lm3630_bl.c

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/*
* Simple driver for Texas Instruments LM3630 Backlight driver chip
* Copyright (C) 2012 Texas Instruments
*
* 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.
*
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/platform_data/lm3630_bl.h>

#define REG_CTRL    0x00
#define REG_CONFIG  0x01
#define REG_BRT_A   0x03
#define REG_BRT_B   0x04
#define REG_INT_STATUS  0x09
#define REG_INT_EN  0x0A
#define REG_FAULT   0x0B
#define REG_PWM_OUTLOW  0x12
#define REG_PWM_OUTHIGH 0x13
#define REG_MAX     0x1F

#define INT_DEBOUNCE_MSEC   10

enum lm3630_leds {
    BLED_ALL = 0,
    BLED_1,
    BLED_2
};

static const char *bled_name[] = {
    [BLED_ALL] = "lm3630_bled", /*Bank1 controls all string */
    [BLED_1] = "lm3630_bled1",  /*Bank1 controls bled1 */
    [BLED_2] = "lm3630_bled2",  /*Bank1 or 2 controls bled2 */
};

struct lm3630_chip_data {
    struct device *dev;
    struct delayed_work work;
    int irq;
    struct workqueue_struct *irqthread;
    struct lm3630_platform_data *pdata;
    struct backlight_device *bled1;
    struct backlight_device *bled2;
    struct regmap *regmap;
};

/* initialize chip */
static int __devinit lm3630_chip_init(struct lm3630_chip_data *pchip)
{
    int ret;
    unsigned int reg_val;
    struct lm3630_platform_data *pdata = pchip->pdata;

    /*pwm control */
    reg_val = ((pdata->pwm_active & 0x01) << 2) | (pdata->pwm_ctrl & 0x03);
    ret = regmap_update_bits(pchip->regmap, REG_CONFIG, 0x07, reg_val);
    if (ret < 0)
        goto out;

    /* bank control */
    reg_val = ((pdata->bank_b_ctrl & 0x01) << 1) |
            (pdata->bank_a_ctrl & 0x07);
    ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x07, reg_val);
    if (ret < 0)
        goto out;

    ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
    if (ret < 0)
        goto out;

    /* set initial brightness */
    if (pdata->bank_a_ctrl != BANK_A_CTRL_DISABLE) {
        ret = regmap_write(pchip->regmap,
                   REG_BRT_A, pdata->init_brt_led1);
        if (ret < 0)
            goto out;
    }

    if (pdata->bank_b_ctrl != BANK_B_CTRL_DISABLE) {
        ret = regmap_write(pchip->regmap,
                   REG_BRT_B, pdata->init_brt_led2);
        if (ret < 0)
            goto out;
    }
    return ret;

out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return ret;
}

/* interrupt handling */
static void lm3630_delayed_func(struct work_struct *work)
{
    int ret;
    unsigned int reg_val;
    struct lm3630_chip_data *pchip;

    pchip = container_of(work, struct lm3630_chip_data, work.work);

    ret = regmap_read(pchip->regmap, REG_INT_STATUS, &reg_val);
    if (ret < 0) {
        dev_err(pchip->dev,
            "i2c failed to access REG_INT_STATUS Register\n");
        return;
    }

    dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", reg_val);
}

static irqreturn_t lm3630_isr_func(int irq, void *chip)
{
    int ret;
    struct lm3630_chip_data *pchip = chip;
    unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);

    queue_delayed_work(pchip->irqthread, &pchip->work, delay);

    ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
    if (ret < 0)
        goto out;

    return IRQ_HANDLED;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return IRQ_HANDLED;
}

static int lm3630_intr_config(struct lm3630_chip_data *pchip)
{
    INIT_DELAYED_WORK(&pchip->work, lm3630_delayed_func);
    pchip->irqthread = create_singlethread_workqueue("lm3630-irqthd");
    if (!pchip->irqthread) {
        dev_err(pchip->dev, "create irq thread fail...\n");
        return -1;
    }
    if (request_threaded_irq
        (pchip->irq, NULL, lm3630_isr_func,
         IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630_irq", pchip)) {
        dev_err(pchip->dev, "request threaded irq fail..\n");
        return -1;
    }
    return 0;
}

static bool
set_intensity(struct backlight_device *bl, struct lm3630_chip_data *pchip)
{
    if (!pchip->pdata->pwm_set_intensity)
        return false;
    pchip->pdata->pwm_set_intensity(bl->props.brightness - 1,
                    pchip->pdata->pwm_period);
    return true;
}

/* update and get brightness */
static int lm3630_bank_a_update_status(struct backlight_device *bl)
{
    int ret;
    struct lm3630_chip_data *pchip = bl_get_data(bl);
    enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

