[PATCH v5 0/3] BPi M2 Zero poweroff support via new regulator-poweroff driver

[PATCH v5 0/3] BPi M2 Zero poweroff support via new regulator-poweroff driver

[Michael Klein]

Changes in v2:
  - rename DT node

Changes in v3:
  - add regulator-poweroff driver
  - use regulator-poweroff driver instead of gpio-poweroff

Changes in v4:
  - hardcode poweroff timeout to 3000ms, not configurable any more
  - remove support for multiple regulators
  - fix Documentation issues

Changes in v5:
  - rename DT property 'power-supply' -> 'cpu-supply'

Michael Klein (3):
  power: reset: new driver regulator-poweroff
  Documentation: DT: binding documentation for regulator-poweroff
  ARM: dts: sun8i-h2-plus-bananapi-m2-zero: add poweroff node

 .../power/reset/regulator-poweroff.yaml       | 37 +++++++++
 .../dts/sun8i-h2-plus-bananapi-m2-zero.dts    |  5 ++
 drivers/power/reset/Kconfig                   |  7 ++
 drivers/power/reset/Makefile                  |  1 +
 drivers/power/reset/regulator-poweroff.c      | 82 +++++++++++++++++++
 5 files changed, 132 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
 create mode 100644 drivers/power/reset/regulator-poweroff.c

-- 
2.29.2

[PATCH v5 1/3] power: reset: new driver regulator-poweroff

[Michael Klein]

This driver registers a pm_power_off function to turn off the board
by force-disabling a devicetree-defined regulator.

Signed-off-by: Michael Klein <michael@fossekall.de>
---
 drivers/power/reset/Kconfig              |  7 ++
 drivers/power/reset/Makefile             |  1 +
 drivers/power/reset/regulator-poweroff.c | 82 ++++++++++++++++++++++++
 3 files changed, 90 insertions(+)
 create mode 100644 drivers/power/reset/regulator-poweroff.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index d55b3727e00e..b22c4fdb2561 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -177,6 +177,13 @@ config POWER_RESET_QNAP
 
 	  Say Y if you have a QNAP NAS.
 
+config POWER_RESET_REGULATOR
+	bool "Regulator subsystem power-off driver"
+	depends on OF && REGULATOR
+	help
+	  This driver supports turning off your board by disabling a
+	  power regulator defined in the devicetree.
+
 config POWER_RESET_RESTART
 	bool "Restart power-off driver"
 	help
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index c51eceba9ea3..9dc49d3a57ff 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
 obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o
 obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
 obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
+obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o
 obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
 obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o
 obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
diff --git a/drivers/power/reset/regulator-poweroff.c b/drivers/power/reset/regulator-poweroff.c
new file mode 100644
index 000000000000..f697088e0ad1
--- /dev/null
+++ b/drivers/power/reset/regulator-poweroff.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Force-disables a regulator to power down a device
+ *
+ * Michael Klein <michael@fossekall.de>
+ *
+ * Copyright (C) 2020 Michael Klein
+ *
+ * Based on the gpio-poweroff driver.
+ */
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#define TIMEOUT_MS 3000
+
+/*
+ * Hold configuration here, cannot be more than one instance of the driver
+ * since pm_power_off itself is global.
+ */
+static struct regulator *cpu_regulator;
+
+static void regulator_poweroff_do_poweroff(void)
+{
+	if (cpu_regulator && regulator_is_enabled(cpu_regulator))
+		regulator_force_disable(cpu_regulator);
+
+	/* give it some time */
+	mdelay(TIMEOUT_MS);
+
+	WARN_ON(1);
+}
+
+static int regulator_poweroff_probe(struct platform_device *pdev)
+{
+	/* 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;
+	}
+
+	cpu_regulator = devm_regulator_get(&pdev->dev, "cpu");
+	if (IS_ERR(cpu_regulator))
+		return PTR_ERR(cpu_regulator);
+
+	pm_power_off = &regulator_poweroff_do_poweroff;
+	return 0;
+}
+
+static int regulator_poweroff_remove(__maybe_unused struct platform_device *pdev)
+{
+	if (pm_power_off == &regulator_poweroff_do_poweroff)
+		pm_power_off = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id of_regulator_poweroff_match[] = {
+	{ .compatible = "regulator-poweroff", },
+	{},
+};
+
+static struct platform_driver regulator_poweroff_driver = {
+	.probe = regulator_poweroff_probe,
+	.remove = regulator_poweroff_remove,
+	.driver = {
+		.name = "poweroff-regulator",
+		.of_match_table = of_regulator_poweroff_match,
+	},
+};
+
+module_platform_driver(regulator_poweroff_driver);
+
+MODULE_AUTHOR("Michael Klein <michael@fossekall.de>");
+MODULE_DESCRIPTION("Regulator poweroff driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:poweroff-regulator");
-- 
2.29.2

[PATCH v5 2/3] Documentation: DT: binding documentation for regulator-poweroff

[Michael Klein]

Add devicetree binding documentation for regulator-poweroff driver.

