[PATCH v4 02/12] pinctrl: Reformat documentation in dm/pinctrl.h

[Sean Anderson <seanga2@gmail.com>]

This normalizes the documentatation to conform to kernel-doc style [1]. It
also moves the documentation for pinctrl_ops inline, and adds argument and
return-value documentation. I have kept the usual function style for these
comments. I could not find any existing examples of function documentation
inside structs.

[1] https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html

Signed-off-by: Sean Anderson <seanga2@gmail.com>
---

Changes in v4:
- New

 include/dm/pinctrl.h | 363 ++++++++++++++++++++++++++++---------------
 1 file changed, 242 insertions(+), 121 deletions(-)

diff --git a/include/dm/pinctrl.h b/include/dm/pinctrl.h
index d50af1ce38..5b994f22cc 100644
--- a/include/dm/pinctrl.h
+++ b/include/dm/pinctrl.h
@@ -11,11 +11,10 @@
 
 /**
  * struct pinconf_param - pin config parameters
- *
- * @property: property name in DT nodes
- * @param: ID for this config parameter
- * @default_value: default value for this config parameter used in case
- *	no value is specified in DT nodes
+ * @property:		Property name in DT nodes
+ * @param:		ID for this config parameter
+ * @default_value:	default value for this config parameter used in case
+ *			no value is specified in DT nodes
  */
 struct pinconf_param {
 	const char * const property;
@@ -27,111 +26,228 @@ struct pinconf_param {
  * struct pinctrl_ops - pin control operations, to be implemented by
  * pin controller drivers.
  *
- * The @set_state is the only mandatory operation.  You can implement your
- * pinctrl driver with its own @set_state.  In this case, the other callbacks
- * are not required.  Otherwise, generic pinctrl framework is also available;
- * use pinctrl_generic_set_state for @set_state, and implement other operations
+ * set_state() is the only mandatory operation. You can implement your pinctrl
+ * driver with its own @set_state. In this case, the other callbacks are not
+ * required. Otherwise, generic pinctrl framework is also available; use
+ * pinctrl_generic_set_state for @set_state, and implement other operations
  * depending on your necessity.
- *
- * @get_pins_count: return number of selectable named pins available
- *	in this driver. (necessary to parse "pins" property in DTS)
- * @get_pin_name: return the pin name of the pin selector,
- *	called by the core to figure out which pin it shall do
- *	operations to. (necessary to parse "pins" property in DTS)
- * @get_groups_count: return number of selectable named groups available
- *	in this driver. (necessary to parse "groups" property in DTS)
- * @get_group_name: return the group name of the group selector,
- *	called by the core to figure out which pin group it shall do
- *	operations to. (necessary to parse "groups" property in DTS)
- * @get_functions_count: return number of selectable named functions available
- *	in this driver. (necessary for pin-muxing)
- * @get_function_name: return the function name of the muxing selector,
- *	called by the core to figure out which mux setting it shall map a
- *	certain device to. (necessary for pin-muxing)
- * @pinmux_set: enable a certain muxing function with a certain pin.
- *	The @func_selector selects a certain function whereas @pin_selector
- *	selects a certain pin to be used. On simple controllers one of them
- *	may be ignored. (necessary for pin-muxing against a single pin)
- * @pinmux_group_set: enable a certain muxing function with a certain pin
- *	group. The @func_selector selects a certain function whereas
- *	@group_selector selects a certain set of pins to be used. On simple
- *	controllers one of them may be ignored.
- *	(necessary for pin-muxing against a pin group)
