[PATCH v1 0/4] power: reset: gpio-poweroff: use sys-off handler API

[PATCH v1 0/4] power: reset: gpio-poweroff: use sys-off handler API

[Francesco Dolcini]

From: Francesco Dolcini <francesco.dolcini@toradex.com>

Use the new sys-off handler API for gpio-poweroff. This allows us to have more
than one power-off handler and to have a priority for the handler. Also, add a
priority property so we can use gpio-poweroff even when registering another
poweroff handler or using the legacy pm_power_off method.

Stefan Eichenberger (4):
  power: reset: gpio-poweroff: use a struct to store the module
    variables
  power: reset: gpio-poweroff: use sys-off handler API
  dt-bindings: power: reset: gpio-poweroff: Add priority property
  power: reset: gpio-poweroff: make sys handler priority configurable

 .../bindings/power/reset/gpio-poweroff.yaml   |  4 +
 drivers/power/reset/gpio-poweroff.c           | 82 ++++++++++---------
 2 files changed, 48 insertions(+), 38 deletions(-)

-- 
2.25.1

[PATCH v1 1/4] power: reset: gpio-poweroff: use a struct to store the module variables

[Francesco Dolcini]

From: Stefan Eichenberger <stefan.eichenberger@toradex.com>

Use a struct to store the module variables. This is required to later
move to notifier_blocks where we can have several instances.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
---
 drivers/power/reset/gpio-poweroff.c | 48 +++++++++++++++++++----------
 1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c
index b28f24da1b3c..dea550e422f3 100644
--- a/drivers/power/reset/gpio-poweroff.c
+++ b/drivers/power/reset/gpio-poweroff.c
@@ -17,32 +17,37 @@
 #include <linux/module.h>
 
 #define DEFAULT_TIMEOUT_MS 3000
+
+struct gpio_poweroff {
+	struct gpio_desc *reset_gpio;
+	u32 timeout_ms;
+	u32 active_delay_ms;
+	u32 inactive_delay_ms;
+};
+
 /*
  * 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 u32 active_delay = 100;
-static u32 inactive_delay = 100;
+static struct gpio_poweroff *gpio_poweroff;
 
 static void gpio_poweroff_do_poweroff(void)
 {
-	BUG_ON(!reset_gpio);
+	BUG_ON(!gpio_poweroff);
 
 	/* drive it active, also inactive->active edge */
-	gpiod_direction_output(reset_gpio, 1);
-	mdelay(active_delay);
+	gpiod_direction_output(gpio_poweroff->reset_gpio, 1);
+	mdelay(gpio_poweroff->active_delay_ms);
 
 	/* drive inactive, also active->inactive edge */
-	gpiod_set_value_cansleep(reset_gpio, 0);
-	mdelay(inactive_delay);
+	gpiod_set_value_cansleep(gpio_poweroff->reset_gpio, 0);
+	mdelay(gpio_poweroff->inactive_delay_ms);
 
 	/* drive it active, also inactive->active edge */
-	gpiod_set_value_cansleep(reset_gpio, 1);
+	gpiod_set_value_cansleep(gpio_poweroff->reset_gpio, 1);
 
 	/* give it some time */
-	mdelay(timeout);
+	mdelay(gpio_poweroff->timeout_ms);
 
 	WARN_ON(1);
 }
@@ -60,20 +65,29 @@ static int gpio_poweroff_probe(struct platform_device *pdev)
 		return -EBUSY;
 	}
 
+	gpio_poweroff = devm_kzalloc(&pdev->dev, sizeof(*gpio_poweroff), GFP_KERNEL);
+	if (!gpio_poweroff)
+		return -ENOMEM;
+
 	input = device_property_read_bool(&pdev->dev, "input");
 	if (input)
 		flags = GPIOD_IN;
 	else
 		flags = GPIOD_OUT_LOW;
 
