/* SPDX-License-Identifier: GPL-2.0+ */ /* * Copyright (c) 2015 Google, Inc * Written by Simon Glass * Copyright (c) 2016, NVIDIA CORPORATION. */ #ifndef _CLK_H_ #define _CLK_H_ #include #include #include #include /** * 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 * externally to the HW module consuming them, by an entity this API calls a * clock provider. This API provides a standard means for drivers to enable and * disable clocks, and to set the rate at which they oscillate. * * A driver that implements UCLASS_CLK is a clock provider. A provider will * often implement multiple separate clocks, since the hardware it manages * often has this capability. clk-uclass.h describes the interface which * clock providers must implement. * * Clock consumers/clients are the HW modules driven by the clock signals. This * header file describes the API used by drivers for those HW modules. */ 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_) * Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined * in struct's for those devices (e.g. struct clk_mux). * @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. * * 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 * information, or (b) replace the id field with an opaque pointer, which the * provider would dynamically allocated during its .of_xlate op, and process * during is .request op. This may require the addition of an extra op to clean * up the allocation. */ struct clk { struct udevice *dev; long long rate; /* in HZ */ u32 flags; int enable_count; /* * Written by of_xlate. In the future, we might add more fields here. */ unsigned long id; unsigned long data; }; /** * struct clk_bulk - A handle to (allowing control of) a bulk of clocks. * * 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; unsigned int count; }; #if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK) struct phandle_1_arg; int clk_get_by_driver_info(struct udevice *dev, struct phandle_1_arg *cells, struct clk *clk); /** * clk_get_by_index - Get/request a clock by integer index. * * 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, * and this function finds and requests one of them. The mapping of client * 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. * * @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. * @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. * * 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 * and requests all of them in a separate structure. The mapping of client * 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. * * 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, * and this function finds and requests one of them. The mapping of client * 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. * @return 0 if OK, or a negative error code. */ int clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk); /** * clk_get_optional_nodev - 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. * * 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 * the function returns 0. */ int clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk); /** * 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.) * * 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. */ 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. * @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. */ struct clk *devm_clk_get_optional(struct udevice *dev, const char *id); /** * clk_release_all() - Disable (turn off)/Free an array of previously * requested clocks. * * 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); /** * devm_clk_put - "free" a managed clock source * @dev: device used to acquire the clock * @clk: clock source acquired with devm_clk_get() * * Note: drivers must ensure that all clk_enable calls made on this * clock source are balanced by clk_disable calls prior to calling * this function. * * clk_put should not be called from within interrupt context. */ void devm_clk_put(struct udevice *dev, struct clk *clk); #else static inline int clk_get_by_index(struct udevice *dev, int index, struct clk *clk) { return -ENOSYS; } static inline int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk) { return -ENOSYS; } static inline int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk) { return -ENOSYS; } static inline int clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk) { return -ENOSYS; } static inline int clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk) { return -ENOSYS; } static inline int clk_release_all(struct clk *clk, int count) { return -ENOSYS; } #endif #if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \ CONFIG_IS_ENABLED(CLK) /** * 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: A integer. 0 indicates that this is called before the device * is probed. 1 indicates that this is called just after the * device has been probed */ int clk_set_defaults(struct udevice *dev, int stage); #else static inline int clk_set_defaults(struct udevice *dev, int stage) { return 0; } #endif /** * clk_release_bulk() - Disable (turn off)/Free an array of previously * requested clocks in a clock bulk struct. * * 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) { return clk_release_all(bulk->clks, bulk->count); } #if CONFIG_IS_ENABLED(CLK) /** * clk_request - Request a clock by provider-specific ID. * * 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_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, or -ve error code. */ 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 * * 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: * * rate = clk_round_rate(clk, r); * * 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); /** * clk_is_match - check if two clk's point to the same hardware clock * @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. */ 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 * * @return true on binded, or false on no */ bool clk_dev_binded(struct clk *clk); #else /* CONFIG_IS_ENABLED(CLK) */ static inline int clk_request(struct udevice *dev, struct clk *clk) { return -ENOSYS; } static inline int clk_free(struct clk *clk) { return 0; } static inline ulong clk_get_rate(struct clk *clk) { return -ENOSYS; } static inline struct clk *clk_get_parent(struct clk *clk) { return ERR_PTR(-ENOSYS); } static inline long long clk_get_parent_rate(struct clk *clk) { return -ENOSYS; } static inline ulong clk_round_rate(struct clk *clk, ulong rate) { return -ENOSYS; } static inline ulong clk_set_rate(struct clk *clk, ulong rate) { return -ENOSYS; } static inline int clk_set_parent(struct clk *clk, struct clk *parent) { return -ENOSYS; } static inline int clk_enable(struct clk *clk) { return 0; } static inline int clk_enable_bulk(struct clk_bulk *bulk) { return 0; } static inline int clk_disable(struct clk *clk) { return 0; } static inline int clk_disable_bulk(struct clk_bulk *bulk) { return 0; } static inline bool clk_is_match(const struct clk *p, const struct clk *q) { return false; } static inline int clk_get_by_id(ulong id, struct clk **clkp) { return -ENOSYS; } static inline bool clk_dev_binded(struct clk *clk) { return false; } #endif /* CONFIG_IS_ENABLED(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) { return clk && !!clk->dev; } int soc_clk_dump(void); #endif #define clk_prepare_enable(clk) clk_enable(clk) #define clk_disable_unprepare(clk) clk_disable(clk)