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This series adds support for gpio-leds "default-state" property. The

PATCH Superseded linux-kernel-dev at beckhoff.com 2 participants 4 messages Mar 7, 2018 – Apr 1, 2018

v1 of 4 Superseded Latest is v4 →

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cover This series adds support for gpio-leds "default-state" property. The

From: Patrick Bruenn <[email protected]>

main usecase in mind are LEDs which indicate a state like "power on". With this patchset applied, all you have to do is:
Add a gpio-led node with 'default-state = "on";' property to your device tree. And the LED will automatically light up during U-Boot startup.

Patrick Bruenn (2):
dm: led: Support "default-state" property
dm: led: auto probe() LEDs with "default-state"

 drivers/led/led_gpio.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)
Signature · 1 line
2.11.0
#1 lore raw

PATCH 1/2 dm: led: Support "default-state" property

From: Patrick Bruenn <[email protected]>

Add support for the device tree property "default-state". This feature might be useful for LEDs indicating "power on" or similar states.

Note: Even with this commit gpio-leds remain in reset state. That's because the led_gpio is not probed until DM_FLAG_ACTIVATED is set.

---

 drivers/led/led_gpio.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
drivers/led/led_gpio.c +15 -1
index 9976635887..e68d8d3864 100644
@@ -60,11 +60,25 @@ static int led_gpio_probe(struct udevice *dev)
 {
 	struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
 	struct led_gpio_priv *priv = dev_get_priv(dev);
+	const char *default_state;
+	int ret;
 
 	/* Ignore the top-level LED node */
 	if (!uc_plat->label)
 		return 0;
-	return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
+
+	ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
+	if (ret)
+		return ret;
+
+	default_state = dev_read_string(dev, "default-state");
+	if (default_state) {
+		if (!strncmp(default_state, "on", 2))
+			gpio_led_set_state(dev, LEDST_ON);
+		else if (!strncmp(default_state, "off", 3))
+			gpio_led_set_state(dev, LEDST_OFF);
+	}
+	return 0;
 }
 
 static int led_gpio_remove(struct udevice *dev)
Signature · 1 line
2.11.0
#3 lore raw

PATCH 2/2 dm: led: auto probe() LEDs with "default-state"

In reply to linux-kernel-dev at beckhoff.com

From: Patrick Bruenn <[email protected]>

To avoid board specificy LED activation code, automatically activate gpio-leds with "default-state" property during bind().

---

 drivers/led/led_gpio.c | 9 +++++++++
 1 file changed, 9 insertions(+)
drivers/led/led_gpio.c +9 -0
index e68d8d3864..d2fe3d5ad5 100644
@@ -11,6 +11,7 @@
 #include <led.h>
 #include <asm/gpio.h>
 #include <dm/lists.h>
+#include <dm/uclass-internal.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -120,6 +121,14 @@ static int led_gpio_bind(struct udevice *parent)
 			return ret;
 		uc_plat = dev_get_uclass_platdata(dev);
 		uc_plat->label = label;
+
+		if (ofnode_read_string(node, "default-state")) {
+			struct udevice *devp;
+
+			ret = uclass_get_device_tail(dev, 0, &devp);
+			if (ret)
+				return ret;
+		}
 	}
 
 	return 0;
Signature · 1 line
2.11.0
#2 lore raw

PATCH 1/2 dm: led: Support "default-state" property

In reply to linux-kernel-dev at beckhoff.com

Hi Patrick,

Quoted 8 lines · On 7 March 2018 at 17:48, <[email protected]> wrote:

From: Patrick Bruenn <[email protected]>

Add support for the device tree property "default-state". This feature might be useful for LEDs indicating "power on" or similar states.

Note: Even with this commit gpio-leds remain in reset state. That's because the led_gpio is not probed until DM_FLAG_ACTIVATED is set.

This looks OK, but please add a test to test/dm/led.c as well.

Quoted 6 lines

---

 drivers/led/led_gpio.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

Regards,
Simon