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/i2c.h>
13 #include <linux/module.h>
14 #include <linux/platform_data/lv5207lp.h>
15 #include <linux/slab.h>
16 
17 #define LV5207LP_CTRL1			0x00
18 #define LV5207LP_CPSW			(1 << 7)
19 #define LV5207LP_SCTEN			(1 << 6)
20 #define LV5207LP_C10			(1 << 5)
21 #define LV5207LP_CKSW			(1 << 4)
22 #define LV5207LP_RSW			(1 << 3)
23 #define LV5207LP_GSW			(1 << 2)
24 #define LV5207LP_BSW			(1 << 1)
25 #define LV5207LP_CTRL2			0x01
26 #define LV5207LP_MSW			(1 << 7)
27 #define LV5207LP_MLED4			(1 << 6)
28 #define LV5207LP_RED			0x02
29 #define LV5207LP_GREEN			0x03
30 #define LV5207LP_BLUE			0x04
31 
32 #define LV5207LP_MAX_BRIGHTNESS		32
33 
34 struct lv5207lp {
35 	struct i2c_client *client;
36 	struct backlight_device *backlight;
37 	struct lv5207lp_platform_data *pdata;
38 };
39 
lv5207lp_write(struct lv5207lp * lv,u8 reg,u8 data)40 static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
41 {
42 	return i2c_smbus_write_byte_data(lv->client, reg, data);
43 }
44 
lv5207lp_backlight_update_status(struct backlight_device * backlight)45 static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
46 {
47 	struct lv5207lp *lv = bl_get_data(backlight);
48 	int brightness = backlight_get_brightness(backlight);
49 
50 	if (brightness) {
51 		lv5207lp_write(lv, LV5207LP_CTRL1,
52 			       LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW);
53 		lv5207lp_write(lv, LV5207LP_CTRL2,
54 			       LV5207LP_MSW | LV5207LP_MLED4 |
55 			       (brightness - 1));
56 	} else {
57 		lv5207lp_write(lv, LV5207LP_CTRL1, 0);
58 		lv5207lp_write(lv, LV5207LP_CTRL2, 0);
59 	}
60 
61 	return 0;
62 }
63 
lv5207lp_backlight_controls_device(struct backlight_device * backlight,struct device * display_dev)64 static bool lv5207lp_backlight_controls_device(struct backlight_device *backlight,
65 					       struct device *display_dev)
66 {
67 	struct lv5207lp *lv = bl_get_data(backlight);
68 
69 	return !lv->pdata->dev || lv->pdata->dev == display_dev;
70 }
71 
72 static const struct backlight_ops lv5207lp_backlight_ops = {
73 	.options	 = BL_CORE_SUSPENDRESUME,
74 	.update_status	 = lv5207lp_backlight_update_status,
75 	.controls_device = lv5207lp_backlight_controls_device,
76 };
77 
lv5207lp_probe(struct i2c_client * client)78 static int lv5207lp_probe(struct i2c_client *client)
79 {
80 	struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev);
81 	struct backlight_device *backlight;
82 	struct backlight_properties props;
83 	struct lv5207lp *lv;
84 
85 	if (pdata == NULL) {
86 		dev_err(&client->dev, "No platform data supplied\n");
87 		return -EINVAL;
88 	}
89 
90 	if (!i2c_check_functionality(client->adapter,
91 				     I2C_FUNC_SMBUS_BYTE_DATA)) {
92 		dev_warn(&client->dev,
93 			 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
94 		return -EIO;
95 	}
96 
97 	lv = devm_kzalloc(&client->dev, sizeof(*lv), GFP_KERNEL);
98 	if (!lv)
99 		return -ENOMEM;
100 
101 	lv->client = client;
102 	lv->pdata = pdata;
103 
104 	memset(&props, 0, sizeof(props));
105 	props.type = BACKLIGHT_RAW;
106 	props.max_brightness = min_t(unsigned int, pdata->max_value,
107 				     LV5207LP_MAX_BRIGHTNESS);
108 	props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
109 				   props.max_brightness);
110 
111 	backlight = devm_backlight_device_register(&client->dev,
112 				dev_name(&client->dev), &lv->client->dev,
113 				lv, &lv5207lp_backlight_ops, &props);
114 	if (IS_ERR(backlight)) {
115 		dev_err(&client->dev, "failed to register backlight\n");
116 		return PTR_ERR(backlight);
117 	}
118 
119 	backlight_update_status(backlight);
120 	i2c_set_clientdata(client, backlight);
121 
122 	return 0;
123 }
124 
lv5207lp_remove(struct i2c_client * client)125 static void lv5207lp_remove(struct i2c_client *client)
126 {
127 	struct backlight_device *backlight = i2c_get_clientdata(client);
128 
129 	backlight->props.brightness = 0;
130 	backlight_update_status(backlight);
131 }
132 
133 static const struct i2c_device_id lv5207lp_ids[] = {
134 	{ "lv5207lp" },
135 	{ }
136 };
137 MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
138 
139 static struct i2c_driver lv5207lp_driver = {
140 	.driver = {
141 		.name = "lv5207lp",
142 	},
143 	.probe = lv5207lp_probe,
144 	.remove = lv5207lp_remove,
145 	.id_table = lv5207lp_ids,
146 };
147 
148 module_i2c_driver(lv5207lp_driver);
149 
150 MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
151 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
152 MODULE_LICENSE("GPL");
153