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/module.h>
13 #include <linux/platform_device.h>
14
15 #include <linux/mfd/da9052/da9052.h>
16 #include <linux/mfd/da9052/reg.h>
17
18 #define DA9052_MAX_BRIGHTNESS 0xFF
19
20 enum {
21 DA9052_WLEDS_OFF,
22 DA9052_WLEDS_ON,
23 };
24
25 enum {
26 DA9052_TYPE_WLED1,
27 DA9052_TYPE_WLED2,
28 DA9052_TYPE_WLED3,
29 };
30
31 static const unsigned char wled_bank[] = {
32 DA9052_LED1_CONF_REG,
33 DA9052_LED2_CONF_REG,
34 DA9052_LED3_CONF_REG,
35 };
36
37 struct da9052_bl {
38 struct da9052 *da9052;
39 uint brightness;
40 uint state;
41 uint led_reg;
42 };
43
da9052_adjust_wled_brightness(struct da9052_bl * wleds)44 static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
45 {
46 unsigned char boost_en;
47 unsigned char i_sink;
48 int ret;
49
50 boost_en = 0x3F;
51 i_sink = 0xFF;
52 if (wleds->state == DA9052_WLEDS_OFF) {
53 boost_en = 0x00;
54 i_sink = 0x00;
55 }
56
57 ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
58 if (ret < 0)
59 return ret;
60
61 ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
62 if (ret < 0)
63 return ret;
64
65 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
66 if (ret < 0)
67 return ret;
68
69 usleep_range(10000, 11000);
70
71 if (wleds->brightness) {
72 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
73 wleds->brightness);
74 if (ret < 0)
75 return ret;
76 }
77
78 return 0;
79 }
80
da9052_backlight_update_status(struct backlight_device * bl)81 static int da9052_backlight_update_status(struct backlight_device *bl)
82 {
83 int brightness = bl->props.brightness;
84 struct da9052_bl *wleds = bl_get_data(bl);
85
86 wleds->brightness = brightness;
87 wleds->state = DA9052_WLEDS_ON;
88
89 return da9052_adjust_wled_brightness(wleds);
90 }
91
da9052_backlight_get_brightness(struct backlight_device * bl)92 static int da9052_backlight_get_brightness(struct backlight_device *bl)
93 {
94 struct da9052_bl *wleds = bl_get_data(bl);
95
96 return wleds->brightness;
97 }
98
99 static const struct backlight_ops da9052_backlight_ops = {
100 .update_status = da9052_backlight_update_status,
101 .get_brightness = da9052_backlight_get_brightness,
102 };
103
da9052_backlight_probe(struct platform_device * pdev)104 static int da9052_backlight_probe(struct platform_device *pdev)
105 {
106 struct backlight_device *bl;
107 struct backlight_properties props;
108 struct da9052_bl *wleds;
109
110 wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
111 if (!wleds)
112 return -ENOMEM;
113
114 wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
115 wleds->brightness = 0;
116 wleds->led_reg = platform_get_device_id(pdev)->driver_data;
117 wleds->state = DA9052_WLEDS_OFF;
118
119 memset(&props, 0, sizeof(struct backlight_properties));
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
da9052_backlight_remove(struct platform_device * pdev)138 static void 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
148 static const struct platform_device_id da9052_wled_ids[] = {
149 {
150 .name = "da9052-wled1",
151 .driver_data = DA9052_TYPE_WLED1,
152 },
153 {
154 .name = "da9052-wled2",
155 .driver_data = DA9052_TYPE_WLED2,
156 },
157 {
158 .name = "da9052-wled3",
159 .driver_data = DA9052_TYPE_WLED3,
160 },
161 { },
162 };
163 MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
164
165 static struct platform_driver da9052_wled_driver = {
166 .probe = da9052_backlight_probe,
167 .remove = da9052_backlight_remove,
168 .id_table = da9052_wled_ids,
169 .driver = {
170 .name = "da9052-wled",
171 },
172 };
173
174 module_platform_driver(da9052_wled_driver);
175
176 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
177 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
178 MODULE_LICENSE("GPL");
179