drivers/video/backlight/da903x_bl.c

   1 /*
   2  * Backlight driver for Dialog Semiconductor DA9030/DA9034
   3  *
   4  * Copyright (C) 2008 Compulab, Ltd.
   5  *      Mike Rapoport <mike@compulab.co.il>
   6  *
   7  * Copyright (C) 2006-2008 Marvell International Ltd.
   8  *      Eric Miao <eric.miao@marvell.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/fb.h>
  19 #include <linux/backlight.h>
  20 #include <linux/mfd/da903x.h>
  21
  22 #define DA9030_WLED_CONTROL     0x25
  23 #define DA9030_WLED_CP_EN       (1 << 6)
  24 #define DA9030_WLED_TRIM(x)     ((x) & 0x7)
  25
  26 #define DA9034_WLED_CONTROL1    0x3C
  27 #define DA9034_WLED_CONTROL2    0x3D
  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         int brightness = bl->props.brightness;
  81
  82         if (bl->props.power != FB_BLANK_UNBLANK)
  83                 brightness = 0;
  84
  85         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
  86                 brightness = 0;
  87
  88         return da903x_backlight_set(bl, brightness);
  89 }
  90
  91 static int da903x_backlight_get_brightness(struct backlight_device *bl)
  92 {
  93         struct da903x_backlight_data *data = bl_get_data(bl);
  94         return data->current_brightness;
  95 }
  96
  97 static struct backlight_ops da903x_backlight_ops = {
  98         .update_status  = da903x_backlight_update_status,
  99         .get_brightness = da903x_backlight_get_brightness,
 100 };
 101
 102 static int da903x_backlight_probe(struct platform_device *pdev)
 103 {
 104         struct da903x_backlight_data *data;
 105         struct backlight_device *bl;
 106         int max_brightness;
 107
 108         data = kzalloc(sizeof(*data), GFP_KERNEL);
 109         if (data == NULL)
 110                 return -ENOMEM;
 111
 112         switch (pdev->id) {
 113         case DA9030_ID_WLED:
 114                 max_brightness = DA9030_MAX_BRIGHTNESS;
 115                 break;
 116         case DA9034_ID_WLED:
 117                 max_brightness = DA9034_MAX_BRIGHTNESS;
 118                 break;
 119         default:
 120                 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
 121                                 pdev->id);
 122                 kfree(data);
 123                 return -EINVAL;
 124         }
 125
 126         data->id = pdev->id;
 127         data->da903x_dev = pdev->dev.parent;
 128         data->current_brightness = 0;
 129
 130         bl = backlight_device_register(pdev->name, data->da903x_dev,
 131                         data, &da903x_backlight_ops);
 132         if (IS_ERR(bl)) {
 133                 dev_err(&pdev->dev, "failed to register backlight\n");
 134                 kfree(data);
 135                 return PTR_ERR(bl);
 136         }
 137
 138         bl->props.max_brightness = max_brightness;
 139         bl->props.brightness = max_brightness;
 140
 141         platform_set_drvdata(pdev, bl);
 142         backlight_update_status(bl);
 143         return 0;
 144 }
 145
 146 static int da903x_backlight_remove(struct platform_device *pdev)
 147 {
 148         struct backlight_device *bl = platform_get_drvdata(pdev);
 149         struct da903x_backlight_data *data = bl_get_data(bl);
 150
 151         backlight_device_unregister(bl);
 152         kfree(data);
 153         return 0;
 154 }
 155
 156 #ifdef CONFIG_PM
 157 static int da903x_backlight_suspend(struct device *dev)
 158 {
 159         struct platform_device *pdev = to_platform_device(dev);
 160         struct backlight_device *bl = platform_get_drvdata(pdev);
 161         return da903x_backlight_set(bl, 0);
 162 }
 163
 164 static int da903x_backlight_resume(struct device *dev)
 165 {
 166         struct platform_device *pdev = to_platform_device(dev);
 167         struct backlight_device *bl = platform_get_drvdata(pdev);
 168
 169         backlight_update_status(bl);
 170         return 0;
 171 }
 172
 173 static struct dev_pm_ops da903x_backlight_pm_ops = {
 174         .suspend        = da903x_backlight_suspend,
 175         .resume         = da903x_backlight_resume,
 176 };
 177 #endif
 178
 179 static struct platform_driver da903x_backlight_driver = {
 180         .driver         = {
 181                 .name   = "da903x-backlight",
 182                 .owner  = THIS_MODULE,
 183 #ifdef CONFIG_PM
 184                 .pm     = &da903x_backlight_pm_ops,
 185 #endif
 186         },
 187         .probe          = da903x_backlight_probe,
 188         .remove         = da903x_backlight_remove,
 189 };
 190
 191 static int __init da903x_backlight_init(void)
 192 {
 193         return platform_driver_register(&da903x_backlight_driver);
 194 }
 195 module_init(da903x_backlight_init);
 196
 197 static void __exit da903x_backlight_exit(void)
 198 {
 199         platform_driver_unregister(&da903x_backlight_driver);
 200 }
 201 module_exit(da903x_backlight_exit);
 202
 203 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
 204 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"
 205               "Mike Rapoport <mike@compulab.co.il>");
 206 MODULE_LICENSE("GPL");
 207 MODULE_ALIAS("platform:da903x-backlight");