kernel/drivers/video/backlight/lv5207lp.c

   1 /*
   2  * Sanyo LV5207LP LED Driver
   3  *
   4  * Copyright (C) 2013 Ideas on board SPRL
   5  *
   6  * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/backlight.h>
  14 #include <linux/err.h>
  15 #include <linux/fb.h>
  16 #include <linux/i2c.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_data/lv5207lp.h>
  19 #include <linux/slab.h>
  20
  21 #define LV5207LP_CTRL1                  0x00
  22 #define LV5207LP_CPSW                   (1 << 7)
  23 #define LV5207LP_SCTEN                  (1 << 6)
  24 #define LV5207LP_C10                    (1 << 5)
  25 #define LV5207LP_CKSW                   (1 << 4)
  26 #define LV5207LP_RSW                    (1 << 3)
  27 #define LV5207LP_GSW                    (1 << 2)
  28 #define LV5207LP_BSW                    (1 << 1)
  29 #define LV5207LP_CTRL2                  0x01
  30 #define LV5207LP_MSW                    (1 << 7)
  31 #define LV5207LP_MLED4                  (1 << 6)
  32 #define LV5207LP_RED                    0x02
  33 #define LV5207LP_GREEN                  0x03
  34 #define LV5207LP_BLUE                   0x04
  35
  36 #define LV5207LP_MAX_BRIGHTNESS         32
  37
  38 struct lv5207lp {
  39         struct i2c_client *client;
  40         struct backlight_device *backlight;
  41         struct lv5207lp_platform_data *pdata;
  42 };
  43
  44 static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
  45 {
  46         return i2c_smbus_write_byte_data(lv->client, reg, data);
  47 }
  48
  49 static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
  50 {
  51         struct lv5207lp *lv = bl_get_data(backlight);
  52         int brightness = backlight->props.brightness;
  53
  54         if (backlight->props.power != FB_BLANK_UNBLANK ||
  55             backlight->props.fb_blank != FB_BLANK_UNBLANK ||
  56             backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
  57                 brightness = 0;
  58
  59         if (brightness) {
  60                 lv5207lp_write(lv, LV5207LP_CTRL1,
  61                                LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW);
  62                 lv5207lp_write(lv, LV5207LP_CTRL2,
  63                                LV5207LP_MSW | LV5207LP_MLED4 |
  64                                (brightness - 1));
  65         } else {
  66                 lv5207lp_write(lv, LV5207LP_CTRL1, 0);
  67                 lv5207lp_write(lv, LV5207LP_CTRL2, 0);
  68         }
  69
  70         return 0;
  71 }
  72
  73 static int lv5207lp_backlight_check_fb(struct backlight_device *backlight,
  74                                        struct fb_info *info)
  75 {
  76         struct lv5207lp *lv = bl_get_data(backlight);
  77
  78         return lv->pdata->fbdev == NULL || lv->pdata->fbdev == info->dev;
  79 }
  80
  81 static const struct backlight_ops lv5207lp_backlight_ops = {
  82         .options        = BL_CORE_SUSPENDRESUME,
  83         .update_status  = lv5207lp_backlight_update_status,
  84         .check_fb       = lv5207lp_backlight_check_fb,
  85 };
  86
  87 static int lv5207lp_probe(struct i2c_client *client,
  88                           const struct i2c_device_id *id)
  89 {
  90         struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev);
  91         struct backlight_device *backlight;
  92         struct backlight_properties props;
  93         struct lv5207lp *lv;
  94
  95         if (pdata == NULL) {
  96                 dev_err(&client->dev, "No platform data supplied\n");
  97                 return -EINVAL;
  98         }
  99
 100         if (!i2c_check_functionality(client->adapter,
 101                                      I2C_FUNC_SMBUS_BYTE_DATA)) {
 102                 dev_warn(&client->dev,
 103                          "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
 104                 return -EIO;
 105         }
 106
 107         lv = devm_kzalloc(&client->dev, sizeof(*lv), GFP_KERNEL);
 108         if (!lv)
 109                 return -ENOMEM;
 110
 111         lv->client = client;
 112         lv->pdata = pdata;
 113
 114         memset(&props, 0, sizeof(props));
 115         props.type = BACKLIGHT_RAW;
 116         props.max_brightness = min_t(unsigned int, pdata->max_value,
 117                                      LV5207LP_MAX_BRIGHTNESS);
 118         props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
 119                                    props.max_brightness);
 120
 121         backlight = devm_backlight_device_register(&client->dev,
 122                                 dev_name(&client->dev), &lv->client->dev,
 123                                 lv, &lv5207lp_backlight_ops, &props);
 124         if (IS_ERR(backlight)) {
 125                 dev_err(&client->dev, "failed to register backlight\n");
 126                 return PTR_ERR(backlight);
 127         }
 128
 129         backlight_update_status(backlight);
 130         i2c_set_clientdata(client, backlight);
 131
 132         return 0;
 133 }
 134
 135 static int lv5207lp_remove(struct i2c_client *client)
 136 {
 137         struct backlight_device *backlight = i2c_get_clientdata(client);
 138
 139         backlight->props.brightness = 0;
 140         backlight_update_status(backlight);
 141
 142         return 0;
 143 }
 144
 145 static const struct i2c_device_id lv5207lp_ids[] = {
 146         { "lv5207lp", 0 },
 147         { }
 148 };
 149 MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
 150
 151 static struct i2c_driver lv5207lp_driver = {
 152         .driver = {
 153                 .name = "lv5207lp",
 154         },
 155         .probe = lv5207lp_probe,
 156         .remove = lv5207lp_remove,
 157         .id_table = lv5207lp_ids,
 158 };
 159
 160 module_i2c_driver(lv5207lp_driver);
 161
 162 MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
 163 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 164 MODULE_LICENSE("GPL");