Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d4cc6a2e AO |
2 | /* |
3 | * leds-regulator.c - LED class driver for regulator driven LEDs. | |
4 | * | |
5 | * Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it> | |
6 | * | |
7 | * Inspired by leds-wm8350 driver. | |
d4cc6a2e AO |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/err.h> | |
5a0e3ad6 | 12 | #include <linux/slab.h> |
d4cc6a2e AO |
13 | #include <linux/leds.h> |
14 | #include <linux/leds-regulator.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/regulator/consumer.h> | |
17 | ||
18 | #define to_regulator_led(led_cdev) \ | |
19 | container_of(led_cdev, struct regulator_led, cdev) | |
20 | ||
21 | struct regulator_led { | |
22 | struct led_classdev cdev; | |
d4cc6a2e AO |
23 | int enabled; |
24 | struct mutex mutex; | |
d4cc6a2e AO |
25 | |
26 | struct regulator *vcc; | |
27 | }; | |
28 | ||
29 | static inline int led_regulator_get_max_brightness(struct regulator *supply) | |
30 | { | |
31 | int ret; | |
32 | int voltage = regulator_list_voltage(supply, 0); | |
33 | ||
34 | if (voltage <= 0) | |
35 | return 1; | |
36 | ||
37 | /* even if regulator can't change voltages, | |
38 | * we still assume it can change status | |
39 | * and the LED can be turned on and off. | |
40 | */ | |
41 | ret = regulator_set_voltage(supply, voltage, voltage); | |
42 | if (ret < 0) | |
43 | return 1; | |
44 | ||
45 | return regulator_count_voltages(supply); | |
46 | } | |
47 | ||
48 | static int led_regulator_get_voltage(struct regulator *supply, | |
49 | enum led_brightness brightness) | |
50 | { | |
51 | if (brightness == 0) | |
52 | return -EINVAL; | |
53 | ||
54 | return regulator_list_voltage(supply, brightness - 1); | |
55 | } | |
56 | ||
57 | ||
58 | static void regulator_led_enable(struct regulator_led *led) | |
59 | { | |
60 | int ret; | |
61 | ||
62 | if (led->enabled) | |
63 | return; | |
64 | ||
65 | ret = regulator_enable(led->vcc); | |
66 | if (ret != 0) { | |
67 | dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret); | |
68 | return; | |
69 | } | |
70 | ||
71 | led->enabled = 1; | |
72 | } | |
73 | ||
74 | static void regulator_led_disable(struct regulator_led *led) | |
75 | { | |
76 | int ret; | |
77 | ||
78 | if (!led->enabled) | |
79 | return; | |
80 | ||
81 | ret = regulator_disable(led->vcc); | |
82 | if (ret != 0) { | |
83 | dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret); | |
84 | return; | |
85 | } | |
86 | ||
87 | led->enabled = 0; | |
88 | } | |
89 | ||
77e85036 AL |
90 | static int regulator_led_brightness_set(struct led_classdev *led_cdev, |
91 | enum led_brightness value) | |
d4cc6a2e | 92 | { |
77e85036 | 93 | struct regulator_led *led = to_regulator_led(led_cdev); |
d4cc6a2e | 94 | int voltage; |
77e85036 | 95 | int ret = 0; |
d4cc6a2e AO |
96 | |
97 | mutex_lock(&led->mutex); | |
98 | ||
77e85036 | 99 | if (value == LED_OFF) { |
d4cc6a2e AO |
100 | regulator_led_disable(led); |
101 | goto out; | |
102 | } | |
103 | ||
104 | if (led->cdev.max_brightness > 1) { | |
77e85036 | 105 | voltage = led_regulator_get_voltage(led->vcc, value); |
d4cc6a2e | 106 | dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n", |
77e85036 | 107 | value, voltage); |
d4cc6a2e AO |
108 | |
109 | ret = regulator_set_voltage(led->vcc, voltage, voltage); | |
110 | if (ret != 0) | |
