leds: leds-gpio: Change blink_set callback to be able to turn off blinking

The leds-gpio blink_set() callback follows the same prototype as the
main leds subsystem blink_set() one.

The problem is that to stop blink, normally, a leds driver does it
in the brightness_set() callback when asked to set a new fixed value.

However, with leds-gpio, the platform has no hook to do so, as this
later callback results in a standard GPIO manipulation.

This changes the leds-gpio specific callback to take a new argument
that indicates whether the LED should be blinking or not and in what
state it should be set if not. We also update the dns323 platform
which seems to be the only user of this so far.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

arch/arm/mach-orion5x/dns323-setup.c

@@ -240,22 +240,23 @@ error_fail:
 
 #define ORION_BLINK_HALF_PERIOD 100 /* ms */
 
-static int dns323_gpio_blink_set(unsigned gpio,
+static int dns323_gpio_blink_set(unsigned gpio, int state,
 	unsigned long *delay_on, unsigned long *delay_off)
 {
-	static int value = 0;
 
-	if (!*delay_on && !*delay_off)
+	if (delay_on && delay_off && !*delay_on && !*delay_off)
 		*delay_on = *delay_off = ORION_BLINK_HALF_PERIOD;
 
-	if (ORION_BLINK_HALF_PERIOD == *delay_on
-	    && ORION_BLINK_HALF_PERIOD == *delay_off) {
-		value = !value;
-		orion_gpio_set_blink(gpio, value);
-		return 0;
+	switch(state) {
+	case GPIO_LED_NO_BLINK_LOW:
+	case GPIO_LED_NO_BLINK_HIGH:
+		orion_gpio_set_blink(gpio, 0);
+		gpio_set_value(gpio, state);
+		break;
+	case GPIO_LED_BLINK:
+		orion_gpio_set_blink(gpio, 1);
 	}
-
-	return -EINVAL;
+	return 0;
 }
 
 static struct gpio_led dns323_leds[] = {
@@ -263,6 +264,7 @@ static struct gpio_led dns323_leds[] = {
 		.name = "power:blue",
 		.gpio = DNS323_GPIO_LED_POWER2,
 		.default_trigger = "timer",
+		.active_low = 1,
 	}, {
 		.name = "right:amber",
 		.gpio = DNS323_GPIO_LED_RIGHT_AMBER,

drivers/leds/leds-gpio.c

@@ -26,7 +26,8 @@ struct gpio_led_data {
 	u8 new_level;
 	u8 can_sleep;
 	u8 active_low;
-	int (*platform_gpio_blink_set)(unsigned gpio,
+	u8 blinking;
+	int (*platform_gpio_blink_set)(unsigned gpio, int state,
 			unsigned long *delay_on, unsigned long *delay_off);
 };
 
@@ -35,7 +36,13 @@ static void gpio_led_work(struct work_struct *work)
 	struct gpio_led_data	*led_dat =
 		container_of(work, struct gpio_led_data, work);
 
-	gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
+	if (led_dat->blinking) {
+		led_dat->platform_gpio_blink_set(led_dat->gpio,
+						 led_dat->new_level,
+						 NULL, NULL);
+		led_dat->blinking = 0;
+	} else
+		gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
 }
 
 static void gpio_led_set(struct led_classdev *led_cdev,
@@ -60,8 +67,14 @@ static void gpio_led_set(struct led_classdev *led_cdev,
 	if (led_dat->can_sleep) {
 		led_dat->new_level = level;
 		schedule_work(&led_dat->work);
-	} else
-		gpio_set_value(led_dat->gpio, level);
+	} else {
+		if (led_dat->blinking) {
+			led_dat->platform_gpio_blink_set(led_dat->gpio, level,
+							 NULL, NULL);
+			led_dat->blinking = 0;
+		} else
+			gpio_set_value(led_dat->gpio, level);
+	}
 }
 
 static int gpio_blink_set(struct led_classdev *led_cdev,
@@ -70,12 +83,14 @@ static int gpio_blink_set(struct led_classdev *led_cdev,
 	struct gpio_led_data *led_dat =
 		container_of(led_cdev, struct gpio_led_data, cdev);
 
-	return led_dat->platform_gpio_blink_set(led_dat->gpio, delay_on, delay_off);
+	led_dat->blinking = 1;
+	return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
+						delay_on, delay_off);
 }
 
 static int __devinit create_gpio_led(const struct gpio_led *template,
 	struct gpio_led_data *led_dat, struct device *parent,
-	int (*blink_set)(unsigned, unsigned long *, unsigned long *))
+	int (*blink_set)(unsigned, int, unsigned long *, unsigned long *))
 {
 	int ret, state;
 
@@ -97,6 +112,7 @@ static int __devinit create_gpio_led(const struct gpio_led *template,
 	led_dat->gpio = template->gpio;
 	led_dat->can_sleep = gpio_cansleep(template->gpio);
 	led_dat->active_low = template->active_low;
+	led_dat->blinking = 0;
 	if (blink_set) {
 		led_dat->platform_gpio_blink_set = blink_set;
 		led_dat->cdev.blink_set = gpio_blink_set;
@@ -113,7 +129,7 @@ static int __devinit create_gpio_led(const struct gpio_led *template,
 	ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
 	if (ret < 0)
 		goto err;
-
+		
 	INIT_WORK(&led_dat->work, gpio_led_work);
 
 	ret = led_classdev_register(parent, &led_dat->cdev);
@@ -234,6 +250,7 @@ static int __devinit of_gpio_leds_probe(struct of_device *ofdev,
 		led.gpio = of_get_gpio_flags(child, 0, &flags);
 		led.active_low = flags & OF_GPIO_ACTIVE_LOW;
 		led.name = of_get_property(child, "label", NULL) ? : child->name;
+		led.blinking = 0;
 		led.default_trigger =
 			of_get_property(child, "linux,default-trigger", NULL);
 		state = of_get_property(child, "default-state", NULL);

include/linux/leds.h

@@ -149,14 +149,18 @@ struct gpio_led {
 	unsigned	default_state : 2;
 	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 };
-#define LEDS_GPIO_DEFSTATE_OFF	0
-#define LEDS_GPIO_DEFSTATE_ON	1
-#define LEDS_GPIO_DEFSTATE_KEEP	2
+#define LEDS_GPIO_DEFSTATE_OFF		0
+#define LEDS_GPIO_DEFSTATE_ON		1
+#define LEDS_GPIO_DEFSTATE_KEEP		2
 
 struct gpio_led_platform_data {
 	int 		num_leds;
 	struct gpio_led *leds;
-	int		(*gpio_blink_set)(unsigned gpio,
+
+#define GPIO_LED_NO_BLINK_LOW	0	/* No blink GPIO state low */
+#define GPIO_LED_NO_BLINK_HIGH	1	/* No blink GPIO state high */
+#define GPIO_LED_BLINK		2	/* Plase, blink */
+	int		(*gpio_blink_set)(unsigned gpio, int state,
 					unsigned long *delay_on,
 					unsigned long *delay_off);
 };