[PATCH v4 0/2] mfd: Add support for Khadas Microcontroller

[PATCH v4 0/2] mfd: Add support for Khadas Microcontroller

[Neil Armstrong]

The new Khadas VIM2, VIM3 and Edge boards embeds an on-board microcontroller
connected via I2C.

This Microcontroller is present on the Khadas VIM1, VIM2, VIM3 and Edge
boards.

It has multiple boot control features like password check, power-on
options, power-off control and system FAN control on recent boards.

Thie serie adds :
- the Thermal Cooling cell driver
- add support into the Khadas VIM3/VIM3L DT

Changes since v3 at [4]:
- Removed Applied patches 1, 2 & 4
- Added reviewed-by tags for patch 3 & 5

Changes since v2 at [3]:
- Removed NVMEM driver for separate submission
- fixed MFD driver, header and Kconfig
- fixed Thermal Kconfig
- fixed MAINTAINERS files and path

Changes since RFC v1 at [2]:
- moved hwmon driver to thermal-only
- moved the SM1 thermal nodes in a separate serie
- added the bindings review tag from rob

[1] http://lore.kernel.org/r/20200512093916.19676-1-narmstrong@baylibre.com
[2] http://lore.kernel.org/r/20200421080102.22796-1-narmstrong@baylibre.com
[3] http://lore.kernel.org/r/20200512132613.31507-1-narmstrong@baylibre.com
[4] http://lore.kernel.org/r/20200608091739.2368-1-narmstrong@baylibre.com

Neil Armstrong (2):
  thermal: add support for the MCU controlled FAN on Khadas boards
  arm64: dts: meson-khadas-vim3: add Khadas MCU nodes

 .../boot/dts/amlogic/meson-khadas-vim3.dtsi   |  23 +++
 drivers/thermal/Kconfig                       |  11 ++
 drivers/thermal/Makefile                      |   1 +
 drivers/thermal/khadas_mcu_fan.c              | 174 ++++++++++++++++++
 4 files changed, 209 insertions(+)
 create mode 100644 drivers/thermal/khadas_mcu_fan.c

-- 
2.22.0

[PATCH v4 1/2] thermal: add support for the MCU controlled FAN on Khadas boards

[Neil Armstrong]

The new Khadas VIM2 and VIM3 boards controls the cooling fan via the
on-board microcontroller.

This implements the FAN control as thermal devices and as cell of the Khadas
MCU MFD driver.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
---
Hi Lee,

Could you apply this patch via the MFD tree since it depends on
the linux/mfd/khadas-mcu.h header ?

This patch is unchanged from the v3 serie.

