linux/drivers/leds/leds-da9052.c
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   1/*
   2 * LED Driver for Dialog DA9052 PMICs.
   3 *
   4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
   5 *
   6 * Author: David Dajun Chen <dchen@diasemi.com>
   7 *
   8 *  This program is free software; you can redistribute  it and/or modify it
   9 *  under  the terms of  the GNU General  Public License as published by the
  10 *  Free Software Foundation;  either version 2 of the  License, or (at your
  11 *  option) any later version.
  12 *
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/kernel.h>
  17#include <linux/init.h>
  18#include <linux/platform_device.h>
  19#include <linux/leds.h>
  20#include <linux/workqueue.h>
  21#include <linux/slab.h>
  22
  23#include <linux/mfd/da9052/reg.h>
  24#include <linux/mfd/da9052/da9052.h>
  25#include <linux/mfd/da9052/pdata.h>
  26
  27#define DA9052_OPENDRAIN_OUTPUT 2
  28#define DA9052_SET_HIGH_LVL_OUTPUT      (1 << 3)
  29#define DA9052_MASK_UPPER_NIBBLE        0xF0
  30#define DA9052_MASK_LOWER_NIBBLE        0x0F
  31#define DA9052_NIBBLE_SHIFT             4
  32#define DA9052_MAX_BRIGHTNESS           0x5f
  33
  34struct da9052_led {
  35        struct led_classdev cdev;
  36        struct work_struct work;
  37        struct da9052 *da9052;
  38        unsigned char led_index;
  39        unsigned char id;
  40        int brightness;
  41};
  42
  43static unsigned char led_reg[] = {
  44        DA9052_LED_CONT_4_REG,
  45        DA9052_LED_CONT_5_REG,
  46};
  47
  48static int da9052_set_led_brightness(struct da9052_led *led)
  49{
  50        u8 val;
  51        int error;
  52
  53        val = (led->brightness & 0x7f) | DA9052_LED_CONT_DIM;
  54
  55        error = da9052_reg_write(led->da9052, led_reg[led->led_index], val);
  56        if (error < 0)
  57                dev_err(led->da9052->dev, "Failed to set led brightness, %d\n",
  58                        error);
  59        return error;
  60}
  61
  62static void da9052_led_work(struct work_struct *work)
  63{
  64        struct da9052_led *led = container_of(work, struct da9052_led, work);
  65
  66        da9052_set_led_brightness(led);
  67}
  68
  69static void da9052_led_set(struct led_classdev *led_cdev,
  70                           enum led_brightness value)
  71{
  72        struct da9052_led *led;
  73
  74        led = container_of(led_cdev, struct da9052_led, cdev);
  75        led->brightness = value;
  76        schedule_work(&led->work);
  77}
  78
  79static int da9052_configure_leds(struct da9052 *da9052)
  80{
  81        int error;
  82        unsigned char register_value = DA9052_OPENDRAIN_OUTPUT
  83                                       | DA9052_SET_HIGH_LVL_OUTPUT;
  84
  85        error = da9052_reg_update(da9052, DA9052_GPIO_14_15_REG,
  86                                  DA9052_MASK_LOWER_NIBBLE,
  87                                  register_value);
  88
  89        if (error < 0) {
  90                dev_err(da9052->dev, "Failed to write GPIO 14-15 reg, %d\n",
  91                        error);
  92                return error;
  93        }
  94
  95        error = da9052_reg_update(da9052, DA9052_GPIO_14_15_REG,
  96                                  DA9052_MASK_UPPER_NIBBLE,
  97                                  register_value << DA9052_NIBBLE_SHIFT);
  98        if (error < 0)
  99                dev_err(da9052->dev, "Failed to write GPIO 14-15 reg, %d\n",
 100                        error);
 101
 102        return error;
 103}
 104
 105static int da9052_led_probe(struct platform_device *pdev)
 106{
 107        struct da9052_pdata *pdata;
 108        struct da9052 *da9052;
 109        struct led_platform_data *pled;
 110        struct da9052_led *led = NULL;
 111        int error = -ENODEV;
