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 #define DA9034_WLED_ISET(x)     ((x) & 0x1f)
  29
  30 #define DA9034_WLED_BOOST_EN    (1 << 5)
  31
  32 #define DA9030_MAX_BRIGHTNESS   7
  33 #define DA9034_MAX_BRIGHTNESS   0x7f
  34
  35 struct da903x_backlight_data {
  36         struct device *da903x_dev;
  37         int id;
  38         int current_brightness;
  39 };
  40
  41 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
  42 {
  43         struct da903x_backlight_data *data = bl_get_data(bl);
  44         struct device *dev = data->da903x_dev;
  45         uint8_t val;
  46         int ret = 0;
  47
  48         switch (data->id) {
  49         case DA9034_ID_WLED:
  50                 ret = da903x_update(dev, DA9034_WLED_CONTROL1,
  51                                 brightness, 0x7f);
  52                 if (ret)
  53                         return ret;
  54
  55                 if (data->current_brightness && brightness == 0)
  56                         ret = da903x_clr_bits(dev,
  57                                         DA9034_WLED_CONTROL2,
  58                                         DA9034_WLED_BOOST_EN);
  59
  60                 if (data->current_brightness == 0 && brightness)
  61                         ret = da903x_set_bits(dev,
  62                                         DA9034_WLED_CONTROL2,
  63                                         DA9034_WLED_BOOST_EN);
  64                 break;
  65         case DA9030_ID_WLED:
  66                 val = DA9030_WLED_TRIM(brightness);
  67                 val |= brightness ? DA9030_WLED_CP_EN : 0;
  68                 ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
  69                 break;
  70         }
  71
  72         if (ret)
  73                 return ret;
  74
  75         data->current_brightness = brightness;
  76         return 0;
  77 }
  78
  79 static int da903x_backlight_update_status(struct backlight_device *bl)
  80 {
  81         int brightness = bl->props.brightness;
  82
  83         if (bl->props.power != FB_BLANK_UNBLANK)
  84                 brightness = 0;
  85
  86         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
  87                 brightness = 0;
  88
  89         return da903x_backlight_set(bl, brightness);
  90 }
  91
  92 static int da903x_backlight_get_brightness(struct backlight_device *bl)
  93 {
  94         struct da903x_backlight_data *data = bl_get_data(bl);
  95         return data->current_brightness;
  96 }
  97
  98 static const struct backlight_ops da903x_backlight_ops = {
  99         .update_status  = da903x_backlight_update_status,
 100         .get_brightness = da903x_backlight_get_brightness,
 101 };
 102
 103 static int da903x_backlight_probe(struct platform_device *pdev)
 104 {
 105         struct da9034_backlight_pdata *pdata = pdev->dev.platform_data;
 106         struct da903x_backlight_data *data;
 107         struct backlight_device *bl;
 108         struct backlight_properties props;
 109         int max_brightness;
 110
 111         data = kzalloc(sizeof(*data), GFP_KERNEL);
 112         if (data == NULL)
 113                 return -ENOMEM;
 114
 115         switch (pdev->id) {
 116         case DA9030_ID_WLED:
 117                 max_brightness = DA9030_MAX_BRIGHTNESS;
 118                 break;
 119         case DA9034_ID_WLED:
 120                 max_brightness = DA9034_MAX_BRIGHTNESS;
 121                 break;
 122         default:
 123                 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
 124                                 pdev->id);
 125                 kfree(data);
 126                 return -EINVAL;
 127         }
 128
 129         data->id = pdev->id;
 130         data->da903x_dev = pdev->dev.parent;
 131         data->current_brightness = 0;
 132
 133         /* adjust the WLED output current */
 134         if (pdata)
 135                 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
 136                                 DA9034_WLED_ISET(pdata->output_current));
 137
 138         props.max_brightness = max_brightness;
 139         bl = backlight_device_register(pdev->name, data->da903x_dev, data,
 140                                        &da903x_backlight_ops, &props);
 141         if (IS_ERR(bl)) {
 142                 dev_err(&pdev->dev, "failed to register backlight\n");
 143                 kfree(data);
 144                 return PTR_ERR(bl);
 145         }
 146
 147         bl->props.brightness = max_brightness;
 148
 149         platform_set_drvdata(pdev, bl);
 150         backlight_update_status(bl);
 151         return 0;
 152 }
 153
 154 static int da903x_backlight_remove(struct platform_device *pdev)
 155 {
 156         struct backlight_device *bl = platform_get_drvdata(pdev);
 157         struct da903x_backlight_data *data = bl_get_data(bl);
 158
 159         backlight_device_unregister(bl);
 160         kfree(data);
 161         return 0;
 162 }
 163
 164 #ifdef CONFIG_PM
 165 static int da903x_backlight_suspend(struct device *dev)
 166 {
 167         struct platform_device *pdev = to_platform_device(dev);
 168         struct backlight_device *bl = platform_get_drvdata(pdev);
 169         return da903x_backlight_set(bl, 0);
 170 }
 171
 172 static int da903x_backlight_resume(struct device *dev)
 173 {
 174         struct platform_device *pdev = to_platform_device(dev);
 175         struct backlight_device *bl = platform_get_drvdata(pdev);
 176
 177         backlight_update_status(bl);
 178         return 0;
 179 }
 180
 181 static const struct dev_pm_ops da903x_backlight_pm_ops = {
 182         .suspend        = da903x_backlight_suspend,
 183         .resume         = da903x_backlight_resume,
 184 };
 185 #endif
 186
 187 static struct platform_driver da903x_backlight_driver = {
 188         .driver         = {
 189                 .name   = "da903x-backlight",
 190                 .owner  = THIS_MODULE,
 191 #ifdef CONFIG_PM
 192                 .pm     = &da903x_backlight_pm_ops,
 193 #endif
 194         },
 195         .probe          = da903x_backlight_probe,
 196         .remove         = da903x_backlight_remove,
 197 };
 198
 199 static int __init da903x_backlight_init(void)
 200 {
 201         return platform_driver_register(&da903x_backlight_driver);
 202 }
 203 module_init(da903x_backlight_init);
 204
 205 static void __exit da903x_backlight_exit(void)
 206 {
 207         platform_driver_unregister(&da903x_backlight_driver);
 208 }
 209 module_exit(da903x_backlight_exit);
 210
 211 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
 212 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"
 213               "Mike Rapoport <mike@compulab.co.il>");
 214 MODULE_LICENSE("GPL");
 215 MODULE_ALIAS("platform:da903x-backlight");