Thanks,
Neil

 drivers/thermal/Kconfig          |  11 ++
 drivers/thermal/Makefile         |   1 +
 drivers/thermal/khadas_mcu_fan.c | 174 +++++++++++++++++++++++++++++++
 3 files changed, 186 insertions(+)
 create mode 100644 drivers/thermal/khadas_mcu_fan.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3eb2348e5242..0125561488c9 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -500,4 +500,15 @@ config SPRD_THERMAL
 	help
 	  Support for the Spreadtrum thermal sensor driver in the Linux thermal
 	  framework.
+
+config KHADAS_MCU_FAN_THERMAL
+	tristate "Khadas MCU controller FAN cooling support"
+	depends on OF || COMPILE_TEST
+	depends on MFD_KHADAS_MCU
+	select MFD_CORE
+	select REGMAP
+	help
+	  If you say yes here you get support for the FAN controlled
+	  by the Microcontroller found on the Khadas VIM boards.
+
 endif
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 0c8b84a09b9a..4b6aabaa7e31 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -61,3 +61,4 @@ obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
 obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
 obj-$(CONFIG_AMLOGIC_THERMAL)     += amlogic_thermal.o
 obj-$(CONFIG_SPRD_THERMAL)	+= sprd_thermal.o
+obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL)	+= khadas_mcu_fan.o
diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/khadas_mcu_fan.c
new file mode 100644
index 000000000000..6995b443cad4
--- /dev/null
+++ b/drivers/thermal/khadas_mcu_fan.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Khadas MCU Controlled FAN driver
+ *
+ * Copyright (C) 2020 BayLibre SAS
+ * Author(s): Neil Armstrong <narmstrong@baylibre.com>
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/khadas-mcu.h>
+#include <linux/regmap.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+#define MAX_LEVEL 3
+
+struct khadas_mcu_fan_ctx {
+	struct khadas_mcu *mcu;
+	unsigned int level;
+	struct thermal_cooling_device *cdev;
+};
+
+static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
+				    unsigned int level)
+{
+	int ret;
+
+	ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
+			   level);
+	if (ret)
+		return ret;
+
+	ctx->level = level;
+
+	return 0;
+}
+
+static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
+					unsigned long *state)
+{
+	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
+
+	if (!ctx)
+		return -EINVAL;
+
+	*state = MAX_LEVEL;
+
+	return 0;
+}
+
+static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
+					unsigned long *state)
+{
+	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
+
+	if (!ctx)
+		return -EINVAL;
+
+	*state = ctx->level;
+
+	return 0;
+}
+
+static int
+khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
+			     unsigned long state)
+{
+	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
+
+	if (!ctx || (state > MAX_LEVEL))
+		return -EINVAL;
+
+	if (state == ctx->level)
+		return 0;
+
+	return khadas_mcu_fan_set_level(ctx, state);
+}
+
+static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
+	.get_max_state = khadas_mcu_fan_get_max_state,
+	.get_cur_state = khadas_mcu_fan_get_cur_state,
+	.set_cur_state = khadas_mcu_fan_set_cur_state,
+};
+
+static int khadas_mcu_fan_probe(struct platform_device *pdev)
+{
+	struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
+	struct thermal_cooling_device *cdev;
+	struct device *dev = &pdev->dev;
+	struct khadas_mcu_fan_ctx *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+	ctx->mcu = mcu;
+	platform_set_drvdata(pdev, ctx);
+
+	cdev = devm_thermal_of_cooling_device_register(dev->parent,
+			dev->parent->of_node, "khadas-mcu-fan", ctx,
+			&khadas_mcu_fan_cooling_ops);
+	if (IS_ERR(cdev)) {
+		ret = PTR_ERR(cdev);
+		dev_err(dev,
+				"Failed to register khadas-mcu-fan as cooling device: %d\n",
+				ret);
+		return ret;
+	}
+	ctx->cdev = cdev;
+	thermal_cdev_update(cdev);
+
+	return 0;
+}
+
+static int khadas_mcu_fan_disable(struct device *dev)
+{
+	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
+	unsigned int level_save = ctx->level;
+	int ret;
+
+	ret = khadas_mcu_fan_set_level(ctx, 0);
+	if (ret)
+		return ret;
+
+	ctx->level = level_save;
+
+	return 0;
+}
+
+static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
+{
+	khadas_mcu_fan_disable(&pdev->dev);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int khadas_mcu_fan_suspend(struct device *dev)
+{
+	return khadas_mcu_fan_disable(dev);
+}
+
+static int khadas_mcu_fan_resume(struct device *dev)
+{
+	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
+
+	return khadas_mcu_fan_set_level(ctx, ctx->level);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
+			 khadas_mcu_fan_resume);
+
+static const struct platform_device_id khadas_mcu_fan_id_table[] = {
+	{ .name = "khadas-mcu-fan-ctrl", },
+	{},
+};
+MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
+
+static struct platform_driver khadas_mcu_fan_driver = {
+	.probe		= khadas_mcu_fan_probe,
+	.shutdown	= khadas_mcu_fan_shutdown,
+	.driver	= {
+		.name		= "khadas-mcu-fan-ctrl",
+		.pm		= &khadas_mcu_fan_pm,
+	},
+	.id_table	= khadas_mcu_fan_id_table,
+};
+
+module_platform_driver(khadas_mcu_fan_driver);
+
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION("Khadas MCU FAN driver");
+MODULE_LICENSE("GPL");
-- 
2.22.0

[PATCH v4 2/2] arm64: dts: meson-khadas-vim3: add Khadas MCU nodes

[Neil Armstrong]

Add the Khadas MCU node with active FAN thermal nodes for all the
Khadas VIM3 variants.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
---
Hi Kevin,

The bindings has been reviewed and merged by Lee,
could you apply this one via the amlogic tree ?