    /* brightness 0 means disable */
    if (!bl->props.brightness) {
        ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x04, 0x00);
        if (ret < 0)
            goto out;
        return bl->props.brightness;
    }

    /* pwm control */
    if (pwm_ctrl == PWM_CTRL_BANK_A || pwm_ctrl == PWM_CTRL_BANK_ALL) {
        if (!set_intensity(bl, pchip))
            dev_err(pchip->dev, "No pwm control func. in plat-data\n");
    } else {

        /* i2c control */
        ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
        if (ret < 0)
            goto out;
        mdelay(1);
        ret = regmap_write(pchip->regmap,
                   REG_BRT_A, bl->props.brightness - 1);
        if (ret < 0)
            goto out;
    }
    return bl->props.brightness;
out:
    dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
    return bl->props.brightness;
}

static int lm3630_bank_a_get_brightness(struct backlight_device *bl)
{
    unsigned int reg_val;
    int brightness, ret;
    struct lm3630_chip_data *pchip = bl_get_data(bl);
    enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

    if (pwm_ctrl == PWM_CTRL_BANK_A || pwm_ctrl == PWM_CTRL_BANK_ALL) {
        ret = regmap_read(pchip->regmap, REG_PWM_OUTHIGH, &reg_val);
        if (ret < 0)
            goto out;
        brightness = reg_val & 0x01;
        ret = regmap_read(pchip->regmap, REG_PWM_OUTLOW, &reg_val);
        if (ret < 0)
            goto out;
        brightness = ((brightness << 8) | reg_val) + 1;
    } else {
        ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
        if (ret < 0)
            goto out;
        mdelay(1);
        ret = regmap_read(pchip->regmap, REG_BRT_A, &reg_val);
        if (ret < 0)
            goto out;
        brightness = reg_val + 1;
    }
    bl->props.brightness = brightness;
    return bl->props.brightness;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return 0;
}

static const struct backlight_ops lm3630_bank_a_ops = {
    .options = BL_CORE_SUSPENDRESUME,
    .update_status = lm3630_bank_a_update_status,
    .get_brightness = lm3630_bank_a_get_brightness,
};

static int lm3630_bank_b_update_status(struct backlight_device *bl)
{
    int ret;
    struct lm3630_chip_data *pchip = bl_get_data(bl);
    enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

    if (pwm_ctrl == PWM_CTRL_BANK_B || pwm_ctrl == PWM_CTRL_BANK_ALL) {
        if (!set_intensity(bl, pchip))
            dev_err(pchip->dev,
                "no pwm control func. in plat-data\n");
    } else {
        ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
        if (ret < 0)
            goto out;
        mdelay(1);
        ret = regmap_write(pchip->regmap,
                   REG_BRT_B, bl->props.brightness - 1);
    }
    return bl->props.brightness;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return bl->props.brightness;
}

static int lm3630_bank_b_get_brightness(struct backlight_device *bl)
{
    unsigned int reg_val;
    int brightness, ret;
    struct lm3630_chip_data *pchip = bl_get_data(bl);
    enum lm3630_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

    if (pwm_ctrl == PWM_CTRL_BANK_B || pwm_ctrl == PWM_CTRL_BANK_ALL) {
        ret = regmap_read(pchip->regmap, REG_PWM_OUTHIGH, &reg_val);
        if (ret < 0)
            goto out;
        brightness = reg_val & 0x01;
        ret = regmap_read(pchip->regmap, REG_PWM_OUTLOW, &reg_val);
        if (ret < 0)
            goto out;
        brightness = ((brightness << 8) | reg_val) + 1;
    } else {
        ret = regmap_update_bits(pchip->regmap, REG_CTRL, 0x80, 0x00);
        if (ret < 0)
            goto out;
        mdelay(1);
        ret = regmap_read(pchip->regmap, REG_BRT_B, &reg_val);
        if (ret < 0)
            goto out;
        brightness = reg_val + 1;
    }
    bl->props.brightness = brightness;

    return bl->props.brightness;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return bl->props.brightness;
}

static const struct backlight_ops lm3630_bank_b_ops = {
    .options = BL_CORE_SUSPENDRESUME,
    .update_status = lm3630_bank_b_update_status,
    .get_brightness = lm3630_bank_b_get_brightness,
};

static int lm3630_backlight_register(struct lm3630_chip_data *pchip,
                     enum lm3630_leds ledno)
{
    const char *name = bled_name[ledno];
    struct backlight_properties props;
    struct lm3630_platform_data *pdata = pchip->pdata;

