leds-lp5523.c

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/*
 * lp5523.c - LP5523 LED Driver
 *
 * Copyright (C) 2010 Nokia Corporation
 *
 * Contact: Samu Onkalo <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/leds.h>
#include <linux/leds-lp5523.h>
#include <linux/workqueue.h>
#include <linux/slab.h>

#define LP5523_REG_ENABLE       0x00
#define LP5523_REG_OP_MODE      0x01
#define LP5523_REG_RATIOMETRIC_MSB  0x02
#define LP5523_REG_RATIOMETRIC_LSB  0x03
#define LP5523_REG_ENABLE_LEDS_MSB  0x04
#define LP5523_REG_ENABLE_LEDS_LSB  0x05
#define LP5523_REG_LED_CNTRL_BASE   0x06
#define LP5523_REG_LED_PWM_BASE     0x16
#define LP5523_REG_LED_CURRENT_BASE 0x26
#define LP5523_REG_CONFIG       0x36
#define LP5523_REG_CHANNEL1_PC      0x37
#define LP5523_REG_CHANNEL2_PC      0x38
#define LP5523_REG_CHANNEL3_PC      0x39
#define LP5523_REG_STATUS       0x3a
#define LP5523_REG_GPO          0x3b
#define LP5523_REG_VARIABLE     0x3c
#define LP5523_REG_RESET        0x3d
#define LP5523_REG_TEMP_CTRL        0x3e
#define LP5523_REG_TEMP_READ        0x3f
#define LP5523_REG_TEMP_WRITE       0x40
#define LP5523_REG_LED_TEST_CTRL    0x41
#define LP5523_REG_LED_TEST_ADC     0x42
#define LP5523_REG_ENG1_VARIABLE    0x45
#define LP5523_REG_ENG2_VARIABLE    0x46
#define LP5523_REG_ENG3_VARIABLE    0x47
#define LP5523_REG_MASTER_FADER1    0x48
#define LP5523_REG_MASTER_FADER2    0x49
#define LP5523_REG_MASTER_FADER3    0x4a
#define LP5523_REG_CH1_PROG_START   0x4c
#define LP5523_REG_CH2_PROG_START   0x4d
#define LP5523_REG_CH3_PROG_START   0x4e
#define LP5523_REG_PROG_PAGE_SEL    0x4f
#define LP5523_REG_PROG_MEM     0x50

#define LP5523_CMD_LOAD         0x15 /* 00010101 */
#define LP5523_CMD_RUN          0x2a /* 00101010 */
#define LP5523_CMD_DISABLED     0x00 /* 00000000 */

#define LP5523_ENABLE           0x40
#define LP5523_AUTO_INC         0x40
#define LP5523_PWR_SAVE         0x20
#define LP5523_PWM_PWR_SAVE     0x04
#define LP5523_CP_1         0x08
#define LP5523_CP_1_5           0x10
#define LP5523_CP_AUTO          0x18
#define LP5523_INT_CLK          0x01
#define LP5523_AUTO_CLK         0x02
#define LP5523_EN_LEDTEST       0x80
#define LP5523_LEDTEST_DONE     0x80

#define LP5523_DEFAULT_CURRENT      50 /* microAmps */
#define LP5523_PROGRAM_LENGTH       32 /* in bytes */
#define LP5523_PROGRAM_PAGES        6
#define LP5523_ADC_SHORTCIRC_LIM    80