Thanks,
Neil

 .../boot/dts/amlogic/meson-khadas-vim3.dtsi   | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi b/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi
index 1ef1e3672b96..27408c10a811 100644
--- a/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi
@@ -183,6 +183,23 @@
 	hdmi-phandle = <&hdmi_tx>;
 };
 
+&cpu_thermal {
+	trips {
+		cpu_active: cpu-active {
+			temperature = <80000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&cpu_active>;
+			cooling-device = <&khadas_mcu THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+		};
+	};
+};
+
 &ext_mdio {
 	external_phy: ethernet-phy@0 {
 		/* Realtek RTL8211F (0x001cc916) */
@@ -222,6 +239,12 @@
 	pinctrl-0 = <&i2c_ao_sck_pins>, <&i2c_ao_sda_pins>;
 	pinctrl-names = "default";
 
+	khadas_mcu: system-controller@18 {
+		compatible = "khadas,mcu";
+		reg = <0x18>;
+		#cooling-cells = <2>;
+	};
+
 	gpio_expander: gpio-controller@20 {
 		compatible = "ti,tca6408";
 		reg = <0x20>;
-- 
2.22.0

Re: [PATCH v4 1/2] thermal: add support for the MCU controlled FAN on Khadas boards

[Lee Jones]

On Thu, 18 Jun 2020, Neil Armstrong wrote:

> The new Khadas VIM2 and VIM3 boards controls the cooling fan via the
> on-board microcontroller.
> 
> This implements the FAN control as thermal devices and as cell of the Khadas
> MCU MFD driver.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>

Is this an Ack?

If so, do you require a pull-request?

> ---
> Hi Lee,
> 
> Could you apply this patch via the MFD tree since it depends on
> the linux/mfd/khadas-mcu.h header ?
> 
> This patch is unchanged from the v3 serie.
> 
> Thanks,
> Neil
> 
>  drivers/thermal/Kconfig          |  11 ++
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/khadas_mcu_fan.c | 174 +++++++++++++++++++++++++++++++
>  3 files changed, 186 insertions(+)
>  create mode 100644 drivers/thermal/khadas_mcu_fan.c

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v4 1/2] thermal: add support for the MCU controlled FAN on Khadas boards

[Amit Kucheria]

On Thu, Jun 18, 2020 at 9:58 PM Lee Jones <lee.jones@linaro.org> wrote:
>
> On Thu, 18 Jun 2020, Neil Armstrong wrote:
>
> > The new Khadas VIM2 and VIM3 boards controls the cooling fan via the
> > on-board microcontroller.
> >
> > This implements the FAN control as thermal devices and as cell of the Khadas
> > MCU MFD driver.
> >
> > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> > Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
>
> Is this an Ack?

Acked-by: Amit Kucheria <amit.kucheria@linaro.org>

> If so, do you require a pull-request?

I'll let Daniel comment about the PR but AFAICT, this can get merged
through the MFD tree.


> > ---
> > Hi Lee,
> >
> > Could you apply this patch via the MFD tree since it depends on
> > the linux/mfd/khadas-mcu.h header ?
> >
> > This patch is unchanged from the v3 serie.
> >
> > Thanks,
> > Neil
> >
> >  drivers/thermal/Kconfig          |  11 ++
> >  drivers/thermal/Makefile         |   1 +
> >  drivers/thermal/khadas_mcu_fan.c | 174 +++++++++++++++++++++++++++++++
> >  3 files changed, 186 insertions(+)
> >  create mode 100644 drivers/thermal/khadas_mcu_fan.c
>
> --
> Lee Jones [李琼斯]
> Senior Technical Lead - Developer Services
> Linaro.org │ Open source software for Arm SoCs
> Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v4 1/2] thermal: add support for the MCU controlled FAN on Khadas boards

[Daniel Lezcano]

