME
                        ": No IRQ. Disabling /dev/freefall\n");
                goto out;
        }

        if (misc_register(&lis3lv02d_misc_device))
                printk(KERN_ERR DRIVER_NAME ": misc_register failed\n");
out:
        return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_init_device);

MODULE_DESCRIPTION("ST LIS3LV02Dx three-axis digital accelerometer driver");
MODULE_AUTHOR("Yan Burman, Eric Piel, Pavel Machek");
MODULE_LICENSE("GPL");