- * @pinmux_property_set: enable a pinmux group. @pinmux_group should specify the
- *      pin identifier and mux settings. The exact format of a pinmux group is
- *      left up to the driver. The pin selector for the mux-ed pin should be
- *      returned on success. (necessary to parse the "pinmux" property in DTS)
- * @pinconf_num_params: number of driver-specific parameters to be parsed
- *	from device trees  (necessary for pin-configuration)
- * @pinconf_params: list of driver_specific parameters to be parsed from
- *	device trees  (necessary for pin-configuration)
- * @pinconf_set: configure an individual pin with a given parameter.
- *	(necessary for pin-configuration against a single pin)
- * @pinconf_group_set: configure all pins in a group with a given parameter.
- *	(necessary for pin-configuration against a pin group)
- * @set_state: do pinctrl operations specified by @config, a pseudo device
- *	pointing a config node. (necessary for pinctrl_full)
- * @set_state_simple: do needed pinctrl operations for a peripherl @periph.
- *	(necessary for pinctrl_simple)
- * @get_pin_muxing: display the muxing of a given pin.
- * @gpio_request_enable: requests and enables GPIO on a certain pin.
- *	Implement this only if you can mux every pin individually as GPIO. The
- *	affected GPIO range is passed along with an offset(pin number) into that
- *	specific GPIO range - function selectors and pin groups are orthogonal
- *	to this, the core will however make sure the pins do not collide.
- * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
- *	@gpio_request_enable
  */
 struct pinctrl_ops {
+	/**
+	 * get_pins_count() - Get the number of selectable pins
+	 * @dev:	Pinctrl device to use
+	 *
+	 * This function is necessary to parse the "pins" property in DTS.
+	 *
+	 * Return: number of selectable named pins available in this driver
+	 */
 	int (*get_pins_count)(struct udevice *dev);
+
+	/**
+	 * get_pin_name() - Get the name of a pin
+	 * @dev:	Pinctrl device of the pin
+	 * @selector:	The pin selector
+	 *
+	 * This function is called by the core to figure out which pin it shall
+	 * do operations to. This function is necessary to parse the "pins"
+	 * property in DTS.
+	 *
+	 * Return: const pointer to the name of the pin
+	 */
 	const char *(*get_pin_name)(struct udevice *dev, unsigned selector);
+
+	/**
+	 * get_groups_count() - Get the number of selectable groups
+	 * @dev:	Pinctrl device to use
+	 *
+	 * This function is necessary to parse the "groups" property in DTS.
+	 *
+	 * Return: number of selectable named groups available in the driver
+	 */
 	int (*get_groups_count)(struct udevice *dev);
+
+	/**
+	 * get_group_name() - Get the name of a group
+	 * @dev:	Pinctrl device of the group
+	 * @selector:	The group selector
+	 *
+	 * This function is called by the core to figure out which group it
+	 * shall do operations to. This function is necessary to parse the
+	 * "groups" property in DTS.
+	 *
+	 * Return: const pointer to the name of the group
+	 */
 	const char *(*get_group_name)(struct udevice *dev, unsigned selector);
+
+	/**
+	 * get_functions_count() - Get the number of selectable functions
+	 * @dev:	Pinctrl device to use
+	 *
+	 * This function is necessary for pin-muxing.
+	 *
+	 * Return: number of selectable named functions available in this driver
+	 */
 	int (*get_functions_count)(struct udevice *dev);
+
+	/**
+	 * get_function_name() - Get the name of a function
+	 * @dev:	Pinmux device of the function
+	 * @selector:	The function selector
+	 *
+	 * This function is called by the core to figure out which mux setting
+	 * it shall map a certain device to. This function is necessary for
+	 * pin-muxing.
+	 *
