1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2017 Sebastian Reichel <sre@kernel.org>
4 */
5
6 #include <linux/leds.h>
7 #include <linux/mfd/motorola-cpcap.h>
8 #include <linux/module.h>
9 #include <linux/mutex.h>
10 #include <linux/of_device.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
13 #include <linux/regulator/consumer.h>
14
15 #define CPCAP_LED_NO_CURRENT 0x0001
16
17 struct cpcap_led_info {
18 u16 reg;
19 u16 mask;
20 u16 limit;
21 u16 init_mask;
22 u16 init_val;
23 };
24
25 static const struct cpcap_led_info cpcap_led_red = {
26 .reg = CPCAP_REG_REDC,
27 .mask = 0x03FF,
28 .limit = 31,
29 };
30
31 static const struct cpcap_led_info cpcap_led_green = {
32 .reg = CPCAP_REG_GREENC,
33 .mask = 0x03FF,
34 .limit = 31,
35 };
36
37 static const struct cpcap_led_info cpcap_led_blue = {
38 .reg = CPCAP_REG_BLUEC,
39 .mask = 0x03FF,
40 .limit = 31,
41 };
42
43 /* aux display light */
44 static const struct cpcap_led_info cpcap_led_adl = {
45 .reg = CPCAP_REG_ADLC,
46 .mask = 0x000F,
47 .limit = 1,
48 .init_mask = 0x7FFF,
49 .init_val = 0x5FF0,
50 };
51
52 /* camera privacy led */
53 static const struct cpcap_led_info cpcap_led_cp = {
54 .reg = CPCAP_REG_CLEDC,
55 .mask = 0x0007,
56 .limit = 1,
57 .init_mask = 0x03FF,
58 .init_val = 0x0008,
59 };
60
61 struct cpcap_led {
62 struct led_classdev led;
63 const struct cpcap_led_info *info;
64 struct device *dev;
65 struct regmap *regmap;
66 struct mutex update_lock;
67 struct regulator *vdd;
68 bool powered;
69
70 u32 current_limit;
71 };
72
cpcap_led_val(u8 current_limit,u8 duty_cycle)73 static u16 cpcap_led_val(u8 current_limit, u8 duty_cycle)
74 {
75 current_limit &= 0x1f; /* 5 bit */
76 duty_cycle &= 0x0f; /* 4 bit */
77
78 return current_limit << 4 | duty_cycle;
79 }
80
cpcap_led_set_power(struct cpcap_led * led,bool status)81 static int cpcap_led_set_power(struct cpcap_led *led, bool status)
82 {
83 int err;
84
85 if (status == led->powered)
86 return 0;
87
88 if (status)
89 err = regulator_enable(led->vdd);
90 else
91 err = regulator_disable(led->vdd);
92
93 if (err) {
94 dev_err(led->dev, "regulator failure: %d", err);
95 return err;
96 }
97
98 led->powered = status;
99
100 return 0;
101 }
102
cpcap_led_set(struct led_classdev * ledc,enum led_brightness value)103 static int cpcap_led_set(struct led_classdev *ledc, enum led_brightness value)
104 {
105 struct cpcap_led *led = container_of(ledc, struct cpcap_led, led);
106 int brightness;
107 int err;
108
109 mutex_lock(&led->update_lock);
110
111 if (value > LED_OFF) {
112 err = cpcap_led_set_power(led, true);
113 if (err)
114 goto exit;
115 }
116
117 if (value == LED_OFF) {
118 /* Avoid HW issue by turning off current before duty cycle */
119 err = regmap_update_bits(led->regmap,
120 led->info->reg, led->info->mask, CPCAP_LED_NO_CURRENT);
121 if (err) {
122 dev_err(led->dev, "regmap failed: %d", err);
123 goto exit;
124 }
125
126 brightness = cpcap_led_val(value, LED_OFF);
127 } else {
128 brightness = cpcap_led_val(value, LED_ON);
129 }
130
131 err = regmap_update_bits(led->regmap, led->info->reg, led->info->mask,
132 brightness);
133 if (err) {
134 dev_err(led->dev, "regmap failed: %d", err);
135 goto exit;
136 }
137
138 if (value == LED_OFF) {
139 err = cpcap_led_set_power(led, false);
140 if (err)
141 goto exit;
142 }
143
144 exit:
145 mutex_unlock(&led->update_lock);
146 return err;
147 }
148
149 static const struct of_device_id cpcap_led_of_match[] = {
150 { .compatible = "motorola,cpcap-led-red", .data = &cpcap_led_red },
151 { .compatible = "motorola,cpcap-led-green", .data = &cpcap_led_green },
152 { .compatible = "motorola,cpcap-led-blue", .data = &cpcap_led_blue },
153 { .compatible = "motorola,cpcap-led-adl", .data = &cpcap_led_adl },
154 { .compatible = "motorola,cpcap-led-cp", .data = &cpcap_led_cp },
155 {},
156 };
157 MODULE_DEVICE_TABLE(of, cpcap_led_of_match);
158
cpcap_led_probe(struct platform_device * pdev)159 static int cpcap_led_probe(struct platform_device *pdev)
160 {
161 struct cpcap_led *led;
162 int err;
163
164 led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
165 if (!led)
166 return -ENOMEM;
167 platform_set_drvdata(pdev, led);
168 led->info = device_get_match_data(&pdev->dev);
169 led->dev = &pdev->dev;
170
171 if (led->info->reg == 0x0000) {
172 dev_err(led->dev, "Unsupported LED");
173 return -ENODEV;
174 }
175
176 led->regmap = dev_get_regmap(pdev->dev.parent, NULL);
177 if (!led->regmap)
178 return -ENODEV;
179
180 led->vdd = devm_regulator_get(&pdev->dev, "vdd");
181 if (IS_ERR(led->vdd)) {
182 err = PTR_ERR(led->vdd);
183 dev_err(led->dev, "Couldn't get regulator: %d", err);
184 return err;
185 }
186
187 err = device_property_read_string(&pdev->dev, "label", &led->led.name);
188 if (err) {
189 dev_err(led->dev, "Couldn't read LED label: %d", err);
190 return err;
191 }
192
193 if (led->info->init_mask) {
194 err = regmap_update_bits(led->regmap, led->info->reg,
195 led->info->init_mask, led->info->init_val);
196 if (err) {
197 dev_err(led->dev, "regmap failed: %d", err);
198 return err;
199 }
200 }
201
202 mutex_init(&led->update_lock);
203
204 led->led.max_brightness = led->info->limit;
205 led->led.brightness_set_blocking = cpcap_led_set;
206 err = devm_led_classdev_register(&pdev->dev, &led->led);
207 if (err) {
208 dev_err(led->dev, "Couldn't register LED: %d", err);
209 return err;
210 }
211
212 return 0;
213 }
214
215 static struct platform_driver cpcap_led_driver = {
216 .probe = cpcap_led_probe,
217 .driver = {
218 .name = "cpcap-led",
219 .of_match_table = cpcap_led_of_match,
220 },
221 };
222 module_platform_driver(cpcap_led_driver);
223
224 MODULE_DESCRIPTION("CPCAP LED driver");
225 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
226 MODULE_LICENSE("GPL");
227