u-boot/include/clk.h

15  * A clock is a hardware signal that oscillates autonomously at a specific
16  * frequency and duty cycle. Most hardware modules require one or more clock
17  * signal to drive their operation. Clock signals are typically generated
19  * clock provider. This API provides a standard means for drivers to enable and
22  * A driver that implements UCLASS_CLOCK is a clock provider. A provider will
25  * clock providers must implement.
27  * Clock consumers/clients are the HW modules driven by the clock signals. This
34  * struct clk - A handle to (allowing control of) a single clock.
36  * Clients provide storage for clock handles. The content of the structure is
37  * managed solely by the clock API and clock drivers. A clock struct is
38  * initialized by "get"ing the clock struct. The clock struct is passed to all
39  * other clock APIs to identify which clock signal to operate upon.
41  * @dev: The device which implements the clock signal.
42  * @id: The clock signal ID within the provider.
45  *	  processed during the various clock ops.
47  * Should additional information to identify and configure any clock signal
49  * either (a) add more fields to allow clock providers to store additional
67  * Clients provide storage for the clock bulk. The content of the structure is
68  * managed solely by the clock API. A clock bulk struct is
69  * initialized by "get"ing the clock bulk struct.
70  * The clock bulk struct is passed to all other bulk clock APIs to apply
71  * the API to all the clock in the bulk struct.
73  * @clks: An array of clock handles.
74  * @count: The number of clock handles in the clks array.
87  * clock_get_by_index - Get/request a clock by integer index.
89  * This looks up and requests a clock. The index is relative to the client
92  * device clock indices to provider clocks may be via device-tree properties,
96  * @index:	The index of the clock to request, within the client's list of
98  * @clock	A pointer to a clock struct to initialize.
109  * device clock indices to provider clocks may be via device-tree properties,
113  * @bulk	A pointer to a clock bulk struct to initialize.
119  * clock_get_by_name - Get/request a clock by name.
121  * This looks up and requests a clock. The name is relative to the client
124  * device clock names to provider clocks may be via device-tree properties,
128  * @name:	The name of the clock to request, within the client's list of
130  * @clock:	A pointer to a clock struct to initialize.
139  * For each clock contained in the clock array, this function will check if
140  * clock has been previously requested and then will disable and free it.
142  * @clk:	A clock struct array that was previously successfully
144  * @count	Number of clock contained in the array
176  * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}'
192  * requested clocks in a clock bulk struct.
194  * For each clock contained in the clock bulk struct, this function will check
195  * if clock has been previously requested and then will disable and free it.
197  * @clk:	A clock bulk struct that was previously successfully
207  * clk_request - Request a clock by provider-specific ID.
209  * This requests a clock using a provider-specific ID. Generally, this function
211  * better separates clients from intimate knowledge of clock providers.
214  * @dev:	The clock provider device.
215  * @clock:	A pointer to a clock struct to initialize. The caller must
217  *		clock provider uses to identify the clock.
223  * clock_free - Free a previously requested clock.
225  * @clock:	A clock struct that was previously successfully requested by
232  * clk_get_rate() - Get current clock rate.
234  * @clk:	A clock struct that was previously successfully requested by
236  * @return clock rate in Hz, or -ve error code.
241  * clk_set_rate() - Set current clock rate.
243  * @clk:	A clock struct that was previously successfully requested by
245  * @rate:	New clock rate in Hz.
251  * clk_set_parent() - Set current clock parent.
253  * @clk:	A clock struct that was previously successfully requested by
255  * @parent:	A clock struct that was previously successfully requested by
262  * clk_enable() - Enable (turn on) a clock.
264  * @clk:	A clock struct that was previously successfully requested by
271  * clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct.
273  * @bulk:	A clock bulk struct that was previously successfully requested
280  * clk_disable() - Disable (turn off) a clock.
282  * @clk:	A clock struct that was previously successfully requested by
289  * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct.
291  * @bulk:	A clock bulk struct that was previously successfully requested
302  * @clk:	the clock to check