Signed-off-by: Michael Klein <michael@fossekall.de>
---
 .../power/reset/regulator-poweroff.yaml       | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml

diff --git a/Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml b/Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
new file mode 100644
index 000000000000..03bd1fa5a623
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/reset/regulator-poweroff.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Force-disable power regulator to turn the power off.
+
+maintainers:
+  - Michael Klein <michael@fossekall.de>
+
+description: |
+  When the power-off handler is called, a power regulator is disabled by
+  calling regulator_force_disable(). If the power is still on and the
+  CPU still running after a 3000ms delay, a warning is emitted.
+
+properties:
+  compatible:
+    const: "regulator-poweroff"
+
+  cpu-supply:
+    description:
+      regulator to disable on power-down
+
+required:
+  - compatible
+  - cpu-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    regulator-poweroff {
+        compatible = "regulator-poweroff";
+        cpu-supply = <&reg_vcc1v2>;
+    };
+...
-- 
2.29.2

[PATCH v5 3/3] ARM: dts: sun8i-h2-plus-bananapi-m2-zero: add poweroff node

[Michael Klein]

Add add devicetree information for the regulator-poweroff driver.

Signed-off-by: Michael Klein <michael@fossekall.de>
---
 arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts b/arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts
index b43028f9e6df..f8a7b1371e97 100644
--- a/arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts
+++ b/arch/arm/boot/dts/sun8i-h2-plus-bananapi-m2-zero.dts
@@ -86,6 +86,11 @@ reg_vcc1v2: vcc1v2 {
 		vin-supply = <&reg_vcc5v0>;
 	};
 
+	poweroff {
+		compatible = "regulator-poweroff";
+		cpu-supply = <&reg_vcc1v2>;
+	};
+
 	wifi_pwrseq: wifi_pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		reset-gpios = <&r_pio 0 7 GPIO_ACTIVE_LOW>; /* PL7 */
-- 
2.29.2

Re: [PATCH v5 2/3] Documentation: DT: binding documentation for regulator-poweroff

[Rob Herring]

On Fri, 11 Dec 2020 16:14:44 +0100, Michael Klein wrote:
> Add devicetree binding documentation for regulator-poweroff driver.
> 
> Signed-off-by: Michael Klein <michael@fossekall.de>
> ---
>  .../power/reset/regulator-poweroff.yaml       | 37 +++++++++++++++++++
>  1 file changed, 37 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 1/3] power: reset: new driver regulator-poweroff

[Sebastian Reichel]

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Hi,

On Fri, Dec 11, 2020 at 04:14:43PM +0100, Michael Klein wrote:
> This driver registers a pm_power_off function to turn off the board
> by force-disabling a devicetree-defined regulator.
> 
> Signed-off-by: Michael Klein <michael@fossekall.de>
> ---

Thanks, queued.

-- Sebastian

>  drivers/power/reset/Kconfig              |  7 ++
>  drivers/power/reset/Makefile             |  1 +
>  drivers/power/reset/regulator-poweroff.c | 82 ++++++++++++++++++++++++
>  3 files changed, 90 insertions(+)
>  create mode 100644 drivers/power/reset/regulator-poweroff.c
> 
> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> index d55b3727e00e..b22c4fdb2561 100644
> --- a/drivers/power/reset/Kconfig
> +++ b/drivers/power/reset/Kconfig
> @@ -177,6 +177,13 @@ config POWER_RESET_QNAP
>  
>  	  Say Y if you have a QNAP NAS.
>  
> +config POWER_RESET_REGULATOR
> +	bool "Regulator subsystem power-off driver"
> +	depends on OF && REGULATOR
> +	help
> +	  This driver supports turning off your board by disabling a
> +	  power regulator defined in the devicetree.
> +
>  config POWER_RESET_RESTART
>  	bool "Restart power-off driver"
>  	help
> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
> index c51eceba9ea3..9dc49d3a57ff 100644
> --- a/drivers/power/reset/Makefile
> +++ b/drivers/power/reset/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
>  obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o
>  obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
>  obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
> +obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o
>  obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
>  obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o
>  obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
> diff --git a/drivers/power/reset/regulator-poweroff.c b/drivers/power/reset/regulator-poweroff.c
> new file mode 100644
> index 000000000000..f697088e0ad1
> --- /dev/null
> +++ b/drivers/power/reset/regulator-poweroff.c
> @@ -0,0 +1,82 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Force-disables a regulator to power down a device
> + *
> + * Michael Klein <michael@fossekall.de>
> + *
> + * Copyright (C) 2020 Michael Klein
> + *
> + * Based on the gpio-poweroff driver.
> + */
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define TIMEOUT_MS 3000
> +
> +/*
> + * Hold configuration here, cannot be more than one instance of the driver
> + * since pm_power_off itself is global.
> + */
> +static struct regulator *cpu_regulator;
> +
> +static void regulator_poweroff_do_poweroff(void)
> +{
> +	if (cpu_regulator && regulator_is_enabled(cpu_regulator))
> +		regulator_force_disable(cpu_regulator);
> +
> +	/* give it some time */
> +	mdelay(TIMEOUT_MS);
> +
> +	WARN_ON(1);
> +}
> +
> +static int regulator_poweroff_probe(struct platform_device *pdev)
> +{
> +	/* 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;
> +	}
> +
> +	cpu_regulator = devm_regulator_get(&pdev->dev, "cpu");
> +	if (IS_ERR(cpu_regulator))
> +		return PTR_ERR(cpu_regulator);
> +
> +	pm_power_off = &regulator_poweroff_do_poweroff;
> +	return 0;
> +}
> +
> +static int regulator_poweroff_remove(__maybe_unused struct platform_device *pdev)
> +{
> +	if (pm_power_off == &regulator_poweroff_do_poweroff)
> +		pm_power_off = NULL;
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id of_regulator_poweroff_match[] = {
> +	{ .compatible = "regulator-poweroff", },
> +	{},
> +};
> +
> +static struct platform_driver regulator_poweroff_driver = {
> +	.probe = regulator_poweroff_probe,
> +	.remove = regulator_poweroff_remove,
> +	.driver = {
> +		.name = "poweroff-regulator",
> +		.of_match_table = of_regulator_poweroff_match,
> +	},
> +};
> +
> +module_platform_driver(regulator_poweroff_driver);
> +
> +MODULE_AUTHOR("Michael Klein <michael@fossekall.de>");
> +MODULE_DESCRIPTION("Regulator poweroff driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:poweroff-regulator");
> -- 
> 2.29.2
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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Re: [PATCH v5 2/3] Documentation: DT: binding documentation for regulator-poweroff