+	 * Return: const pointer to the function name of the muxing selector
+	 */
 	const char *(*get_function_name)(struct udevice *dev,
 					 unsigned selector);
+
+	/**
+	 * pinmux_set() - Mux a pin to a function
+	 * @dev:		Pinctrl device to use
+	 * @pin_selector:	The pin selector
+	 * @func_selector:	The func selector
+	 *
+	 * On simple controllers one of @pin_selector or @func_selector may be
+	 * ignored. This function is necessary for pin-muxing against a single
+	 * pin.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
+	 */
 	int (*pinmux_set)(struct udevice *dev, unsigned pin_selector,
 			  unsigned func_selector);
+
+	/**
+	 * pinmux_set() - Mux a group of pins to a function
+	 * @dev:		Pinctrl device to use
+	 * @group_selector:	The group selector
+	 * @func_selector:	The func selector
+	 *
+	 * On simple controllers one of @group_selector or @func_selector may be
+	 * ignored. This function is necessary for pin-muxing against a group of
+	 * pins.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
+	 */
 	int (*pinmux_group_set)(struct udevice *dev, unsigned group_selector,
 				unsigned func_selector);
+
+	/**
+	 * pinmux_property_set() - Enable a pinmux group
+	 * @dev:		Pinctrl device to use
+	 * @pinmux_group:	A u32 representing the pin identifier and mux
+	 *			settings. The exact format of a pinmux group is
+	 *			left up to the driver.
+	 *
+	 * Mux a single pin to a single function based on a driver-specific
+	 * pinmux group. This function is necessary for parsing the "pinmux"
+	 * property in DTS, and for pin-muxing against a pinmux group.
+	 *
+	 * Return: pin selector for the muxed pin if OK, or negative error code
+	 * on failure
+	 */
 	int (*pinmux_property_set)(struct udevice *dev, u32 pinmux_group);
+
+	/**
+	 * @pinconf_num_params:	Number of driver-specific parameters to be
+	 *			parsed from device trees. This member is
+	 *			necessary for pin configuration.
+	 */
 	unsigned int pinconf_num_params;
+
+	/**
+	 * @pinconf_params:	List of driver-specific parameters to be parsed
+	 *			from the device tree. This member is necessary
+	 *			for pin configuration.
+	 */
 	const struct pinconf_param *pinconf_params;
+
+	/**
+	 * pinconf_set() - configure an individual pin with a parameter
+	 * @dev:		Pinctrl device to use
+	 * @pin_selector:	The pin selector
+	 * @param:		A &enum pin_config_param from @pinconf_params
+	 * @argument:		The argument to this param from the device tree
+	 *
+	 * This function is necessary for pin configuration against a single
+	 * pin.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
+	 */
 	int (*pinconf_set)(struct udevice *dev, unsigned pin_selector,
 			   unsigned param, unsigned argument);
+
+	/**
+	 * pinconf_group_set() - configure all pins in a group with a parameter
+	 * @dev:		Pinctrl device to use
+	 * @pin_selector:	The group selector
+	 * @param:		A &enum pin_config_param from @pinconf_params
+	 * @argument:		The argument to this param from the device tree
+	 *
+	 * This function is necessary for pin configuration against a group of
+	 * pins.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
+	 */
 	int (*pinconf_group_set)(struct udevice *dev, unsigned group_selector,
 				 unsigned param, unsigned argument);
+
+	/**
+	 * set_state() - Configure a pinctrl device
+	 * @dev:	Pinctrl device to use
+	 * @config:	Pseudo device pointing a config node
+	 *
+	 * This function is required to be implemented by all pinctrl drivers.
+	 * Drivers may set this member to pinctrl_generic_set_state(), which
+	 * will call other functions in &struct pinctrl_ops to parse @config.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
+	 */
 	int (*set_state)(struct udevice *dev, struct udevice *config);
 
