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 #include <linux/slab.h>
  22
  23 #define DA9030_WLED_CONTROL     0x25
  24 #define DA9030_WLED_CP_EN       (1 << 6)
  25 #define DA9030_WLED_TRIM(x)     ((x) & 0x7)
  26
  27 #define DA9034_WLED_CONTROL1    0x3C
  28 #define DA9034_WLED_CONTROL2    0x3D
  29 #define DA9034_WLED_ISET(x)     ((x) & 0x1f)
  30
  31 #define DA9034_WLED_BOOST_EN    (1 << 5)
  32
  33 #define DA9030_MAX_BRIGHTNESS   7
  34 #define DA9034_MAX_BRIGHTNESS   0x7f
  35
  36 struct da903x_backlight_data {
  37         struct device *da903x_dev;
  38         int id;
  39         int current_brightness;
  40 };
  41
  42 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
  43 {
  44         struct da903x_backlight_data *data = bl_get_data(bl);
  45         struct device *dev = data->da903x_dev;
  46         uint8_t val;
  47         int ret = 0;
  48
  49         switch (data->id) {
  50         case DA9034_ID_WLED:
  51                 ret = da903x_update(dev, DA9034_WLED_CONTROL1,
  52                                 brightness, 0x7f);
  53                 if (ret)
  54                         return ret;
  55
  56                 if (data->current_brightness && brightness == 0)
  57                         ret = da903x_clr_bits(dev,
  58                                         DA9034_WLED_CONTROL2,
  59                                         DA9034_WLED_BOOST_EN);
  60
  61                 if (data->current_brightness == 0 && brightness)
  62                         ret = da903x_set_bits(dev,
  63                                         DA9034_WLED_CONTROL2,
  64                                         DA9034_WLED_BOOST_EN);
  65                 break;
  66         case DA9030_ID_WLED:
  67                 val = DA9030_WLED_TRIM(brightness);
  68                 val |= brightness ? DA9030_WLED_CP_EN : 0;
  69                 ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
  70                 break;
  71         }
  72
  73         if (ret)
  74                 return ret;
  75
  76         data->current_brightness = brightness;
  77         return 0;
  78 }
  79
  80 static int da903x_backlight_update_status(struct backlight_device *bl)
  81 {
  82         int brightness = bl->props.brightness;
  83
  84         if (bl->props.power != FB_BLANK_UNBLANK)
  85                 brightness = 0;
  86
  87         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
  88                 brightness = 0;
  89
  90         return da903x_backlight_set(bl, brightness);
  91 }
  92
  93 static int da903x_backlight_get_brightness(struct backlight_device *bl)
  94 {
  95         struct da903x_backlight_data *data = bl_get_data(bl);
  96         return data->current_brightness;
  97 }
  98
  99 static const struct backlight_ops da903x_backlight_ops = {
 100         .update_status  = da903x_backlight_update_status,
 101         .get_brightness = da903x_backlight_get_brightness,
 102 };
 103
 104 static int da903x_backlight_probe(struct platform_device *pdev)
 105 {
 106         struct da9034_backlight_pdata *pdata = pdev->dev.platform_data;
 107         struct da903x_backlight_data *data;
 108         struct backlight_device *bl;
 109         struct backlight_properties props;
 110         int max_brightness;
 111
 112         data = kzalloc(sizeof(*data), GFP_KERNEL);
 113         if (data == NULL)
 114                 return -ENOMEM;
 115
 116         switch (pdev->id) {
 117         case DA9030_ID_WLED:
 118                 max_brightness = DA9030_MAX_BRIGHTNESS;
 119                 break;
 120         case DA9034_ID_WLED:
 121                 max_brightness = DA9034_MAX_BRIGHTNESS;
 122                 break;
 123         default:
 124                 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
 125                                 pdev->id);
 126                 kfree(data);
 127                 return -EINVAL;
 128         }
 129
 130         data->id = pdev->id;
 131         data->da903x_dev = pdev->dev.parent;
 132         data->current_brightness = 0;
 133
 134         /* adjust the WLED output current */
 135         if (pdata)
 136                 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
 137                                 DA9034_WLED_ISET(pdata->output_current));
 138
 139         props.max_brightness = max_brightness;
 140         bl = backlight_device_register(pdev->name, data->da903x_dev, data,
 141                                        &da903x_backlight_ops, &props);
 142         if (IS_ERR(bl)) {
 143                 dev_err(&pdev->dev, "failed to register backlight\n");
 144                 kfree(data);
 145                 return PTR_ERR(bl);
 146         }
 147
 148         bl->props.brightness = max_brightness;
 149
 150         platform_set_drvdata(pdev, bl);
 151         backlight_update_status(bl);
 152         return 0;
 153 }
 154
 155 static int da903x_backlight_remove(struct platform_device *pdev)
 156 {
 157         struct backlight_device *bl = platform_get_drvdata(pdev);
 158         struct da903x_backlight_data *data = bl_get_data(bl);
 159
 160         backlight_device_unregister(bl);
 161         kfree(data);
 162         return 0;
 163 }
 164
 165 #ifdef CONFIG_PM
 166 static int da903x_backlight_suspend(struct device *dev)
 167 {
 168         struct platform_device *pdev = to_platform_device(dev);
 169         struct backlight_device *bl = platform_get_drvdata(pdev);
 170         return da903x_backlight_set(bl, 0);
 171 }
 172
 173 static int da903x_backlight_resume(struct device *dev)
 174 {
 175         struct platform_device *pdev = to_platform_device(dev);
 176         struct backlight_device *bl = platform_get_drvdata(pdev);
 177
 178         backlight_update_status(bl);
 179         return 0;
 180 }
 181
 182 static const struct dev_pm_ops da903x_backlight_pm_ops = {
 183         .suspend        = da903x_backlight_suspend,
 184         .resume         = da903x_backlight_resume,
 185 };
 186 #endif
 187
 188 static struct platform_driver da903x_backlight_driver = {
 189         .driver         = {
 190                 .name   = "da903x-backlight",
 191                 .owner  = THIS_MODULE,
 192 #ifdef CONFIG_PM
 193                 .pm     = &da903x_backlight_pm_ops,
 194 #endif
 195         },
 196         .probe          = da903x_backlight_probe,
 197         .remove         = da903x_backlight_remove,
 198 };
 199
 200 static int __init da903x_backlight_init(void)
 201 {
 202         return platform_driver_register(&da903x_backlight_driver);
 203 }
 204 module_init(da903x_backlight_init);
 205
 206 static void __exit da903x_backlight_exit(void)
 207 {
 208         platform_driver_unregister(&da903x_backlight_driver);
 209 }
 210 module_exit(da903x_backlight_exit);
 211
 212 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
 213 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"
 214               "Mike Rapoport <mike@compulab.co.il>");
 215 MODULE_LICENSE("GPL");
 216 MODULE_ALIAS("platform:da903x-backlight");