From 9c88b13a9031e8c1d9f4c2422791f84cd6604242 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Wed, 22 Dec 2021 12:11:12 -0500 Subject: [PATCH] clk: Add client API to HTML docs This converts the existing client (aka clk.h) documentation to kernel doc format, and adds it to the HTML docs. I have tried to preserve existing comments as much as possible, refraining from semantic changes. Signed-off-by: Sean Anderson Tested-by: Heinrich Schuchardt Reviewed-by: Simon Glass Link: https://lore.kernel.org/r/20211222171114.3091780-4-seanga2@gmail.com [rebased onto u-boot/master and resolved conflicts] Signed-off-by: Sean Anderson --- doc/api/clk.rst | 13 ++++ doc/api/index.rst | 1 + include/clk.h | 176 ++++++++++++++++++++++------------------------ 3 files changed, 99 insertions(+), 91 deletions(-) create mode 100644 doc/api/clk.rst diff --git a/doc/api/clk.rst b/doc/api/clk.rst new file mode 100644 index 0000000000..7eb3b5645a --- /dev/null +++ b/doc/api/clk.rst @@ -0,0 +1,13 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +Clock API +========= + +.. kernel-doc:: include/clk.h + :doc: Overview + +Client API +---------- + +.. kernel-doc:: include/clk.h + :internal: diff --git a/doc/api/index.rst b/doc/api/index.rst index 3f36174167..72fea981b7 100644 --- a/doc/api/index.rst +++ b/doc/api/index.rst @@ -6,6 +6,7 @@ U-Boot API documentation .. toctree:: :maxdepth: 2 + clk dfu dm efi diff --git a/include/clk.h b/include/clk.h index 6706afa55d..303b04a726 100644 --- a/include/clk.h +++ b/include/clk.h @@ -14,6 +14,8 @@ #include /** + * DOC: Overview + * * A clock is a hardware signal that oscillates autonomously at a specific * frequency and duty cycle. Most hardware modules require one or more clock * signal to drive their operation. Clock signals are typically generated @@ -34,22 +36,22 @@ struct udevice; /** * struct clk - A handle to (allowing control of) a single clock. - * - * Clients provide storage for clock handles. The content of the structure is - * managed solely by the clock API and clock drivers. A clock struct is - * initialized by "get"ing the clock struct. The clock struct is passed to all - * other clock APIs to identify which clock signal to operate upon. - * * @dev: The device which implements the clock signal. * @rate: The clock rate (in HZ). - * @flags: Flags used across common clock structure (e.g. CLK_) + * @flags: Flags used across common clock structure (e.g. %CLK_) * Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined - * in struct's for those devices (e.g. struct clk_mux). + * in struct's for those devices (e.g. &struct clk_mux). + * @enable_count: The number of times this clock has been enabled. * @id: The clock signal ID within the provider. * @data: An optional data field for scenarios where a single integer ID is not * sufficient. If used, it can be populated through an .of_xlate op and * processed during the various clock ops. * + * Clients provide storage for clock handles. The content of the structure is + * managed solely by the clock API and clock drivers. A clock struct is + * initialized by "get"ing the clock struct. The clock struct is passed to all + * other clock APIs to identify which clock signal to operate upon. + * * Should additional information to identify and configure any clock signal * for any provider be required in the future, the struct could be expanded to * either (a) add more fields to allow clock providers to store additional @@ -72,15 +74,14 @@ struct clk { /** * struct clk_bulk - A handle to (allowing control of) a bulk of clocks. + * @clks: An array of clock handles. + * @count: The number of clock handles in the clks array. * * Clients provide storage for the clock bulk. The content of the structure is * managed solely by the clock API. A clock bulk struct is * initialized by "get"ing the clock bulk struct. * The clock bulk struct is passed to all other bulk clock APIs to apply * the API to all the clock in the bulk struct. - * - * @clks: An array of clock handles. - * @count: The number of clock handles in the clks array. */ struct clk_bulk { struct clk *clks; @@ -91,16 +92,19 @@ struct clk_bulk { struct phandle_1_arg; /** * clk_get_by_phandle() - Get a clock by its phandle information (of-platadata) + * @dev: Device containing the phandle + * @cells: Phandle info + * @clk: A pointer to a clock struct to initialise * * This function is used when of-platdata is enabled. * * This looks up a clock using the phandle info. With dtoc, each phandle in the - * 'clocks' property is transformed into an idx representing the device. For - * example: + * 'clocks' property is transformed into an idx representing the device. + * For example:: * * clocks = <&dpll_mpu_ck 23>; * - * might result in: + * might result