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
da9052_adjust_wled_brightness(struct da9052_bl * wleds)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
da9052_backlight_update_status(struct backlight_device * bl)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
da9052_backlight_get_brightness(struct backlight_device * bl)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
da9052_backlight_probe(struct platform_device * pdev)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 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
da9052_backlight_remove(struct platform_device * pdev)139 static 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
149 static 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 };
164 MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
165
166 static 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
175 module_platform_driver(da9052_wled_driver);
176
177 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
178 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
179 MODULE_LICENSE("GPL");
180