[v4,1/2] thermal: add support for the MCU controlled FAN on Khadas boards
diff mbox series

Message ID 20200618133818.15857-2-narmstrong@baylibre.com
State New
Delegated to: Daniel Lezcano
Headers show
Series
  • mfd: Add support for Khadas Microcontroller
Related show

Commit Message

Neil Armstrong June 18, 2020, 1:38 p.m. UTC
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

Comments

Lee Jones June 18, 2020, 4:28 p.m. UTC | #1
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
Amit Kucheria June 22, 2020, 9:04 a.m. UTC | #2
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
Daniel Lezcano June 22, 2020, 7:46 p.m. UTC | #3
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");
>
Neil Armstrong June 23, 2020, 8:25 a.m. UTC | #4
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");
>>
> 
>
Daniel Lezcano June 23, 2020, 8:47 a.m. UTC | #5
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

Patch
diff mbox series

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");