    props.type = BACKLIGHT_RAW;
    switch (ledno) {
    case BLED_1:
    case BLED_ALL:
        props.brightness = pdata->init_brt_led1;
        props.max_brightness = pdata->max_brt_led1;
        pchip->bled1 =
            backlight_device_register(name, pchip->dev, pchip,
                          &lm3630_bank_a_ops, &props);
        if (IS_ERR(pchip->bled1))
            return -EIO;
        break;
    case BLED_2:
        props.brightness = pdata->init_brt_led2;
        props.max_brightness = pdata->max_brt_led2;
        pchip->bled2 =
            backlight_device_register(name, pchip->dev, pchip,
                          &lm3630_bank_b_ops, &props);
        if (IS_ERR(pchip->bled2))
            return -EIO;
        break;
    }
    return 0;
}

static void lm3630_backlight_unregister(struct lm3630_chip_data *pchip)
{
    if (pchip->bled1)
        backlight_device_unregister(pchip->bled1);
    if (pchip->bled2)
        backlight_device_unregister(pchip->bled2);
}

static const struct regmap_config lm3630_regmap = {
    .reg_bits = 8,
    .val_bits = 8,
    .max_register = REG_MAX,
};

static int __devinit lm3630_probe(struct i2c_client *client,
                  const struct i2c_device_id *id)
{
    struct lm3630_platform_data *pdata = client->dev.platform_data;
    struct lm3630_chip_data *pchip;
    int ret;

    if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
        dev_err(&client->dev, "fail : i2c functionality check...\n");
        return -EOPNOTSUPP;
    }

    if (pdata == NULL) {
        dev_err(&client->dev, "fail : no platform data.\n");
        return -ENODATA;
    }

    pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630_chip_data),
                 GFP_KERNEL);
    if (!pchip)
        return -ENOMEM;
    pchip->pdata = pdata;
    pchip->dev = &client->dev;

    pchip->regmap = devm_regmap_init_i2c(client, &lm3630_regmap);
    if (IS_ERR(pchip->regmap)) {
        ret = PTR_ERR(pchip->regmap);
        dev_err(&client->dev, "fail : allocate register map: %d\n",
            ret);
        return ret;
    }
    i2c_set_clientdata(client, pchip);

    /* chip initialize */
    ret = lm3630_chip_init(pchip);
    if (ret < 0) {
        dev_err(&client->dev, "fail : init chip\n");
        goto err_chip_init;
    }

    switch (pdata->bank_a_ctrl) {
    case BANK_A_CTRL_ALL:
        ret = lm3630_backlight_register(pchip, BLED_ALL);
        pdata->bank_b_ctrl = BANK_B_CTRL_DISABLE;
        break;
    case BANK_A_CTRL_LED1:
        ret = lm3630_backlight_register(pchip, BLED_1);
        break;
    case BANK_A_CTRL_LED2:
        ret = lm3630_backlight_register(pchip, BLED_2);
        pdata->bank_b_ctrl = BANK_B_CTRL_DISABLE;
        break;
    default:
        break;
    }

    if (ret < 0)
        goto err_bl_reg;

    if (pdata->bank_b_ctrl && pchip->bled2 == NULL) {
        ret = lm3630_backlight_register(pchip, BLED_2);
        if (ret < 0)
            goto err_bl_reg;
    }

    /* interrupt enable  : irq 0 is not allowed for lm3630 */
    pchip->irq = client->irq;
    if (pchip->irq)
        lm3630_intr_config(pchip);

    dev_info(&client->dev, "LM3630 backlight register OK.\n");
    return 0;

err_bl_reg:
    dev_err(&client->dev, "fail : backlight register.\n");
    lm3630_backlight_unregister(pchip);
err_chip_init:
    return ret;
}

static int __devexit lm3630_remove(struct i2c_client *client)
{
    int ret;
    struct lm3630_chip_data *pchip = i2c_get_clientdata(client);

    ret = regmap_write(pchip->regmap, REG_BRT_A, 0);
    if (ret < 0)
        dev_err(pchip->dev, "i2c failed to access register\n");

    ret = regmap_write(pchip->regmap, REG_BRT_B, 0);
    if (ret < 0)
        dev_err(pchip->dev, "i2c failed to access register\n");

    lm3630_backlight_unregister(pchip);
    if (pchip->irq) {
        free_irq(pchip->irq, pchip);
        flush_workqueue(pchip->irqthread);
        destroy_workqueue(pchip->irqthread);
    }
    return 0;
}

static const struct i2c_device_id lm3630_id[] = {
    {LM3630_NAME, 0},
    {}
};

MODULE_DEVICE_TABLE(i2c, lm3630_id);

static struct i2c_driver lm3630_i2c_driver = {
    .driver = {
           .name = LM3630_NAME,
           },
    .probe = lm3630_probe,
    .remove = __devexit_p(lm3630_remove),
    .id_table = lm3630_id,
};

module_i2c_driver(lm3630_i2c_driver);

MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630");
MODULE_AUTHOR("G.Shark Jeong <[email protected]>");
MODULE_AUTHOR("Daniel Jeong <[email protected]>");
MODULE_LICENSE("GPL v2");