video/backlight/lv5207lp.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Sanyo LV5207LP LED Driver
0004  *
0005  * Copyright (C) 2013 Ideas on board SPRL
0006  *
0007  * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
0008  */
0009
0010 #include <linux/backlight.h>
0011 #include <linux/err.h>
0012 #include <linux/fb.h>
0013 #include <linux/i2c.h>
0014 #include <linux/module.h>
0015 #include <linux/platform_data/lv5207lp.h>
0016 #include <linux/slab.h>
0017
0018 #define LV5207LP_CTRL1          0x00
0019 #define LV5207LP_CPSW           (1 << 7)
0020 #define LV5207LP_SCTEN          (1 << 6)
0021 #define LV5207LP_C10            (1 << 5)
0022 #define LV5207LP_CKSW           (1 << 4)
0023 #define LV5207LP_RSW            (1 << 3)
0024 #define LV5207LP_GSW            (1 << 2)
0025 #define LV5207LP_BSW            (1 << 1)
0026 #define LV5207LP_CTRL2          0x01
0027 #define LV5207LP_MSW            (1 << 7)
0028 #define LV5207LP_MLED4          (1 << 6)
0029 #define LV5207LP_RED            0x02
0030 #define LV5207LP_GREEN          0x03
0031 #define LV5207LP_BLUE           0x04
0032
0033 #define LV5207LP_MAX_BRIGHTNESS     32
0034
0035 struct lv5207lp {
0036     struct i2c_client *client;
0037     struct backlight_device *backlight;
0038     struct lv5207lp_platform_data *pdata;
0039 };
0040
0041 static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
0042 {
0043     return i2c_smbus_write_byte_data(lv->client, reg, data);
0044 }
0045
0046 static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
0047 {
0048     struct lv5207lp *lv = bl_get_data(backlight);
0049     int brightness = backlight_get_brightness(backlight);
0050
0051     if (brightness) {
0052         lv5207lp_write(lv, LV5207LP_CTRL1,
0053                    LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW);
0054         lv5207lp_write(lv, LV5207LP_CTRL2,
0055                    LV5207LP_MSW | LV5207LP_MLED4 |
0056                    (brightness - 1));
0057     } else {
0058         lv5207lp_write(lv, LV5207LP_CTRL1, 0);
0059         lv5207lp_write(lv, LV5207LP_CTRL2, 0);
0060     }
0061
0062     return 0;
0063 }
0064
0065 static int lv5207lp_backlight_check_fb(struct backlight_device *backlight,
0066                        struct fb_info *info)
0067 {
0068     struct lv5207lp *lv = bl_get_data(backlight);
0069
0070     return lv->pdata->fbdev == NULL || lv->pdata->fbdev == info->dev;
0071 }
0072
0073 static const struct backlight_ops lv5207lp_backlight_ops = {
0074     .options    = BL_CORE_SUSPENDRESUME,
0075     .update_status  = lv5207lp_backlight_update_status,
0076     .check_fb   = lv5207lp_backlight_check_fb,
0077 };
0078
0079 static int lv5207lp_probe(struct i2c_client *client,
0080               const struct i2c_device_id *id)
0081 {
0082     struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev);
0083     struct backlight_device *backlight;
0084     struct backlight_properties props;
0085     struct lv5207lp *lv;
0086
0087     if (pdata == NULL) {
0088         dev_err(&client->dev, "No platform data supplied\n");
0089         return -EINVAL;
0090     }
0091
0092     if (!i2c_check_functionality(client->adapter,
0093                      I2C_FUNC_SMBUS_BYTE_DATA)) {
0094         dev_warn(&client->dev,
0095              "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
0096         return -EIO;
0097     }
0098
0099     lv = devm_kzalloc(&client->dev, sizeof(*lv), GFP_KERNEL);
0100     if (!lv)
0101         return -ENOMEM;
0102
0103     lv->client = client;
0104     lv->pdata = pdata;
0105
0106     memset(&props, 0, sizeof(props));
0107     props.type = BACKLIGHT_RAW;
0108     props.max_brightness = min_t(unsigned int, pdata->max_value,
0109                      LV5207LP_MAX_BRIGHTNESS);
0110     props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
0111                    props.max_brightness);
0112
0113     backlight = devm_backlight_device_register(&client->dev,
0114                 dev_name(&client->dev), &lv->client->dev,
0115                 lv, &lv5207lp_backlight_ops, &props);
0116     if (IS_ERR(backlight)) {
0117         dev_err(&client->dev, "failed to register backlight\n");
0118         return PTR_ERR(backlight);
0119     }
0120
0121     backlight_update_status(backlight);
0122     i2c_set_clientdata(client, backlight);
0123
0124     return 0;
0125 }
0126
0127 static int lv5207lp_remove(struct i2c_client *client)
0128 {
0129     struct backlight_device *backlight = i2c_get_clientdata(client);
0130
0131     backlight->props.brightness = 0;
0132     backlight_update_status(backlight);
0133
0134     return 0;
0135 }
0136
0137 static const struct i2c_device_id lv5207lp_ids[] = {
0138     { "lv5207lp", 0 },
0139     { }
0140 };
0141 MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
0142
0143 static struct i2c_driver lv5207lp_driver = {
0144     .driver = {
0145         .name = "lv5207lp",
0146     },
0147     .probe = lv5207lp_probe,
0148     .remove = lv5207lp_remove,
0149     .id_table = lv5207lp_ids,
0150 };
0151
0152 module_i2c_driver(lv5207lp_driver);
0153
0154 MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
0155 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
0156 MODULE_LICENSE("GPL");