[PATCH v2 1/2] dt-bindings: power: reset: gpio-poweroff: Add 'timeout_ms' property

Add 'timeout_ms' property to support boards where the 3s timeout that the
current driver defaults to is too short.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
---

Changes from v1:
- Addressed Rob's feedback (timeout -> timeout_ms)
- Added to old example rather than creating separate one

---
 Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt
index e62d53d844cc..3f557b344dc4 100644
--- a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt
+++ b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt

@@ -27,10 +27,13 @@ Optional properties:
   it to an output when the power-off handler is called. If this optional
   property is not specified, the GPIO is initialized as an output in its
   inactive state.
+- timeout_ms: Time to wait before asserting a WARN_ON(1). If nothing is
+              specified, 3000 ms is used.
 
 Examples:
 
 gpio-poweroff {
 	compatible = "gpio-poweroff";
 	gpios = <&gpio 4 0>;
+	timeout_ms = <3000>;
 };

-- 
2.16.1

Add support for reading a timeout value from devicetree.
Fall back to previous default of 3s if nothing is specified.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
---

Changes from v1:
- of_property_read_u32() overwrites the output only if it succeeds,
  simplify error handling
---
 drivers/power/reset/gpio-poweroff.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c
index be3d81ff51cc..265cc37646a9 100644
--- a/drivers/power/reset/gpio-poweroff.c
+++ b/drivers/power/reset/gpio-poweroff.c

@@ -19,11 +19,13 @@
 #include <linux/of_platform.h>
 #include <linux/module.h>
 
+#define DEFAULT_TIMEOUT_MS 3000
 /*
  * Hold configuration here, cannot be more than one instance of the driver
  * since pm_power_off itself is global.
  */
 static struct gpio_desc *reset_gpio;
+static u32 timeout = DEFAULT_TIMEOUT_MS;
 
 static void gpio_poweroff_do_poweroff(void)
 {

@@ -40,7 +42,7 @@ static void gpio_poweroff_do_poweroff(void)
 	gpiod_set_value(reset_gpio, 1);
 
 	/* give it some time */
-	mdelay(3000);
+	mdelay(timeout);
 
 	WARN_ON(1);
 }

@@ -64,6 +66,8 @@ static int gpio_poweroff_probe(struct platform_device *pdev)
 	else
 		flags = GPIOD_OUT_LOW;
 
+	of_property_read_u32(pdev->dev.of_node, "timeout_ms", &timeout);
+
 	reset_gpio = devm_gpiod_get(&pdev->dev, NULL, flags);
 	if (IS_ERR(reset_gpio))
 		return PTR_ERR(reset_gpio);

-- 
2.16.1

On Tue, Feb 20, 2018 at 12:59 AM, Moritz Fischer [off-list ref] wrote:

Add support for reading a timeout value from devicetree.
Fall back to previous default of 3s if nothing is specified.

+       of_property_read_u32(pdev->dev.of_node, "timeout_ms", &timeout);

Perhaps stop being OF-centric by using device_property_read_u32() instead?

-- 
With Best Regards,
Andy Shevchenko

On Mon, Feb 19, 2018 at 4:59 PM, Moritz Fischer [off-list ref] wrote:

timeout-ms

On Tue, Feb 20, 2018 at 04:12:59PM +0200, Andy Shevchenko wrote:

On Tue, Feb 20, 2018 at 12:59 AM, Moritz Fischer [off-list ref] wrote:

quoted

Add support for reading a timeout value from devicetree.
Fall back to previous default of 3s if nothing is specified.

quoted

+       of_property_read_u32(pdev->dev.of_node, "timeout_ms", &timeout);

Perhaps stop being OF-centric by using device_property_read_u32() instead?

Good catch, will do. Should probably change commit message accordingly,
too.

Thanks,

Moritz