in:: * * .clocks = {1, {23}},}, * @@ -109,9 +113,6 @@ struct phandle_1_arg; * this example it would return a clock containing the 'dpll_mpu_ck' device and * the clock ID 23. * - * @dev: Device containing the phandle - * @cells: Phandle info - * @clock: A pointer to a clock struct to initialise * Return: 0 if OK, or a negative error code. */ int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells, @@ -119,6 +120,10 @@ int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells, /** * clk_get_by_index() - Get/request a clock by integer index. + * @dev: The client device. + * @index: The index of the clock to request, within the client's list of + * clocks. + * @clk: A pointer to a clock struct to initialize. * * This looks up and requests a clock. The index is relative to the client * device; each device is assumed to have n clocks associated with it somehow, @@ -126,30 +131,26 @@ int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells, * device clock indices to provider clocks may be via device-tree properties, * board-provided mapping tables, or some other mechanism. * - * @dev: The client device. - * @index: The index of the clock to request, within the client's list of - * clocks. - * @clock A pointer to a clock struct to initialize. * Return: 0 if OK, or a negative error code. */ int clk_get_by_index(struct udevice *dev, int index, struct clk *clk); /** - * clk_get_by_index_nodev - Get/request a clock by integer index - * without a device. - * - * This is a version of clk_get_by_index() that does not use a device. - * + * clk_get_by_index_nodev() - Get/request a clock by integer index without a + * device. * @node: The client ofnode. * @index: The index of the clock to request, within the client's list of * clocks. - * @clock A pointer to a clock struct to initialize. + * @clk: A pointer to a clock struct to initialize. + * * Return: 0 if OK, or a negative error code. */ int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk); /** - * clk_get_bulk - Get/request all clocks of a device. + * clk_get_bulk() - Get/request all clocks of a device. + * @dev: The client device. + * @bulk: A pointer to a clock bulk struct to initialize. * * This looks up and requests all clocks of the client device; each device is * assumed to have n clocks associated with it somehow, and this function finds @@ -157,14 +158,16 @@ int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk); * device clock indices to provider clocks may be via device-tree properties, * board-provided mapping tables, or some other mechanism. * - * @dev: The client device. - * @bulk A pointer to a clock bulk struct to initialize. * Return: 0 if OK, or a negative error code. */ int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk); /** - * clk_get_by_name - Get/request a clock by name. + * clk_get_by_name() - Get/request a clock by name. + * @dev: The client device. + * @name: The name of the clock to request, within the client's list of + * clocks. + * @clk: A pointer to a clock struct to initialize. * * This looks up and requests a clock. The name is relative to the client * device; each device is assumed to have n clocks associated with it somehow, @@ -172,55 +175,49 @@ int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk); * device clock names to provider clocks may be via device-tree properties, * board-provided mapping tables, or some other mechanism. * - * @dev: The client device. - * @name: The name of the clock to request, within the client's list of - * clocks. - * @clock: A pointer to a clock struct to initialize. * Return: 0 if OK, or a negative error code. */ int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk); /** * clk_get_by_name_nodev - Get/request a clock by name without a device. - * - * This is a version of clk_get_by_name() that does not use a device. - * * @node: The client ofnode. * @name: The name of the clock to request, within the client's list of * clocks. - * @clock: A pointer to a clock struct to initialize. + * @clk: A pointer to a clock struct to initialize. + * * Return: 0 if OK, or a negative error code. */ int clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk); /** - * devm_clk_get - lookup and obtain a managed reference to a clock producer. + * devm_clk_get() - lookup and obtain a managed reference to a clock producer. * @dev: device for clock "consumer" * @id: clock consumer ID * - * Returns a struct clk corresponding to the clock producer, or - * valid IS_ERR() condition containing errno. The implementation - * uses @dev and @id to determine the clock consumer, and thereby - * the clock producer. (IOW, @id may be identical strings, but - * clk_get may return different clock producers depending on @dev.) + * The implementation