111 | dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n", | |
112 | voltage, ret); | |
113 | } | |
114 | ||
115 | regulator_led_enable(led); | |
116 | ||
117 | out: | |
118 | mutex_unlock(&led->mutex); | |
77e85036 | 119 | return ret; |
d4cc6a2e AO |
120 | } |
121 | ||
98ea1ea2 | 122 | static int regulator_led_probe(struct platform_device *pdev) |
d4cc6a2e | 123 | { |
87aae1ea JH |
124 | struct led_regulator_platform_data *pdata = |
125 | dev_get_platdata(&pdev->dev); | |
d4cc6a2e AO |
126 | struct regulator_led *led; |
127 | struct regulator *vcc; | |
128 | int ret = 0; | |
129 | ||
130 | if (pdata == NULL) { | |
131 | dev_err(&pdev->dev, "no platform data\n"); | |
132 | return -ENODEV; | |
133 | } | |
134 | ||
29ce9feb | 135 | vcc = devm_regulator_get_exclusive(&pdev->dev, "vled"); |
d4cc6a2e AO |
136 | if (IS_ERR(vcc)) { |
137 | dev_err(&pdev->dev, "Cannot get vcc for %s\n", pdata->name); | |
138 | return PTR_ERR(vcc); | |
139 | } | |
140 | ||
d4158965 | 141 | led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL); |
29ce9feb AL |
142 | if (led == NULL) |
143 | return -ENOMEM; | |
d4cc6a2e AO |
144 | |
145 | led->cdev.max_brightness = led_regulator_get_max_brightness(vcc); | |
146 | if (pdata->brightness > led->cdev.max_brightness) { | |
147 | dev_err(&pdev->dev, "Invalid default brightness %d\n", | |
148 | pdata->brightness); | |
29ce9feb | 149 | return -EINVAL; |
d4cc6a2e | 150 | } |
d4cc6a2e | 151 | |
77e85036 | 152 | led->cdev.brightness_set_blocking = regulator_led_brightness_set; |
d4cc6a2e AO |
153 | led->cdev.name = pdata->name; |
154 | led->cdev.flags |= LED_CORE_SUSPENDRESUME; | |
155 | led->vcc = vcc; | |
156 | ||
592ce316 AO |
157 | /* to handle correctly an already enabled regulator */ |
158 | if (regulator_is_enabled(led->vcc)) | |
159 | led->enabled = 1; | |
160 | ||
d4cc6a2e | 161 | mutex_init(&led->mutex); |
d4cc6a2e AO |
162 | |
163 | platform_set_drvdata(pdev, led); | |
164 | ||
165 | ret = led_classdev_register(&pdev->dev, &led->cdev); | |
77e85036 | 166 | if (ret < 0) |
29ce9feb | 167 | return ret; |
d4cc6a2e AO |
168 | |
169 | /* to expose the default value to userspace */ | |
77e85036 | 170 | led->cdev.brightness = pdata->brightness; |
d4cc6a2e AO |
171 | |
172 | /* Set the default led status */ | |
77e85036 | 173 | regulator_led_brightness_set(&led->cdev, led->cdev.brightness); |
d4cc6a2e AO |
174 | |
175 | return 0; | |
d4cc6a2e AO |
176 | } |
177 | ||
678e8a6b | 178 | static int regulator_led_remove(struct platform_device *pdev) |
d4cc6a2e AO |
179 | { |
180 | struct regulator_led *led = platform_get_drvdata(pdev); | |
181 | ||
182 | led_classdev_unregister(&led->cdev); | |
d4cc6a2e | 183 | regulator_led_disable(led); |
d4cc6a2e AO |
184 | return 0; |
185 | } | |
186 | ||
187 | static struct platform_driver regulator_led_driver = { | |
188 | .driver = { | |
189 | .name = "leds-regulator", | |
d4cc6a2e AO |
190 | }, |
191 | .probe = regulator_led_probe, | |
df07cf81 | 192 | .remove = regulator_led_remove, |
d4cc6a2e AO |
193 | }; |
194 | ||
892a8843 | 195 | module_platform_driver(regulator_led_driver); |
d4cc6a2e AO |
196 | |
197 | MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>"); | |
198 | MODULE_DESCRIPTION("Regulator driven LED driver"); | |
199 | MODULE_LICENSE("GPL"); | |
200 | MODULE_ALIAS("platform:leds-regulator"); |