-	device_property_read_u32(&pdev->dev, "active-delay-ms", &active_delay);
+
+	gpio_poweroff->active_delay_ms = 100;
+	gpio_poweroff->inactive_delay_ms = 100;
+	gpio_poweroff->timeout_ms = DEFAULT_TIMEOUT_MS;
+
+	device_property_read_u32(&pdev->dev, "active-delay-ms", &gpio_poweroff->active_delay_ms);
 	device_property_read_u32(&pdev->dev, "inactive-delay-ms",
-				 &inactive_delay);
-	device_property_read_u32(&pdev->dev, "timeout-ms", &timeout);
+				 &gpio_poweroff->inactive_delay_ms);
+	device_property_read_u32(&pdev->dev, "timeout-ms", &gpio_poweroff->timeout_ms);
 
-	reset_gpio = devm_gpiod_get(&pdev->dev, NULL, flags);
-	if (IS_ERR(reset_gpio))
-		return PTR_ERR(reset_gpio);
+	gpio_poweroff->reset_gpio = devm_gpiod_get(&pdev->dev, NULL, flags);
+	if (IS_ERR(gpio_poweroff->reset_gpio))
+		return PTR_ERR(gpio_poweroff->reset_gpio);
 
 	pm_power_off = &gpio_poweroff_do_poweroff;
 	return 0;
-- 
2.25.1

[PATCH v1 2/4] power: reset: gpio-poweroff: use sys-off handler API

[Francesco Dolcini]

From: Stefan Eichenberger <stefan.eichenberger@toradex.com>

Use the new sys-off handler API for gpio-poweroff. This allows us to
have more than one poweroff handler and prioritise them.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
---
 drivers/power/reset/gpio-poweroff.c | 37 ++++++++++-------------------
 1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c
index dea550e422f3..0deb293eb2d6 100644
--- a/drivers/power/reset/gpio-poweroff.c
+++ b/drivers/power/reset/gpio-poweroff.c
@@ -15,6 +15,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
+#include <linux/reboot.h>
 
 #define DEFAULT_TIMEOUT_MS 3000
 
@@ -25,15 +26,9 @@ struct gpio_poweroff {
 	u32 inactive_delay_ms;
 };
 
-/*
- * Hold configuration here, cannot be more than one instance of the driver
- * since pm_power_off itself is global.
- */
-static struct gpio_poweroff *gpio_poweroff;
-
-static void gpio_poweroff_do_poweroff(void)
+static int gpio_poweroff_do_poweroff(struct sys_off_data *data)
 {
-	BUG_ON(!gpio_poweroff);
+	struct gpio_poweroff *gpio_poweroff = data->cb_data;
 
 	/* drive it active, also inactive->active edge */
 	gpiod_direction_output(gpio_poweroff->reset_gpio, 1);
@@ -50,20 +45,16 @@ static void gpio_poweroff_do_poweroff(void)
 	mdelay(gpio_poweroff->timeout_ms);
 
 	WARN_ON(1);
+
+	return NOTIFY_DONE;
 }
 
 static int gpio_poweroff_probe(struct platform_device *pdev)
 {
+	struct gpio_poweroff *gpio_poweroff;
 	bool input = false;
 	enum gpiod_flags flags;
-
-	/* If a pm_power_off function has already been added, leave it alone */
-	if (pm_power_off != NULL) {
-		dev_err(&pdev->dev,
-			"%s: pm_power_off function already registered\n",
-		       __func__);
-		return -EBUSY;
-	}
+	int ret;
 
 	gpio_poweroff = devm_kzalloc(&pdev->dev, sizeof(*gpio_poweroff), GFP_KERNEL);
 	if (!gpio_poweroff)
@@ -89,14 +80,11 @@ static int gpio_poweroff_probe(struct platform_device *pdev)
 	if (IS_ERR(gpio_poweroff->reset_gpio))
 		return PTR_ERR(gpio_poweroff->reset_gpio);
 
-	pm_power_off = &gpio_poweroff_do_poweroff;
-	return 0;
-}
-
-static int gpio_poweroff_remove(struct platform_device *pdev)
-{
-	if (pm_power_off == &gpio_poweroff_do_poweroff)
-		pm_power_off = NULL;
+	ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_POWER_OFF,
+					    SYS_OFF_PRIO_DEFAULT, gpio_poweroff_do_poweroff,
+					    gpio_poweroff);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Cannot register poweroff handler\n");
 
 	return 0;
 }
@@ -109,7 +97,6 @@ MODULE_DEVICE_TABLE(of, of_gpio_poweroff_match);
 
 static struct platform_driver gpio_poweroff_driver = {
 	.probe = gpio_poweroff_probe,
-	.remove = gpio_poweroff_remove,
 	.driver = {
 		.name = "poweroff-gpio",
 		.of_match_table = of_gpio_poweroff_match,
-- 
2.25.1

