[PATCH 3/5] leds: implement OpenFirmare GPIO LEDs driver
Anton Vorontsov
avorontsov at ru.mvista.com
Thu Mar 27 07:24:53 EST 2008
Despite leds-gpio and leds-of-gpio similar names and purposes, there
is actually very few code can be shared between the two (both drivers
are mostly the driver bindings anyway).
Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
---
This patch depends on the not yet applied OF/PowerPC GPIO patches, so
please consider this for RFC only.
Thanks.
drivers/leds/Kconfig | 8 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-of-gpio.c | 196 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 205 insertions(+), 0 deletions(-)
create mode 100644 drivers/leds/leds-of-gpio.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 09aac5d..8bed058 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -113,6 +113,14 @@ config LEDS_GPIO
outputs. To be useful the particular board must have LEDs
and they must be connected to the GPIO lines.
+config LEDS_OF_GPIO
+ tristate "LED Support for GPIO connected LEDs"
+ depends on LEDS_CLASS && OF_GPIO
+ help
+ This option enables support for the LEDs connected to GPIO
+ outputs. To be useful the particular board must have LEDs
+ and they must be connected to the GPIO lines.
+
config LEDS_CM_X270
tristate "LED Support for the CM-X270 LEDs"
depends on LEDS_CLASS && MACH_ARMCORE
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 84ced3b..78926ca 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_LEDS_H1940) += leds-h1940.o
obj-$(CONFIG_LEDS_COBALT_QUBE) += leds-cobalt-qube.o
obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o
obj-$(CONFIG_LEDS_GPIO) += leds-gpio.o
+obj-$(CONFIG_LEDS_OF_GPIO) += leds-of-gpio.o
obj-$(CONFIG_LEDS_CM_X270) += leds-cm-x270.o
obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o
obj-$(CONFIG_LEDS_HP6XX) += leds-hp6xx.o
diff --git a/drivers/leds/leds-of-gpio.c b/drivers/leds/leds-of-gpio.c
new file mode 100644
index 0000000..aeb2f39
--- /dev/null
+++ b/drivers/leds/leds-of-gpio.c
@@ -0,0 +1,196 @@
+/*
+ * LEDs driver for GPIOs (OpenFirmware bindings)
+ *
+ * Copyright (C) 2007 8D Technologies inc.
+ * Raphael Assenat <raph at 8d.com>
+ * Copyright (C) 2008 MontaVista Software, Inc.
+ * Anton Vorontsov <avorontsov at ru.mvista.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/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/leds.h>
+#include <linux/workqueue.h>
+
+struct of_gpio_led {
+ struct device_node *np;
+ struct led_classdev cdev;
+ unsigned int gpio;
+ struct work_struct work;
+ bool new_level;
+ bool can_sleep;
+ bool active_low;
+};
+
+static void gpio_led_work(struct work_struct *work)
+{
+ struct of_gpio_led *led = container_of(work, struct of_gpio_led, work);
+
+ gpio_set_value_cansleep(led->gpio, led->new_level);
+}
+
+static void gpio_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct of_gpio_led *led = container_of(led_cdev, struct of_gpio_led,
+ cdev);
+ bool level;
+
+ if (value == LED_OFF)
+ level = false;
+ else
+ level = true;
+
+ if (led->active_low)
+ level = !level;
+
+ /* setting GPIOs with I2C/etc requires a preemptible task context */
+ if (led->can_sleep) {
+ if (preempt_count()) {
+ led->new_level = level;
+ schedule_work(&led->work);
+ } else {
+ gpio_set_value_cansleep(led->gpio, level);
+ }
+ } else {
+ gpio_set_value(led->gpio, level);
+ }
+}
+
+static int __devinit of_gpio_leds_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
+{
+ int ret;
+ struct of_gpio_led *led;
+ struct device_node *np = ofdev->node;
+
+ led = kzalloc(sizeof(*led), GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ led->np = np;
+
+ ret = of_get_gpio(np, 0);
+ if (!gpio_is_valid(ret)) {
+ dev_err(&ofdev->dev, "gpio is invalid\n");
+ goto err_get_gpio;
+ }
+ led->gpio = ret;
+ led->can_sleep = gpio_cansleep(led->gpio);
+
+ led->cdev.name = of_get_property(np, "linux,name", NULL);
+ if (!led->cdev.name)
+ led->cdev.name = ofdev->dev.bus_id;
+ led->cdev.default_trigger = of_get_property(np,
+ "linux,default-trigger", NULL);
+ led->active_low = of_get_property(np, "linux,active-low", NULL) ?