-	/* for pinctrl-simple */
+	/**
+	 * set_state_simple() - Configure a pinctrl device
+	 * @dev:	Pinctrl device to use
+	 * @config:	Pseudo-device pointing a config node
+	 *
+	 * This function is usually a simpler version of set_state(). Only the
+	 * first pinctrl device on the system is supported by this function.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
+	 */
 	int (*set_state_simple)(struct udevice *dev, struct udevice *periph);
+
 	/**
 	 * request() - Request a particular pinctrl function
+	 * @dev:	Device to adjust (UCLASS_PINCTRL)
+	 * @func:	Function number (driver-specific)
 	 *
 	 * This activates the selected function.
 	 *
-	 * @dev:	Device to adjust (UCLASS_PINCTRL)
-	 * @func:	Function number (driver-specific)
-	 * @return 0 if OK, -ve on error
+	 * Return: 0 if OK, or negative error code on failure
 	 */
 	int (*request)(struct udevice *dev, int func, int flags);
 
 	/**
 	* get_periph_id() - get the peripheral ID for a device
+	* @dev:		Pinctrl device to use for decoding
+	* @periph:	Device to check
 	*
 	* This generally looks at the peripheral's device tree node to work
 	* out the peripheral ID. The return value is normally interpreted as
 	* enum periph_id. so long as this is defined by the platform (which it
 	* should be).
 	*
-	* @dev:		Pinctrl device to use for decoding
-	* @periph:	Device to check
-	* @return peripheral ID of @periph, or -ENOENT on error
+	* Return: peripheral ID of @periph, or -ENOENT on error
 	*/
 	int (*get_periph_id)(struct udevice *dev, struct udevice *periph);
 
 	/**
 	 * get_gpio_mux() - get the mux value for a particular GPIO
+	 * @dev:	Pinctrl device to use
+	 * @banknum:	GPIO bank number
+	 * @index:	GPIO index within the bank
 	 *
 	 * This allows the raw mux value for a GPIO to be obtained. It is
 	 * useful for displaying the function being used by that GPIO, such
@@ -139,46 +255,50 @@ struct pinctrl_ops {
 	 * subsystem and should not be used by generic code. Typically it is
 	 * used by a GPIO driver with knowledge of the SoC pinctrl setup.
 	 *
-	* @dev:		Pinctrl device to use
-	* @banknum:	GPIO bank number
-	* @index:	GPIO index within the bank
-	* @return mux value (SoC-specific, e.g. 0 for input, 1 for output)
+	 * Return: mux value (SoC-specific, e.g. 0 for input, 1 for output)
 	 */
 	int (*get_gpio_mux)(struct udevice *dev, int banknum, int index);
 
 	/**
 	 * get_pin_muxing() - show pin muxing
-	 *
-	 * This allows to display the muxing of a given pin. It's useful for
-	 * debug purpose to know if a pin is configured as GPIO or as an
-	 * alternate function and which one.
-	 * Typically it is used by a PINCTRL driver with knowledge of the SoC
-	 * pinctrl setup.
-	 *
 	 * @dev:	Pinctrl device to use
 	 * @selector:	Pin selector
 	 * @buf		Pin's muxing description
 	 * @size	Pin's muxing description length
-	 * return 0 if OK, -ve on error
+	 *
+	 * This allows to display the muxing of a given pin. It's useful for
+	 * debug purposes to know if a pin is configured as GPIO or as an
+	 * alternate function and which one. Typically it is used by a PINCTRL
+	 * driver with knowledge of the SoC pinctrl setup.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
 	 */
 	 int (*get_pin_muxing)(struct udevice *dev, unsigned int selector,
 			       char *buf, int size);
 
 	/**
-	 * gpio_request_enable: requests and enables GPIO on a certain pin.
-	 *
+	 * gpio_request_enable() - request and enable GPIO on a certain pin.
 	 * @dev:	Pinctrl device to use
 	 * @selector:	Pin selector
-	 * return 0 if OK, -ve on error
+	 *
+	 * Implement this only if you can mux every pin individually as GPIO.
+	 * The affected GPIO range is passed along with an offset(pin number)
+	 * into that specific GPIO range - function selectors and pin groups are
+	 * orthogonal to this, the core will however make sure the pins do not
+	 * collide.
+	 *
+	 * Return: 0 if OK, or negative error code on failure
 	 */
 	int (*gpio_request_enable)(struct udevice *dev, unsigned int selector);
 