#define LP5523_LEDS         9
#define LP5523_ENGINES          3

#define LP5523_ENG_MASK_BASE        0x30 /* 00110000 */

#define LP5523_ENG_STATUS_MASK          0x07 /* 00000111 */

#define LP5523_IRQ_FLAGS                IRQF_TRIGGER_FALLING

#define LP5523_EXT_CLK_USED     0x08

#define LED_ACTIVE(mux, led)        (!!(mux & (0x0001 << led)))
#define SHIFT_MASK(id)          (((id) - 1) * 2)

enum lp5523_chip_id {
    LP5523,
    LP55231,
};

struct lp5523_engine {
    int     id;
    u8      mode;
    u8      prog_page;
    u8      mux_page;
    u16     led_mux;
    u8      engine_mask;
};

struct lp5523_led {
    int         id;
    u8          chan_nr;
    u8          led_current;
    u8          max_current;
    struct led_classdev     cdev;
    struct work_struct  brightness_work;
    u8          brightness;
};

struct lp5523_chip {
    struct mutex        lock; /* Serialize control */
    struct i2c_client   *client;
    struct lp5523_engine    engines[LP5523_ENGINES];
    struct lp5523_led   leds[LP5523_LEDS];
    struct lp5523_platform_data *pdata;
    u8          num_channels;
    u8          num_leds;
};

static inline struct lp5523_led *cdev_to_led(struct led_classdev *cdev)
{
    return container_of(cdev, struct lp5523_led, cdev);
}

static inline struct lp5523_chip *engine_to_lp5523(struct lp5523_engine *engine)
{
    return container_of(engine, struct lp5523_chip,
                engines[engine->id - 1]);
}

static inline struct lp5523_chip *led_to_lp5523(struct lp5523_led *led)
{
    return container_of(led, struct lp5523_chip,
                leds[led->id]);
}

static void lp5523_set_mode(struct lp5523_engine *engine, u8 mode);
static int lp5523_set_engine_mode(struct lp5523_engine *engine, u8 mode);
static int lp5523_load_program(struct lp5523_engine *engine, const u8 *pattern);

static void lp5523_led_brightness_work(struct work_struct *work);

static int lp5523_write(struct i2c_client *client, u8 reg, u8 value)
{
    return i2c_smbus_write_byte_data(client, reg, value);
}

static int lp5523_read(struct i2c_client *client, u8 reg, u8 *buf)
{
    s32 ret = i2c_smbus_read_byte_data(client, reg);

    if (ret < 0)
        return -EIO;

    *buf = ret;
    return 0;
}

static int lp5523_detect(struct i2c_client *client)
{
    int ret;
    u8 buf;

    ret = lp5523_write(client, LP5523_REG_ENABLE, LP5523_ENABLE);
    if (ret)
        return ret;
    ret = lp5523_read(client, LP5523_REG_ENABLE, &buf);
    if (ret)
        return ret;
    if (buf == 0x40)
        return 0;
    else
        return -ENODEV;
}

static int lp5523_configure(struct i2c_client *client)
{
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    int ret = 0;
    u8 status;

    /* one pattern per engine setting led mux start and stop addresses */
    static const u8 pattern[][LP5523_PROGRAM_LENGTH] =  {
        { 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
        { 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
        { 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
    };

    ret |= lp5523_write(client, LP5523_REG_ENABLE, LP5523_ENABLE);
    /* Chip startup time is 500 us, 1 - 2 ms gives some margin */
    usleep_range(1000, 2000);

    ret |= lp5523_write(client, LP5523_REG_CONFIG,
                LP5523_AUTO_INC | LP5523_PWR_SAVE |
                LP5523_CP_AUTO | LP5523_AUTO_CLK |
                LP5523_PWM_PWR_SAVE);

    /* turn on all leds */
    ret |= lp5523_write(client, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
    ret |= lp5523_write(client, LP5523_REG_ENABLE_LEDS_LSB, 0xff);

    /* hardcode 32 bytes of memory for each engine from program memory */
    ret |= lp5523_write(client, LP5523_REG_CH1_PROG_START, 0x00);
    ret |= lp5523_write(client, LP5523_REG_CH2_PROG_START, 0x10);
    ret |= lp5523_write(client, LP5523_REG_CH3_PROG_START, 0x20);