uses @dev and @id to determine the clock consumer, and + * thereby the clock producer. (IOW, @id may be identical strings, but clk_get + * may return different clock producers depending on @dev.) * * Drivers must assume that the clock source is not enabled. * - * devm_clk_get should not be called from within interrupt context. - * * The clock will automatically be freed when the device is unbound * from the bus. + * + * Return: + * a struct clk corresponding to the clock producer, or + * valid IS_ERR() condition containing errno */ struct clk *devm_clk_get(struct udevice *dev, const char *id); /** - * devm_clk_get_optional - lookup and obtain a managed reference to an optional - * clock producer. + * devm_clk_get_optional() - lookup and obtain a managed reference to an + * optional clock producer. * @dev: device for clock "consumer" * @id: clock consumer ID * * Behaves the same as devm_clk_get() except where there is no clock producer. - * In this case, instead of returning -ENOENT, the function returns NULL. + * In this case, instead of returning -%ENOENT, the function returns NULL. */ static inline struct clk *devm_clk_get_optional(struct udevice *dev, const char *id) @@ -236,13 +233,13 @@ static inline struct clk *devm_clk_get_optional(struct udevice *dev, /** * clk_release_all() - Disable (turn off)/Free an array of previously * requested clocks. + * @clk: A clock struct array that was previously successfully + * requested by clk_request/get_by_*(). + * @count: Number of clock contained in the array * * For each clock contained in the clock array, this function will check if * clock has been previously requested and then will disable and free it. * - * @clk: A clock struct array that was previously successfully - * requested by clk_request/get_by_*(). - * @count Number of clock contained in the array * Return: zero on success, or -ve error code. */ int clk_release_all(struct clk *clk, int count); @@ -294,13 +291,12 @@ static inline int clk_release_all(struct clk *clk, int count) * clk_get_by_name_nodev_optional - Get/request an optinonal clock by name * without a device. * @node: The client ofnode. - * @name: The name of the clock to request. * @name: The name of the clock to request, within the client's list of * clocks. - * @clock: A pointer to a clock struct to initialize. + * @clk: A pointer to a clock struct to initialize. * * Behaves the same as clk_get_by_name_nodev() except where there is - * no clock producer, in this case, skip the error number -ENODATA, and + * no clock producer, in this case, skip the error number -%ENODATA, and * the function returns 0. */ static inline int clk_get_by_name_nodev_optional(ofnode node, const char *name, @@ -340,12 +336,13 @@ enum clk_defaults_stage { #if CONFIG_IS_ENABLED(OF_REAL) && CONFIG_IS_ENABLED(CLK) /** - * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}' + * clk_set_defaults - Process ``assigned-{clocks/clock-parents/clock-rates}`` * properties to configure clocks - * * @dev: A device to process (the ofnode associated with this device * will be processed). * @stage: The stage of the probing process this function is called during. + * + * Return: zero on success, or -ve error code. */ int clk_set_defaults(struct udevice *dev, enum clk_defaults_stage stage); #else @@ -358,12 +355,12 @@ static inline int clk_set_defaults(struct udevice *dev, int stage) /** * clk_release_bulk() - Disable (turn off)/Free an array of previously * requested clocks in a clock bulk struct. + * @bulk: A clock bulk struct that was previously successfully + * requested by clk_get_bulk(). * * For each clock contained in the clock bulk struct, this function will check * if clock has been previously requested and then will disable and free it. * - * @clk: A clock bulk struct that was previously successfully - * requested by clk_get_bulk(). * Return: zero on success, or -ve error code. */ static inline int clk_release_bulk(struct clk_bulk *bulk) @@ -373,35 +370,35 @@ static inline int clk_release_bulk(struct clk_bulk *bulk) #if CONFIG_IS_ENABLED(CLK) /** - * clk_request - Request a clock by provider-specific ID. + * clk_request() - Request a clock by provider-specific ID. + * @dev: The clock provider device. + * @clk: A pointer to a clock struct to initialize. The caller must + * have already initialized any field in this struct which the + * clock provider uses to identify the clock. * * This requests a clock using a provider-specific ID. Generally, this function * should not be used, since clk_get_by_index/name() provide an interface that * better separates clients from intimate knowledge of clock providers. * However, this function may be useful in core SoC-specific code. * - * @dev: The clock provider device. - * @clock: A pointer to a clock struct to initialize. The caller must - * have already initialized any field in this struct which the - * clock provider uses to identify the clock. * Return: 0 if OK, or a negative error code. */ int clk_request(struct udevice *dev, struct clk *clk); /** - * clk_free - Free a previously requested clock. - * - * @clock: A clock struct that was previously successfully requested by + * clk_free() - Free a previously requested clock. + * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: 0 if OK, or a negative error code. */ int clk_free(struct clk *clk); /** * clk_get_rate() - Get current clock rate. