[PATCH v3 18/19] ACPI: platform_profile: Add documentation

Kurt Borja
2025-01-15T07:13:27Z

Add kerneldoc and sysfs class documentation.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
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 | 10 +++++
3 files changed, 87 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 8a1454e66cf1..4895f37dd549 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -425,6 +425,10 @@ 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) {
@@ -434,6 +438,11 @@ 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;
@@ -477,6 +486,15 @@ 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)
@@ -546,6 +564,12 @@ 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);
@@ -571,6 +595,15 @@ 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..8ab5b0e8eb2c 100644
--- a/include/linux/platform_profile.h
+++ b/include/linux/platform_profile.h
@@ -28,6 +28,16 @@ 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. These
+ * choices will only be enforced when setting a new profile, not when
+ * getting the current one.
+ * @profile_get: Callback that will be called when showing the current platform
+ * profile in sysfs.
+ * @profile_set: Callback that will be called when storing a new platform
+ * profile in sysfs.
+ */
struct platform_profile_ops {
int (*probe)(void *drvdata, unsigned long *choices);
int (*profile_get)(struct device *dev, enum platform_profile_option *profile);
--
2.48.0