LXR linux/drivers/leds/leds-s3c24xx.c

   1/* drivers/leds/leds-s3c24xx.c
   2 *
   3 * (c) 2006 Simtec Electronics
   4 *      http://armlinux.simtec.co.uk/
   5 *      Ben Dooks <ben@simtec.co.uk>
   6 *
   7 * S3C24XX - LEDs GPIO driver
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12*/
  13
  14#include <linux/kernel.h>
  15#include <linux/platform_device.h>
  16#include <linux/leds.h>
  17#include <linux/gpio.h>
  18#include <linux/slab.h>
  19#include <linux/module.h>
  20#include <linux/platform_data/leds-s3c24xx.h>
  21
  22#include <mach/regs-gpio.h>
  23#include <plat/gpio-cfg.h>
  24
  25/* our context */
  26
  27struct s3c24xx_gpio_led {
  28        struct led_classdev              cdev;
  29        struct s3c24xx_led_platdata     *pdata;
  30};
  31
  32static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  33{
  34        return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  35}
  36
  37static void s3c24xx_led_set(struct led_classdev *led_cdev,
  38                            enum led_brightness value)
  39{
  40        struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  41        struct s3c24xx_led_platdata *pd = led->pdata;
  42        int state = (value ? 1 : 0) ^ (pd->flags & S3C24XX_LEDF_ACTLOW);
  43
  44        /* there will be a short delay between setting the output and
  45         * going from output to input when using tristate. */
  46
  47        gpio_set_value(pd->gpio, state);
  48
  49        if (pd->flags & S3C24XX_LEDF_TRISTATE) {
  50                if (value)
  51                        gpio_direction_output(pd->gpio, state);
  52                else
  53                        gpio_direction_input(pd->gpio);
  54        }
  55}
  56
  57static int s3c24xx_led_probe(struct platform_device *dev)
  58{
  59        struct s3c24xx_led_platdata *pdata = dev_get_platdata(&dev->dev);
  60        struct s3c24xx_gpio_led *led;
  61        int ret;
  62
  63        led = devm_kzalloc(&dev->dev, sizeof(struct s3c24xx_gpio_led),
  64                           GFP_KERNEL);
  65        if (!led)
  66                return -ENOMEM;
  67
  68        led->cdev.brightness_set = s3c24xx_led_set;
  69        led->cdev.default_trigger = pdata->def_trigger;
  70        led->cdev.name = pdata->name;
  71        led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  72
  73        led->pdata = pdata;
  74
  75        ret = devm_gpio_request(&dev->dev, pdata->gpio, "S3C24XX_LED");
  76        if (ret < 0)
  77                return ret;
  78
  79        /* no point in having a pull-up if we are always driving */
  80
  81        s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);
  82
  83        if (pdata->flags & S3C24XX_LEDF_TRISTATE)
  84                gpio_direction_input(pdata->gpio);
  85        else
  86                gpio_direction_output(pdata->gpio,
  87                        pdata->flags & S3C24XX_LEDF_ACTLOW ? 1 : 0);
  88
  89        /* register our new led device */
  90
  91        ret = devm_led_classdev_register(&dev->dev, &led->cdev);
  92        if (ret < 0)
  93                dev_err(&dev->dev, "led_classdev_register failed\n");
  94
  95        return ret;
  96}
  97
  98static struct platform_driver s3c24xx_led_driver = {
  99        .probe          = s3c24xx_led_probe,
 100        .driver         = {
 101                .name           = "s3c24xx_led",
 102        },
 103};
 104
 105module_platform_driver(s3c24xx_led_driver);
 106
 107MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 108MODULE_DESCRIPTION("S3C24XX LED driver");
 109MODULE_LICENSE("GPL");
 110MODULE_ALIAS("platform:s3c24xx_led");
 111