drivers/video/backlight/da9052_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Backlight Driver for Dialog DA9052 PMICs
   4  *
   5  * Copyright(c) 2012 Dialog Semiconductor Ltd.
   6  *
   7  * Author: David Dajun Chen <dchen@diasemi.com>
   8  */
   9
  10 #include <linux/backlight.h>
  11 #include <linux/delay.h>
  12 #include <linux/fb.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15
  16 #include <linux/mfd/da9052/da9052.h>
  17 #include <linux/mfd/da9052/reg.h>
  18
  19 #define DA9052_MAX_BRIGHTNESS           0xFF
  20
  21 enum {
  22         DA9052_WLEDS_OFF,
  23         DA9052_WLEDS_ON,
  24 };
  25
  26 enum {
  27         DA9052_TYPE_WLED1,
  28         DA9052_TYPE_WLED2,
  29         DA9052_TYPE_WLED3,
  30 };
  31
  32 static const unsigned char wled_bank[] = {
  33         DA9052_LED1_CONF_REG,
  34         DA9052_LED2_CONF_REG,
  35         DA9052_LED3_CONF_REG,
  36 };
  37
  38 struct da9052_bl {
  39         struct da9052 *da9052;
  40         uint brightness;
  41         uint state;
  42         uint led_reg;
  43 };
  44
  45 static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
  46 {
  47         unsigned char boost_en;
  48         unsigned char i_sink;
  49         int ret;
  50
  51         boost_en = 0x3F;
  52         i_sink = 0xFF;
  53         if (wleds->state == DA9052_WLEDS_OFF) {
  54                 boost_en = 0x00;
  55                 i_sink = 0x00;
  56         }
  57
  58         ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
  59         if (ret < 0)
  60                 return ret;
  61
  62         ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
  63         if (ret < 0)
  64                 return ret;
  65
  66         ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
  67         if (ret < 0)
  68                 return ret;
  69
  70         usleep_range(10000, 11000);
  71
  72         if (wleds->brightness) {
  73                 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
  74                                        wleds->brightness);
  75                 if (ret < 0)
  76                         return ret;
  77         }
  78
  79         return 0;
  80 }
  81
  82 static int da9052_backlight_update_status(struct backlight_device *bl)
  83 {
  84         int brightness = bl->props.brightness;
  85         struct da9052_bl *wleds = bl_get_data(bl);
  86
  87         wleds->brightness = brightness;
  88         wleds->state = DA9052_WLEDS_ON;
  89
  90         return da9052_adjust_wled_brightness(wleds);
  91 }
  92
  93 static int da9052_backlight_get_brightness(struct backlight_device *bl)
  94 {
  95         struct da9052_bl *wleds = bl_get_data(bl);
  96
  97         return wleds->brightness;
  98 }
  99
 100 static const struct backlight_ops da9052_backlight_ops = {
 101         .update_status = da9052_backlight_update_status,
 102         .get_brightness = da9052_backlight_get_brightness,
 103 };
 104
 105 static int da9052_backlight_probe(struct platform_device *pdev)
 106 {
 107         struct backlight_device *bl;
 108         struct backlight_properties props;
 109         struct da9052_bl *wleds;
 110
 111         wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
 112         if (!wleds)
 113                 return -ENOMEM;
 114
 115         wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
 116         wleds->brightness = 0;
 117         wleds->led_reg = platform_get_device_id(pdev)->driver_data;
 118         wleds->state = DA9052_WLEDS_OFF;
 119
 120         memset(&props, 0, sizeof(struct backlight_properties));
 121         props.type = BACKLIGHT_RAW;
 122         props.max_brightness = DA9052_MAX_BRIGHTNESS;
 123
 124         bl = devm_backlight_device_register(&pdev->dev, pdev->name,
 125                                         wleds->da9052->dev, wleds,
 126                                         &da9052_backlight_ops, &props);
 127         if (IS_ERR(bl)) {
 128                 dev_err(&pdev->dev, "Failed to register backlight\n");
 129                 return PTR_ERR(bl);
 130         }
 131
 132         bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
 133         bl->props.brightness = 0;
 134         platform_set_drvdata(pdev, bl);
 135
 136         return da9052_adjust_wled_brightness(wleds);
 137 }
 138
 139 static void da9052_backlight_remove(struct platform_device *pdev)
 140 {
 141         struct backlight_device *bl = platform_get_drvdata(pdev);
 142         struct da9052_bl *wleds = bl_get_data(bl);
 143
 144         wleds->brightness = 0;
 145         wleds->state = DA9052_WLEDS_OFF;
 146         da9052_adjust_wled_brightness(wleds);
 147 }
 148
 149 static const struct platform_device_id da9052_wled_ids[] = {
 150         {
 151                 .name           = "da9052-wled1",
 152                 .driver_data    = DA9052_TYPE_WLED1,
 153         },
 154         {
 155                 .name           = "da9052-wled2",
 156                 .driver_data    = DA9052_TYPE_WLED2,
 157         },
 158         {
 159                 .name           = "da9052-wled3",
 160                 .driver_data    = DA9052_TYPE_WLED3,
 161         },
 162         { },
 163 };
 164 MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
 165
 166 static struct platform_driver da9052_wled_driver = {
 167         .probe          = da9052_backlight_probe,
 168         .remove_new     = da9052_backlight_remove,
 169         .id_table       = da9052_wled_ids,
 170         .driver = {
 171                 .name   = "da9052-wled",
 172         },
 173 };
 174
 175 module_platform_driver(da9052_wled_driver);
 176
 177 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 178 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
 179 MODULE_LICENSE("GPL");