    /* write led mux address space for each channel */
    ret |= lp5523_load_program(&chip->engines[0], pattern[0]);
    ret |= lp5523_load_program(&chip->engines[1], pattern[1]);
    ret |= lp5523_load_program(&chip->engines[2], pattern[2]);

    if (ret) {
        dev_err(&client->dev, "could not load mux programs\n");
        return -1;
    }

    /* set all engines exec state and mode to run 00101010 */
    ret |= lp5523_write(client, LP5523_REG_ENABLE,
                (LP5523_CMD_RUN | LP5523_ENABLE));

    ret |= lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_RUN);

    if (ret) {
        dev_err(&client->dev, "could not start mux programs\n");
        return -1;
    }

    /* Let the programs run for couple of ms and check the engine status */
    usleep_range(3000, 6000);
    lp5523_read(client, LP5523_REG_STATUS, &status);
    status &= LP5523_ENG_STATUS_MASK;

    if (status == LP5523_ENG_STATUS_MASK) {
        dev_dbg(&client->dev, "all engines configured\n");
    } else {
        dev_info(&client->dev, "status == %x\n", status);
        dev_err(&client->dev, "cound not configure LED engine\n");
        return -1;
    }

    dev_info(&client->dev, "disabling engines\n");

    ret |= lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_DISABLED);

    return ret;
}

static int lp5523_set_engine_mode(struct lp5523_engine *engine, u8 mode)
{
    struct lp5523_chip *chip = engine_to_lp5523(engine);
    struct i2c_client *client = chip->client;
    int ret;
    u8 engine_state;

    ret = lp5523_read(client, LP5523_REG_OP_MODE, &engine_state);
    if (ret)
        goto fail;

    engine_state &= ~(engine->engine_mask);

    /* set mode only for this engine */
    mode &= engine->engine_mask;

    engine_state |= mode;

    ret |= lp5523_write(client, LP5523_REG_OP_MODE, engine_state);
fail:
    return ret;
}

static int lp5523_load_mux(struct lp5523_engine *engine, u16 mux)
{
    struct lp5523_chip *chip = engine_to_lp5523(engine);
    struct i2c_client *client = chip->client;
    int ret = 0;

    ret |= lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);

    ret |= lp5523_write(client, LP5523_REG_PROG_PAGE_SEL, engine->mux_page);
    ret |= lp5523_write(client, LP5523_REG_PROG_MEM,
                (u8)(mux >> 8));
    ret |= lp5523_write(client, LP5523_REG_PROG_MEM + 1, (u8)(mux));
    engine->led_mux = mux;

    return ret;
}

static int lp5523_load_program(struct lp5523_engine *engine, const u8 *pattern)
{
    struct lp5523_chip *chip = engine_to_lp5523(engine);
    struct i2c_client *client = chip->client;

    int ret = 0;

    ret |= lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);

    ret |= lp5523_write(client, LP5523_REG_PROG_PAGE_SEL,
                engine->prog_page);
    ret |= i2c_smbus_write_i2c_block_data(client, LP5523_REG_PROG_MEM,
                          LP5523_PROGRAM_LENGTH, pattern);

    return ret;
}

static int lp5523_run_program(struct lp5523_engine *engine)
{
    struct lp5523_chip *chip = engine_to_lp5523(engine);
    struct i2c_client *client = chip->client;
    int ret;

    ret = lp5523_write(client, LP5523_REG_ENABLE,
                    LP5523_CMD_RUN | LP5523_ENABLE);
    if (ret)
        goto fail;

    ret = lp5523_set_engine_mode(engine, LP5523_CMD_RUN);
fail:
    return ret;
}

static int lp5523_mux_parse(const char *buf, u16 *mux, size_t len)
{
    int i;
    u16 tmp_mux = 0;

    len = min_t(int, len, LP5523_LEDS);
    for (i = 0; i < len; i++) {
        switch (buf[i]) {
        case '1':
            tmp_mux |= (1 << i);
            break;
        case '0':
            break;
        case '\n':
            i = len;
            break;
        default:
            return -1;
        }
    }
    *mux = tmp_mux;

