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
35struct lv5207lp {
36 struct i2c_client *client;
37 struct backlight_device *backlight;
38 struct lv5207lp_platform_data *pdata;
39};
40
41static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
42{
43 return i2c_smbus_write_byte_data(client: lv->client, command: reg, value: data);
44}
45
46static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
47{
48 struct lv5207lp *lv = bl_get_data(bl_dev: backlight);
49 int brightness = backlight_get_brightness(bd: 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, data: 0);
59 lv5207lp_write(lv, LV5207LP_CTRL2, data: 0);
60 }
61
62 return 0;
63}
64
65static int lv5207lp_backlight_check_fb(struct backlight_device *backlight,
66 struct fb_info *info)
67{
68 struct lv5207lp *lv = bl_get_data(bl_dev: backlight);
69
70 return !lv->pdata->dev || lv->pdata->dev == info->device;
71}
72
73static 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
79static int lv5207lp_probe(struct i2c_client *client)
80{
81 struct lv5207lp_platform_data *pdata = dev_get_platdata(dev: &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(adap: 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(dev: &client->dev, size: 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(dev: &client->dev,
113 name: dev_name(dev: &client->dev), parent: &lv->client->dev,
114 devdata: lv, ops: &lv5207lp_backlight_ops, props: &props);
115 if (IS_ERR(ptr: backlight)) {
116 dev_err(&client->dev, "failed to register backlight\n");
117 return PTR_ERR(ptr: backlight);
118 }
119
120 backlight_update_status(bd: backlight);
121 i2c_set_clientdata(client, data: backlight);
122
123 return 0;
124}
125
126static 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(bd: backlight);
132}
133
134static const struct i2c_device_id lv5207lp_ids[] = {
135 { "lv5207lp", 0 },
136 { }
137};
138MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
139
140static struct i2c_driver lv5207lp_driver = {
141 .driver = {
142 .name = "lv5207lp",
143 },
144 .probe = lv5207lp_probe,
145 .remove = lv5207lp_remove,
146 .id_table = lv5207lp_ids,
147};
148
149module_i2c_driver(lv5207lp_driver);
150
151MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
152MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
153MODULE_LICENSE("GPL");
154

source code of linux/drivers/video/backlight/lv5207lp.c