Re: [PATCH v3 2/2] platform/x86: toshiba_acpi: Add fan RPM reading (hwmon interface)

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Sep 02, 2022 at 07:40:18PM +0200, Arvid Norlander wrote:
> This expands on the previous commit, exporting the fan RPM via hwmon.
> 
> This will look something like the following when using the "sensors"
> command from lm_sensors:
> 
> toshiba_acpi_sensors-acpi-0
> Adapter: ACPI interface
> fan1:           0 RPM
> 
> Signed-off-by: Arvid Norlander <lkml@vorpal.se>
> ---
>  drivers/platform/x86/Kconfig        |  1 +
>  drivers/platform/x86/toshiba_acpi.c | 70 +++++++++++++++++++++++++++++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index f2f98e942cf2..4d0d2676939a 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -797,6 +797,7 @@ config ACPI_TOSHIBA
>  	depends on INPUT
>  	depends on SERIO_I8042 || SERIO_I8042 = n
>  	depends on ACPI_VIDEO || ACPI_VIDEO = n
> +	depends on HWMON || HWMON = n
>  	depends on RFKILL || RFKILL = n
>  	depends on IIO
>  	select INPUT_SPARSEKMAP
> diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
> index 02e3522f4eeb..0949b1bcab83 100644
> --- a/drivers/platform/x86/toshiba_acpi.c
> +++ b/drivers/platform/x86/toshiba_acpi.c
> @@ -42,10 +42,12 @@
>  #include <linux/uaccess.h>
>  #include <linux/miscdevice.h>
>  #include <linux/rfkill.h>
> +#include <linux/hwmon.h>
>  #include <linux/iio/iio.h>
>  #include <linux/toshiba.h>
>  #include <acpi/video.h>
>  
> +

Unnecessary double empty line

Otherwise 

Acked-by: Guenter Roeck <linux@roeck-us.net>

Guenter

>  MODULE_AUTHOR("John Belmonte");
>  MODULE_DESCRIPTION("Toshiba Laptop ACPI Extras Driver");
>  MODULE_LICENSE("GPL");
> @@ -171,6 +173,9 @@ struct toshiba_acpi_dev {
>  	struct miscdevice miscdev;
>  	struct rfkill *wwan_rfk;
>  	struct iio_dev *indio_dev;
> +#if IS_ENABLED(CONFIG_HWMON)
> +	struct device *hwmon_device;
> +#endif
>  
>  	int force_fan;
>  	int last_key_event;
> @@ -2941,6 +2946,54 @@ static int toshiba_acpi_setup_backlight(struct toshiba_acpi_dev *dev)
>  	return 0;
>  }
>  
> +/* HWMON support for fan */
> +#if IS_ENABLED(CONFIG_HWMON)
> +umode_t toshiba_acpi_hwmon_is_visible(const void *drvdata,
> +				      enum hwmon_sensor_types type,
> +				      u32 attr, int channel)
> +{
> +	return 0444;
> +}
> +
> +int toshiba_acpi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> +			    u32 attr, int channel, long *val)
> +{
> +	/*
> +	 * There is only a single channel and single attribute (for the
> +	 * fan) at this point.
> +	 * This can be replaced with more advanced logic in the future,
> +	 * should the need arise.
> +	 */
> +	if (type == hwmon_fan && channel == 0 && attr == hwmon_fan_input) {
> +		u32 value;
> +		int ret;
> +
> +		ret = get_fan_rpm(toshiba_acpi, &value);
> +		if (ret)
> +			return ret;
> +
> +		*val = value;
> +		return 0;
> +	}
> +	return -EOPNOTSUPP;
> +}
> +
> +static const struct hwmon_channel_info *toshiba_acpi_hwmon_info[] = {
> +	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
> +	NULL
> +};
> +
> +static const struct hwmon_ops toshiba_acpi_hwmon_ops = {
> +	.is_visible = toshiba_acpi_hwmon_is_visible,
> +	.read = toshiba_acpi_hwmon_read,
> +};
> +
> +static const struct hwmon_chip_info toshiba_acpi_hwmon_chip_info = {
> +	.ops = &toshiba_acpi_hwmon_ops,
> +	.info = toshiba_acpi_hwmon_info,
> +};
> +#endif
> +
>  static void print_supported_features(struct toshiba_acpi_dev *dev)
>  {
>  	pr_info("Supported laptop features:");
> @@ -2995,6 +3048,11 @@ static int toshiba_acpi_remove(struct acpi_device *acpi_dev)
>  
>  	remove_toshiba_proc_entries(dev);
>  
> +#if IS_ENABLED(CONFIG_HWMON)
> +	if (dev->hwmon_device)
> +		hwmon_device_unregister(dev->hwmon_device);
> +#endif
> +
>  	if (dev->accelerometer_supported && dev->indio_dev) {
>  		iio_device_unregister(dev->indio_dev);
>  		iio_device_free(dev->indio_dev);
> @@ -3187,6 +3245,18 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
>  	ret = get_fan_rpm(dev, &dummy);
>  	dev->fan_rpm_supported = !ret;
>  
> +#if IS_ENABLED(CONFIG_HWMON)
> +	if (dev->fan_rpm_supported) {
> +		dev->hwmon_device = hwmon_device_register_with_info(
> +			&dev->acpi_dev->dev, "toshiba_acpi_sensors", NULL,
> +			&toshiba_acpi_hwmon_chip_info, NULL);
> +		if (IS_ERR(dev->hwmon_device)) {
> +			dev->hwmon_device = NULL;
> +			pr_warn("unable to register hwmon device, skipping\n");
> +		}
> +	}
> +#endif
> +
>  	toshiba_wwan_available(dev);
>  	if (dev->wwan_supported)
>  		toshiba_acpi_setup_wwan_rfkill(dev);
> -- 
> 2.37.3
>