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![Antonio Ospite](/assets/img/avatar_default.png)
This driver provides an interface for controlling LEDs (or vibrators) connected to PMICs for which there is a regulator framework driver. This driver can be used, for instance, to control vibrator on all Motorola EZX phones using the pcap-regulator driver services. Signed-off-by: Antonio Ospite <ospite@studenti.unina.it> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
242 lines
5.2 KiB
C
242 lines
5.2 KiB
C
/*
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* leds-regulator.c - LED class driver for regulator driven LEDs.
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*
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* Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
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*
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* Inspired by leds-wm8350 driver.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/workqueue.h>
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#include <linux/leds.h>
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#include <linux/leds-regulator.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#define to_regulator_led(led_cdev) \
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container_of(led_cdev, struct regulator_led, cdev)
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struct regulator_led {
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struct led_classdev cdev;
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enum led_brightness value;
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int enabled;
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struct mutex mutex;
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struct work_struct work;
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struct regulator *vcc;
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};
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static inline int led_regulator_get_max_brightness(struct regulator *supply)
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{
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int ret;
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int voltage = regulator_list_voltage(supply, 0);
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if (voltage <= 0)
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return 1;
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/* even if regulator can't change voltages,
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* we still assume it can change status
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* and the LED can be turned on and off.
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*/
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ret = regulator_set_voltage(supply, voltage, voltage);
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if (ret < 0)
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return 1;
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return regulator_count_voltages(supply);
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}
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static int led_regulator_get_voltage(struct regulator *supply,
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enum led_brightness brightness)
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{
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if (brightness == 0)
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return -EINVAL;
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return regulator_list_voltage(supply, brightness - 1);
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}
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static void regulator_led_enable(struct regulator_led *led)
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{
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int ret;
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if (led->enabled)
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return;
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ret = regulator_enable(led->vcc);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret);
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return;
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}
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led->enabled = 1;
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}
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static void regulator_led_disable(struct regulator_led *led)
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{
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int ret;
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if (!led->enabled)
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return;
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ret = regulator_disable(led->vcc);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret);
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return;
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}
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led->enabled = 0;
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}
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static void regulator_led_set_value(struct regulator_led *led)
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{
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int voltage;
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int ret;
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mutex_lock(&led->mutex);
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if (led->value == LED_OFF) {
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regulator_led_disable(led);
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goto out;
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}
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if (led->cdev.max_brightness > 1) {
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voltage = led_regulator_get_voltage(led->vcc, led->value);
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dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
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led->value, voltage);
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ret = regulator_set_voltage(led->vcc, voltage, voltage);
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if (ret != 0)
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dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n",
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voltage, ret);
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}
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regulator_led_enable(led);
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out:
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mutex_unlock(&led->mutex);
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}
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static void led_work(struct work_struct *work)
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{
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struct regulator_led *led;
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led = container_of(work, struct regulator_led, work);
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regulator_led_set_value(led);
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}
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static void regulator_led_brightness_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct regulator_led *led = to_regulator_led(led_cdev);
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led->value = value;
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schedule_work(&led->work);
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}
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static int __devinit regulator_led_probe(struct platform_device *pdev)
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{
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struct led_regulator_platform_data *pdata = pdev->dev.platform_data;
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struct regulator_led *led;
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struct regulator *vcc;
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int ret = 0;
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if (pdata == NULL) {
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dev_err(&pdev->dev, "no platform data\n");
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return -ENODEV;
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}
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vcc = regulator_get_exclusive(&pdev->dev, "vled");
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if (IS_ERR(vcc)) {
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dev_err(&pdev->dev, "Cannot get vcc for %s\n", pdata->name);
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return PTR_ERR(vcc);
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}
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led = kzalloc(sizeof(*led), GFP_KERNEL);
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if (led == NULL) {
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ret = -ENOMEM;
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goto err_vcc;
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}
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led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
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if (pdata->brightness > led->cdev.max_brightness) {
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dev_err(&pdev->dev, "Invalid default brightness %d\n",
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pdata->brightness);
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ret = -EINVAL;
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goto err_led;
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}
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led->value = pdata->brightness;
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led->cdev.brightness_set = regulator_led_brightness_set;
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led->cdev.name = pdata->name;
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led->cdev.flags |= LED_CORE_SUSPENDRESUME;
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led->vcc = vcc;
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mutex_init(&led->mutex);
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INIT_WORK(&led->work, led_work);
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platform_set_drvdata(pdev, led);
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ret = led_classdev_register(&pdev->dev, &led->cdev);
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if (ret < 0) {
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cancel_work_sync(&led->work);
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goto err_led;
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}
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/* to expose the default value to userspace */
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led->cdev.brightness = led->value;
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/* Set the default led status */
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regulator_led_set_value(led);
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return 0;
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err_led:
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kfree(led);
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err_vcc:
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regulator_put(vcc);
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return ret;
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}
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static int __devexit regulator_led_remove(struct platform_device *pdev)
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{
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struct regulator_led *led = platform_get_drvdata(pdev);
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led_classdev_unregister(&led->cdev);
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cancel_work_sync(&led->work);
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regulator_led_disable(led);
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regulator_put(led->vcc);
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kfree(led);
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return 0;
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}
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static struct platform_driver regulator_led_driver = {
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.driver = {
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.name = "leds-regulator",
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.owner = THIS_MODULE,
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},
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.probe = regulator_led_probe,
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.remove = __devexit_p(regulator_led_remove),
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};
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static int __init regulator_led_init(void)
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{
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return platform_driver_register(®ulator_led_driver);
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}
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module_init(regulator_led_init);
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static void __exit regulator_led_exit(void)
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{
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platform_driver_unregister(®ulator_led_driver);
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}
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module_exit(regulator_led_exit);
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MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
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MODULE_DESCRIPTION("Regulator driven LED driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:leds-regulator");
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