include/linux/clk.h

Source file repositories/reference/linux-study-clean/include/linux/clk.h

File Facts

System
Linux kernel
Corpus path
include/linux/clk.h
Extension
.h
Size
38104 bytes
Lines
1259
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct clk_notifier {
	struct clk			*clk;
	struct srcu_notifier_head	notifier_head;
	struct list_head		node;
};

/**
 * struct clk_notifier_data - rate data to pass to the notifier callback
 * @clk: struct clk * being changed
 * @old_rate: previous rate of this clk
 * @new_rate: new rate of this clk
 *
 * For a pre-notifier, old_rate is the clk's rate before this rate
 * change, and new_rate is what the rate will be in the future.  For a
 * post-notifier, old_rate and new_rate are both set to the clk's
 * current rate (this was done to optimize the implementation).
 */
struct clk_notifier_data {
	struct clk		*clk;
	unsigned long		old_rate;
	unsigned long		new_rate;
};

/**
 * struct clk_bulk_data - Data used for bulk clk operations.
 *
 * @id: clock consumer ID
 * @clk: struct clk * to store the associated clock
 *
 * The CLK APIs provide a series of clk_bulk_() API calls as
 * a convenience to consumers which require multiple clks.  This
 * structure is used to manage data for these calls.
 */
struct clk_bulk_data {
	const char		*id;
	struct clk		*clk;
};

#ifdef CONFIG_COMMON_CLK

/**
 * clk_notifier_register - register a clock rate-change notifier callback
 * @clk: clock whose rate we are interested in
 * @nb: notifier block with callback function pointer
 *
 * ProTip: debugging across notifier chains can be frustrating. Make sure that
 * your notifier callback function prints a nice big warning in case of
 * failure.
 */
int clk_notifier_register(struct clk *clk, struct notifier_block *nb);

/**
 * clk_notifier_unregister - unregister a clock rate-change notifier callback
 * @clk: clock whose rate we are no longer interested in
 * @nb: notifier block which will be unregistered
 */
int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);

/**
 * devm_clk_notifier_register - register a managed rate-change notifier callback
 * @dev: device for clock "consumer"
 * @clk: clock whose rate we are interested in
 * @nb: notifier block with callback function pointer
 *
 * Returns 0 on success, -EERROR otherwise
 */
int devm_clk_notifier_register(struct device *dev, struct clk *clk,
			       struct notifier_block *nb);

/**
 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
 *		      for a clock source.
 * @clk: clock source
 *
 * This gets the clock source accuracy expressed in ppb.
 * A perfect clock returns 0.
 */
long clk_get_accuracy(struct clk *clk);

/**
 * clk_set_phase - adjust the phase shift of a clock signal
 * @clk: clock signal source
 * @degrees: number of degrees the signal is shifted
 *
 * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
 * success, -EERROR otherwise.
 */
int clk_set_phase(struct clk *clk, int degrees);

/**

Annotation

Implementation Notes