kernel/drivers/leds/leds-da9052.c

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