1/*
2 * Backlight Driver for Dialog DA9052 PMICs
3 *
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
5 *
6 * Author: David Dajun Chen <dchen@diasemi.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 */
14
15#include <linux/backlight.h>
16#include <linux/delay.h>
17#include <linux/fb.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20
21#include <linux/mfd/da9052/da9052.h>
22#include <linux/mfd/da9052/reg.h>
23
24#define DA9052_MAX_BRIGHTNESS		0xFF
25
26enum {
27	DA9052_WLEDS_OFF,
28	DA9052_WLEDS_ON,
29};
30
31enum {
32	DA9052_TYPE_WLED1,
33	DA9052_TYPE_WLED2,
34	DA9052_TYPE_WLED3,
35};
36
37static unsigned char wled_bank[] = {
38	DA9052_LED1_CONF_REG,
39	DA9052_LED2_CONF_REG,
40	DA9052_LED3_CONF_REG,
41};
42
43struct da9052_bl {
44	struct da9052 *da9052;
45	uint brightness;
46	uint state;
47	uint led_reg;
48};
49
50static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
51{
52	unsigned char boost_en;
53	unsigned char i_sink;
54	int ret;
55
56	boost_en = 0x3F;
57	i_sink = 0xFF;
58	if (wleds->state == DA9052_WLEDS_OFF) {
59		boost_en = 0x00;
60		i_sink = 0x00;
61	}
62
63	ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
64	if (ret < 0)
65		return ret;
66
67	ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
68	if (ret < 0)
69		return ret;
70
71	ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
72	if (ret < 0)
73		return ret;
74
75	msleep(10);
76
77	if (wleds->brightness) {
78		ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
79				       wleds->brightness);
80		if (ret < 0)
81			return ret;
82	}
83
84	return 0;
85}
86
87static int da9052_backlight_update_status(struct backlight_device *bl)
88{
89	int brightness = bl->props.brightness;
90	struct da9052_bl *wleds = bl_get_data(bl);
91
92	wleds->brightness = brightness;
93	wleds->state = DA9052_WLEDS_ON;
94
95	return da9052_adjust_wled_brightness(wleds);
96}
97
98static int da9052_backlight_get_brightness(struct backlight_device *bl)
99{
100	struct da9052_bl *wleds = bl_get_data(bl);
101
102	return wleds->brightness;
103}
104
105static const struct backlight_ops da9052_backlight_ops = {
106	.update_status = da9052_backlight_update_status,
107	.get_brightness = da9052_backlight_get_brightness,
108};
109
110static int da9052_backlight_probe(struct platform_device *pdev)
111{
112	struct backlight_device *bl;
113	struct backlight_properties props;
114	struct da9052_bl *wleds;
115
116	wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
117	if (!wleds)
118		return -ENOMEM;
119
120	wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
121	wleds->brightness = 0;
122	wleds->led_reg = platform_get_device_id(pdev)->driver_data;
123	wleds->state = DA9052_WLEDS_OFF;
124
125	props.type = BACKLIGHT_RAW;
126	props.max_brightness = DA9052_MAX_BRIGHTNESS;
127
128	bl = backlight_device_register(pdev->name, wleds->da9052->dev, wleds,
129				       &da9052_backlight_ops, &props);
130	if (IS_ERR(bl)) {
131		dev_err(&pdev->dev, "Failed to register backlight\n");
132		devm_kfree(&pdev->dev, wleds);
133		return PTR_ERR(bl);
134	}
135
136	bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
137	bl->props.brightness = 0;
138	platform_set_drvdata(pdev, bl);
139
140	return da9052_adjust_wled_brightness(wleds);
141}
142
143static int da9052_backlight_remove(struct platform_device *pdev)
144{
145	struct backlight_device *bl = platform_get_drvdata(pdev);
146	struct da9052_bl *wleds = bl_get_data(bl);
147
148	wleds->brightness = 0;
149	wleds->state = DA9052_WLEDS_OFF;
150	da9052_adjust_wled_brightness(wleds);
151	backlight_device_unregister(bl);
152	devm_kfree(&pdev->dev, wleds);
153
154	return 0;
155}
156
157static struct platform_device_id da9052_wled_ids[] = {
158	{
159		.name		= "da9052-wled1",
160		.driver_data	= DA9052_TYPE_WLED1,
161	},
162	{
163		.name		= "da9052-wled2",
164		.driver_data	= DA9052_TYPE_WLED2,
165	},
166	{
167		.name		= "da9052-wled3",
168		.driver_data	= DA9052_TYPE_WLED3,
169	},
170};
171
172static struct platform_driver da9052_wled_driver = {
173	.probe		= da9052_backlight_probe,
174	.remove		= da9052_backlight_remove,
175	.id_table	= da9052_wled_ids,
176	.driver	= {
177		.name	= "da9052-wled",
178		.owner	= THIS_MODULE,
179	},
180};
181
182module_platform_driver(da9052_wled_driver);
183
184MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
185MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
186MODULE_LICENSE("GPL");
187MODULE_ALIAS("platform:da9052-backlight");
188