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1// SPDX-License-Identifier: GPL-2.0-only
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.
8 */
9
10#include <linux/module.h>
11#include <linux/mod_devicetable.h>
12#include <linux/err.h>
13#include <linux/slab.h>
14#include <linux/leds.h>
15#include <linux/leds-regulator.h>
16#include <linux/platform_device.h>
17#include <linux/regulator/consumer.h>
18
19#define to_regulator_led(led_cdev) \
20 container_of(led_cdev, struct regulator_led, cdev)
21
22struct regulator_led {
23 struct led_classdev cdev;
24 int enabled;
25 struct mutex mutex;
26
27 struct regulator *vcc;
28};
29
30static inline int led_regulator_get_max_brightness(struct regulator *supply)
31{
32 int ret;
33 int voltage = regulator_list_voltage(supply, 0);
34
35 if (voltage <= 0)
36 return 1;
37
38 /* even if regulator can't change voltages,
39 * we still assume it can change status
40 * and the LED can be turned on and off.
41 */
42 ret = regulator_set_voltage(supply, voltage, voltage);
43 if (ret < 0)
44 return 1;
45
46 return regulator_count_voltages(supply);
47}
48
49static int led_regulator_get_voltage(struct regulator *supply,
50 enum led_brightness brightness)
51{
52 if (brightness == 0)
53 return -EINVAL;
54
55 return regulator_list_voltage(supply, brightness - 1);
56}
57
58
59static void regulator_led_enable(struct regulator_led *led)
60{
61 int ret;
62
63 if (led->enabled)
64 return;
65
66 ret = regulator_enable(led->vcc);
67 if (ret != 0) {
68 dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret);
69 return;
70 }
71
72 led->enabled = 1;
73}
74
75static void regulator_led_disable(struct regulator_led *led)
76{
77 int ret;
78
79 if (!led->enabled)
80 return;
81
82 ret = regulator_disable(led->vcc);
83 if (ret != 0) {
84 dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret);
85 return;
86 }
87
88 led->enabled = 0;
89}
90
91static int regulator_led_brightness_set(struct led_classdev *led_cdev,
92 enum led_brightness value)
93{
94 struct regulator_led *led = to_regulator_led(led_cdev);
95 int voltage;
96 int ret = 0;
97
98 mutex_lock(&led->mutex);
99
100 if (value == LED_OFF) {
101 regulator_led_disable(led);
102 goto out;
103 }
104
105 if (led->cdev.max_brightness > 1) {
106 voltage = led_regulator_get_voltage(led->vcc, value);
107 dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
108 value, voltage);
109
110 ret = regulator_set_voltage(led->vcc, voltage, voltage);
111 if (ret != 0)
112 dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n",
113 voltage, ret);
114 }
115
116 regulator_led_enable(led);
117
118out:
119 mutex_unlock(&led->mutex);
120 return ret;
121}
122
123static int regulator_led_probe(struct platform_device *pdev)
124{
125 struct led_regulator_platform_data *pdata =
126 dev_get_platdata(&pdev->dev);
127 struct device *dev = &pdev->dev;
128 struct led_init_data init_data = {};
129 struct regulator_led *led;
130 struct regulator *vcc;
131 int ret = 0;
132
133 vcc = devm_regulator_get_exclusive(dev, "vled");
134 if (IS_ERR(vcc)) {
135 dev_err(dev, "Cannot get vcc\n");
136 return PTR_ERR(vcc);
137 }
138
139 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
140 if (led == NULL)
141 return -ENOMEM;
142
143 init_data.fwnode = dev->fwnode;
144
145 led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
146 /* Legacy platform data label assignment */
147 if (pdata) {
148 if (pdata->brightness > led->cdev.max_brightness) {
149 dev_err(dev, "Invalid default brightness %d\n",
150 pdata->brightness);
151 return -EINVAL;
152 }
153 led->cdev.brightness = pdata->brightness;
154 init_data.default_label = pdata->name;
155 }
156
157 led->cdev.brightness_set_blocking = regulator_led_brightness_set;
158 led->cdev.flags |= LED_CORE_SUSPENDRESUME;
159 led->vcc = vcc;
160
161 /* to handle correctly an already enabled regulator */
162 if (regulator_is_enabled(led->vcc))
163 led->enabled = 1;
164
165 mutex_init(&led->mutex);
166
167 platform_set_drvdata(pdev, led);
168
