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
38struct lv5207lp {
39	struct i2c_client *client;
40	struct backlight_device *backlight;
41	struct lv5207lp_platform_data *pdata;
42};
43
44static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
45{
46	return i2c_smbus_write_byte_data(lv->client, reg, data);
47}
48
49static 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
73static 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
81static 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
87static 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
135static 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
145static const struct i2c_device_id lv5207lp_ids[] = {
146	{ "lv5207lp", 0 },
147	{ }
148};
149MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
150
151static 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
160module_i2c_driver(lv5207lp_driver);
161
162MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
163MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
164MODULE_LICENSE("GPL");
165