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9e578f6340
Improve clk_get_rate() @return documentation that otherwise is a bit ambiguous. At the moment I expect to return 0 as error since the return type is 'ulong', instead the function really returns negative value in case the corresponding function pointer is null and returns 0 if the clock is invalid. Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com> Reviewed-by: Sean Anderson <seanga2@gmail.com>
622 lines
19 KiB
C
622 lines
19 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright (c) 2015 Google, Inc
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* Written by Simon Glass <sjg@chromium.org>
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* Copyright (c) 2016, NVIDIA CORPORATION.
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*/
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#ifndef _CLK_H_
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#define _CLK_H_
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#include <dm/ofnode.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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/**
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* A clock is a hardware signal that oscillates autonomously at a specific
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* frequency and duty cycle. Most hardware modules require one or more clock
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* signal to drive their operation. Clock signals are typically generated
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* externally to the HW module consuming them, by an entity this API calls a
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* clock provider. This API provides a standard means for drivers to enable and
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* disable clocks, and to set the rate at which they oscillate.
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*
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* A driver that implements UCLASS_CLK is a clock provider. A provider will
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* often implement multiple separate clocks, since the hardware it manages
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* often has this capability. clk-uclass.h describes the interface which
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* clock providers must implement.
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*
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* Clock consumers/clients are the HW modules driven by the clock signals. This
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* header file describes the API used by drivers for those HW modules.
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*/
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struct udevice;
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/**
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* struct clk - A handle to (allowing control of) a single clock.
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*
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* Clients provide storage for clock handles. The content of the structure is
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* managed solely by the clock API and clock drivers. A clock struct is
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* initialized by "get"ing the clock struct. The clock struct is passed to all
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* other clock APIs to identify which clock signal to operate upon.
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*
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* @dev: The device which implements the clock signal.
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* @rate: The clock rate (in HZ).
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* @flags: Flags used across common clock structure (e.g. CLK_)
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* Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined
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* in struct's for those devices (e.g. struct clk_mux).
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* @id: The clock signal ID within the provider.
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* @data: An optional data field for scenarios where a single integer ID is not
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* sufficient. If used, it can be populated through an .of_xlate op and
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* processed during the various clock ops.
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*
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* Should additional information to identify and configure any clock signal
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* for any provider be required in the future, the struct could be expanded to
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* either (a) add more fields to allow clock providers to store additional
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* information, or (b) replace the id field with an opaque pointer, which the
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* provider would dynamically allocated during its .of_xlate op, and process
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* during is .request op. This may require the addition of an extra op to clean
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* up the allocation.
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*/
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struct clk {
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struct udevice *dev;
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long long rate; /* in HZ */
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u32 flags;
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int enable_count;
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/*
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* Written by of_xlate. In the future, we might add more fields here.
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*/
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unsigned long id;
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unsigned long data;
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};
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/**
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* struct clk_bulk - A handle to (allowing control of) a bulk of clocks.
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*
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* Clients provide storage for the clock bulk. The content of the structure is
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* managed solely by the clock API. A clock bulk struct is
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* initialized by "get"ing the clock bulk struct.
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* The clock bulk struct is passed to all other bulk clock APIs to apply
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* the API to all the clock in the bulk struct.
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*
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* @clks: An array of clock handles.
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* @count: The number of clock handles in the clks array.
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*/
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struct clk_bulk {
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struct clk *clks;
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unsigned int count;
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};
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#if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK)
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struct phandle_1_arg;
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/**
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* clk_get_by_phandle() - Get a clock by its phandle information (of-platadata)
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*
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* This function is used when of-platdata is enabled.
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*
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* This looks up a clock using the phandle info. With dtoc, each phandle in the
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* 'clocks' property is transformed into an idx representing the device. For
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* example:
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*
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* clocks = <&dpll_mpu_ck 23>;
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*
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* might result in:
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*
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* .clocks = {1, {23}},},
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*
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* indicating that the clock is udevice idx 1 in dt-plat.c with an argument of
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* 23. This function can return a valid clock given the above information. In
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* this example it would return a clock containing the 'dpll_mpu_ck' device and
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* the clock ID 23.
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*
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* @dev: Device containing the phandle
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* @cells: Phandle info
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* @clock: A pointer to a clock struct to initialise
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* @return 0 if OK, or a negative error code.
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*/
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int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
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struct clk *clk);
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/**
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* clk_get_by_index() - Get/request a clock by integer index.
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*
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* This looks up and requests a clock. The index is relative to the client
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* device; each device is assumed to have n clocks associated with it somehow,
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* and this function finds and requests one of them. The mapping of client
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* device clock indices to provider clocks may be via device-tree properties,
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* board-provided mapping tables, or some other mechanism.
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*
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* @dev: The client device.
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* @index: The index of the clock to request, within the client's list of
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* clocks.
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* @clock A pointer to a clock struct to initialize.
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* @return 0 if OK, or a negative error code.
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*/
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int clk_get_by_index(struct udevice *dev, int index, struct clk *clk);
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/**
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* clk_get_by_index_nodev - Get/request a clock by integer index
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* without a device.
