kernel/drivers/video/backlight/da9052_bl.c

   1 /*
   2  * Backlight 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
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  */
  14
  15 #include <linux/backlight.h>
  16 #include <linux/delay.h>
  17 #include <linux/fb.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20
  21 #include <linux/mfd/da9052/da9052.h>
  22 #include <linux/mfd/da9052/reg.h>
  23
  24 #define DA9052_MAX_BRIGHTNESS           0xFF
  25
  26 enum {
  27         DA9052_WLEDS_OFF,
  28         DA9052_WLEDS_ON,
  29 };
  30
  31 enum {
  32         DA9052_TYPE_WLED1,
  33         DA9052_TYPE_WLED2,
  34         DA9052_TYPE_WLED3,
  35 };
  36
  37 static const unsigned char wled_bank[] = {
  38         DA9052_LED1_CONF_REG,
  39         DA9052_LED2_CONF_REG,
  40         DA9052_LED3_CONF_REG,
  41 };
  42
  43 struct da9052_bl {
  44         struct da9052 *da9052;
  45         uint brightness;
  46         uint state;
  47         uint led_reg;
  48 };
  49
  50 static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
  51 {
  52         unsigned char boost_en;
  53         unsigned char i_sink;
  54         int ret;
  55
  56         boost_en = 0x3F;
  57         i_sink = 0xFF;
  58         if (wleds->state == DA9052_WLEDS_OFF) {
  59                 boost_en = 0x00;
  60                 i_sink = 0x00;
  61         }
  62
  63         ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
  64         if (ret < 0)
  65                 return ret;
  66
  67         ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
  68         if (ret < 0)
  69                 return ret;
  70
  71         ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
  72         if (ret < 0)
  73                 return ret;
  74
  75         usleep_range(10000, 11000);
  76
  77         if (wleds->brightness) {
  78                 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
  79                                        wleds->brightness);
  80                 if (ret < 0)
  81                         return ret;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static int da9052_backlight_update_status(struct backlight_device *bl)
  88 {
  89         int brightness = bl->props.brightness;
  90         struct da9052_bl *wleds = bl_get_data(bl);
  91
  92         wleds->brightness = brightness;
  93         wleds->state = DA9052_WLEDS_ON;
  94
  95         return da9052_adjust_wled_brightness(wleds);
  96 }
  97
  98 static int da9052_backlight_get_brightness(struct backlight_device *bl)
  99 {
 100         struct da9052_bl *wleds = bl_get_data(bl);
 101
 102         return wleds->brightness;
 103 }
 104
 105 static const struct backlight_ops da9052_backlight_ops = {
 106         .update_status = da9052_backlight_update_status,
 107         .get_brightness = da9052_backlight_get_brightness,
 108 };
 109
 110 static int da9052_backlight_probe(struct platform_device *pdev)
 111 {
 112         struct backlight_device *bl;
 113         struct backlight_properties props;
 114         struct da9052_bl *wleds;
 115
 116         wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
 117         if (!wleds)
 118                 return -ENOMEM;
 119
 120         wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
 121         wleds->brightness = 0;
 122         wleds->led_reg = platform_get_device_id(pdev)->driver_data;
 123         wleds->state = DA9052_WLEDS_OFF;
 124
 125         props.type = BACKLIGHT_RAW;
 126         props.max_brightness = DA9052_MAX_BRIGHTNESS;
 127
 128         bl = devm_backlight_device_register(&pdev->dev, pdev->name,
 129                                         wleds->da9052->dev, wleds,
 130                                         &da9052_backlight_ops, &props);
 131         if (IS_ERR(bl)) {
 132                 dev_err(&pdev->dev, "Failed to register backlight\n");
 133                 return PTR_ERR(bl);
 134         }
 135
 136         bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
 137         bl->props.brightness = 0;
 138         platform_set_drvdata(pdev, bl);
 139
 140         return da9052_adjust_wled_brightness(wleds);
 141 }
 142
 143 static int da9052_backlight_remove(struct platform_device *pdev)
 144 {
 145         struct backlight_device *bl = platform_get_drvdata(pdev);
 146         struct da9052_bl *wleds = bl_get_data(bl);
 147
 148         wleds->brightness = 0;
 149         wleds->state = DA9052_WLEDS_OFF;
 150         da9052_adjust_wled_brightness(wleds);
 151
 152         return 0;
 153 }
 154
 155 static struct platform_device_id da9052_wled_ids[] = {
 156         {
 157                 .name           = "da9052-wled1",
 158                 .driver_data    = DA9052_TYPE_WLED1,
 159         },
 160         {
 161                 .name           = "da9052-wled2",
 162                 .driver_data    = DA9052_TYPE_WLED2,
 163         },
 164         {
 165                 .name           = "da9052-wled3",
 166                 .driver_data    = DA9052_TYPE_WLED3,
 167         },
 168         { },
 169 };
 170
 171 static struct platform_driver da9052_wled_driver = {
 172         .probe          = da9052_backlight_probe,
 173         .remove         = da9052_backlight_remove,
 174         .id_table       = da9052_wled_ids,
 175         .driver = {
 176                 .name   = "da9052-wled",
 177         },
 178 };
 179
 180 module_platform_driver(da9052_wled_driver);
 181
 182 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 183 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
 184 MODULE_LICENSE("GPL");
 185 MODULE_ALIAS("platform:da9052-backlight");