    return 0;
}

static void lp5523_mux_to_array(u16 led_mux, char *array)
{
    int i, pos = 0;
    for (i = 0; i < LP5523_LEDS; i++)
        pos += sprintf(array + pos, "%x", LED_ACTIVE(led_mux, i));

    array[pos] = '\0';
}

/*--------------------------------------------------------------*/
/*          Sysfs interface             */
/*--------------------------------------------------------------*/

static ssize_t show_engine_leds(struct device *dev,
                struct device_attribute *attr,
                char *buf, int nr)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    char mux[LP5523_LEDS + 1];

    lp5523_mux_to_array(chip->engines[nr - 1].led_mux, mux);

    return sprintf(buf, "%s\n", mux);
}

#define show_leds(nr)                           \
static ssize_t show_engine##nr##_leds(struct device *dev,       \
                struct device_attribute *attr,      \
                char *buf)                  \
{                                   \
    return show_engine_leds(dev, attr, buf, nr);            \
}
show_leds(1)
show_leds(2)
show_leds(3)

static ssize_t store_engine_leds(struct device *dev,
                 struct device_attribute *attr,
                 const char *buf, size_t len, int nr)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    u16 mux = 0;
    ssize_t ret;

    if (lp5523_mux_parse(buf, &mux, len))
        return -EINVAL;

    mutex_lock(&chip->lock);
    ret = -EINVAL;
    if (chip->engines[nr - 1].mode != LP5523_CMD_LOAD)
        goto leave;

    if (lp5523_load_mux(&chip->engines[nr - 1], mux))
        goto leave;

    ret = len;
leave:
    mutex_unlock(&chip->lock);
    return ret;
}

#define store_leds(nr)                      \
static ssize_t store_engine##nr##_leds(struct device *dev,  \
                 struct device_attribute *attr, \
                 const char *buf, size_t len)   \
{                               \
    return store_engine_leds(dev, attr, buf, len, nr);  \
}
store_leds(1)
store_leds(2)
store_leds(3)

static ssize_t lp5523_selftest(struct device *dev,
                   struct device_attribute *attr,
                   char *buf)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    int i, ret, pos = 0;
    int led = 0;
    u8 status, adc, vdd;

    mutex_lock(&chip->lock);

    ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
    if (ret < 0)
        goto fail;

    /* Check that ext clock is really in use if requested */
    if ((chip->pdata) && (chip->pdata->clock_mode == LP5523_CLOCK_EXT))
        if  ((status & LP5523_EXT_CLK_USED) == 0)
            goto fail;

    /* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
    lp5523_write(chip->client, LP5523_REG_LED_TEST_CTRL,
                    LP5523_EN_LEDTEST | 16);
    usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
    ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
    if (!(status & LP5523_LEDTEST_DONE))
        usleep_range(3000, 6000); /* Was not ready. Wait little bit */

    ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &vdd);
    vdd--;  /* There may be some fluctuation in measurement */

    for (i = 0; i < LP5523_LEDS; i++) {
        /* Skip non-existing channels */
        if (chip->pdata->led_config[i].led_current == 0)
            continue;

        /* Set default current */
        lp5523_write(chip->client,
            LP5523_REG_LED_CURRENT_BASE + i,
            chip->pdata->led_config[i].led_current);

        lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0xff);
        /* let current stabilize 2 - 4ms before measurements start */
        usleep_range(2000, 4000);
        lp5523_write(chip->client,
                 LP5523_REG_LED_TEST_CTRL,
                 LP5523_EN_LEDTEST | i);
        /* ADC conversion time is 2.7 ms typically */
        usleep_range(3000, 6000);
        ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
        if (!(status & LP5523_LEDTEST_DONE))
            usleep_range(3000, 6000);/* Was not ready. Wait. */
        ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &adc);

        if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
            pos += sprintf(buf + pos, "LED %d FAIL\n", i);

        lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0x00);