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*
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* This is a version of clk_get_by_index() that does not use a device.
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*
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* @node: The client ofnode.
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* @index: The index of the clock to request, within the client's list of
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* clocks.
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* @clock A pointer to a clock struct to initialize.
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* @return 0 if OK, or a negative error code.
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*/
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int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk);
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/**
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* clk_get_bulk - Get/request all clocks of a device.
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*
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* This looks up and requests all clocks of the client device; each device is
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* assumed to have n clocks associated with it somehow, and this function finds
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* and requests all of them in a separate structure. The mapping of client
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* device clock indices to provider clocks may be via device-tree properties,
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* board-provided mapping tables, or some other mechanism.
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*
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* @dev: The client device.
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* @bulk A pointer to a clock bulk struct to initialize.
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* @return 0 if OK, or a negative error code.
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*/
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int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
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/**
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* clk_get_by_name - Get/request a clock by name.
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*
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* This looks up and requests a clock. The name is relative to the client
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* device; each device is assumed to have n clocks associated with it somehow,
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* and this function finds and requests one of them. The mapping of client
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* device clock names to provider clocks may be via device-tree properties,
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* board-provided mapping tables, or some other mechanism.
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*
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* @dev: The client device.
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* @name: The name of the clock to request, within the client's list of
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* clocks.
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* @clock: A pointer to a clock struct to initialize.
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* @return 0 if OK, or a negative error code.
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*/
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int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
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/**
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* clk_get_by_name_nodev - Get/request a clock by name without a device.
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*
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* This is a version of clk_get_by_name() that does not use a device.
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*
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* @node: The client ofnode.
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* @name: The name of the clock to request, within the client's list of
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* clocks.
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* @clock: A pointer to a clock struct to initialize.
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* @return 0 if OK, or a negative error code.
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*/
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int clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk);
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/**
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* clk_get_optional_nodev - Get/request an optinonal clock by name
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* without a device.
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* @node: The client ofnode.
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* @name: The name of the clock to request.
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* @name: The name of the clock to request, within the client's list of
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* clocks.
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* @clock: A pointer to a clock struct to initialize.
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*
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* Behaves the same as clk_get_by_name_nodev() except where there is
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* no clock producer, in this case, skip the error number -ENODATA, and
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* the function returns 0.
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*/
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int clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk);
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/**
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* devm_clk_get - lookup and obtain a managed reference to a clock producer.
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* @dev: device for clock "consumer"
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* @id: clock consumer ID
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*
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* Returns a struct clk corresponding to the clock producer, or
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* valid IS_ERR() condition containing errno. The implementation
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* uses @dev and @id to determine the clock consumer, and thereby
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* the clock producer. (IOW, @id may be identical strings, but
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* clk_get may return different clock producers depending on @dev.)
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*
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* Drivers must assume that the clock source is not enabled.
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*
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* devm_clk_get should not be called from within interrupt context.
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*
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* The clock will automatically be freed when the device is unbound
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* from the bus.
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*/
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struct clk *devm_clk_get(struct udevice *dev, const char *id);
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/**
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* devm_clk_get_optional - lookup and obtain a managed reference to an optional
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* clock producer.
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* @dev: device for clock "consumer"
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* @id: clock consumer ID
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*
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* Behaves the same as devm_clk_get() except where there is no clock producer.
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* In this case, instead of returning -ENOENT, the function returns NULL.
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*/
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struct clk *devm_clk_get_optional(struct udevice *dev, const char *id);
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/**
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* clk_release_all() - Disable (turn off)/Free an array of previously
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* requested clocks.
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*
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* For each clock contained in the clock array, this function will check if
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* clock has been previously requested and then will disable and free it.
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*
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* @clk: A clock struct array that was previously successfully
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* requested by clk_request/get_by_*().
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* @count Number of clock contained in the array
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* @return zero on success, or -ve error code.
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*/
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int clk_release_all(struct clk *clk, int count);
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/**
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* devm_clk_put - "free" a managed clock source
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* @dev: device used to acquire the clock
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* @clk: clock source acquired with devm_clk_get()
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*
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* Note: drivers must ensure that all clk_enable calls made on this
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* clock source are balanced by clk_disable calls prior to calling
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* this function.
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*
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* clk_put should not be called from within interrupt context.
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*/
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void devm_clk_put(struct udevice *dev, struct clk *clk);
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#else
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static inline int clk_get_by_index(struct udevice *dev, int index,
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struct clk *clk)
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{
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return -ENOSYS;
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}
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static inline int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
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{
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return -ENOSYS;
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}
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static inline int clk_get_by_name(struct udevice *dev, const char *name,
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struct clk *clk)
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{
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return -ENOSYS;
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}
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static inline int
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clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk)
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{
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return -ENOSYS;
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}
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static inline int
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clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk)
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{
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return -ENOSYS;
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}
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static inline int clk_release_all(struct clk *clk, int count)
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{
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return -ENOSYS;
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}
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#endif
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/**
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* enum clk_defaults_stage - What stage clk_set_defaults() is called at
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* @CLK_DEFAULTS_PRE: Called before probe. Setting of defaults for clocks owned
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* by this clock driver will be defered until after probing.