On 18/06/2020 15:38, Neil Armstrong wrote:
> The new Khadas VIM2 and VIM3 boards controls the cooling fan via the
> on-board microcontroller.
> 
> This implements the FAN control as thermal devices and as cell of the Khadas
> MCU MFD driver.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
> ---
> Hi Lee,
> 
> Could you apply this patch via the MFD tree since it depends on
> the linux/mfd/khadas-mcu.h header ?
> 
> This patch is unchanged from the v3 serie.
> 
> Thanks,
> Neil
> 
>  drivers/thermal/Kconfig          |  11 ++
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/khadas_mcu_fan.c | 174 +++++++++++++++++++++++++++++++
>  3 files changed, 186 insertions(+)
>  create mode 100644 drivers/thermal/khadas_mcu_fan.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 3eb2348e5242..0125561488c9 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -500,4 +500,15 @@ config SPRD_THERMAL
>  	help
>  	  Support for the Spreadtrum thermal sensor driver in the Linux thermal
>  	  framework.
> +
> +config KHADAS_MCU_FAN_THERMAL
> +	tristate "Khadas MCU controller FAN cooling support"
> +	depends on OF || COMPILE_TEST
> +	depends on MFD_KHADAS_MCU
> +	select MFD_CORE
> +	select REGMAP
> +	help
> +	  If you say yes here you get support for the FAN controlled
> +	  by the Microcontroller found on the Khadas VIM boards.
> +
>  endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 0c8b84a09b9a..4b6aabaa7e31 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -61,3 +61,4 @@ obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
>  obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
>  obj-$(CONFIG_AMLOGIC_THERMAL)     += amlogic_thermal.o
>  obj-$(CONFIG_SPRD_THERMAL)	+= sprd_thermal.o
> +obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL)	+= khadas_mcu_fan.o
> diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/khadas_mcu_fan.c
> new file mode 100644
> index 000000000000..6995b443cad4
> --- /dev/null
> +++ b/drivers/thermal/khadas_mcu_fan.c
> @@ -0,0 +1,174 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Khadas MCU Controlled FAN driver
> + *
> + * Copyright (C) 2020 BayLibre SAS
> + * Author(s): Neil Armstrong <narmstrong@baylibre.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/khadas-mcu.h>
> +#include <linux/regmap.h>
> +#include <linux/sysfs.h>
> +#include <linux/thermal.h>
> +
> +#define MAX_LEVEL 3
> +
> +struct khadas_mcu_fan_ctx {
> +	struct khadas_mcu *mcu;
> +	unsigned int level;
> +	struct thermal_cooling_device *cdev;
> +};
> +
> +static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
> +				    unsigned int level)
> +{
> +	int ret;
> +
> +	ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
> +			   level);
> +	if (ret)
> +		return ret;
> +
> +	ctx->level = level;
> +
> +	return 0;
> +}
> +
> +static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
> +					unsigned long *state)
> +{
> +	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
> +
> +	if (!ctx)
> +		return -EINVAL;

It is pointless to check 'ctx' is NULL, that was done at probe time.

> +	*state = MAX_LEVEL;
> +
> +	return 0;
> +}
> +
> +static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
> +					unsigned long *state)
> +{
> +	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
> +
> +	if (!ctx)
> +		return -EINVAL;

Ditto

> +	*state = ctx->level;
> +
> +	return 0;
> +}
> +
> +static int
> +khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
> +			     unsigned long state)
> +{
> +	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
> +
> +	if (!ctx || (state > MAX_LEVEL))
> +		return -EINVAL;

