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/fb.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_new	= 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");
180