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* @CLK_DEFAULTS_POST: Called after probe. Only defaults for clocks owned by
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* this clock driver will be set.
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* @CLK_DEFAULTS_POST_FORCE: Called after probe, and always set defaults, even
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* before relocation. Usually, defaults are not set
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* pre-relocation to avoid setting them twice (when
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* the device is probed again post-relocation). This
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* may incur a performance cost as device tree
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* properties must be parsed for a second time.
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* However, when not using SPL, pre-relocation may be
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* the only time we can set defaults for some clocks
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* (such as those used for the RAM we will relocate
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* into).
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*/
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enum clk_defaults_stage {
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CLK_DEFAULTS_PRE = 0,
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CLK_DEFAULTS_POST = 1,
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CLK_DEFAULTS_POST_FORCE,
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};
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#if CONFIG_IS_ENABLED(OF_REAL) && CONFIG_IS_ENABLED(CLK)
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/**
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* clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}'
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* properties to configure clocks
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*
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* @dev: A device to process (the ofnode associated with this device
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* will be processed).
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* @stage: The stage of the probing process this function is called during.
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*/
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int clk_set_defaults(struct udevice *dev, enum clk_defaults_stage stage);
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#else
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static inline int clk_set_defaults(struct udevice *dev, int stage)
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{
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return 0;
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}
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#endif
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/**
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* clk_release_bulk() - Disable (turn off)/Free an array of previously
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* requested clocks in a clock bulk struct.
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*
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* For each clock contained in the clock bulk struct, this function will check
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* if clock has been previously requested and then will disable and free it.
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*
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* @clk: A clock bulk struct that was previously successfully
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* requested by clk_get_bulk().
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* @return zero on success, or -ve error code.
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*/
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static inline int clk_release_bulk(struct clk_bulk *bulk)
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{
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return clk_release_all(bulk->clks, bulk->count);
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}
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#if CONFIG_IS_ENABLED(CLK)
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/**
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* clk_request - Request a clock by provider-specific ID.
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*
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* This requests a clock using a provider-specific ID. Generally, this function
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* should not be used, since clk_get_by_index/name() provide an interface that
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* better separates clients from intimate knowledge of clock providers.
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* However, this function may be useful in core SoC-specific code.
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*
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* @dev: The clock provider device.
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* @clock: A pointer to a clock struct to initialize. The caller must
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* have already initialized any field in this struct which the
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* clock provider uses to identify the clock.
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* @return 0 if OK, or a negative error code.
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*/
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int clk_request(struct udevice *dev, struct clk *clk);
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/**
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* clk_free - Free a previously requested clock.
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*
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* @clock: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @return 0 if OK, or a negative error code.
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*/
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int clk_free(struct clk *clk);
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/**
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* clk_get_rate() - Get current clock rate.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @return clock rate in Hz on success, 0 for invalid clock, or -ve error code
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* for other errors.
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*/
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ulong clk_get_rate(struct clk *clk);
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/**
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* clk_get_parent() - Get current clock's parent.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @return pointer to parent's struct clk, or error code passed as pointer
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*/
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struct clk *clk_get_parent(struct clk *clk);
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/**
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* clk_get_parent_rate() - Get parent of current clock rate.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @return clock rate in Hz, or -ve error code.
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*/
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long long clk_get_parent_rate(struct clk *clk);
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/**
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* clk_round_rate() - Adjust a rate to the exact rate a clock can provide
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*
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* This answers the question "if I were to pass @rate to clk_set_rate(),
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* what clock rate would I end up with?" without changing the hardware
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* in any way. In other words:
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*
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* rate = clk_round_rate(clk, r);
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*
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* and:
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*
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* rate = clk_set_rate(clk, r);
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*
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* are equivalent except the former does not modify the clock hardware
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* in any way.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @rate: desired clock rate in Hz.
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* @return rounded rate in Hz, or -ve error code.
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*/
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ulong clk_round_rate(struct clk *clk, ulong rate);
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/**
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* clk_set_rate() - Set current clock rate.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @rate: New clock rate in Hz.
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* @return new rate, or -ve error code.
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*/
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ulong clk_set_rate(struct clk *clk, ulong rate);
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/**
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* clk_set_parent() - Set current clock parent.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @parent: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @return new rate, or -ve error code.
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*/
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int clk_set_parent(struct clk *clk, struct clk *parent);
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/**
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* clk_enable() - Enable (turn on) a clock.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @return zero on success, or -ve error code.
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*/
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int clk_enable(struct clk *clk);
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/**
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* clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct.
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*
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* @bulk: A clock bulk struct that was previously successfully requested
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* by clk_get_bulk().
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* @return zero on success, or -ve error code.
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*/
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int clk_enable_bulk(struct clk_bulk *bulk);
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/**
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* clk_disable() - Disable (turn off) a clock.
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*
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* @clk: A clock struct that was previously successfully requested by
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* clk_request/get_by_*().
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* @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)
|