1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ROHM Semiconductor BD6107 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/delay.h>
12#include <linux/err.h>
13#include <linux/fb.h>
14#include <linux/gpio/consumer.h>
15#include <linux/i2c.h>
16#include <linux/module.h>
17#include <linux/platform_data/bd6107.h>
18#include <linux/slab.h>
19
20#define BD6107_PSCNT1				0x00
21#define BD6107_PSCNT1_PSCNTREG2			(1 << 2)
22#define BD6107_PSCNT1_PSCNTREG1			(1 << 0)
23#define BD6107_REGVSET				0x02
24#define BD6107_REGVSET_REG1VSET_2_85V		(1 << 2)
25#define BD6107_REGVSET_REG1VSET_2_80V		(0 << 2)
26#define BD6107_LEDCNT1				0x03
27#define BD6107_LEDCNT1_LEDONOFF2		(1 << 1)
28#define BD6107_LEDCNT1_LEDONOFF1		(1 << 0)
29#define BD6107_PORTSEL				0x04
30#define BD6107_PORTSEL_LEDM(n)			(1 << (n))
31#define BD6107_RGB1CNT1				0x05
32#define BD6107_RGB1CNT2				0x06
33#define BD6107_RGB1CNT3				0x07
34#define BD6107_RGB1CNT4				0x08
35#define BD6107_RGB1CNT5				0x09
36#define BD6107_RGB1FLM				0x0a
37#define BD6107_RGB2CNT1				0x0b
38#define BD6107_RGB2CNT2				0x0c
39#define BD6107_RGB2CNT3				0x0d
40#define BD6107_RGB2CNT4				0x0e
41#define BD6107_RGB2CNT5				0x0f
42#define BD6107_RGB2FLM				0x10
43#define BD6107_PSCONT3				0x11
44#define BD6107_SMMONCNT				0x12
45#define BD6107_DCDCCNT				0x13
46#define BD6107_IOSEL				0x14
47#define BD6107_OUT1				0x15
48#define BD6107_OUT2				0x16
49#define BD6107_MASK1				0x17
50#define BD6107_MASK2				0x18
51#define BD6107_FACTOR1				0x19
52#define BD6107_FACTOR2				0x1a
53#define BD6107_CLRFACT1				0x1b
54#define BD6107_CLRFACT2				0x1c
55#define BD6107_STATE1				0x1d
56#define BD6107_LSIVER				0x1e
57#define BD6107_GRPSEL				0x1f
58#define BD6107_LEDCNT2				0x20
59#define BD6107_LEDCNT3				0x21
60#define BD6107_MCURRENT				0x22
61#define BD6107_MAINCNT1				0x23
62#define BD6107_MAINCNT2				0x24
63#define BD6107_SLOPECNT				0x25
64#define BD6107_MSLOPE				0x26
65#define BD6107_RGBSLOPE				0x27
66#define BD6107_TEST				0x29
67#define BD6107_SFTRST				0x2a
68#define BD6107_SFTRSTGD				0x2b
69
70struct bd6107 {
71	struct i2c_client *client;
72	struct backlight_device *backlight;
73	struct bd6107_platform_data *pdata;
74	struct gpio_desc *reset;
75};
76
77static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
78{
79	return i2c_smbus_write_byte_data(bd->client, reg, data);
80}
81
82static int bd6107_backlight_update_status(struct backlight_device *backlight)
83{
84	struct bd6107 *bd = bl_get_data(backlight);
85	int brightness = backlight_get_brightness(backlight);
86
87	if (brightness) {
88		bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
89			     BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
90		bd6107_write(bd, BD6107_MAINCNT1, brightness);
91		bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
92	} else {
93		/* Assert the reset line (gpiolib will handle active low) */
94		gpiod_set_value(bd->reset, 1);
95		msleep(24);
96		gpiod_set_value(bd->reset, 0);
97	}
98
99	return 0;
100}
101
102static int bd6107_backlight_check_fb(struct backlight_device *backlight,
103				       struct fb_info *info)
104{
105	struct bd6107 *bd = bl_get_data(backlight);
106
107	return !bd->pdata->dev || bd->pdata->dev == info->device;
108}
109
110static const struct backlight_ops bd6107_backlight_ops = {
111	.options	= BL_CORE_SUSPENDRESUME,
112	.update_status	= bd6107_backlight_update_status,
113	.check_fb	= bd6107_backlight_check_fb,
114};
115
116static int bd6107_probe(struct i2c_client *client)
117{
118	struct bd6107_platform_data *pdata = dev_get_platdata(&client->dev);
119	struct backlight_device *backlight;
120	struct backlight_properties props;
121	struct bd6107 *bd;
122
123	if (pdata == NULL) {
124		dev_err(&client->dev, "No platform data\n");
125		return -EINVAL;
126	}
127
128	if (!i2c_check_functionality(client->adapter,
129				     I2C_FUNC_SMBUS_BYTE_DATA)) {
130		dev_warn(&client->dev,
131			 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
132		return -EIO;
133	}
134
135	bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
136	if (!bd)
137		return -ENOMEM;
138
139	bd->client = client;
140	bd->pdata = pdata;
141
142	/*
143	 * Request the reset GPIO line with GPIOD_OUT_HIGH meaning asserted,
144	 * so in the machine descriptor table (or other hardware description),
145	 * the line should be flagged as active low so this will assert
146	 * the reset.
147	 */
148	bd->reset = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
149	if (IS_ERR(bd->reset))
150		return dev_err_probe(&client->dev, PTR_ERR(bd->reset),
151				     "unable to request reset GPIO\n");
152
153	memset(&props, 0, sizeof(props));
154	props.type = BACKLIGHT_RAW;
155	props.max_brightness = 128;
156	props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
157				   props.max_brightness);
158
159	backlight = devm_backlight_device_register(&client->dev,
160					      dev_name(&client->dev),
161					      &bd->client->dev, bd,
162					      &bd6107_backlight_ops, &props);
163	if (IS_ERR(backlight)) {
164		dev_err(&client->dev, "failed to register backlight\n");
165		return PTR_ERR(backlight);
166	}
167
168	backlight_update_status(backlight);
169	i2c_set_clientdata(client, backlight);
170
171	return 0;
172}
173
174static void bd6107_remove(struct i2c_client *client)
175{
176	struct backlight_device *backlight = i2c_get_clientdata(client);
177
178	backlight->props.brightness = 0;
179	backlight_update_status(backlight);
180}
181
182static const struct i2c_device_id bd6107_ids[] = {
183	{ "bd6107", 0 },
184	{ }
185};
186MODULE_DEVICE_TABLE(i2c, bd6107_ids);
187
188static struct i2c_driver bd6107_driver = {
189	.driver = {
190		.name = "bd6107",
191	},
192	.probe = bd6107_probe,
193	.remove = bd6107_remove,
194	.id_table = bd6107_ids,
195};
196
197module_i2c_driver(bd6107_driver);
198
199MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
200MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
201MODULE_LICENSE("GPL");
202