+ 1 : 0;
+ led->cdev.brightness_set = gpio_led_set;
+ led->cdev.brightness = LED_OFF;
+
+ ret = gpio_request(led->gpio, ofdev->dev.bus_id);
+ if (ret < 0) {
+ dev_err(&ofdev->dev, "could not request gpio, status is %d\n",
+ ret);
+ goto err_gpio;
+ }
+
+ ret = gpio_direction_output(led->gpio, led->active_low);
+ if (ret) {
+ dev_err(&ofdev->dev, "gpio could not be an output, "
+ "status is %d\n", ret);
+ goto err_gpio;
+ }
+
+ INIT_WORK(&led->work, gpio_led_work);
+
+ ret = led_classdev_register(&ofdev->dev, &led->cdev);
+ if (ret < 0) {
+ dev_err(&ofdev->dev, "could register led cdev, status is %d\n",
+ ret);
+ gpio_free(led->gpio);
+ goto err_reg_cdev;
+ }
+
+ dev_set_drvdata(&ofdev->dev, led);
+
+ return 0;
+
+err_reg_cdev:
+ cancel_work_sync(&led->work);
+err_gpio:
+ gpio_free(led->gpio);
+err_get_gpio:
+ kfree(led);
+ return ret;
+}
+
+static int __devexit of_gpio_leds_remove(struct of_device *ofdev)
+{
+ struct of_gpio_led *led = dev_get_drvdata(&ofdev->dev);
+
+ led_classdev_unregister(&led->cdev);
+ cancel_work_sync(&led->work);
+ gpio_free(led->gpio);
+ of_node_put(led->np);
+ kfree(led);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int of_gpio_led_suspend(struct of_device *ofdev, pm_message_t state)
+{
+ struct of_gpio_led *led = dev_get_drvdata(&ofdev->dev);
+
+ led_classdev_suspend(&led->cdev);
+ return 0;
+}
+
+static int of_gpio_led_resume(struct of_device *ofdev)
+{
+ struct of_gpio_led *led = dev_get_drvdata(&ofdev->dev);
+
+ led_classdev_resume(&led->cdev);
+ return 0;
+}
+#else
+#define of_gpio_led_suspend NULL
+#define of_gpio_led_resume NULL
+#endif /* CONFIG_PM */
+
+static const struct of_device_id of_gpio_leds_match[] = {
+ { .compatible = "gpio-led", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
+
+static struct of_platform_driver of_gpio_leds_drv = {
+ .name = "of_gpio_leds",
+ .match_table = of_gpio_leds_match,
+ .probe = of_gpio_leds_probe,
+ .remove = __devexit_p(of_gpio_leds_remove),
+ .suspend = of_gpio_led_suspend,
+ .resume = of_gpio_led_resume,
+};
+
+static int __init of_gpio_leds_init(void)
+{
+ return of_register_platform_driver(&of_gpio_leds_drv);
+}
+module_init(of_gpio_leds_init);
+
+static void __exit of_gpio_leds_exit(void)
+{
+ of_unregister_platform_driver(&of_gpio_leds_drv);
+}
+module_exit(of_gpio_leds_exit);
+
+MODULE_DESCRIPTION("OF-platform GPIO LEDs driver");
+MODULE_AUTHOR("Anton Vorontsov <avorontsov at ru.mvista.com>");
+MODULE_LICENSE("GPL");
--
1.5.2.2
More information about the Linuxppc-dev
mailing list