        /* Restore current */
        lp5523_write(chip->client,
            LP5523_REG_LED_CURRENT_BASE + i,
            chip->leds[led].led_current);
        led++;
    }
    if (pos == 0)
        pos = sprintf(buf, "OK\n");
    goto release_lock;
fail:
    pos = sprintf(buf, "FAIL\n");

release_lock:
    mutex_unlock(&chip->lock);

    return pos;
}

static void lp5523_set_brightness(struct led_classdev *cdev,
                 enum led_brightness brightness)
{
    struct lp5523_led *led = cdev_to_led(cdev);

    led->brightness = (u8)brightness;

    schedule_work(&led->brightness_work);
}

static void lp5523_led_brightness_work(struct work_struct *work)
{
    struct lp5523_led *led = container_of(work,
                          struct lp5523_led,
                          brightness_work);
    struct lp5523_chip *chip = led_to_lp5523(led);
    struct i2c_client *client = chip->client;

    mutex_lock(&chip->lock);

    lp5523_write(client, LP5523_REG_LED_PWM_BASE + led->chan_nr,
             led->brightness);

    mutex_unlock(&chip->lock);
}

static int lp5523_do_store_load(struct lp5523_engine *engine,
                const char *buf, size_t len)
{
    struct lp5523_chip *chip = engine_to_lp5523(engine);
    struct i2c_client *client = chip->client;
    int  ret, nrchars, offset = 0, i = 0;
    char c[3];
    unsigned cmd;
    u8 pattern[LP5523_PROGRAM_LENGTH] = {0};

    if (engine->mode != LP5523_CMD_LOAD)
        return -EINVAL;

    while ((offset < len - 1) && (i < LP5523_PROGRAM_LENGTH)) {
        /* separate sscanfs because length is working only for %s */
        ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
        ret = sscanf(c, "%2x", &cmd);
        if (ret != 1)
            goto fail;
        pattern[i] = (u8)cmd;

        offset += nrchars;
        i++;
    }

    /* Each instruction is 16bit long. Check that length is even */
    if (i % 2)
        goto fail;

    mutex_lock(&chip->lock);
    ret = lp5523_load_program(engine, pattern);
    mutex_unlock(&chip->lock);

    if (ret) {
        dev_err(&client->dev, "failed loading pattern\n");
        return ret;
    }

    return len;
fail:
    dev_err(&client->dev, "wrong pattern format\n");
    return -EINVAL;
}

static ssize_t store_engine_load(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t len, int nr)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    return lp5523_do_store_load(&chip->engines[nr - 1], buf, len);
}

#define store_load(nr)                          \
static ssize_t store_engine##nr##_load(struct device *dev,      \
                     struct device_attribute *attr, \
                     const char *buf, size_t len)   \
{                                   \
    return store_engine_load(dev, attr, buf, len, nr);      \
}
store_load(1)
store_load(2)
store_load(3)

static ssize_t show_engine_mode(struct device *dev,
                struct device_attribute *attr,
                char *buf, int nr)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    switch (chip->engines[nr - 1].mode) {
    case LP5523_CMD_RUN:
        return sprintf(buf, "run\n");
    case LP5523_CMD_LOAD:
        return sprintf(buf, "load\n");
    case LP5523_CMD_DISABLED:
        return sprintf(buf, "disabled\n");
    default:
        return sprintf(buf, "disabled\n");
    }
}

