nuc970添加led heartbeat

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nuc970添加led heartbeat

Linux 驱动的注册过程：

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通过 Platform 机制开发发底层驱动的大致流程为: 定义platform_add_devices --> 注册platform_device --> 定义platform_add_driver --> 注册platform_driver 。

platform_device 和 platform_driver 通过.name 关联， 名字需要一样。

1.   dev.c  -- arch\arm\mach-nuc970， 添加platform_device

#if defined(CONFIG_LEDS_TRIGGERS) || defined(CONFIG_LEDS_TRIGGERS_MODULE)#if defined(CONFIG_LEDS_TRIGGER_HEARTBEAT)
static struct gpio_led gpio_leds[]  = {{.name			= "led0",.default_trigger	= "heartbeat",.gpio			= NUC970_PI2,},};static struct gpio_led_platform_data gpio_led_info = {.leds		= gpio_leds,.num_leds	= ARRAY_SIZE(gpio_leds),
};static struct platform_device leds_gpio = {.name	= "leds-nuc970",.id	= -1,.dev	= {.platform_data	= &gpio_led_info,},
};
#endif#endif

2. 添加platform_driver

   leds-nuc970.c  -- drivers\leds, 

   leds-nuc970.h -- include\linux\platform_data 

static void nuc970_led_set(struct led_classdev *led_cdev,enum led_brightness value)
{struct nuc970_gpio_led *led = to_gpio(led_cdev);struct gpio_led *pd = led->pdata;int state = (value ? 1 : 0);/* there will be a short delay between setting the output and* going from output to input when using tristate. */pr_notice("nuc970_led_set: GPIO%d = %d\n", pd->gpio, state);gpio_set_value(pd->gpio, state);/*if (pd->flags & NUC970_LEDF_TRISTATE) {if (value)gpio_direction_output(pd->gpio, state);elsegpio_direction_input(pd->gpio);} */
}static int nuc970_led_probe(struct platform_device *dev)
{struct gpio_led_platform_data *pdata_a = dev->dev.platform_data;struct gpio_led *pdata;struct nuc970_gpio_led *led;int ret;pdata = &(pdata_a->leds[0]);led = devm_kzalloc(&dev->dev, sizeof(struct nuc970_gpio_led),GFP_KERNEL);if (led == NULL) {dev_err(&dev->dev, "No memory for device\n");return -ENOMEM;}pr_notice("nuc970_led_probe\n");platform_set_drvdata(dev, led);led->cdev.brightness_set = nuc970_led_set;led->cdev.default_trigger = pdata->default_trigger;led->cdev.name = pdata->name;led->cdev.flags |= LED_CORE_SUSPENDRESUME;led->pdata = pdata;ret = devm_gpio_request(&dev->dev, pdata->gpio, "NUC970_LED");if (ret < 0)return ret;/* no point in having a pull-up if we are always driving *///s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);pr_notice("leds-nuc970: set(%s)(%d) output\n", pdata->name, pdata->gpio);gpio_direction_output(pdata->gpio, 1);/* register our new led device */ret = led_classdev_register(&dev->dev, &led->cdev);if (ret < 0)dev_err(&dev->dev, "led_classdev_register failed\n");return ret;
}
static struct platform_driver nuc970_led_driver = {.probe		= nuc970_led_probe,.remove		= nuc970_led_remove,.driver		= {.name		= "leds-nuc970",.owner		= THIS_MODULE,},
};

3. platform_driver 的 Kconfig 和 Makefile 修改

Kconfig：

config LEDS_S3C24XXtristate "LED Support for Samsung S3C24XX GPIO LEDs"depends on LEDS_CLASSdepends on ARCH_S3C24XXhelpThis option enables support for LEDs connected to GPIO lineson Samsung S3C24XX series CPUs, such as the S3C2410 and S3C2440.++config LEDS_NUC970
++	tristate "LED Support for nuc970 LEDs (PI2)"
++	depends on LEDS_CLASS
++	depends on MACH_NUC970
++	default y
++	help
++	  nuc970 trigger led .

Makefile：

obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
++obj-$(CONFIG_LEDS_NUC970)		+= leds-nuc970.o

4. Make menuconfig

Device drivers -> LED Support->

5. Trigger 间隔修改（没试），

ledtrig-heartbeat.c ->

static void led_heartbeat_function(unsigned long data)