lv5207lp.c

  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
 34struct lv5207lp {
 35	struct i2c_client *client;
 36	struct backlight_device *backlight;
 37	struct lv5207lp_platform_data *pdata;
 38};
 39
 40static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
 41{
 42	return i2c_smbus_write_byte_data(lv->client, reg, data);
 43}
 44
 45static 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
 64static 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
 72static 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
 78static 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
125static 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
133static const struct i2c_device_id lv5207lp_ids[] = {
134	{ "lv5207lp" },
135	{ }
136};
137MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
138
139static 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
148module_i2c_driver(lv5207lp_driver);
149
150MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
151MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
152MODULE_LICENSE("GPL");