drivers/video/backlight/lv5207lp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Sanyo LV5207LP LED Driver
   4  *
   5  * Copyright (C) 2013 Ideas on board SPRL
   6  *
   7  * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   8  */
   9
  10 #include <linux/backlight.h>
  11 #include <linux/err.h>
  12 #include <linux/fb.h>
  13 #include <linux/i2c.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_data/lv5207lp.h>
  16 #include <linux/slab.h>
  17
  18 #define LV5207LP_CTRL1                  0x00
  19 #define LV5207LP_CPSW                   (1 << 7)
  20 #define LV5207LP_SCTEN                  (1 << 6)
  21 #define LV5207LP_C10                    (1 << 5)
  22 #define LV5207LP_CKSW                   (1 << 4)
  23 #define LV5207LP_RSW                    (1 << 3)
  24 #define LV5207LP_GSW                    (1 << 2)
  25 #define LV5207LP_BSW                    (1 << 1)
  26 #define LV5207LP_CTRL2                  0x01
  27 #define LV5207LP_MSW                    (1 << 7)
  28 #define LV5207LP_MLED4                  (1 << 6)
  29 #define LV5207LP_RED                    0x02
  30 #define LV5207LP_GREEN                  0x03
  31 #define LV5207LP_BLUE                   0x04
  32
  33 #define LV5207LP_MAX_BRIGHTNESS         32
  34
  35 struct lv5207lp {
  36         struct i2c_client *client;
  37         struct backlight_device *backlight;
  38         struct lv5207lp_platform_data *pdata;
  39 };
  40
  41 static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
  42 {
  43         return i2c_smbus_write_byte_data(lv->client, reg, data);
  44 }
  45
  46 static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
  47 {
  48         struct lv5207lp *lv = bl_get_data(backlight);
  49         int brightness = backlight_get_brightness(backlight);
  50
  51         if (brightness) {
  52                 lv5207lp_write(lv, LV5207LP_CTRL1,
  53                                LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW);
  54                 lv5207lp_write(lv, LV5207LP_CTRL2,
  55                                LV5207LP_MSW | LV5207LP_MLED4 |
  56                                (brightness - 1));
  57         } else {
  58                 lv5207lp_write(lv, LV5207LP_CTRL1, 0);
  59                 lv5207lp_write(lv, LV5207LP_CTRL2, 0);
  60         }
  61
  62         return 0;
  63 }
  64
  65 static int lv5207lp_backlight_check_fb(struct backlight_device *backlight,
  66                                        struct fb_info *info)
  67 {
  68         struct lv5207lp *lv = bl_get_data(backlight);
  69
  70         return lv->pdata->fbdev == NULL || lv->pdata->fbdev == info->dev;
  71 }
  72
  73 static const struct backlight_ops lv5207lp_backlight_ops = {
  74         .options        = BL_CORE_SUSPENDRESUME,
  75         .update_status  = lv5207lp_backlight_update_status,
  76         .check_fb       = lv5207lp_backlight_check_fb,
  77 };
  78
  79 static int lv5207lp_probe(struct i2c_client *client)
  80 {
  81         struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev);
  82         struct backlight_device *backlight;
  83         struct backlight_properties props;
  84         struct lv5207lp *lv;
  85
  86         if (pdata == NULL) {
  87                 dev_err(&client->dev, "No platform data supplied\n");
  88                 return -EINVAL;
  89         }
  90
  91         if (!i2c_check_functionality(client->adapter,
  92                                      I2C_FUNC_SMBUS_BYTE_DATA)) {
  93                 dev_warn(&client->dev,
  94                          "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
  95                 return -EIO;
  96         }
  97
  98         lv = devm_kzalloc(&client->dev, sizeof(*lv), GFP_KERNEL);
  99         if (!lv)
 100                 return -ENOMEM;
 101
 102         lv->client = client;
 103         lv->pdata = pdata;
 104
 105         memset(&props, 0, sizeof(props));
 106         props.type = BACKLIGHT_RAW;
 107         props.max_brightness = min_t(unsigned int, pdata->max_value,
 108                                      LV5207LP_MAX_BRIGHTNESS);
 109         props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
 110                                    props.max_brightness);
 111
 112         backlight = devm_backlight_device_register(&client->dev,
 113                                 dev_name(&client->dev), &lv->client->dev,
 114                                 lv, &lv5207lp_backlight_ops, &props);
 115         if (IS_ERR(backlight)) {
 116                 dev_err(&client->dev, "failed to register backlight\n");
 117                 return PTR_ERR(backlight);
 118         }
 119
 120         backlight_update_status(backlight);
 121         i2c_set_clientdata(client, backlight);
 122
 123         return 0;
 124 }
 125
 126 static void lv5207lp_remove(struct i2c_client *client)
 127 {
 128         struct backlight_device *backlight = i2c_get_clientdata(client);
 129
 130         backlight->props.brightness = 0;
 131         backlight_update_status(backlight);
 132 }
 133
 134 static const struct i2c_device_id lv5207lp_ids[] = {
 135         { "lv5207lp", 0 },
 136         { }
 137 };
 138 MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
 139
 140 static struct i2c_driver lv5207lp_driver = {
 141         .driver = {
 142                 .name = "lv5207lp",
 143         },
 144         .probe_new = lv5207lp_probe,
 145         .remove = lv5207lp_remove,
 146         .id_table = lv5207lp_ids,
 147 };
 148
 149 module_i2c_driver(lv5207lp_driver);
 150
 151 MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
 152 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 153 MODULE_LICENSE("GPL");