Ditto

> +	if (state == ctx->level)
> +		return 0;
> +
> +	return khadas_mcu_fan_set_level(ctx, state);
> +}
> +
> +static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
> +	.get_max_state = khadas_mcu_fan_get_max_state,
> +	.get_cur_state = khadas_mcu_fan_get_cur_state,
> +	.set_cur_state = khadas_mcu_fan_set_cur_state,
> +};
> +
> +static int khadas_mcu_fan_probe(struct platform_device *pdev)
> +{
> +	struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
> +	struct thermal_cooling_device *cdev;
> +	struct device *dev = &pdev->dev;
> +	struct khadas_mcu_fan_ctx *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +	ctx->mcu = mcu;
> +	platform_set_drvdata(pdev, ctx);
> +
> +	cdev = devm_thermal_of_cooling_device_register(dev->parent,
> +			dev->parent->of_node, "khadas-mcu-fan", ctx,
> +			&khadas_mcu_fan_cooling_ops);
> +	if (IS_ERR(cdev)) {
> +		ret = PTR_ERR(cdev);
> +		dev_err(dev,
> +				"Failed to register khadas-mcu-fan as cooling device: %d\n",
> +				ret);
> +		return ret;
> +	}
> +	ctx->cdev = cdev;
> +	thermal_cdev_update(cdev);
> +
> +	return 0;
> +}
> +
> +static int khadas_mcu_fan_disable(struct device *dev)
> +{
> +	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
> +	unsigned int level_save = ctx->level;
> +	int ret;
> +
> +	ret = khadas_mcu_fan_set_level(ctx, 0);
> +	if (ret)
> +		return ret;
> +
> +	ctx->level = level_save;

Nitpicking : move the save section to suspend.

> +	return 0;
> +}
> +
> +static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
> +{
> +	khadas_mcu_fan_disable(&pdev->dev);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int khadas_mcu_fan_suspend(struct device *dev)
> +{
> +	return khadas_mcu_fan_disable(dev);
> +}
> +
> +static int khadas_mcu_fan_resume(struct device *dev)
> +{
> +	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
> +
> +	return khadas_mcu_fan_set_level(ctx, ctx->level);

Out of curiosity, did you check the fan is not continuously spinning
after a resume when the suspend happened during a mitigation phase?

> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
> +			 khadas_mcu_fan_resume);
> +
> +static const struct platform_device_id khadas_mcu_fan_id_table[] = {
> +	{ .name = "khadas-mcu-fan-ctrl", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
> +
> +static struct platform_driver khadas_mcu_fan_driver = {
> +	.probe		= khadas_mcu_fan_probe,
> +	.shutdown	= khadas_mcu_fan_shutdown,
> +	.driver	= {
> +		.name		= "khadas-mcu-fan-ctrl",
> +		.pm		= &khadas_mcu_fan_pm,
> +	},
> +	.id_table	= khadas_mcu_fan_id_table,
> +};
> +
> +module_platform_driver(khadas_mcu_fan_driver);
> +
> +MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
> +MODULE_DESCRIPTION("Khadas MCU FAN driver");
> +MODULE_LICENSE("GPL");
> 


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Re: [PATCH v4 1/2] thermal: add support for the MCU controlled FAN on Khadas boards

[Neil Armstrong]

