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
  27 struct s3c24xx_gpio_led {
  28         struct led_classdev              cdev;
  29         struct s3c24xx_led_platdata     *pdata;
  30 };
  31
  32 static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  33 {
  34         return platform_get_drvdata(dev);
  35 }
  36
  37 static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  38 {
  39         return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  40 }
  41
  42 static void s3c24xx_led_set(struct led_classdev *led_cdev,
  43                             enum led_brightness value)
  44 {
  45         struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  46         struct s3c24xx_led_platdata *pd = led->pdata;
  47         int state = (value ? 1 : 0) ^ (pd->flags & S3C24XX_LEDF_ACTLOW);
  48
  49         /* there will be a short delay between setting the output and
  50          * going from output to input when using tristate. */
  51
  52         gpio_set_value(pd->gpio, state);
  53
  54         if (pd->flags & S3C24XX_LEDF_TRISTATE) {
  55                 if (value)
  56                         gpio_direction_output(pd->gpio, state);
  57                 else
  58                         gpio_direction_input(pd->gpio);
  59         }
  60 }
  61
  62 static int s3c24xx_led_remove(struct platform_device *dev)
  63 {
  64         struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
  65
  66         led_classdev_unregister(&led->cdev);
  67
  68         return 0;
  69 }
  70
  71 static int s3c24xx_led_probe(struct platform_device *dev)
  72 {
  73         struct s3c24xx_led_platdata *pdata = dev_get_platdata(&dev->dev);
  74         struct s3c24xx_gpio_led *led;
  75         int ret;
  76
  77         led = devm_kzalloc(&dev->dev, sizeof(struct s3c24xx_gpio_led),
  78                            GFP_KERNEL);
  79         if (led == NULL) {
  80                 dev_err(&dev->dev, "No memory for device\n");
  81                 return -ENOMEM;
  82         }
  83
  84         platform_set_drvdata(dev, led);
  85
  86         led->cdev.brightness_set = s3c24xx_led_set;
  87         led->cdev.default_trigger = pdata->def_trigger;
  88         led->cdev.name = pdata->name;
  89         led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  90
  91         led->pdata = pdata;
  92
  93         ret = devm_gpio_request(&dev->dev, pdata->gpio, "S3C24XX_LED");
  94         if (ret < 0)
  95                 return ret;
  96
  97         /* no point in having a pull-up if we are always driving */
  98
  99         s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);
 100
 101         if (pdata->flags & S3C24XX_LEDF_TRISTATE)
 102                 gpio_direction_input(pdata->gpio);
 103         else
 104                 gpio_direction_output(pdata->gpio,
 105                         pdata->flags & S3C24XX_LEDF_ACTLOW ? 1 : 0);
 106
 107         /* register our new led device */
 108
 109         ret = led_classdev_register(&dev->dev, &led->cdev);
 110         if (ret < 0)
 111                 dev_err(&dev->dev, "led_classdev_register failed\n");
 112
 113         return ret;
 114 }
 115
 116 static struct platform_driver s3c24xx_led_driver = {
 117         .probe          = s3c24xx_led_probe,
 118         .remove         = s3c24xx_led_remove,
 119         .driver         = {
 120                 .name           = "s3c24xx_led",
 121                 .owner          = THIS_MODULE,
 122         },
 123 };
 124
 125 module_platform_driver(s3c24xx_led_driver);
 126
 127 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 128 MODULE_DESCRIPTION("S3C24XX LED driver");
 129 MODULE_LICENSE("GPL");
 130 MODULE_ALIAS("platform:s3c24xx_led");