Re: [PATCH v2 18/18] ACPI: platform_profile: Add documentation

Ilpo Järvinen
2025-01-14T16:57:22Z

On Tue, 14 Jan 2025, Kurt Borja wrote:

> Add kerneldoc and sysfs class documentation.
>
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
> ---
> .../ABI/testing/sysfs-class-platform-profile | 44 +++++++++++++++++++
> drivers/acpi/platform_profile.c | 33 ++++++++++++++
> include/linux/platform_profile.h | 24 ++++++++++
> 3 files changed, 101 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-platform-profile
>
> diff --git a/Documentation/ABI/testing/sysfs-class-platform-profile b/Documentation/ABI/testing/sysfs-class-platform-profile
> new file mode 100644
> index 000000000000..b5a3600080bc
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-platform-profile
> @@ -0,0 +1,44 @@
> +What: /sys/class/platform-profile/platform-profile-X/name
> +Date: January 2025
> +Description: Name of the class device given by the driver.
> +
> + RO
> +
> +What: /sys/class/platform-profile/platform-profile-X/choices
> +Date: January 2025
> +Description: This file contains a space-separated list of profiles supported for this device.
> +
> + Drivers must use the following standard profile-names:
> +
> + ==================== ========================================
> + low-power Low power consumption
> + cool Cooler operation
> + quiet Quieter operation
> + balanced Balance between low power consumption
> + and performance
> + balanced-performance Balance between performance and low
> + power consumption with a slight bias
> + towards performance
> + performance High performance operation
> + custom Driver defined custom profile
> + ==================== ========================================
> +
> + RO
> +
> +What: /sys/class/platform-profile/platform-profile-X/profile
> +Date: January 2025
> +Description: Reading this file gives the current selected profile for this
> + device. Writing this file with one of the strings from
> + platform_profile_choices changes the profile to the new value.
> +
> + This file can be monitored for changes by polling for POLLPRI,
> + POLLPRI will be signaled on any changes, independent of those
> + changes coming from a userspace write; or coming from another
> + source such as e.g. a hotkey triggered profile change handled
> + either directly by the embedded-controller or fully handled
> + inside the kernel.
> +
> + This file may also emit the string 'custom' to indicate
> + that the driver is using a driver defined custom profile.
> +
> + RW
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index c44989801f8e..9caddac695b8 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -426,6 +426,10 @@ static const struct attribute_group platform_profile_group = {
> .is_visible = profile_class_is_visible,
> };
>
> +/**
> + * platform_profile_notify - Notify class device and legacy sysfs interface
> + * @dev: The class device
> + */
> void platform_profile_notify(struct device *dev)
> {
> scoped_cond_guard(mutex_intr, return, &profile_lock) {
> @@ -435,6 +439,11 @@ void platform_profile_notify(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(platform_profile_notify);
>
> +/**
> + * platform_profile_cycle - Cycles profiles available on all registered class devices
> + *
> + * Return: 0 on success, -errno on failure
> + */
> int platform_profile_cycle(void)
> {
> enum platform_profile_option next = PLATFORM_PROFILE_LAST;
> @@ -478,6 +487,15 @@ int platform_profile_cycle(void)
> }
> EXPORT_SYMBOL_GPL(platform_profile_cycle);
>
> +/**
> + * platform_profile_register - Creates and registers a platform profile class device
> + * @dev: Parent device
> + * @name: Name of the class device
> + * @drvdata: Driver data that will be attached to the class device
> + * @ops: Platform profile's mandatory operations
> + *
> + * Return: pointer to the new class device on success, ERR_PTR on failure
> + */
> struct device *platform_profile_register(struct device *dev, const char *name,
> void *drvdata,
> const struct platform_profile_ops *ops)
> @@ -544,6 +562,12 @@ struct device *platform_profile_register(struct device *dev, const char *name,
> }
> EXPORT_SYMBOL_GPL(platform_profile_register);
>
> +/**
> + * platform_profile_remove - Unregisters a platform profile class device
> + * @dev: Class device
> + *
> + * Return: 0
> + */
> int platform_profile_remove(struct device *dev)
> {
> struct platform_profile_handler *pprof = to_pprof_handler(dev);
> @@ -569,6 +593,15 @@ static void devm_platform_profile_release(struct device *dev, void *res)
> platform_profile_remove(*ppdev);
> }
>
> +/**
> + * devm_platform_profile_register - Device managed version of platform_profile_register
> + * @dev: Parent device
> + * @name: Name of the class device
> + * @drvdata: Driver data that will be attached to the class device
> + * @ops: Platform profile's mandatory operations
> + *
> + * Return: pointer to the new class device on success, ERR_PTR on failure
> + */
> struct device *devm_platform_profile_register(struct device *dev, const char *name,
> void *drvdata,
> const struct platform_profile_ops *ops)
> diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h
> index eea1daf85616..eb4dc85dc18c 100644
> --- a/include/linux/platform_profile.h
> +++ b/include/linux/platform_profile.h
> @@ -28,6 +28,30 @@ enum platform_profile_option {
> PLATFORM_PROFILE_LAST, /*must always be last */
> };
>
> +/**
> + * struct platform_profile_ops - platform profile operations
> + * @probe: Callback to setup choices available to the new class device.
> + * Parameters are:
> + * @drvdata: drvdata pointer passed to platform_profile_register.
> + * @choices: Empty choices bitmap which the driver has to manually
> + * setup, by using set_bit() in bits corresponding to
> + * platform_profile_option values. These values will only
> + * be enforced when a new profile is selected from
> + * user-space.
> + * @profile_get: Callback that will be called when showing the current platform
> + * profile.
> + * Parameters are:
> + * @dev: Class device.
> + * @profile: Pointer to the profile which will be read from
> + * user-space. Selected choices are not enforced when
> + * modifying this value.
> + * @profile_set: Callback that will be called when storing the new platform
> + * profile.
> + * Parameters are:
> + * @dev: Class device.
> + * @profile: New platform profile to be set. Guaranteed to be a
> + * value selected in the @probe callback.

Does kerneldoc render this sensibly?

> + */
> struct platform_profile_ops {
> int (*probe)(void *drvdata, unsigned long *choices);
> int (*profile_get)(struct device *dev, enum platform_profile_option *profile);
>

--
i.