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: clock rate in Hz on success, 0 for invalid clock, or -ve error code * for other errors. */ @@ -409,98 +406,98 @@ ulong clk_get_rate(struct clk *clk); /** * clk_get_parent() - Get current clock's parent. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: pointer to parent's struct clk, or error code passed as pointer */ struct clk *clk_get_parent(struct clk *clk); /** * clk_get_parent_rate() - Get parent of current clock rate. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: clock rate in Hz, or -ve error code. */ long long clk_get_parent_rate(struct clk *clk); /** * clk_round_rate() - Adjust a rate to the exact rate a clock can provide + * @clk: A clock struct that was previously successfully requested by + * clk_request/get_by_*(). + * @rate: desired clock rate in Hz. * * This answers the question "if I were to pass @rate to clk_set_rate(), * what clock rate would I end up with?" without changing the hardware - * in any way. In other words: + * in any way. In other words:: * * rate = clk_round_rate(clk, r); * - * and: + * and:: * * rate = clk_set_rate(clk, r); * * are equivalent except the former does not modify the clock hardware * in any way. * - * @clk: A clock struct that was previously successfully requested by - * clk_request/get_by_*(). - * @rate: desired clock rate in Hz. * Return: rounded rate in Hz, or -ve error code. */ ulong clk_round_rate(struct clk *clk, ulong rate); /** * clk_set_rate() - Set current clock rate. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). * @rate: New clock rate in Hz. + * * Return: new rate, or -ve error code. */ ulong clk_set_rate(struct clk *clk, ulong rate); /** * clk_set_parent() - Set current clock parent. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). * @parent: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: new rate, or -ve error code. */ int clk_set_parent(struct clk *clk, struct clk *parent); /** * clk_enable() - Enable (turn on) a clock. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: zero on success, or -ve error code. */ int clk_enable(struct clk *clk); /** * clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct. - * * @bulk: A clock bulk struct that was previously successfully requested * by clk_get_bulk(). + * * Return: zero on success, or -ve error code. */ int clk_enable_bulk(struct clk_bulk *bulk); /** * clk_disable() - Disable (turn off) a clock. - * * @clk: A clock struct that was previously successfully requested by * clk_request/get_by_*(). + * * Return: zero on success, or -ve error code. */ int clk_disable(struct clk *clk); /** * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct. - * * @bulk: A clock bulk struct that was previously successfully requested * by clk_get_bulk(). + * * Return: zero on success, or -ve error code. */ int clk_disable_bulk(struct clk_bulk *bulk); @@ -510,28 +507,25 @@ int clk_disable_bulk(struct clk_bulk *bulk); * @p: clk compared against q * @q: clk compared against p * - * Returns true if the two struct clk pointers both point to the same hardware - * clock node. - * - * Returns false otherwise. Note that two NULL clks are treated as matching. + * Return: + * %true if the two struct clk pointers both point to the same hardware clock + * node, and %false otherwise. Note that two %NULL clks are treated as matching. */ bool clk_is_match(const struct clk *p, const struct clk *q); /** * clk_get_by_id() - Get the clock by its ID - * * @id: The clock ID to search for - * * @clkp: A pointer to clock struct that has been found among added clocks * to UCLASS_CLK + * * Return: zero on success, or -ENOENT on error */ int clk_get_by_id(ulong id, struct clk **clkp); /** * clk_dev_binded() - Check whether the clk has a device binded - * - * @clk A pointer to the clk + * @clk: A pointer to the clk * * Return: true on binded, or false on no */ @@ -617,8 +611,8 @@ static inline bool clk_dev_binded(struct clk *clk) /** * clk_valid() - check if clk is valid - * * @clk: the clock to check + * * Return: true if valid, or false */ static inline bool clk_valid(struct clk *clk) -- 2.39.5