#define show_mode(nr)                           \
static ssize_t show_engine##nr##_mode(struct device *dev,       \
                    struct device_attribute *attr,  \
                    char *buf)              \
{                                   \
    return show_engine_mode(dev, attr, buf, nr);            \
}
show_mode(1)
show_mode(2)
show_mode(3)

static ssize_t store_engine_mode(struct device *dev,
                 struct device_attribute *attr,
                 const char *buf, size_t len, int nr)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    struct lp5523_engine *engine = &chip->engines[nr - 1];
    mutex_lock(&chip->lock);

    if (!strncmp(buf, "run", 3))
        lp5523_set_mode(engine, LP5523_CMD_RUN);
    else if (!strncmp(buf, "load", 4))
        lp5523_set_mode(engine, LP5523_CMD_LOAD);
    else if (!strncmp(buf, "disabled", 8))
        lp5523_set_mode(engine, LP5523_CMD_DISABLED);

    mutex_unlock(&chip->lock);
    return len;
}

#define store_mode(nr)                          \
static ssize_t store_engine##nr##_mode(struct device *dev,      \
                     struct device_attribute *attr, \
                     const char *buf, size_t len)   \
{                                   \
    return store_engine_mode(dev, attr, buf, len, nr);      \
}
store_mode(1)
store_mode(2)
store_mode(3)

static ssize_t show_max_current(struct device *dev,
                struct device_attribute *attr,
                char *buf)
{
    struct led_classdev *led_cdev = dev_get_drvdata(dev);
    struct lp5523_led *led = cdev_to_led(led_cdev);

    return sprintf(buf, "%d\n", led->max_current);
}

static ssize_t show_current(struct device *dev,
                struct device_attribute *attr,
                char *buf)
{
    struct led_classdev *led_cdev = dev_get_drvdata(dev);
    struct lp5523_led *led = cdev_to_led(led_cdev);

    return sprintf(buf, "%d\n", led->led_current);
}

static ssize_t store_current(struct device *dev,
                 struct device_attribute *attr,
                 const char *buf, size_t len)
{
    struct led_classdev *led_cdev = dev_get_drvdata(dev);
    struct lp5523_led *led = cdev_to_led(led_cdev);
    struct lp5523_chip *chip = led_to_lp5523(led);
    ssize_t ret;
    unsigned long curr;

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

    if (curr > led->max_current)
        return -EINVAL;

    mutex_lock(&chip->lock);
    ret = lp5523_write(chip->client,
            LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
            (u8)curr);
    mutex_unlock(&chip->lock);

    if (ret < 0)
        return ret;

    led->led_current = (u8)curr;

    return len;
}

/* led class device attributes */
static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, show_current, store_current);
static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);

static struct attribute *lp5523_led_attributes[] = {
    &dev_attr_led_current.attr,
    &dev_attr_max_current.attr,
    NULL,
};

static struct attribute_group lp5523_led_attribute_group = {
    .attrs = lp5523_led_attributes
};

/* device attributes */
static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUSR,
           show_engine1_mode, store_engine1_mode);
static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUSR,
           show_engine2_mode, store_engine2_mode);
static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUSR,
           show_engine3_mode, store_engine3_mode);
static DEVICE_ATTR(engine1_leds, S_IRUGO | S_IWUSR,
           show_engine1_leds, store_engine1_leds);
static DEVICE_ATTR(engine2_leds, S_IRUGO | S_IWUSR,
           show_engine2_leds, store_engine2_leds);
static DEVICE_ATTR(engine3_leds, S_IRUGO | S_IWUSR,
           show_engine3_leds, store_engine3_leds);
static DEVICE_ATTR(engine1_load, S_IWUSR, NULL, store_engine1_load);
static DEVICE_ATTR(engine2_load, S_IWUSR, NULL, store_engine2_load);
static DEVICE_ATTR(engine3_load, S_IWUSR, NULL, store_engine3_load);
static DEVICE_ATTR(selftest, S_IRUGO, lp5523_selftest, NULL);

static struct attribute *lp5523_attributes[] = {
    &dev_attr_engine1_mode.attr,
    &dev_attr_engine2_mode.attr,
    &dev_attr_engine3_mode.attr,
    &dev_attr_selftest.attr,
    &dev_attr_engine1_load.attr,
    &dev_attr_engine1_leds.attr,
    &dev_attr_engine2_load.attr,
    &dev_attr_engine2_leds.attr,
    &dev_attr_engine3_load.attr,
    &dev_attr_engine3_leds.attr,
    NULL,
};

