Commit 54e73016 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Mike Turquette
Browse files

clk: Improve clk_ops documentation 



General:
  - Add parameter names to .round_rate() and .set_rate().

Documentation/clk.txt:
  - Add missing parameter for .set_rate(),
  - Add missing .debug_init().

include/linux/clk-provider.h:
  - Add parent rate documentation for .round_rate(),
  - Reorder documentation to match implementation order,
  - Add missing documentation for .init().

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
parent 725b418b

Documentation/clk.txt

+11 −5
Original line number Diff line number Diff line
@@ -68,21 +68,27 @@ the operations defined in clk.h: 
		int		(*is_enabled)(struct clk_hw *hw);

		unsigned long	(*recalc_rate)(struct clk_hw *hw,

						unsigned long parent_rate);

		long		(*round_rate)(struct clk_hw *hw, unsigned long,

						unsigned long *);

		long		(*round_rate)(struct clk_hw *hw,

						unsigned long rate,

						unsigned long *parent_rate);

		long		(*determine_rate)(struct clk_hw *hw,

						unsigned long rate,

						unsigned long *best_parent_rate,

						struct clk **best_parent_clk);

		int		(*set_parent)(struct clk_hw *hw, u8 index);

		u8		(*get_parent)(struct clk_hw *hw);

		int		(*set_rate)(struct clk_hw *hw, unsigned long);

		int		(*set_rate)(struct clk_hw *hw,

					    unsigned long rate,

					    unsigned long parent_rate);

		int		(*set_rate_and_parent)(struct clk_hw *hw,

					    unsigned long rate,

					    unsigned long parent_rate, u8 index);

					    unsigned long parent_rate,

					    u8 index);

		unsigned long	(*recalc_accuracy)(struct clk_hw *hw,

						unsigned long parent_accuracy);

		void		(*init)(struct clk_hw *hw);

		int		(*debug_init)(struct clk_hw *hw,

					      struct dentry *dentry);

	};



	Part 3 - hardware clk implementations

include/linux/clk-provider.h

+25 −19
Original line number Diff line number Diff line
@@ -81,12 +81,20 @@ struct dentry; 
 *		this op is not set then clock rate will be initialized to 0.

 *

 * @round_rate:	Given a target rate as input, returns the closest rate actually

 *		supported by the clock.

 *		supported by the clock. The parent rate is an input/output

 *		parameter.

 *

 * @determine_rate: Given a target rate as input, returns the closest rate

 *		actually supported by the clock, and optionally the parent clock

 *		that should be used to provide the clock rate.

 *

 * @set_parent:	Change the input source of this clock; for clocks with multiple

 *		possible parents specify a new parent by passing in the index

 *		as a u8 corresponding to the parent in either the .parent_names

 *		or .parents arrays.  This function in affect translates an

 *		array index into the value programmed into the hardware.

 *		Returns 0 on success, -EERROR otherwise.

 *

 * @get_parent:	Queries the hardware to determine the parent of a clock.  The

 *		return value is a u8 which specifies the index corresponding to

 *		the parent clock.  This index can be applied to either the
@@ -97,26 +105,12 @@ struct dentry; 
 *		multiple parents.  It is optional (and unnecessary) for clocks

 *		with 0 or 1 parents.

 *

 * @set_parent:	Change the input source of this clock; for clocks with multiple

 *		possible parents specify a new parent by passing in the index

 *		as a u8 corresponding to the parent in either the .parent_names

 *		or .parents arrays.  This function in affect translates an

 *		array index into the value programmed into the hardware.

 *		Returns 0 on success, -EERROR otherwise.

 *

 * @set_rate:	Change the rate of this clock. The requested rate is specified

 *		by the second argument, which should typically be the return

 *		of .round_rate call.  The third argument gives the parent rate

 *		which is likely helpful for most .set_rate implementation.

 *		Returns 0 on success, -EERROR otherwise.

 *

 * @recalc_accuracy: Recalculate the accuracy of this clock. The clock accuracy

 *		is expressed in ppb (parts per billion). The parent accuracy is

 *		an input parameter.

 *		Returns the calculated accuracy.  Optional - if	this op is not

 *		set then clock accuracy will be initialized to parent accuracy

 *		or 0 (perfect clock) if clock has no parent.

 *

 * @set_rate_and_parent: Change the rate and the parent of this clock. The

 *		requested rate is specified by the second argument, which

 *		should typically be the return of .round_rate call.  The
@@ -128,6 +122,18 @@ struct dentry; 
 *		separately via calls to .set_parent and .set_rate.

 *		Returns 0 on success, -EERROR otherwise.

 *

 * @recalc_accuracy: Recalculate the accuracy of this clock. The clock accuracy

 *		is expressed in ppb (parts per billion). The parent accuracy is

 *		an input parameter.

 *		Returns the calculated accuracy.  Optional - if	this op is not

 *		set then clock accuracy will be initialized to parent accuracy

 *		or 0 (perfect clock) if clock has no parent.

 *

 * @init:	Perform platform-specific initialization magic.

 *		This is not not used by any of the basic clock types.

 *		Please consider other ways of solving initialization problems

 *		before using this callback, as its use is discouraged.

 *

 * @debug_init:	Set up type-specific debugfs entries for this clock.  This

 *		is called once, after the debugfs directory entry for this

 *		clock has been created.  The dentry pointer representing that
@@ -157,15 +163,15 @@ struct clk_ops { 
	void		(*disable_unused)(struct clk_hw *hw);

	unsigned long	(*recalc_rate)(struct clk_hw *hw,

					unsigned long parent_rate);

	long		(*round_rate)(struct clk_hw *hw, unsigned long,

					unsigned long *);

	long		(*round_rate)(struct clk_hw *hw, unsigned long rate,

					unsigned long *parent_rate);

	long		(*determine_rate)(struct clk_hw *hw, unsigned long rate,

					unsigned long *best_parent_rate,

					struct clk **best_parent_clk);

	int		(*set_parent)(struct clk_hw *hw, u8 index);

	u8		(*get_parent)(struct clk_hw *hw);

	int		(*set_rate)(struct clk_hw *hw, unsigned long,

				    unsigned long);

	int		(*set_rate)(struct clk_hw *hw, unsigned long rate,

				    unsigned long parent_rate);

	int		(*set_rate_and_parent)(struct clk_hw *hw,

				    unsigned long rate,

				    unsigned long parent_rate, u8 index);

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