Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 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. |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #include <linux/module.h> |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 11 | #include <linux/mod_devicetable.h> |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 12 | #include <linux/err.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 13 | #include <linux/slab.h> |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 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 | |
| 22 | struct regulator_led { |
| 23 | struct led_classdev cdev; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 24 | int enabled; |
| 25 | struct mutex mutex; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 26 | |
| 27 | struct regulator *vcc; |
| 28 | }; |
| 29 | |
| 30 | static 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 | |
| 49 | static 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 | |
| 59 | static 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 | |
| 75 | static 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 | |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 91 | static int regulator_led_brightness_set(struct led_classdev *led_cdev, |
| 92 | enum led_brightness value) |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 93 | { |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 94 | struct regulator_led *led = to_regulator_led(led_cdev); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 95 | int voltage; |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 96 | int ret = 0; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 97 | |
| 98 | mutex_lock(&led->mutex); |
| 99 | |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 100 | if (value == LED_OFF) { |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 101 | regulator_led_disable(led); |
| 102 | goto out; |
| 103 | } |
| 104 | |
| 105 | if (led->cdev.max_brightness > 1) { |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 106 | voltage = led_regulator_get_voltage(led->vcc, value); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 107 | dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n", |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 108 | value, voltage); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 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 | |
| 118 | out: |
| 119 | mutex_unlock(&led->mutex); |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 120 | return ret; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 121 | } |
| 122 | |
Bill Pemberton | 98ea1ea | 2012-11-19 13:23:02 -0500 | [diff] [blame] | 123 | static int regulator_led_probe(struct platform_device *pdev) |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 124 | { |
Jingoo Han | 87aae1e | 2013-07-30 01:07:35 -0700 | [diff] [blame] | 125 | struct led_regulator_platform_data *pdata = |
| 126 | dev_get_platdata(&pdev->dev); |
Linus Walleij | 4c350c6 | 2022-04-04 22:35:21 +0200 | [diff] [blame] | 127 | struct device *dev = &pdev->dev; |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 128 | struct led_init_data init_data = {}; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 129 | struct regulator_led *led; |
| 130 | struct regulator *vcc; |
| 131 | int ret = 0; |
| 132 | |
Linus Walleij | 4c350c6 | 2022-04-04 22:35:21 +0200 | [diff] [blame] | 133 | vcc = devm_regulator_get_exclusive(dev, "vled"); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 134 | if (IS_ERR(vcc)) { |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 135 | dev_err(dev, "Cannot get vcc\n"); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 136 | return PTR_ERR(vcc); |
| 137 | } |
| 138 | |
Linus Walleij | 4c350c6 | 2022-04-04 22:35:21 +0200 | [diff] [blame] | 139 | led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); |
Axel Lin | 29ce9fe | 2014-10-24 07:45:58 -0700 | [diff] [blame] | 140 | if (led == NULL) |
| 141 | return -ENOMEM; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 142 | |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 143 | init_data.fwnode = dev->fwnode; |
| 144 | |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 145 | led->cdev.max_brightness = led_regulator_get_max_brightness(vcc); |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 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", |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 150 | pdata->brightness); |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 151 | return -EINVAL; |
| 152 | } |
| 153 | led->cdev.brightness = pdata->brightness; |
| 154 | init_data.default_label = pdata->name; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 155 | } |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 156 | |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 157 | led->cdev.brightness_set_blocking = regulator_led_brightness_set; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 158 | led->cdev.flags |= LED_CORE_SUSPENDRESUME; |
| 159 | led->vcc = vcc; |
| 160 | |
Antonio Ospite | 592ce31 | 2011-04-14 15:21:59 -0700 | [diff] [blame] | 161 | /* to handle correctly an already enabled regulator */ |
| 162 | if (regulator_is_enabled(led->vcc)) |
| 163 | led->enabled = 1; |
| 164 | |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 165 | mutex_init(&led->mutex); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 166 | |
| 167 | platform_set_drvdata(pdev, led); |
| 168 | |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 169 | ret = led_classdev_register_ext(dev, &led->cdev, &init_data); |
Andrew Lunn | 77e8503 | 2015-08-20 12:55:39 +0200 | [diff] [blame] | 170 | if (ret < 0) |
Axel Lin | 29ce9fe | 2014-10-24 07:45:58 -0700 | [diff] [blame] | 171 | return ret; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 172 | |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 173 | return 0; |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 174 | } |
| 175 | |
Uwe Kleine-König | 6061302 | 2023-09-17 15:09:47 +0200 | [diff] [blame] | 176 | static void regulator_led_remove(struct platform_device *pdev) |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 177 | { |
| 178 | struct regulator_led *led = platform_get_drvdata(pdev); |
| 179 | |
| 180 | led_classdev_unregister(&led->cdev); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 181 | regulator_led_disable(led); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 182 | } |
| 183 | |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 184 | static const struct of_device_id regulator_led_of_match[] = { |
| 185 | { .compatible = "regulator-led", }, |
| 186 | {} |
| 187 | }; |
| 188 | MODULE_DEVICE_TABLE(of, regulator_led_of_match); |
| 189 | |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 190 | static struct platform_driver regulator_led_driver = { |
| 191 | .driver = { |
Linus Walleij | 835fc89 | 2022-04-04 22:35:22 +0200 | [diff] [blame] | 192 | .name = "leds-regulator", |
| 193 | .of_match_table = regulator_led_of_match, |
| 194 | }, |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 195 | .probe = regulator_led_probe, |
Uwe Kleine-König | 6061302 | 2023-09-17 15:09:47 +0200 | [diff] [blame] | 196 | .remove_new = regulator_led_remove, |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 197 | }; |
| 198 | |
Axel Lin | 892a884 | 2012-01-10 15:09:24 -0800 | [diff] [blame] | 199 | module_platform_driver(regulator_led_driver); |
Antonio Ospite | d4cc6a2 | 2009-12-07 15:08:13 +0100 | [diff] [blame] | 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"); |