static const struct attribute_group lp5523_group = {
    .attrs = lp5523_attributes,
};

static int lp5523_register_sysfs(struct i2c_client *client)
{
    struct device *dev = &client->dev;
    int ret;

    ret = sysfs_create_group(&dev->kobj, &lp5523_group);
    if (ret < 0)
        return ret;

    return 0;
}

static void lp5523_unregister_sysfs(struct i2c_client *client)
{
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    struct device *dev = &client->dev;
    int i;

    sysfs_remove_group(&dev->kobj, &lp5523_group);

    for (i = 0; i < chip->num_leds; i++)
        sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
                &lp5523_led_attribute_group);
}

/*--------------------------------------------------------------*/
/*          Set chip operating mode         */
/*--------------------------------------------------------------*/
static void lp5523_set_mode(struct lp5523_engine *engine, u8 mode)
{
    /* if in that mode already do nothing, except for run */
    if (mode == engine->mode && mode != LP5523_CMD_RUN)
        return;

    switch (mode) {
    case LP5523_CMD_RUN:
        lp5523_run_program(engine);
        break;
    case LP5523_CMD_LOAD:
        lp5523_set_engine_mode(engine, LP5523_CMD_DISABLED);
        lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
        break;
    case LP5523_CMD_DISABLED:
        lp5523_set_engine_mode(engine, LP5523_CMD_DISABLED);
        break;
    default:
        return;
    }

    engine->mode = mode;
}

/*--------------------------------------------------------------*/
/*          Probe, Attach, Remove           */
/*--------------------------------------------------------------*/
static int __init lp5523_init_engine(struct lp5523_engine *engine, int id)
{
    if (id < 1 || id > LP5523_ENGINES)
        return -1;
    engine->id = id;
    engine->engine_mask = LP5523_ENG_MASK_BASE >> SHIFT_MASK(id);
    engine->prog_page = id - 1;
    engine->mux_page = id + 2;

    return 0;
}

static int __devinit lp5523_init_led(struct lp5523_led *led, struct device *dev,
               int chan, struct lp5523_platform_data *pdata,
               const char *chip_name)
{
    char name[32];
    int res;

    if (chan >= LP5523_LEDS)
        return -EINVAL;

    if (pdata->led_config[chan].led_current) {
        led->led_current = pdata->led_config[chan].led_current;
        led->max_current = pdata->led_config[chan].max_current;
        led->chan_nr = pdata->led_config[chan].chan_nr;

        if (led->chan_nr >= LP5523_LEDS) {
            dev_err(dev, "Use channel numbers between 0 and %d\n",
                LP5523_LEDS - 1);
            return -EINVAL;
        }

        if (pdata->led_config[chan].name) {
            led->cdev.name = pdata->led_config[chan].name;
        } else {
            snprintf(name, sizeof(name), "%s:channel%d",
                pdata->label ? : chip_name, chan);
            led->cdev.name = name;
        }

        led->cdev.brightness_set = lp5523_set_brightness;
        res = led_classdev_register(dev, &led->cdev);
        if (res < 0) {
            dev_err(dev, "couldn't register led on channel %d\n",
                chan);
            return res;
        }
        res = sysfs_create_group(&led->cdev.dev->kobj,
                &lp5523_led_attribute_group);
        if (res < 0) {
            dev_err(dev, "couldn't register current attribute\n");
            led_classdev_unregister(&led->cdev);
            return res;
        }
    } else {
        led->led_current = 0;
    }
    return 0;
}

static int __devinit lp5523_probe(struct i2c_client *client,
            const struct i2c_device_id *id)
{
    struct lp5523_chip      *chip;
    struct lp5523_platform_data *pdata;
    int ret, i, led;

    chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
    if (!chip)
        return -ENOMEM;

    i2c_set_clientdata(client, chip);
    chip->client = client;