 	/**
-	 * gpio_disable_free: free up GPIO muxing on a certain pin.
-	 *
+	 * gpio_disable_free() - free up GPIO muxing on a certain pin.
 	 * @dev:	Pinctrl device to use
 	 * @selector:	Pin selector
-	 * return 0 if OK, -ve on error
+	 *
+	 * This function is the reverse of gpio_request_enable().
+	 *
+	 * Return: 0 if OK, or negative error code on failure
 	 */
 	int (*gpio_disable_free)(struct udevice *dev, unsigned int selector);
 };
@@ -230,8 +350,8 @@ struct pinctrl_ops {
  *	push-pull mode, the argument is ignored.
  * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
  *	passed as argument. The argument is in mA.
- * @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current
- *	passed as argument. The argument is in uA.
+ * @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the
+ *	current passed as argument. The argument is in uA.
  * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
  *	which means it will wait for signals to settle when reading inputs. The
  *	argument gives the debounce time in usecs. Setting the
@@ -307,12 +427,13 @@ enum pin_config_param {
 #if CONFIG_IS_ENABLED(PINCTRL_GENERIC)
 /**
  * pinctrl_generic_set_state() - generic set_state operation
+ * @pctldev:	Pinctrl device to use
+ * @config:	Config device (pseudo device), pointing a config node in DTS
+ *
  * Parse the DT node of @config and its children and handle generic properties
  * such as "pins", "groups", "functions", and pin configuration parameters.
  *
- * @pctldev: pinctrl device
- * @config: config device (pseudo device), pointing a config node in DTS
- * @return: 0 on success, or negative error code on failure
+ * Return: 0 on success, or negative error code on failure
  */
 int pinctrl_generic_set_state(struct udevice *pctldev, struct udevice *config);
 #else
@@ -326,10 +447,10 @@ static inline int pinctrl_generic_set_state(struct udevice *pctldev,
 #if CONFIG_IS_ENABLED(PINCTRL)
 /**
  * pinctrl_select_state() - set a device to a given state
+ * @dev:	Peripheral device
+ * @statename:	State name, like "default"
  *
- * @dev: peripheral device
- * @statename: state name, like "default"
- * @return: 0 on success, or negative error code on failure
+ * Return: 0 on success, or negative error code on failure
  */
 int pinctrl_select_state(struct udevice *dev, const char *statename);
 #else
@@ -342,40 +463,43 @@ static inline int pinctrl_select_state(struct udevice *dev,
 
 /**
  * pinctrl_request() - Request a particular pinctrl function
- *
- * @dev:	Device to check (UCLASS_PINCTRL)
+ * @dev:	Pinctrl device to use
  * @func:	Function number (driver-specific)
  * @flags:	Flags (driver-specific)
- * @return 0 if OK, -ve on error
+ *
+ * Return: 0 if OK, or negative error code on failure
  */
 int pinctrl_request(struct udevice *dev, int func, int flags);
 
 /**
  * pinctrl_request_noflags() - Request a particular pinctrl function
+ * @dev:	Pinctrl device to use
+ * @func:	Function number (driver-specific)
  *
  * This is similar to pinctrl_request() but uses 0 for @flags.
  *
- * @dev:	Device to check (UCLASS_PINCTRL)
- * @func:	Function number (driver-specific)
- * @return 0 if OK, -ve on error
+ * Return: 0 if OK, or negative error code on failure
  */
 int pinctrl_request_noflags(struct udevice *dev, int func);
 
 /**
  * pinctrl_get_periph_id() - get the peripheral ID for a device
+ * @dev:	Pinctrl device to use for decoding
+ * @periph:	Device to check
  *
  * This generally looks at the peripheral's device tree node to work out the
  * peripheral ID. The return value is normally interpreted as enum periph_id.
  * so long as this is defined by the platform (which it should be).
  *
- * @dev:	Pinctrl device to use for decoding
- * @periph:	Device to check
- * @return peripheral ID of @periph, or -ENOENT on error
+ * Return: peripheral ID of @periph, or -ENOENT on error
  */
 int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph);
 