[PATCH v1 3/4] dt-bindings: power: reset: gpio-poweroff: Add priority property

[Francesco Dolcini]

From: Stefan Eichenberger <stefan.eichenberger@toradex.com>

Add the priority property to the gpio-poweroff bindings description.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
---
 .../devicetree/bindings/power/reset/gpio-poweroff.yaml        | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml
index b54ec003a1e0..c6404841bcd7 100644
--- a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml
+++ b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml
@@ -40,6 +40,10 @@ properties:
     default: 100
     description: Delay to wait after driving gpio inactive
 
+  priority:
+    default: 0
+    description: Priority of the power off handler
+
   timeout-ms:
     default: 3000
     description: Time to wait before assuming the power off sequence failed.
-- 
2.25.1

[PATCH v1 4/4] power: reset: gpio-poweroff: make sys handler priority configurable

[Francesco Dolcini]

From: Stefan Eichenberger <stefan.eichenberger@toradex.com>

Add a priority property equal to gpio-restart to allow increasing the
priority of the gpio-poweroff handler.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
---
 drivers/power/reset/gpio-poweroff.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c
index 0deb293eb2d6..52cfeee2cb28 100644
--- a/drivers/power/reset/gpio-poweroff.c
+++ b/drivers/power/reset/gpio-poweroff.c
@@ -54,6 +54,7 @@ static int gpio_poweroff_probe(struct platform_device *pdev)
 	struct gpio_poweroff *gpio_poweroff;
 	bool input = false;
 	enum gpiod_flags flags;
+	int priority = SYS_OFF_PRIO_DEFAULT;
 	int ret;
 
 	gpio_poweroff = devm_kzalloc(&pdev->dev, sizeof(*gpio_poweroff), GFP_KERNEL);
@@ -75,14 +76,18 @@ static int gpio_poweroff_probe(struct platform_device *pdev)
 	device_property_read_u32(&pdev->dev, "inactive-delay-ms",
 				 &gpio_poweroff->inactive_delay_ms);
 	device_property_read_u32(&pdev->dev, "timeout-ms", &gpio_poweroff->timeout_ms);
+	device_property_read_u32(&pdev->dev, "priority", &priority);
+	if (priority > 255) {
+		dev_err(&pdev->dev, "Invalid priority property: %u\n", priority);
+		return -EINVAL;
+	}
 
 	gpio_poweroff->reset_gpio = devm_gpiod_get(&pdev->dev, NULL, flags);
 	if (IS_ERR(gpio_poweroff->reset_gpio))
 		return PTR_ERR(gpio_poweroff->reset_gpio);
 
 	ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_POWER_OFF,
-					    SYS_OFF_PRIO_DEFAULT, gpio_poweroff_do_poweroff,
-					    gpio_poweroff);
+					    priority, gpio_poweroff_do_poweroff, gpio_poweroff);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret, "Cannot register poweroff handler\n");
 
-- 
2.25.1

Re: [PATCH v1 3/4] dt-bindings: power: reset: gpio-poweroff: Add priority property

[Rob Herring]

On Thu, Sep 28, 2023 at 02:37:27PM +0200, Francesco Dolcini wrote:
> From: Stefan Eichenberger <stefan.eichenberger@toradex.com>
> 
> Add the priority property to the gpio-poweroff bindings description.
> 
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> ---
>  .../devicetree/bindings/power/reset/gpio-poweroff.yaml        | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml
> index b54ec003a1e0..c6404841bcd7 100644
> --- a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml
> +++ b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.yaml
> @@ -40,6 +40,10 @@ properties:
>      default: 100
>      description: Delay to wait after driving gpio inactive
>  
> +  priority:
> +    default: 0
> +    description: Priority of the power off handler
> +

You also need a $ref to restart-handler.yaml (at the top level).

>    timeout-ms:
>      default: 3000
>      description: Time to wait before assuming the power off sequence failed.
> -- 
> 2.25.1
>