MX28针对GPIO驱动的修正

其实问题很简单,就是GPIO-Key的驱动中需要的条件IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,但是MX28并不支持.修复方法很简单,主要有以下几步:

1. irqflags判断方式修改.
2. 修改IRQ触发方式,当进入IRQ事件时候,因为MX28不能同时具备两个方法,所以...
3. 随时随地需要修改IRQ方式,所以应该独立成一个函数.

所以,最终补丁是如此的:

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index b8213fd..9138f13 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -340,6 +340,22 @@ static void gpio_keys_timer(unsigned long _data)
 	schedule_work(&data->work);
 }
+static void gpio_keys_update_trigger_type(int irq, struct gpio_button_data *bdata, struct gpio_keys_button *button)
+{
+	bool current_level;
+	bool level_for_trigger;
+
+	/* Set new IRQ trigger type. Re-check after changing it, to deal with
+	 * race conditions, i.e. the GPIO changing while we're changing trigger
+	 * type. */
+	current_level = gpio_get_value(button->gpio);
+	do {
+		level_for_trigger = current_level;
+		set_irq_type(irq, level_for_trigger ? IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING);
+		current_level = gpio_get_value(button->gpio);
+	} while (current_level != level_for_trigger);
+}
+
 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
 {
 	struct gpio_button_data *bdata = dev_id;
@@ -353,6 +369,8 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
 	else
 		schedule_work(&bdata->work);
+	gpio_keys_update_trigger_type(irq, bdata, button);
+
 	return IRQ_HANDLED;
 }
@@ -391,7 +409,8 @@ static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
 		goto fail3;
 	}
-	irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
+	irqflags = button->active_low ? IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
+
 	/*
 	 * If platform has specified that the button can be disabled,
 	 * we don't want it to share the interrupt line.
@@ -405,6 +424,7 @@ static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
 			irq, error);
 		goto fail3;
 	}
+	gpio_keys_update_trigger_type(irq, bdata, button);
 	return 0;
--
1.8.1.2