da9052_bl.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Backlight Driver for Dialog DA9052 PMICs
  4 *
  5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
  6 *
  7 * Author: David Dajun Chen <dchen@diasemi.com>
  8 */
  9
 10#include <linux/backlight.h>
 11#include <linux/delay.h>
 12#include <linux/mod_devicetable.h>
 13#include <linux/module.h>
 14#include <linux/platform_device.h>
 15
 16#include <linux/mfd/da9052/da9052.h>
 17#include <linux/mfd/da9052/reg.h>
 18
 19#define DA9052_MAX_BRIGHTNESS		0xFF
 20
 21enum {
 22	DA9052_WLEDS_OFF,
 23	DA9052_WLEDS_ON,
 24};
 25
 26enum {
 27	DA9052_TYPE_WLED1,
 28	DA9052_TYPE_WLED2,
 29	DA9052_TYPE_WLED3,
 30};
 31
 32static const unsigned char wled_bank[] = {
 33	DA9052_LED1_CONF_REG,
 34	DA9052_LED2_CONF_REG,
 35	DA9052_LED3_CONF_REG,
 36};
 37
 38struct da9052_bl {
 39	struct da9052 *da9052;
 40	uint brightness;
 41	uint state;
 42	uint led_reg;
 43};
 44
 45static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
 46{
 47	unsigned char boost_en;
 48	unsigned char i_sink;
 49	int ret;
 50
 51	boost_en = 0x3F;
 52	i_sink = 0xFF;
 53	if (wleds->state == DA9052_WLEDS_OFF) {
 54		boost_en = 0x00;
 55		i_sink = 0x00;
 56	}
 57
 58	ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
 59	if (ret < 0)
 60		return ret;
 61
 62	ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
 63	if (ret < 0)
 64		return ret;
 65
 66	ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
 67	if (ret < 0)
 68		return ret;
 69
 70	usleep_range(10000, 11000);
 71
 72	if (wleds->brightness) {
 73		ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
 74				       wleds->brightness);
 75		if (ret < 0)
 76			return ret;
 77	}
 78
 79	return 0;
 80}
 81
 82static int da9052_backlight_update_status(struct backlight_device *bl)
 83{
 84	int brightness = bl->props.brightness;
 85	struct da9052_bl *wleds = bl_get_data(bl);
 86
 87	wleds->brightness = brightness;
 88	wleds->state = DA9052_WLEDS_ON;
 89
 90	return da9052_adjust_wled_brightness(wleds);
 91}
 92
 93static int da9052_backlight_get_brightness(struct backlight_device *bl)
 94{
 95	struct da9052_bl *wleds = bl_get_data(bl);
 96
 97	return wleds->brightness;
 98}
 99
100static const struct backlight_ops da9052_backlight_ops = {
101	.update_status = da9052_backlight_update_status,
102	.get_brightness = da9052_backlight_get_brightness,
103};
104
105static int da9052_backlight_probe(struct platform_device *pdev)
106{
107	struct backlight_device *bl;
108	struct backlight_properties props;
109	struct da9052_bl *wleds;
110
111	wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
112	if (!wleds)
113		return -ENOMEM;
114
115	wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
116	wleds->brightness = 0;
117	wleds->led_reg = platform_get_device_id(pdev)->driver_data;
118	wleds->state = DA9052_WLEDS_OFF;
119
120	memset(&props, 0, sizeof(struct backlight_properties));
121	props.type = BACKLIGHT_RAW;
122	props.max_brightness = DA9052_MAX_BRIGHTNESS;
123
124	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
125					wleds->da9052->dev, wleds,
126					&da9052_backlight_ops, &props);
127	if (IS_ERR(bl)) {
128		dev_err(&pdev->dev, "Failed to register backlight\n");
129		return PTR_ERR(bl);
130	}
131
132	bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
133	bl->props.brightness = 0;
134	platform_set_drvdata(pdev, bl);
135
136	return da9052_adjust_wled_brightness(wleds);
137}
138
139static void da9052_backlight_remove(struct platform_device *pdev)
140{
141	struct backlight_device *bl = platform_get_drvdata(pdev);
142	struct da9052_bl *wleds = bl_get_data(bl);
143
144	wleds->brightness = 0;
145	wleds->state = DA9052_WLEDS_OFF;
146	da9052_adjust_wled_brightness(wleds);
147}
148
149static const struct platform_device_id da9052_wled_ids[] = {
150	{
151		.name		= "da9052-wled1",
152		.driver_data	= DA9052_TYPE_WLED1,
153	},
154	{
155		.name		= "da9052-wled2",
156		.driver_data	= DA9052_TYPE_WLED2,
157	},
158	{
159		.name		= "da9052-wled3",
160		.driver_data	= DA9052_TYPE_WLED3,
161	},
162	{ },
163};
164MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
165
166static struct platform_driver da9052_wled_driver = {
167	.probe		= da9052_backlight_probe,
168	.remove		= da9052_backlight_remove,
169	.id_table	= da9052_wled_ids,
170	.driver	= {
171		.name	= "da9052-wled",
172	},
173};
174
175module_platform_driver(da9052_wled_driver);
176
177MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
178MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
179MODULE_LICENSE("GPL");