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![Raphael Assenat](/assets/img/avatar_default.png)
When gpio_direction_output() is called, led_dat->active_low is used as default value. This means that the led will always be off by default. cdev.brightness should really have been set to LED_OFF unconditionally to reflect this behavior. Signed-off-by: Raphael Assenat <raph@8d.com> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
201 lines
4.4 KiB
C
201 lines
4.4 KiB
C
/*
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* LEDs driver for GPIOs
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*
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* Copyright (C) 2007 8D Technologies inc.
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* Raphael Assenat <raph@8d.com>
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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/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/leds.h>
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#include <linux/workqueue.h>
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#include <asm/gpio.h>
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struct gpio_led_data {
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struct led_classdev cdev;
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unsigned gpio;
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struct work_struct work;
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u8 new_level;
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u8 can_sleep;
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u8 active_low;
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};
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static void gpio_led_work(struct work_struct *work)
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{
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struct gpio_led_data *led_dat =
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container_of(work, struct gpio_led_data, work);
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gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
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}
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static void gpio_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct gpio_led_data *led_dat =
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container_of(led_cdev, struct gpio_led_data, cdev);
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int level;
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if (value == LED_OFF)
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level = 0;
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else
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level = 1;
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if (led_dat->active_low)
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level = !level;
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/* setting GPIOs with I2C/etc requires a preemptible task context */
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if (led_dat->can_sleep) {
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if (preempt_count()) {
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led_dat->new_level = level;
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schedule_work(&led_dat->work);
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} else
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gpio_set_value_cansleep(led_dat->gpio, level);
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} else
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gpio_set_value(led_dat->gpio, level);
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}
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static int gpio_led_probe(struct platform_device *pdev)
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{
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struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
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struct gpio_led *cur_led;
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struct gpio_led_data *leds_data, *led_dat;
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int i, ret = 0;
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if (!pdata)
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return -EBUSY;
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leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
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GFP_KERNEL);
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if (!leds_data)
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return -ENOMEM;
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for (i = 0; i < pdata->num_leds; i++) {
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cur_led = &pdata->leds[i];
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led_dat = &leds_data[i];
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led_dat->cdev.name = cur_led->name;
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led_dat->cdev.default_trigger = cur_led->default_trigger;
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led_dat->gpio = cur_led->gpio;
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led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
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led_dat->active_low = cur_led->active_low;
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led_dat->cdev.brightness_set = gpio_led_set;
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led_dat->cdev.brightness = LED_OFF;
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ret = gpio_request(led_dat->gpio, led_dat->cdev.name);
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if (ret < 0)
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goto err;
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gpio_direction_output(led_dat->gpio, led_dat->active_low);
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INIT_WORK(&led_dat->work, gpio_led_work);
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ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
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if (ret < 0) {
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gpio_free(led_dat->gpio);
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goto err;
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}
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}
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platform_set_drvdata(pdev, leds_data);
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return 0;
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err:
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if (i > 0) {
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for (i = i - 1; i >= 0; i--) {
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led_classdev_unregister(&leds_data[i].cdev);
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cancel_work_sync(&leds_data[i].work);
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gpio_free(leds_data[i].gpio);
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}
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}
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kfree(leds_data);
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return ret;
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}
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static int __devexit gpio_led_remove(struct platform_device *pdev)
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{
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int i;
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struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
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struct gpio_led_data *leds_data;
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leds_data = platform_get_drvdata(pdev);
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for (i = 0; i < pdata->num_leds; i++) {
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led_classdev_unregister(&leds_data[i].cdev);
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cancel_work_sync(&leds_data[i].work);
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gpio_free(leds_data[i].gpio);
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}
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kfree(leds_data);
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return 0;
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}
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#ifdef CONFIG_PM
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static int gpio_led_suspend(struct platform_device *pdev, pm_message_t state)
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{
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struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
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struct gpio_led_data *leds_data;
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int i;
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leds_data = platform_get_drvdata(pdev);
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for (i = 0; i < pdata->num_leds; i++)
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led_classdev_suspend(&leds_data[i].cdev);
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return 0;
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}
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static int gpio_led_resume(struct platform_device *pdev)
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{
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struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
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struct gpio_led_data *leds_data;
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int i;
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leds_data = platform_get_drvdata(pdev);
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for (i = 0; i < pdata->num_leds; i++)
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led_classdev_resume(&leds_data[i].cdev);
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return 0;
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}
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#else
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#define gpio_led_suspend NULL
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#define gpio_led_resume NULL
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#endif
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static struct platform_driver gpio_led_driver = {
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.probe = gpio_led_probe,
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.remove = __devexit_p(gpio_led_remove),
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.suspend = gpio_led_suspend,
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.resume = gpio_led_resume,
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.driver = {
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.name = "leds-gpio",
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.owner = THIS_MODULE,
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},
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};
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static int __init gpio_led_init(void)
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{
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return platform_driver_register(&gpio_led_driver);
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}
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static void __exit gpio_led_exit(void)
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{
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platform_driver_unregister(&gpio_led_driver);
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}
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module_init(gpio_led_init);
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module_exit(gpio_led_exit);
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MODULE_AUTHOR("Raphael Assenat <raph@8d.com>");
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MODULE_DESCRIPTION("GPIO LED driver");
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MODULE_LICENSE("GPL");
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