Hi Daniel,

On 22/06/2020 21:46, Daniel Lezcano wrote:
> On 18/06/2020 15:38, Neil Armstrong wrote:
>> The new Khadas VIM2 and VIM3 boards controls the cooling fan via the
>> on-board microcontroller.
>>
>> This implements the FAN control as thermal devices and as cell of the Khadas
>> MCU MFD driver.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
>> ---
>> Hi Lee,
>>
>> Could you apply this patch via the MFD tree since it depends on
>> the linux/mfd/khadas-mcu.h header ?
>>
>> This patch is unchanged from the v3 serie.
>>
>> Thanks,
>> Neil
>>
>>  drivers/thermal/Kconfig          |  11 ++
>>  drivers/thermal/Makefile         |   1 +
>>  drivers/thermal/khadas_mcu_fan.c | 174 +++++++++++++++++++++++++++++++
>>  3 files changed, 186 insertions(+)
>>  create mode 100644 drivers/thermal/khadas_mcu_fan.c
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index 3eb2348e5242..0125561488c9 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -500,4 +500,15 @@ config SPRD_THERMAL
>>  	help
>>  	  Support for the Spreadtrum thermal sensor driver in the Linux thermal
>>  	  framework.
>> +
>> +config KHADAS_MCU_FAN_THERMAL
>> +	tristate "Khadas MCU controller FAN cooling support"
>> +	depends on OF || COMPILE_TEST
>> +	depends on MFD_KHADAS_MCU
>> +	select MFD_CORE
>> +	select REGMAP
>> +	help
>> +	  If you say yes here you get support for the FAN controlled
>> +	  by the Microcontroller found on the Khadas VIM boards.
>> +
>>  endif
>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>> index 0c8b84a09b9a..4b6aabaa7e31 100644
>> --- a/drivers/thermal/Makefile
>> +++ b/drivers/thermal/Makefile
>> @@ -61,3 +61,4 @@ obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
>>  obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
>>  obj-$(CONFIG_AMLOGIC_THERMAL)     += amlogic_thermal.o
>>  obj-$(CONFIG_SPRD_THERMAL)	+= sprd_thermal.o
>> +obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL)	+= khadas_mcu_fan.o
>> diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/khadas_mcu_fan.c
>> new file mode 100644
>> index 000000000000..6995b443cad4
>> --- /dev/null
>> +++ b/drivers/thermal/khadas_mcu_fan.c
>> @@ -0,0 +1,174 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Khadas MCU Controlled FAN driver
>> + *
>> + * Copyright (C) 2020 BayLibre SAS
>> + * Author(s): Neil Armstrong <narmstrong@baylibre.com>
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/mfd/khadas-mcu.h>
>> +#include <linux/regmap.h>
>> +#include <linux/sysfs.h>
>> +#include <linux/thermal.h>
>> +
>> +#define MAX_LEVEL 3
>> +
>> +struct khadas_mcu_fan_ctx {
>> +	struct khadas_mcu *mcu;
>> +	unsigned int level;
>> +	struct thermal_cooling_device *cdev;
>> +};
>> +
>> +static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
>> +				    unsigned int level)
>> +{
>> +	int ret;
>> +
>> +	ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
>> +			   level);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ctx->level = level;
>> +
>> +	return 0;
>> +}
>> +
>> +static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
>> +					unsigned long *state)
>> +{
>> +	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
>> +
>> +	if (!ctx)
>> +		return -EINVAL;
> 
> It is pointless to check 'ctx' is NULL, that was done at probe time.
> 
>> +	*state = MAX_LEVEL;
>> +
>> +	return 0;
>> +}
>> +
>> +static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
>> +					unsigned long *state)
>> +{
>> +	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
>> +
>> +	if (!ctx)
>> +		return -EINVAL;
> 
> Ditto
> 
>> +	*state = ctx->level;
>> +
>> +	return 0;
>> +}
>> +
>> +static int
>> +khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
>> +			     unsigned long state)
>> +{
>> +	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
>> +
>> +	if (!ctx || (state > MAX_LEVEL))
>> +		return -EINVAL;
> 
> Ditto

Will remove these.

> 
>> +	if (state == ctx->level)
>> +		return 0;
>> +
>> +	return khadas_mcu_fan_set_level(ctx, state);
>> +}
>> +
>> +static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
>> +	.get_max_state = khadas_mcu_fan_get_max_state,
>> +	.get_cur_state = khadas_mcu_fan_get_cur_state,
>> +	.set_cur_state = khadas_mcu_fan_set_cur_state,
>> +};
>> +
>> +static int khadas_mcu_fan_probe(struct platform_device *pdev)
>> +{
>> +	struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
>> +	struct thermal_cooling_device *cdev;
>> +	struct device *dev = &pdev->dev;
>> +	struct khadas_mcu_fan_ctx *ctx;
>> +	int ret;
>> +
>> +	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>> +	if (!ctx)
>> +		return -ENOMEM;
>> +	ctx->mcu = mcu;
>> +	platform_set_drvdata(pdev, ctx);
>> +
>> +	cdev = devm_thermal_of_cooling_device_register(dev->parent,
>> +			dev->parent->of_node, "khadas-mcu-fan", ctx,
>> +			&khadas_mcu_fan_cooling_ops);
>> +	if (IS_ERR(cdev)) {
>> +		ret = PTR_ERR(cdev);
>> +		dev_err(dev,
>> +				"Failed to register khadas-mcu-fan as cooling device: %d\n",
>> +				ret);
>> +		return ret;
>> +	}
>> +	ctx->cdev = cdev;
>> +	thermal_cdev_update(cdev);
>> +
>> +	return 0;
>> +}
>> +
>> +static int khadas_mcu_fan_disable(struct device *dev)
>> +{
>> +	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
>> +	unsigned int level_save = ctx->level;
>> +	int ret;
>> +
>> +	ret = khadas_mcu_fan_set_level(ctx, 0);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ctx->level = level_save;
> 
> Nitpicking : move the save section to suspend.