    pdata = client->dev.platform_data;

    if (!pdata) {
        dev_err(&client->dev, "no platform data\n");
        return -EINVAL;
    }

    mutex_init(&chip->lock);

    chip->pdata   = pdata;

    if (pdata->setup_resources) {
        ret = pdata->setup_resources();
        if (ret < 0)
            return ret;
    }

    if (pdata->enable) {
        pdata->enable(0);
        usleep_range(1000, 2000); /* Keep enable down at least 1ms */
        pdata->enable(1);
        usleep_range(1000, 2000); /* 500us abs min. */
    }

    lp5523_write(client, LP5523_REG_RESET, 0xff);
    usleep_range(10000, 20000); /*
                     * Exact value is not available. 10 - 20ms
                     * appears to be enough for reset.
                     */
    ret = lp5523_detect(client);
    if (ret)
        goto fail1;

    dev_info(&client->dev, "%s Programmable led chip found\n", id->name);

    /* Initialize engines */
    for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
        ret = lp5523_init_engine(&chip->engines[i], i + 1);
        if (ret) {
            dev_err(&client->dev, "error initializing engine\n");
            goto fail1;
        }
    }
    ret = lp5523_configure(client);
    if (ret < 0) {
        dev_err(&client->dev, "error configuring chip\n");
        goto fail1;
    }

    /* Initialize leds */
    chip->num_channels = pdata->num_channels;
    chip->num_leds = 0;
    led = 0;
    for (i = 0; i < pdata->num_channels; i++) {
        /* Do not initialize channels that are not connected */
        if (pdata->led_config[i].led_current == 0)
            continue;

        INIT_WORK(&chip->leds[led].brightness_work,
            lp5523_led_brightness_work);

        ret = lp5523_init_led(&chip->leds[led], &client->dev, i, pdata,
                id->name);
        if (ret) {
            dev_err(&client->dev, "error initializing leds\n");
            goto fail2;
        }
        chip->num_leds++;

        chip->leds[led].id = led;
        /* Set LED current */
        lp5523_write(client,
              LP5523_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
              chip->leds[led].led_current);

        led++;
    }

    ret = lp5523_register_sysfs(client);
    if (ret) {
        dev_err(&client->dev, "registering sysfs failed\n");
        goto fail2;
    }
    return ret;
fail2:
    for (i = 0; i < chip->num_leds; i++) {
        led_classdev_unregister(&chip->leds[i].cdev);
        flush_work(&chip->leds[i].brightness_work);
    }
fail1:
    if (pdata->enable)
        pdata->enable(0);
    if (pdata->release_resources)
        pdata->release_resources();
    return ret;
}

static int lp5523_remove(struct i2c_client *client)
{
    struct lp5523_chip *chip = i2c_get_clientdata(client);
    int i;

    /* Disable engine mode */
    lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_DISABLED);

    lp5523_unregister_sysfs(client);

    for (i = 0; i < chip->num_leds; i++) {
        led_classdev_unregister(&chip->leds[i].cdev);
        flush_work(&chip->leds[i].brightness_work);
    }

    if (chip->pdata->enable)
        chip->pdata->enable(0);
    if (chip->pdata->release_resources)
        chip->pdata->release_resources();
    return 0;
}

static const struct i2c_device_id lp5523_id[] = {
    { "lp5523",  LP5523 },
    { "lp55231", LP55231 },
    { }
};

MODULE_DEVICE_TABLE(i2c, lp5523_id);

static struct i2c_driver lp5523_driver = {
    .driver = {
        .name   = "lp5523x",
    },
    .probe      = lp5523_probe,
    .remove     = lp5523_remove,
    .id_table   = lp5523_id,
};

module_i2c_driver(lp5523_driver);

MODULE_AUTHOR("Mathias Nyman <[email protected]>");
MODULE_DESCRIPTION("LP5523 LED engine");
MODULE_LICENSE("GPL");