[PATCH v5 02/11] pinctrl: Reformat documentation in dm/pinctrl.h

Sean Anderson
2020-08-15T15:52:28Z

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>
Reviewed-by: Simon Glass <sjg@chromium.org>
---

(no changes since v4)

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);

--
2.28.0