OK, but moving this makes khadas_mcu_fan_disable() useless.

> 
>> +	return 0;
>> +}
>> +
>> +static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
>> +{
>> +	khadas_mcu_fan_disable(&pdev->dev);
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int khadas_mcu_fan_suspend(struct device *dev)
>> +{
>> +	return khadas_mcu_fan_disable(dev);
>> +}
>> +
>> +static int khadas_mcu_fan_resume(struct device *dev)
>> +{
>> +	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
>> +
>> +	return khadas_mcu_fan_set_level(ctx, ctx->level);
> 
> Out of curiosity, did you check the fan is not continuously spinning
> after a resume when the suspend happened during a mitigation phase?

No, but I took the logic from the hmwmon pwm-fan driver.

Not sure this is critical here.

Neil

> 
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
>> +			 khadas_mcu_fan_resume);
>> +
>> +static const struct platform_device_id khadas_mcu_fan_id_table[] = {
>> +	{ .name = "khadas-mcu-fan-ctrl", },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
>> +
>> +static struct platform_driver khadas_mcu_fan_driver = {
>> +	.probe		= khadas_mcu_fan_probe,
>> +	.shutdown	= khadas_mcu_fan_shutdown,
>> +	.driver	= {
>> +		.name		= "khadas-mcu-fan-ctrl",
>> +		.pm		= &khadas_mcu_fan_pm,
>> +	},
>> +	.id_table	= khadas_mcu_fan_id_table,
>> +};
>> +
>> +module_platform_driver(khadas_mcu_fan_driver);
>> +
>> +MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
>> +MODULE_DESCRIPTION("Khadas MCU FAN driver");
>> +MODULE_LICENSE("GPL");
>>
> 
> 

Re: [PATCH v4 1/2] thermal: add support for the MCU controlled FAN on Khadas boards

[Daniel Lezcano]

Hi Neil,

On 23/06/2020 10:25, Neil Armstrong wrote:
> Hi Daniel,
> 
> On 22/06/2020 21:46, Daniel Lezcano wrote:
>> On 18/06/2020 15:38, Neil Armstrong wrote:
>>> The new Khadas VIM2 and VIM3 boards controls the cooling fan via the
>>> on-board microcontroller.
>>>
>>> This implements the FAN control as thermal devices and as cell of the Khadas
>>> MCU MFD driver.
>>>
>>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>>> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
>>> ---
>>> Hi Lee,
>>>
>>> Could you apply this patch via the MFD tree since it depends on
>>> the linux/mfd/khadas-mcu.h header ?
>>>
>>> This patch is unchanged from the v3 serie.
>>>

[ ... ]

>> Nitpicking : move the save section to suspend.
> 
> OK, but moving this makes khadas_mcu_fan_disable() useless.

It is fine. Seeing the shutdown calling the disable function which in
turn saves the state looks strange but it is not critical.

If you want to keep it as it is, I'm fine with that too.

>>> +	return 0;
>>> +}
>>> +
>>> +static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
>>> +{
>>> +	khadas_mcu_fan_disable(&pdev->dev);
>>> +}
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int khadas_mcu_fan_suspend(struct device *dev)
>>> +{
>>> +	return khadas_mcu_fan_disable(dev);
>>> +}
>>> +
>>> +static int khadas_mcu_fan_resume(struct device *dev)
>>> +{
>>> +	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
>>> +
>>> +	return khadas_mcu_fan_set_level(ctx, ctx->level);
>>
>> Out of curiosity, did you check the fan is not continuously spinning
>> after a resume when the suspend happened during a mitigation phase?
> 
> No, but I took the logic from the hmwmon pwm-fan driver.
> 
> Not sure this is critical here.
No, logically you should the fan spinning at resume time even if the
board is not hot, until the post resume notification is called which
will update the thermal zone and set the cooling device state to zero again.

Thanks
  -- Daniel


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