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