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/* 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/err.h>
#include <linux/errno.h>
#include <linux/types.h>
/**
* 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
* 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.
* @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).
* @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
* 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.
* @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.
*/
struct clk_bulk {
struct clk *clks;
unsigned int count;
};
struct phandle_1_arg;
#if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK)
/**
* 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 = <&dpll_mpu_ck 23>;
*
* might result in::
*
* .clocks = {1, {23}},},
*
* indicating that the clock is udevice idx 1 in dt-plat.c with an argument of
* 23. This function can return a valid clock given the above information. In
* this example it would return a clock containing the 'dpll_mpu_ck' device and
* the clock ID 23.
*
* Return: 0 if OK, or a negative error code.
*/
int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
struct clk *clk);
/**
* 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,
* 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.
*
* 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.
* @node: The client ofnode.
* @index: The index of the clock to request, within the client's list of
* clocks.
* @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.
* @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
* 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.
*
* 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.
* @dev: The client device.
* @name: The name of the clock to request, within the client's list of
* clocks, or NULL to request the first clock in the list.
* @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,
* 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.
*
* 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.
* @node: The client ofnode.
* @name: The name of the clock to request, within the client's list of
* clocks, or NULL to request the first clock in the list.
* @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.
* @dev: device for clock "consumer"
* @id: clock consumer ID
*
* 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.
*
* 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.
* @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.
*/
static inline struct clk *devm_clk_get_optional(struct udevice *dev,
const char *id)
{
int ret;
struct clk *clk = devm_clk_get(dev, id);
ret = PTR_ERR(clk);
if (ret == -ENODATA || ret == -ENOENT)
return NULL;
return clk;
}
/**
* 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.
*
* Return: zero on success, or -ve error code.
*/
int clk_release_all(struct clk *clk, unsigned int count);
#else
static inline int clk_get_by_phandle(struct udevice *dev, const
struct phandle_1_arg *cells,
struct clk *clk)
{
return -ENOSYS;
}
static inline int clk_get_by_index(struct udevice *dev, int index,
struct clk *clk)
{
return -ENOSYS;
}
static inline int clk_get_by_index_nodev(ofnode node, 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 struct clk *devm_clk_get(struct udevice *dev, const char *id)
{
return ERR_PTR(-ENOSYS);
}
static inline struct clk *devm_clk_get_optional(struct udevice *dev,
const char *id)
{
return ERR_PTR(-ENOSYS);
}
static inline int
clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk)
{
return -ENOSYS;
}
static inline int clk_release_all(struct clk *clk, unsigned int count)
{
return -ENOSYS;
}
#endif
/**
* clk_get_by_name_optional() - Get/request a optional 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.
*
* Behaves the same as clk_get_by_name(), except when there is no clock
* provider. In the latter case, return 0.
*
* Return: 0 if OK, or a negative error code.
*/
static inline int clk_get_by_name_optional(struct udevice *dev,
const char *name, struct clk *clk)
{
int ret;
ret = clk_get_by_name(dev, name, clk);
if (ret == -ENODATA || ret == -ENOENT)
return 0;
return ret;
}
/**
* 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, within the client's list of
* clocks.
* @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
* the function returns 0.
*/
static inline int clk_get_by_name_nodev_optional(ofnode node, const char *name,
struct clk *clk)
{
int ret;
ret = clk_get_by_name_nodev(node, name, clk);
if (ret == -ENODATA || ret == -ENOENT)
return 0;
return ret;
}
/**
* enum clk_defaults_stage - What stage clk_set_defaults() is called at
* @CLK_DEFAULTS_PRE: Called before probe. Setting of defaults for clocks owned
* by this clock driver will be defered until after probing.
* @CLK_DEFAULTS_POST: Called after probe. Only defaults for clocks owned by
* this clock driver will be set.
* @CLK_DEFAULTS_POST_FORCE: Called after probe, and always set defaults, even
* before relocation. Usually, defaults are not set
* pre-relocation to avoid setting them twice (when
* the device is probed again post-relocation). This
* may incur a performance cost as device tree
* properties must be parsed for a second time.
* However, when not using SPL, pre-relocation may be
* the only time we can set defaults for some clocks
* (such as those used for the RAM we will relocate
* into).
*/
enum clk_defaults_stage {
CLK_DEFAULTS_PRE = 0,
CLK_DEFAULTS_POST = 1,
CLK_DEFAULTS_POST_FORCE,
};
#if CONFIG_IS_ENABLED(OF_REAL) && 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: 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
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.
* @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.
*
* 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.
* @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.
*
* Return: 0 if OK, or a negative error code.
*/
int clk_request(struct udevice *dev, 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.
*/
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.
*/
ulong 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::
*
* 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.
*
* 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
*
* 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
*
* 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 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 ulong 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;
}
#endif
#define clk_prepare_enable(clk) clk_enable(clk)
#define clk_disable_unprepare(clk) clk_disable(clk)