 112        int i;
 113
 114        da9052 = dev_get_drvdata(pdev->dev.parent);
 115        pdata = da9052->dev->platform_data;
 116        if (pdata == NULL) {
 117                dev_err(&pdev->dev, "No platform data\n");
 118                goto err;
 119        }
 120
 121        pled = pdata->pled;
 122        if (pled == NULL) {
 123                dev_err(&pdev->dev, "No platform data for LED\n");
 124                goto err;
 125        }
 126
 127        led = devm_kzalloc(&pdev->dev,
 128                           sizeof(struct da9052_led) * pled->num_leds,
 129                           GFP_KERNEL);
 130        if (led == NULL) {
 131                dev_err(&pdev->dev, "Failed to alloc memory\n");
 132                error = -ENOMEM;
 133                goto err;
 134        }
 135
 136        for (i = 0; i < pled->num_leds; i++) {
 137                led[i].cdev.name = pled->leds[i].name;
 138                led[i].cdev.brightness_set = da9052_led_set;
 139                led[i].cdev.brightness = LED_OFF;
 140                led[i].cdev.max_brightness = DA9052_MAX_BRIGHTNESS;
 141                led[i].brightness = LED_OFF;
 142                led[i].led_index = pled->leds[i].flags;
 143                led[i].da9052 = dev_get_drvdata(pdev->dev.parent);
 144                INIT_WORK(&led[i].work, da9052_led_work);
 145
 146                error = led_classdev_register(pdev->dev.parent, &led[i].cdev);
 147                if (error) {
 148                        dev_err(&pdev->dev, "Failed to register led %d\n",
 149                                led[i].led_index);
 150                        goto err_register;
 151                }
 152
 153                error = da9052_set_led_brightness(&led[i]);
 154                if (error) {
 155                        dev_err(&pdev->dev, "Unable to init led %d\n",
 156                                led[i].led_index);
 157                        continue;
 158                }
 159        }
 160        error = da9052_configure_leds(led->da9052);
 161        if (error) {
 162                dev_err(&pdev->dev, "Failed to configure GPIO LED%d\n", error);
 163                goto err_register;
 164        }
 165
 166        platform_set_drvdata(pdev, led);
 167
 168        return 0;
 169
 170err_register:
 171        for (i = i - 1; i >= 0; i--) {
 172                led_classdev_unregister(&led[i].cdev);
 173                cancel_work_sync(&led[i].work);
 174        }
 175err:
 176        return error;
 177}
 178
 179static int da9052_led_remove(struct platform_device *pdev)
 180{
 181        struct da9052_led *led = platform_get_drvdata(pdev);
 182        struct da9052_pdata *pdata;
 183        struct da9052 *da9052;
 184        struct led_platform_data *pled;
 185        int i;
 186
 187        da9052 = dev_get_drvdata(pdev->dev.parent);
 188        pdata = da9052->dev->platform_data;
 189        pled = pdata->pled;
 190
 191        for (i = 0; i < pled->num_leds; i++) {
 192                led[i].brightness = 0;
 193                da9052_set_led_brightness(&led[i]);
 194                led_classdev_unregister(&led[i].cdev);
 195                cancel_work_sync(&led[i].work);
 196        }
 197
 198        return 0;
 199}
 200
 201static struct platform_driver da9052_led_driver = {
 202        .driver         = {
 203                .name   = "da9052-leds",
 204                .owner  = THIS_MODULE,
 205        },
 206        .probe          = da9052_led_probe,
 207        .remove         = da9052_led_remove,
 208};
 209
 210module_platform_driver(da9052_led_driver);
 211
 212MODULE_AUTHOR("Dialog Semiconductor Ltd <dchen@diasemi.com>");
 213MODULE_DESCRIPTION("LED driver for Dialog DA9052 PMIC");
 214MODULE_LICENSE("GPL");
 215
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