 /**
  * pinctrl_get_gpio_mux() - get the mux value for a particular GPIO
+ * @dev:	Pinctrl device to use
+ * @banknum:	GPIO bank number
+ * @index:	GPIO index within the bank
  *
  * This allows the raw mux value for a GPIO to be obtained. It is
  * useful for displaying the function being used by that GPIO, such
@@ -383,66 +507,63 @@ int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph);
  * subsystem and should not be used by generic code. Typically it is
  * used by a GPIO driver with knowledge of the SoC pinctrl setup.
  *
- * @dev:	Pinctrl device to use
- * @banknum:	GPIO bank number
- * @index:	GPIO index within the bank
- * @return mux value (SoC-specific, e.g. 0 for input, 1 for output)
+ * Return: mux value (SoC-specific, e.g. 0 for input, 1 for output)
 */
 int pinctrl_get_gpio_mux(struct udevice *dev, int banknum, int index);
 
 /**
  * pinctrl_get_pin_muxing() - Returns the muxing description
+ * @dev:	Pinctrl device to use
+ * @selector:	Pin index within pin-controller
+ * @buf:	Pin's muxing description
+ * @size:	Pin's muxing description length
  *
  * This allows to display the muxing description of the given pin for
  * debug purpose
  *
- * @dev:	Pinctrl device to use
- * @selector	Pin index within pin-controller
- * @buf		Pin's muxing description
- * @size	Pin's muxing description length
- * @return 0 if OK, -ve on error
+ * Return: 0 if OK, or negative error code on failure
  */
 int pinctrl_get_pin_muxing(struct udevice *dev, int selector, char *buf,
 			   int size);
 
 /**
  * pinctrl_get_pins_count() - display pin-controller pins number
+ * @dev:	Pinctrl device to use
  *
  * This allows to know the number of pins owned by a given pin-controller
  *
- * @dev:	Pinctrl device to use
- * @return pins number if OK, -ve on error
+ * Return: number of pins if OK, or negative error code on failure
  */
 int pinctrl_get_pins_count(struct udevice *dev);
 
 /**
  * pinctrl_get_pin_name() - Returns the pin's name
+ * @dev:	Pinctrl device to use
+ * @selector:	Pin index within pin-controller
+ * @buf:	Pin's name
  *
  * This allows to display the pin's name for debug purpose
  *
- * @dev:	Pinctrl device to use
- * @selector	Pin index within pin-controller
- * @buf		Pin's name
- * @return 0 if OK, -ve on error
+ * Return: 0 if OK, or negative error code on failure
  */
 int pinctrl_get_pin_name(struct udevice *dev, int selector, char *buf,
 			 int size);
 
 /**
  * pinctrl_gpio_request() - request a single pin to be used as GPIO
+ * @dev:	GPIO peripheral device
+ * @offset:	GPIO pin offset from the GPIO controller
  *
- * @dev: GPIO peripheral device
- * @offset: the GPIO pin offset from the GPIO controller
- * @return: 0 on success, or negative error code on failure
+ * Return: 0 on success, or negative error code on failure
  */
 int pinctrl_gpio_request(struct udevice *dev, unsigned offset);
 
 /**
  * pinctrl_gpio_free() - free a single pin used as GPIO
+ * @dev:	GPIO peripheral device
+ * @offset:	GPIO pin offset from the GPIO controller
  *
- * @dev: GPIO peripheral device
- * @offset: the GPIO pin offset from the GPIO controller
- * @return: 0 on success, or negative error code on failure
+ * Return: 0 on success, or negative error code on failure
  */
 int pinctrl_gpio_free(struct udevice *dev, unsigned offset);
 
-- 
2.26.2