bd6107.c

  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/gpio/consumer.h>
 14#include <linux/i2c.h>
 15#include <linux/module.h>
 16#include <linux/platform_data/bd6107.h>
 17#include <linux/slab.h>
 18
 19#define BD6107_PSCNT1				0x00
 20#define BD6107_PSCNT1_PSCNTREG2			(1 << 2)
 21#define BD6107_PSCNT1_PSCNTREG1			(1 << 0)
 22#define BD6107_REGVSET				0x02
 23#define BD6107_REGVSET_REG1VSET_2_85V		(1 << 2)
 24#define BD6107_REGVSET_REG1VSET_2_80V		(0 << 2)
 25#define BD6107_LEDCNT1				0x03
 26#define BD6107_LEDCNT1_LEDONOFF2		(1 << 1)
 27#define BD6107_LEDCNT1_LEDONOFF1		(1 << 0)
 28#define BD6107_PORTSEL				0x04
 29#define BD6107_PORTSEL_LEDM(n)			(1 << (n))
 30#define BD6107_RGB1CNT1				0x05
 31#define BD6107_RGB1CNT2				0x06
 32#define BD6107_RGB1CNT3				0x07
 33#define BD6107_RGB1CNT4				0x08
 34#define BD6107_RGB1CNT5				0x09
 35#define BD6107_RGB1FLM				0x0a
 36#define BD6107_RGB2CNT1				0x0b
 37#define BD6107_RGB2CNT2				0x0c
 38#define BD6107_RGB2CNT3				0x0d
 39#define BD6107_RGB2CNT4				0x0e
 40#define BD6107_RGB2CNT5				0x0f
 41#define BD6107_RGB2FLM				0x10
 42#define BD6107_PSCONT3				0x11
 43#define BD6107_SMMONCNT				0x12
 44#define BD6107_DCDCCNT				0x13
 45#define BD6107_IOSEL				0x14
 46#define BD6107_OUT1				0x15
 47#define BD6107_OUT2				0x16
 48#define BD6107_MASK1				0x17
 49#define BD6107_MASK2				0x18
 50#define BD6107_FACTOR1				0x19
 51#define BD6107_FACTOR2				0x1a
 52#define BD6107_CLRFACT1				0x1b
 53#define BD6107_CLRFACT2				0x1c
 54#define BD6107_STATE1				0x1d
 55#define BD6107_LSIVER				0x1e
 56#define BD6107_GRPSEL				0x1f
 57#define BD6107_LEDCNT2				0x20
 58#define BD6107_LEDCNT3				0x21
 59#define BD6107_MCURRENT				0x22
 60#define BD6107_MAINCNT1				0x23
 61#define BD6107_MAINCNT2				0x24
 62#define BD6107_SLOPECNT				0x25
 63#define BD6107_MSLOPE				0x26
 64#define BD6107_RGBSLOPE				0x27
 65#define BD6107_TEST				0x29
 66#define BD6107_SFTRST				0x2a
 67#define BD6107_SFTRSTGD				0x2b
 68
 69struct bd6107 {
 70	struct i2c_client *client;
 71	struct backlight_device *backlight;
 72	struct bd6107_platform_data *pdata;
 73	struct gpio_desc *reset;
 74};
 75
 76static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
 77{
 78	return i2c_smbus_write_byte_data(bd->client, reg, data);
 79}
 80
 81static int bd6107_backlight_update_status(struct backlight_device *backlight)
 82{
 83	struct bd6107 *bd = bl_get_data(backlight);
 84	int brightness = backlight_get_brightness(backlight);
 85
 86	if (brightness) {
 87		bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
 88			     BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
 89		bd6107_write(bd, BD6107_MAINCNT1, brightness);
 90		bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
 91	} else {
 92		/* Assert the reset line (gpiolib will handle active low) */
 93		gpiod_set_value(bd->reset, 1);
 94		msleep(24);
 95		gpiod_set_value(bd->reset, 0);
 96	}
 97
 98	return 0;
 99}
100
101static bool bd6107_backlight_controls_device(struct backlight_device *backlight,
102					     struct device *display_dev)
103{
104	struct bd6107 *bd = bl_get_data(backlight);
105
106	return !bd->pdata->dev || bd->pdata->dev == display_dev;
107}
108
109static const struct backlight_ops bd6107_backlight_ops = {
110	.options	 = BL_CORE_SUSPENDRESUME,
111	.update_status	 = bd6107_backlight_update_status,
112	.controls_device = bd6107_backlight_controls_device,
113};
114
115static int bd6107_probe(struct i2c_client *client)
116{
117	struct bd6107_platform_data *pdata = dev_get_platdata(&client->dev);
118	struct backlight_device *backlight;
119	struct backlight_properties props;
120	struct bd6107 *bd;
121
122	if (pdata == NULL) {
123		dev_err(&client->dev, "No platform data\n");
124		return -EINVAL;
125	}
126
127	if (!i2c_check_functionality(client->adapter,
128				     I2C_FUNC_SMBUS_BYTE_DATA)) {
129		dev_warn(&client->dev,
130			 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
131		return -EIO;
132	}
133
134	bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
135	if (!bd)
136		return -ENOMEM;
137
138	bd->client = client;
139	bd->pdata = pdata;
140
141	/*
142	 * Request the reset GPIO line with GPIOD_OUT_HIGH meaning asserted,
143	 * so in the machine descriptor table (or other hardware description),
144	 * the line should be flagged as active low so this will assert
145	 * the reset.
146	 */
147	bd->reset = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
148	if (IS_ERR(bd->reset))
149		return dev_err_probe(&client->dev, PTR_ERR(bd->reset),
150				     "unable to request reset GPIO\n");
151
152	memset(&props, 0, sizeof(props));
153	props.type = BACKLIGHT_RAW;
154	props.max_brightness = 128;
155	props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
156				   props.max_brightness);
157
158	backlight = devm_backlight_device_register(&client->dev,
159					      dev_name(&client->dev),
160					      &bd->client->dev, bd,
161					      &bd6107_backlight_ops, &props);
162	if (IS_ERR(backlight)) {
163		dev_err(&client->dev, "failed to register backlight\n");
164		return PTR_ERR(backlight);
165	}
166
167	backlight_update_status(backlight);
168	i2c_set_clientdata(client, backlight);
169
170	return 0;
171}
172
173static void bd6107_remove(struct i2c_client *client)
174{
175	struct backlight_device *backlight = i2c_get_clientdata(client);
176
177	backlight->props.brightness = 0;
178	backlight_update_status(backlight);
179}
180
181static const struct i2c_device_id bd6107_ids[] = {
182	{ "bd6107" },
183	{ }
184};
185MODULE_DEVICE_TABLE(i2c, bd6107_ids);
186
187static struct i2c_driver bd6107_driver = {
188	.driver = {
189		.name = "bd6107",
190	},
191	.probe = bd6107_probe,
192	.remove = bd6107_remove,
193	.id_table = bd6107_ids,
194};
195
196module_i2c_driver(bd6107_driver);
197
198MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
199MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
200MODULE_LICENSE("GPL");