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Subject[PATCH v2] leds: implement OpenFirmare GPIO LED driver
Despite leds-gpio and leds-of-gpio similar names and purposes, there
is not much code can be shared between the two drivers (both are mostly
driver bindings anyway).

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---
Documentation/powerpc/dts-bindings/gpio/led.txt | 15 ++
drivers/leds/Kconfig | 8 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-of-gpio.c | 193 +++++++++++++++++++++++
4 files changed, 217 insertions(+), 0 deletions(-)
create mode 100644 Documentation/powerpc/dts-bindings/gpio/led.txt
create mode 100644 drivers/leds/leds-of-gpio.c

diff --git a/Documentation/powerpc/dts-bindings/gpio/led.txt b/Documentation/powerpc/dts-bindings/gpio/led.txt
new file mode 100644
index 0000000..7e9ce81
--- /dev/null
+++ b/Documentation/powerpc/dts-bindings/gpio/led.txt
@@ -0,0 +1,15 @@
+LED connected to GPIO
+
+Required properties:
+- compatible : should be "gpio-led".
+- label : (optional) the label for this LED. If omitted, the label is
+ taken from the node name (excluding the unit address).
+- gpios : should specify LED GPIO.
+
+Example:
+
+led@0 {
+ compatible = "gpio-led";
+ label = "hdd";
+ gpios = <&mcu_pio 0 0>;
+};
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 1c35dfa..ad7eab3 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -119,6 +119,14 @@ 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 (OpenFirmware bindings)"
+ 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 7156f99..593775c 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_LEDS_COBALT_QUBE) += leds-cobalt-qube.o
obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o
obj-$(CONFIG_LEDS_PCA9532) += leds-pca9532.o
obj-$(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..02c4290
--- /dev/null
+++ b/drivers/leds/leds-of-gpio.c
@@ -0,0 +1,193 @@
+/*
+ * LEDs driver for GPIOs (OpenFirmware bindings)
+ *
+ * Copyright (C) 2007 8D Technologies inc.
+ * Raphael Assenat <raph@8d.com>
+ * Copyright (C) 2008 MontaVista Software, Inc.
+ * Anton Vorontsov <avorontsov@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/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.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;
+ u8 new_level;
+ u8 can_sleep;
+};
+
+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);
+ int level;
+
+ if (value == LED_OFF)
+ level = 0;
+ else
+ level = 1;
+
+ /* Setting GPIOs with I2C/etc requires a task context, and we don't
+ * seem to have a reliable way to know if we're already in one; so
+ * let's just assume the worst.
+ */
+ if (led->can_sleep) {
+ led->new_level = level;
+ schedule_work(&led->work);
+ } 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 = of_node_get(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, "label", NULL);
+ if (!led->cdev.name)
+ led->cdev.name = dev_name(&ofdev->dev);
+ led->cdev.brightness_set = gpio_led_set;
+
+ ret = gpio_request(led->gpio, dev_name(&ofdev->dev));
+ 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, 0);
+ 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);
+ dev_set_drvdata(&ofdev->dev, led);
+
+ 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;
+ }
+
+ return 0;
+
+err_reg_cdev:
+ cancel_work_sync(&led->work);
+err_gpio:
+ gpio_free(led->gpio);
+err_get_gpio:
+ of_node_put(led->np);
+ 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_driver = {
+ .driver = {
+ .name = "of_gpio_leds",
+ .owner = THIS_MODULE,
+ },
+ .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_driver);
+}
+module_init(of_gpio_leds_init);
+
+static void __exit of_gpio_leds_exit(void)
+{
+ of_unregister_platform_driver(&of_gpio_leds_driver);
+}
+module_exit(of_gpio_leds_exit);
+
+MODULE_DESCRIPTION("OF GPIO LED driver");
+MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
+MODULE_LICENSE("GPL");
--
1.5.5.4

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