X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=include%2Fclk.h;h=d24e99713a3591f4565ecf30b49b9358cd582a0d;hb=1f1075c6e385a746d58d2ca0cd2f2f9dde1c2f5d;hp=df4570c6f54abb0f5e6aac166b8096c19becdf69;hpb=9c1d0e9f16b5718da47018da0a5c3e0eafbff81b;p=oweals%2Fu-boot.git diff --git a/include/clk.h b/include/clk.h index df4570c6f5..d24e99713a 100644 --- a/include/clk.h +++ b/include/clk.h @@ -1,6 +1,324 @@ +/* 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 + +/** + * 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_CLOCK 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. + * @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; + /* + * 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_index_platdata(struct udevice *dev, int index, + struct phandle_1_arg *cells, struct clk *clk); + +/** + * clock_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); + +/** + * clock_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); + +/** + * clock_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); + +/** + * clock_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_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); + +#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_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). + */ +int clk_set_defaults(struct udevice *dev); +#else +static inline int clk_set_defaults(struct udevice *dev) +{ + 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); +} + +/** + * 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); + +/** + * clock_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_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); + int soc_clk_dump(void); -#endif /* _CLK_H_ */ +/** + * 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->dev; +} +#endif