1/*
2 * ROHM Semiconductor BD6107 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/delay.h>
15#include <linux/err.h>
16#include <linux/fb.h>
17#include <linux/gpio.h>
18#include <linux/i2c.h>
19#include <linux/module.h>
20#include <linux/platform_data/bd6107.h>
21#include <linux/slab.h>
22
23#define BD6107_PSCNT1				0x00
24#define BD6107_PSCNT1_PSCNTREG2			(1 << 2)
25#define BD6107_PSCNT1_PSCNTREG1			(1 << 0)
26#define BD6107_REGVSET				0x02
27#define BD6107_REGVSET_REG1VSET_2_85V		(1 << 2)
28#define BD6107_REGVSET_REG1VSET_2_80V		(0 << 2)
29#define BD6107_LEDCNT1				0x03
30#define BD6107_LEDCNT1_LEDONOFF2		(1 << 1)
31#define BD6107_LEDCNT1_LEDONOFF1		(1 << 0)
32#define BD6107_PORTSEL				0x04
33#define BD6107_PORTSEL_LEDM(n)			(1 << (n))
34#define BD6107_RGB1CNT1				0x05
35#define BD6107_RGB1CNT2				0x06
36#define BD6107_RGB1CNT3				0x07
37#define BD6107_RGB1CNT4				0x08
38#define BD6107_RGB1CNT5				0x09
39#define BD6107_RGB1FLM				0x0a
40#define BD6107_RGB2CNT1				0x0b
41#define BD6107_RGB2CNT2				0x0c
42#define BD6107_RGB2CNT3				0x0d
43#define BD6107_RGB2CNT4				0x0e
44#define BD6107_RGB2CNT5				0x0f
45#define BD6107_RGB2FLM				0x10
46#define BD6107_PSCONT3				0x11
47#define BD6107_SMMONCNT				0x12
48#define BD6107_DCDCCNT				0x13
49#define BD6107_IOSEL				0x14
50#define BD6107_OUT1				0x15
51#define BD6107_OUT2				0x16
52#define BD6107_MASK1				0x17
53#define BD6107_MASK2				0x18
54#define BD6107_FACTOR1				0x19
55#define BD6107_FACTOR2				0x1a
56#define BD6107_CLRFACT1				0x1b
57#define BD6107_CLRFACT2				0x1c
58#define BD6107_STATE1				0x1d
59#define BD6107_LSIVER				0x1e
60#define BD6107_GRPSEL				0x1f
61#define BD6107_LEDCNT2				0x20
62#define BD6107_LEDCNT3				0x21
63#define BD6107_MCURRENT				0x22
64#define BD6107_MAINCNT1				0x23
65#define BD6107_MAINCNT2				0x24
66#define BD6107_SLOPECNT				0x25
67#define BD6107_MSLOPE				0x26
68#define BD6107_RGBSLOPE				0x27
69#define BD6107_TEST				0x29
70#define BD6107_SFTRST				0x2a
71#define BD6107_SFTRSTGD				0x2b
72
73struct bd6107 {
74	struct i2c_client *client;
75	struct backlight_device *backlight;
76	struct bd6107_platform_data *pdata;
77};
78
79static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
80{
81	return i2c_smbus_write_byte_data(bd->client, reg, data);
82}
83
84static int bd6107_backlight_update_status(struct backlight_device *backlight)
85{
86	struct bd6107 *bd = bl_get_data(backlight);
87	int brightness = backlight->props.brightness;
88
89	if (backlight->props.power != FB_BLANK_UNBLANK ||
90	    backlight->props.fb_blank != FB_BLANK_UNBLANK ||
91	    backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
92		brightness = 0;
93
94	if (brightness) {
95		bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
96			     BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
97		bd6107_write(bd, BD6107_MAINCNT1, brightness);
98		bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
99	} else {
100		gpio_set_value(bd->pdata->reset, 0);
101		msleep(24);
102		gpio_set_value(bd->pdata->reset, 1);
103	}
104
105	return 0;
106}
107
108static int bd6107_backlight_check_fb(struct backlight_device *backlight,
109				       struct fb_info *info)
110{
111	struct bd6107 *bd = bl_get_data(backlight);
112
113	return bd->pdata->fbdev == NULL || bd->pdata->fbdev == info->dev;
114}
115
116static const struct backlight_ops bd6107_backlight_ops = {
117	.options	= BL_CORE_SUSPENDRESUME,
118	.update_status	= bd6107_backlight_update_status,
119	.check_fb	= bd6107_backlight_check_fb,
120};
121
122static int bd6107_probe(struct i2c_client *client,
123			  const struct i2c_device_id *id)
124{
125	struct bd6107_platform_data *pdata = dev_get_platdata(&client->dev);
126	struct backlight_device *backlight;
127	struct backlight_properties props;
128	struct bd6107 *bd;
129	int ret;
130
131	if (pdata == NULL || !pdata->reset) {
132		dev_err(&client->dev, "No reset GPIO in platform data\n");
133		return -EINVAL;
134	}
135
136	if (!i2c_check_functionality(client->adapter,
137				     I2C_FUNC_SMBUS_BYTE_DATA)) {
138		dev_warn(&client->dev,
139			 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
140		return -EIO;
141	}
142
143	bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
144	if (!bd)
145		return -ENOMEM;
146
147	bd->client = client;
148	bd->pdata = pdata;
149
150	ret = devm_gpio_request_one(&client->dev, pdata->reset,
151				    GPIOF_DIR_OUT | GPIOF_INIT_LOW, "reset");
152	if (ret < 0) {
153		dev_err(&client->dev, "unable to request reset GPIO\n");
154		return ret;
155	}
156
157	memset(&props, 0, sizeof(props));
158	props.type = BACKLIGHT_RAW;
159	props.max_brightness = 128;
160	props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
161				   props.max_brightness);
162
163	backlight = devm_backlight_device_register(&client->dev,
164					      dev_name(&client->dev),
165					      &bd->client->dev, bd,
166					      &bd6107_backlight_ops, &props);
167	if (IS_ERR(backlight)) {
168		dev_err(&client->dev, "failed to register backlight\n");
169		return PTR_ERR(backlight);
170	}
171
172	backlight_update_status(backlight);
173	i2c_set_clientdata(client, backlight);
174
175	return 0;
176}
177
178static int bd6107_remove(struct i2c_client *client)
179{
180	struct backlight_device *backlight = i2c_get_clientdata(client);
181
182	backlight->props.brightness = 0;
183	backlight_update_status(backlight);
184
185	return 0;
186}
187
188static const struct i2c_device_id bd6107_ids[] = {
189	{ "bd6107", 0 },
190	{ }
191};
192MODULE_DEVICE_TABLE(i2c, bd6107_ids);
193
194static struct i2c_driver bd6107_driver = {
195	.driver = {
196		.name = "bd6107",
197	},
198	.probe = bd6107_probe,
199	.remove = bd6107_remove,
200	.id_table = bd6107_ids,
201};
202
203module_i2c_driver(bd6107_driver);
204
205MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
206MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
207MODULE_LICENSE("GPL");
208