drivers/video/backlight/da903x_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Backlight driver for Dialog Semiconductor DA9030/DA9034
   4  *
   5  * Copyright (C) 2008 Compulab, Ltd.
   6  *      Mike Rapoport <mike@compulab.co.il>
   7  *
   8  * Copyright (C) 2006-2008 Marvell International Ltd.
   9  *      Eric Miao <eric.miao@marvell.com>
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/fb.h>
  16 #include <linux/backlight.h>
  17 #include <linux/mfd/da903x.h>
  18 #include <linux/slab.h>
  19 #include <linux/module.h>
  20
  21 #define DA9030_WLED_CONTROL     0x25
  22 #define DA9030_WLED_CP_EN       (1 << 6)
  23 #define DA9030_WLED_TRIM(x)     ((x) & 0x7)
  24
  25 #define DA9034_WLED_CONTROL1    0x3C
  26 #define DA9034_WLED_CONTROL2    0x3D
  27 #define DA9034_WLED_ISET(x)     ((x) & 0x1f)
  28
  29 #define DA9034_WLED_BOOST_EN    (1 << 5)
  30
  31 #define DA9030_MAX_BRIGHTNESS   7
  32 #define DA9034_MAX_BRIGHTNESS   0x7f
  33
  34 struct da903x_backlight_data {
  35         struct device *da903x_dev;
  36         int id;
  37         int current_brightness;
  38 };
  39
  40 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
  41 {
  42         struct da903x_backlight_data *data = bl_get_data(bl);
  43         struct device *dev = data->da903x_dev;
  44         uint8_t val;
  45         int ret = 0;
  46
  47         switch (data->id) {
  48         case DA9034_ID_WLED:
  49                 ret = da903x_update(dev, DA9034_WLED_CONTROL1,
  50                                 brightness, 0x7f);
  51                 if (ret)
  52                         return ret;
  53
  54                 if (data->current_brightness && brightness == 0)
  55                         ret = da903x_clr_bits(dev,
  56                                         DA9034_WLED_CONTROL2,
  57                                         DA9034_WLED_BOOST_EN);
  58
  59                 if (data->current_brightness == 0 && brightness)
  60                         ret = da903x_set_bits(dev,
  61                                         DA9034_WLED_CONTROL2,
  62                                         DA9034_WLED_BOOST_EN);
  63                 break;
  64         case DA9030_ID_WLED:
  65                 val = DA9030_WLED_TRIM(brightness);
  66                 val |= brightness ? DA9030_WLED_CP_EN : 0;
  67                 ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
  68                 break;
  69         }
  70
  71         if (ret)
  72                 return ret;
  73
  74         data->current_brightness = brightness;
  75         return 0;
  76 }
  77
  78 static int da903x_backlight_update_status(struct backlight_device *bl)
  79 {
  80         return da903x_backlight_set(bl, backlight_get_brightness(bl));
  81 }
  82
  83 static int da903x_backlight_get_brightness(struct backlight_device *bl)
  84 {
  85         struct da903x_backlight_data *data = bl_get_data(bl);
  86
  87         return data->current_brightness;
  88 }
  89
  90 static const struct backlight_ops da903x_backlight_ops = {
  91         .options        = BL_CORE_SUSPENDRESUME,
  92         .update_status  = da903x_backlight_update_status,
  93         .get_brightness = da903x_backlight_get_brightness,
  94 };
  95
  96 static int da903x_backlight_probe(struct platform_device *pdev)
  97 {
  98         struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
  99         struct da903x_backlight_data *data;
 100         struct backlight_device *bl;
 101         struct backlight_properties props;
 102         int max_brightness;
 103
 104         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 105         if (data == NULL)
 106                 return -ENOMEM;
 107
 108         switch (pdev->id) {
 109         case DA9030_ID_WLED:
 110                 max_brightness = DA9030_MAX_BRIGHTNESS;
 111                 break;
 112         case DA9034_ID_WLED:
 113                 max_brightness = DA9034_MAX_BRIGHTNESS;
 114                 break;
 115         default:
 116                 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
 117                                 pdev->id);
 118                 return -EINVAL;
 119         }
 120
 121         data->id = pdev->id;
 122         data->da903x_dev = pdev->dev.parent;
 123         data->current_brightness = 0;
 124
 125         /* adjust the WLED output current */
 126         if (pdata)
 127                 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
 128                                 DA9034_WLED_ISET(pdata->output_current));
 129
 130         memset(&props, 0, sizeof(props));
 131         props.type = BACKLIGHT_RAW;
 132         props.max_brightness = max_brightness;
 133         bl = devm_backlight_device_register(&pdev->dev, pdev->name,
 134                                         data->da903x_dev, data,
 135                                         &da903x_backlight_ops, &props);
 136         if (IS_ERR(bl)) {
 137                 dev_err(&pdev->dev, "failed to register backlight\n");
 138                 return PTR_ERR(bl);
 139         }
 140
 141         bl->props.brightness = max_brightness;
 142
 143         platform_set_drvdata(pdev, bl);
 144         backlight_update_status(bl);
 145         return 0;
 146 }
 147
 148 static struct platform_driver da903x_backlight_driver = {
 149         .driver         = {
 150                 .name   = "da903x-backlight",
 151         },
 152         .probe          = da903x_backlight_probe,
 153 };
 154
 155 module_platform_driver(da903x_backlight_driver);
 156
 157 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
 158 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
 159 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
 160 MODULE_LICENSE("GPL");
 161 MODULE_ALIAS("platform:da903x-backlight");