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 
21 enum {
22 	DA9052_WLEDS_OFF,
23 	DA9052_WLEDS_ON,
24 };
25 
26 enum {
27 	DA9052_TYPE_WLED1,
28 	DA9052_TYPE_WLED2,
29 	DA9052_TYPE_WLED3,
30 };
31 
32 static const unsigned char wled_bank[] = {
33 	DA9052_LED1_CONF_REG,
34 	DA9052_LED2_CONF_REG,
35 	DA9052_LED3_CONF_REG,
36 };
37 
38 struct da9052_bl {
39 	struct da9052 *da9052;
40 	uint brightness;
41 	uint state;
42 	uint led_reg;
43 };
44 
45 static 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 
82 static 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 
93 static 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 
100 static const struct backlight_ops da9052_backlight_ops = {
101 	.update_status = da9052_backlight_update_status,
102 	.get_brightness = da9052_backlight_get_brightness,
103 };
104 
105 static 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 	props.type = BACKLIGHT_RAW;
121 	props.max_brightness = DA9052_MAX_BRIGHTNESS;
122 
123 	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
124 					wleds->da9052->dev, wleds,
125 					&da9052_backlight_ops, &props);
126 	if (IS_ERR(bl)) {
127 		dev_err(&pdev->dev, "Failed to register backlight\n");
128 		return PTR_ERR(bl);
129 	}
130 
131 	bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
132 	bl->props.brightness = 0;
133 	platform_set_drvdata(pdev, bl);
134 
135 	return da9052_adjust_wled_brightness(wleds);
136 }
137 
138 static int da9052_backlight_remove(struct platform_device *pdev)
139 {
140 	struct backlight_device *bl = platform_get_drvdata(pdev);
141 	struct da9052_bl *wleds = bl_get_data(bl);
142 
143 	wleds->brightness = 0;
144 	wleds->state = DA9052_WLEDS_OFF;
145 	da9052_adjust_wled_brightness(wleds);
146 
147 	return 0;
148 }
149 
150 static const struct platform_device_id da9052_wled_ids[] = {
151 	{
152 		.name		= "da9052-wled1",
153 		.driver_data	= DA9052_TYPE_WLED1,
154 	},
155 	{
156 		.name		= "da9052-wled2",
157 		.driver_data	= DA9052_TYPE_WLED2,
158 	},
159 	{
160 		.name		= "da9052-wled3",
161 		.driver_data	= DA9052_TYPE_WLED3,
162 	},
163 	{ },
164 };
165 MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
166 
167 static struct platform_driver da9052_wled_driver = {
168 	.probe		= da9052_backlight_probe,
169 	.remove		= da9052_backlight_remove,
170 	.id_table	= da9052_wled_ids,
171 	.driver	= {
172 		.name	= "da9052-wled",
173 	},
174 };
175 
176 module_platform_driver(da9052_wled_driver);
177 
178 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
179 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
180 MODULE_LICENSE("GPL");
181