| /* SPDX-License-Identifier: GPL-2.0+ */ |
| /* |
| * Copyright (c) 2015 Google, Inc |
| * Written by Simon Glass <sjg@chromium.org> |
| * Copyright (c) 2016, NVIDIA CORPORATION. |
| */ |
| |
| #ifndef _CLK_H_ |
| #define _CLK_H_ |
| |
| #include <dm/ofnode.h> |
| #include <linux/errno.h> |
| #include <linux/types.h> |
| |
| /** |
| * 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; |
| /* |
| * 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_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_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); |
| |
| int soc_clk_dump(void); |
| |
| /** |
| * 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; |
| } |
| |
| /** |
| * 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); |
| #endif |