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path: root/drivers/leds/leds-gpio.c
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Diffstat (limited to 'drivers/leds/leds-gpio.c')
-rw-r--r--drivers/leds/leds-gpio.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
new file mode 100644
index 000000000000..47d90db280ce
--- /dev/null
+++ b/drivers/leds/leds-gpio.c
@@ -0,0 +1,199 @@
+/*
+ * LEDs driver for GPIOs
+ *
+ * Copyright (C) 2007 8D Technologies inc.
+ * Raphael Assenat <raph@8d.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/workqueue.h>
+
+#include <asm/gpio.h>
+
+struct gpio_led_data {
+ struct led_classdev cdev;
+ unsigned gpio;
+ struct work_struct work;
+ u8 new_level;
+ u8 can_sleep;
+ u8 active_low;
+};
+
+static void gpio_led_work(struct work_struct *work)
+{
+ struct gpio_led_data *led_dat =
+ container_of(work, struct gpio_led_data, work);
+
+ gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
+}
+
+static void gpio_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct gpio_led_data *led_dat =
+ container_of(led_cdev, struct gpio_led_data, cdev);
+ int level;
+
+ if (value == LED_OFF)
+ level = 0;
+ else
+ level = 1;
+
+ if (led_dat->active_low)
+ level = !level;
+
+ /* setting GPIOs with I2C/etc requires a preemptible task context */
+ if (led_dat->can_sleep) {
+ if (preempt_count()) {
+ led_dat->new_level = level;
+ schedule_work(&led_dat->work);
+ } else
+ gpio_set_value_cansleep(led_dat->gpio, level);
+ } else
+ gpio_set_value(led_dat->gpio, level);
+}
+
+static int __init gpio_led_probe(struct platform_device *pdev)
+{
+ struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_led *cur_led;
+ struct gpio_led_data *leds_data, *led_dat;
+ int i, ret = 0;
+
+ if (!pdata)
+ return -EBUSY;
+
+ leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
+ GFP_KERNEL);
+ if (!leds_data)
+ return -ENOMEM;
+
+ for (i = 0; i < pdata->num_leds; i++) {
+ cur_led = &pdata->leds[i];
+ led_dat = &leds_data[i];
+
+ led_dat->cdev.name = cur_led->name;
+ led_dat->cdev.default_trigger = cur_led->default_trigger;
+ led_dat->gpio = cur_led->gpio;
+ led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
+ led_dat->active_low = cur_led->active_low;
+ led_dat->cdev.brightness_set = gpio_led_set;
+ led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF;
+
+ ret = gpio_request(led_dat->gpio, led_dat->cdev.name);
+ if (ret < 0)
+ goto err;
+
+ gpio_direction_output(led_dat->gpio, led_dat->active_low);
+
+ ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
+ if (ret < 0) {
+ gpio_free(led_dat->gpio);
+ goto err;
+ }
+
+ INIT_WORK(&led_dat->work, gpio_led_work);
+ }
+
+ platform_set_drvdata(pdev, leds_data);
+
+ return 0;
+
+err:
+ if (i > 0) {
+ for (i = i - 1; i >= 0; i--) {
+ led_classdev_unregister(&leds_data[i].cdev);
+ gpio_free(leds_data[i].gpio);
+ }
+ }
+
+ flush_scheduled_work();
+ kfree(leds_data);
+
+ return ret;
+}
+
+static int __exit gpio_led_remove(struct platform_device *pdev)
+{
+ int i;
+ struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_led_data *leds_data;
+
+ leds_data = platform_get_drvdata(pdev);
+
+ for (i = 0; i < pdata->num_leds; i++) {
+ led_classdev_unregister(&leds_data[i].cdev);
+ gpio_free(leds_data[i].gpio);
+ }
+
+ kfree(leds_data);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int gpio_led_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_led_data *leds_data;
+ int i;
+
+ leds_data = platform_get_drvdata(pdev);
+
+ for (i = 0; i < pdata->num_leds; i++)
+ led_classdev_suspend(&leds_data[i].cdev);
+
+ return 0;
+}
+
+static int gpio_led_resume(struct platform_device *pdev)
+{
+ struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_led_data *leds_data;
+ int i;
+
+ leds_data = platform_get_drvdata(pdev);
+
+ for (i = 0; i < pdata->num_leds; i++)
+ led_classdev_resume(&leds_data[i].cdev);
+
+ return 0;
+}
+#else
+#define gpio_led_suspend NULL
+#define gpio_led_resume NULL
+#endif
+
+static struct platform_driver gpio_led_driver = {
+ .remove = __exit_p(gpio_led_remove),
+ .suspend = gpio_led_suspend,
+ .resume = gpio_led_resume,
+ .driver = {
+ .name = "leds-gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init gpio_led_init(void)
+{
+ return platform_driver_probe(&gpio_led_driver, gpio_led_probe);
+}
+
+static void __exit gpio_led_exit(void)
+{
+ platform_driver_unregister(&gpio_led_driver);
+}
+
+module_init(gpio_led_init);
+module_exit(gpio_led_exit);
+
+MODULE_AUTHOR("Raphael Assenat <raph@8d.com>");
+MODULE_DESCRIPTION("GPIO LED driver");
+MODULE_LICENSE("GPL");