leds-da9052.c

Go to the documentation of this file.

/*
 * LED Driver for Dialog DA9052 PMICs.
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: David Dajun Chen <[email protected]>
 *
 *  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.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/workqueue.h>
#include <linux/slab.h>

#include <linux/mfd/da9052/reg.h>
#include <linux/mfd/da9052/da9052.h>
#include <linux/mfd/da9052/pdata.h>

#define DA9052_OPENDRAIN_OUTPUT 2
#define DA9052_SET_HIGH_LVL_OUTPUT  (1 << 3)
#define DA9052_MASK_UPPER_NIBBLE    0xF0
#define DA9052_MASK_LOWER_NIBBLE    0x0F
#define DA9052_NIBBLE_SHIFT     4
#define DA9052_MAX_BRIGHTNESS       0x5f

struct da9052_led {
    struct led_classdev cdev;
    struct work_struct work;
    struct da9052 *da9052;
    unsigned char led_index;
    unsigned char id;
    int brightness;
};

static unsigned char led_reg[] = {
    DA9052_LED_CONT_4_REG,
    DA9052_LED_CONT_5_REG,
};

static int da9052_set_led_brightness(struct da9052_led *led)
{
    u8 val;
    int error;

    val = (led->brightness & 0x7f) | DA9052_LED_CONT_DIM;

    error = da9052_reg_write(led->da9052, led_reg[led->led_index], val);
    if (error < 0)
        dev_err(led->da9052->dev, "Failed to set led brightness, %d\n",
            error);
    return error;
}

static void da9052_led_work(struct work_struct *work)
{
    struct da9052_led *led = container_of(work, struct da9052_led, work);

    da9052_set_led_brightness(led);
}

static void da9052_led_set(struct led_classdev *led_cdev,
               enum led_brightness value)
{
    struct da9052_led *led;

    led = container_of(led_cdev, struct da9052_led, cdev);
    led->brightness = value;
    schedule_work(&led->work);
}

static int da9052_configure_leds(struct da9052 *da9052)
{
    int error;
    unsigned char register_value = DA9052_OPENDRAIN_OUTPUT
                       | DA9052_SET_HIGH_LVL_OUTPUT;

    error = da9052_reg_update(da9052, DA9052_GPIO_14_15_REG,
                  DA9052_MASK_LOWER_NIBBLE,
                  register_value);

    if (error < 0) {
        dev_err(da9052->dev, "Failed to write GPIO 14-15 reg, %d\n",
            error);
        return error;
    }

    error = da9052_reg_update(da9052, DA9052_GPIO_14_15_REG,
                  DA9052_MASK_UPPER_NIBBLE,
                  register_value << DA9052_NIBBLE_SHIFT);
    if (error < 0)
        dev_err(da9052->dev, "Failed to write GPIO 14-15 reg, %d\n",
            error);

    return error;
}

static int __devinit da9052_led_probe(struct platform_device *pdev)
{
    struct da9052_pdata *pdata;
    struct da9052 *da9052;
    struct led_platform_data *pled;
    struct da9052_led *led = NULL;
    int error = -ENODEV;
    int i;

    da9052 = dev_get_drvdata(pdev->dev.parent);
    pdata = da9052->dev->platform_data;
    if (pdata == NULL) {
        dev_err(&pdev->dev, "No platform data\n");
        goto err;
    }

    pled = pdata->pled;
    if (pled == NULL) {
        dev_err(&pdev->dev, "No platform data for LED\n");
        goto err;
    }

    led = devm_kzalloc(&pdev->dev,
               sizeof(struct da9052_led) * pled->num_leds,
               GFP_KERNEL);
    if (led == NULL) {
        dev_err(&pdev->dev, "Failed to alloc memory\n");
        error = -ENOMEM;
        goto err;
    }

    for (i = 0; i < pled->num_leds; i++) {
        led[i].cdev.name = pled->leds[i].name;
        led[i].cdev.brightness_set = da9052_led_set;
        led[i].cdev.brightness = LED_OFF;
        led[i].cdev.max_brightness = DA9052_MAX_BRIGHTNESS;
        led[i].brightness = LED_OFF;
        led[i].led_index = pled->leds[i].flags;
        led[i].da9052 = dev_get_drvdata(pdev->dev.parent);
        INIT_WORK(&led[i].work, da9052_led_work);

        error = led_classdev_register(pdev->dev.parent, &led[i].cdev);
        if (error) {
            dev_err(&pdev->dev, "Failed to register led %d\n",
                led[i].led_index);
            goto err_register;
        }

        error = da9052_set_led_brightness(&led[i]);
        if (error) {
            dev_err(&pdev->dev, "Unable to init led %d\n",
                led[i].led_index);
            continue;
        }
    }
    error = da9052_configure_leds(led->da9052);
    if (error) {
        dev_err(&pdev->dev, "Failed to configure GPIO LED%d\n", error);
        goto err_register;
    }

    platform_set_drvdata(pdev, led);

    return 0;

err_register:
    for (i = i - 1; i >= 0; i--) {
        led_classdev_unregister(&led[i].cdev);
        cancel_work_sync(&led[i].work);
    }
err:
    return error;
}

static int __devexit da9052_led_remove(struct platform_device *pdev)
{
    struct da9052_led *led = platform_get_drvdata(pdev);
    struct da9052_pdata *pdata;
    struct da9052 *da9052;
    struct led_platform_data *pled;
    int i;

    da9052 = dev_get_drvdata(pdev->dev.parent);
    pdata = da9052->dev->platform_data;
    pled = pdata->pled;

    for (i = 0; i < pled->num_leds; i++) {
        led[i].brightness = 0;
        da9052_set_led_brightness(&led[i]);
        led_classdev_unregister(&led[i].cdev);
        cancel_work_sync(&led[i].work);
    }

    return 0;
}

static struct platform_driver da9052_led_driver = {
    .driver     = {
        .name   = "da9052-leds",
        .owner  = THIS_MODULE,
    },
    .probe      = da9052_led_probe,
    .remove     = __devexit_p(da9052_led_remove),
};

module_platform_driver(da9052_led_driver);

MODULE_AUTHOR("Dialog Semiconductor Ltd <[email protected]>");
MODULE_DESCRIPTION("LED driver for Dialog DA9052 PMIC");
MODULE_LICENSE("GPL");