[Sebastian Reichel]

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Hi,

On Fri, Dec 11, 2020 at 04:14:44PM +0100, Michael Klein wrote:
> Add devicetree binding documentation for regulator-poweroff driver.
> 
> Signed-off-by: Michael Klein <michael@fossekall.de>
> ---

Thanks, queued.

-- Sebastian

>  .../power/reset/regulator-poweroff.yaml       | 37 +++++++++++++++++++
>  1 file changed, 37 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
> 
> diff --git a/Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml b/Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
> new file mode 100644
> index 000000000000..03bd1fa5a623
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/reset/regulator-poweroff.yaml
> @@ -0,0 +1,37 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/power/reset/regulator-poweroff.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Force-disable power regulator to turn the power off.
> +
> +maintainers:
> +  - Michael Klein <michael@fossekall.de>
> +
> +description: |
> +  When the power-off handler is called, a power regulator is disabled by
> +  calling regulator_force_disable(). If the power is still on and the
> +  CPU still running after a 3000ms delay, a warning is emitted.
> +
> +properties:
> +  compatible:
> +    const: "regulator-poweroff"
> +
> +  cpu-supply:
> +    description:
> +      regulator to disable on power-down
> +
> +required:
> +  - compatible
> +  - cpu-supply
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    regulator-poweroff {
> +        compatible = "regulator-poweroff";
> +        cpu-supply = <&reg_vcc1v2>;
> +    };
> +...
> -- 
> 2.29.2
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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Re: [PATCH v5 1/3] power: reset: new driver regulator-poweroff

[Maxime Ripard]

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Hi Sebastian,

On Sun, Dec 13, 2020 at 12:41:16AM +0100, Sebastian Reichel wrote:
> Hi,
> 
> On Fri, Dec 11, 2020 at 04:14:43PM +0100, Michael Klein wrote:
> > This driver registers a pm_power_off function to turn off the board
> > by force-disabling a devicetree-defined regulator.
> > 
> > Signed-off-by: Michael Klein <michael@fossekall.de>
> > ---
> 
> Thanks, queued.

Did you also merge the binding?

Maxime

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Re: [PATCH v5 3/3] ARM: dts: sun8i-h2-plus-bananapi-m2-zero: add poweroff node

[Maxime Ripard]

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On Fri, Dec 11, 2020 at 04:14:45PM +0100, Michael Klein wrote:
> Add add devicetree information for the regulator-poweroff driver.
> 
> Signed-off-by: Michael Klein <michael@fossekall.de>

Queued for 5.12, thanks!
Maxime

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Re: [PATCH v5 1/3] power: reset: new driver regulator-poweroff

[Sebastian Reichel]

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Hi Maxime,

On Mon, Dec 14, 2020 at 11:02:04AM +0100, Maxime Ripard wrote:
> Hi Sebastian,
> 
> On Sun, Dec 13, 2020 at 12:41:16AM +0100, Sebastian Reichel wrote:
> > Hi,
> > 
> > On Fri, Dec 11, 2020 at 04:14:43PM +0100, Michael Klein wrote:
> > > This driver registers a pm_power_off function to turn off the board
> > > by force-disabling a devicetree-defined regulator.
> > > 
> > > Signed-off-by: Michael Klein <michael@fossekall.de>
> > > ---
> > 
> > Thanks, queued.
> 
> Did you also merge the binding?

Yes.

-- Sebastian

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