leds: Add generic GPIO LED driver

This patch adds support for GPIO connected leds via the new GPIO framework.

Information about leds (gpio, polarity, name, default trigger) is passed
to the driver via platform_data.

Signed-off-by: Raphael Assenat <raph@8d.com>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 87d2046f866caa29b7e1b8f541b640789be3ec63..9ce3ca109c2f03b6b1488298742ed056340ed0ea 100644 (file)
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -95,6 +95,14 @@ config LEDS_COBALT
        help
          This option enables support for the front LED on Cobalt Server
 
+config LEDS_GPIO
+       tristate "LED Support for GPIO connected LEDs"
+       depends on LEDS_CLASS && GENERIC_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.
+
 comment "LED Triggers"
 
 config LEDS_TRIGGERS

diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index aa2c18efa5b2f150dffbfbf81a96669bb9d4fb45..f8995c9bc2eaae764ff4212d596f2e460546ade4 100644 (file)
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_LEDS_NET48XX)            += leds-net48xx.o
 obj-$(CONFIG_LEDS_WRAP)                        += leds-wrap.o
 obj-$(CONFIG_LEDS_H1940)               += leds-h1940.o
 obj-$(CONFIG_LEDS_COBALT)              += leds-cobalt.o
+obj-$(CONFIG_LEDS_GPIO)                        += leds-gpio.o
 
 # LED Triggers
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)       += ledtrig-timer.o

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
new file mode 100644 (file)
index 0000000..431dcb6
--- /dev/null
+++ b/drivers/leds/leds-gpio.c
@@ -0,0 +1,174 @@
+/*
+ * 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 <asm/gpio.h>
+
+struct gpio_led_data {
+       struct led_classdev cdev;
+       unsigned gpio;
+       u8 active_low;
+};
+
+
+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;
+
+       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->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;
+               }
+       }
+
+       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);
+               }
+       }
+       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");

diff --git a/include/linux/leds.h b/include/linux/leds.h
index 88afceffb7cb45df03ecbcd1045af2117f429fb1..059abfe219dc1dacbb40e463a022e75045531507 100644 (file)
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -110,4 +110,18 @@ extern void ledtrig_ide_activity(void);
 #define ledtrig_ide_activity() do {} while(0)
 #endif
 
+/* For the leds-gpio driver */
+struct gpio_led {
+       const char *name;
+       char *default_trigger;
+       unsigned        gpio;
+       u8              active_low;
+};
+
+struct gpio_led_platform_data {
+       int             num_leds;
+       struct gpio_led *leds;
+};
+
+
 #endif         /* __LINUX_LEDS_H_INCLUDED */