169 ret = led_classdev_register_ext(dev, &led->cdev, &init_data);
170 if (ret < 0)
171 return ret;
172
173 return 0;
174}
175
176static void regulator_led_remove(struct platform_device *pdev)
177{
178 struct regulator_led *led = platform_get_drvdata(pdev);
179
180 led_classdev_unregister(&led->cdev);
181 regulator_led_disable(led);
182}
183
184static const struct of_device_id regulator_led_of_match[] = {
185 { .compatible = "regulator-led", },
186 {}
187};
188MODULE_DEVICE_TABLE(of, regulator_led_of_match);
189
190static struct platform_driver regulator_led_driver = {
191 .driver = {
192 .name = "leds-regulator",
193 .of_match_table = regulator_led_of_match,
194 },
195 .probe = regulator_led_probe,
196 .remove_new = regulator_led_remove,
197};
198
199module_platform_driver(regulator_led_driver);
200
201MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
202MODULE_DESCRIPTION("Regulator driven LED driver");
203MODULE_LICENSE("GPL");
204MODULE_ALIAS("platform:leds-regulator");
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>
16#include <linux/slab.h>
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
25struct regulator_led {
26 struct led_classdev cdev;
27 int enabled;
28 struct mutex mutex;
29
30 struct regulator *vcc;
31};
32
33static 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
52static 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
62static 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
78static 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
94static int regulator_led_brightness_set(struct led_classdev *led_cdev,
95 enum led_brightness value)
96{
97 struct regulator_led *led = to_regulator_led(led_cdev);
98 int voltage;
99 int ret = 0;
100
101 mutex_lock(&led->mutex);
102
103 if (value == LED_OFF) {
104 regulator_led_disable(led);
105 goto out;
106 }
107
108 if (led->cdev.max_brightness > 1) {
109 voltage = led_regulator_get_voltage(led->vcc, value);
110 dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
111 value, voltage);
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
121out:
122 mutex_unlock(&led->mutex);
123 return ret;
124}
125
126static int regulator_led_probe(struct platform_device *pdev)
127{
128 struct led_regulator_platform_data *pdata =
129 dev_get_platdata(&pdev->dev);
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
139 vcc = devm_regulator_get_exclusive(&pdev->dev, "vled");
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
145 led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
146 if (led == NULL)
147 return -ENOMEM;
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);
153 return -EINVAL;
154 }
155
156 led->cdev.brightness_set_blocking = regulator_led_brightness_set;
157 led->cdev.name = pdata->name;
158 led->cdev.flags |= LED_CORE_SUSPENDRESUME;
159 led->vcc = vcc;
160
161 /* to handle correctly an already enabled regulator */
162 if (regulator_is_enabled(led->vcc))
163 led->enabled = 1;
164
165 mutex_init(&led->mutex);
166
167 platform_set_drvdata(pdev, led);
168
169 ret = led_classdev_register(&pdev->dev, &led->cdev);
170 if (ret < 0)
171 return ret;
172
173 /* to expose the default value to userspace */
174 led->cdev.brightness = pdata->brightness;
175
176 /* Set the default led status */
177 regulator_led_brightness_set(&led->cdev, led->cdev.brightness);
178
179 return 0;
180}
181
182static int regulator_led_remove(struct platform_device *pdev)
183{
184 struct regulator_led *led = platform_get_drvdata(pdev);
185
186 led_classdev_unregister(&led->cdev);
187 regulator_led_disable(led);
188 return 0;
189}
190
191static struct platform_driver regulator_led_driver = {
192 .driver = {
193 .name = "leds-regulator",
194 },
195 .probe = regulator_led_probe,
196 .remove = regulator_led_remove,
197};
198
199module_platform_driver(regulator_led_driver);
200
201MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
202MODULE_DESCRIPTION("Regulator driven LED driver");
203MODULE_LICENSE("GPL");
204MODULE_ALIAS("platform:leds-regulator");