firmware: ti_sci: Add support for Clock control

Texas Instrument's System Control Interface (TI-SCI) Message Protocol
is used in Texas Instrument's System on Chip (SoC) such as those
in keystone family K2G SoC to communicate between various compute
processors with a central system controller entity.

TI-SCI message protocol provides support for management of various
hardware entities within the SoC. Add support driver to allow
communication with system controller entity within the SoC using the
mailbox client.

In general, we expect to function at a device level of abstraction,
however, for proper operation of hardware blocks, many clocks directly
supplying the hardware block needs to be queried or configured.

Introduce support for the set of SCI message protocol support that
provide us with this capability.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/include/linux/soc/ti/ti_sci_protocol.h b/include/linux/soc/ti/ti_sci_protocol.h
index 87fa73851471..76378fddf609 100644
--- a/include/linux/soc/ti/ti_sci_protocol.h
+++ b/include/linux/soc/ti/ti_sci_protocol.h
@@ -115,11 +115,89 @@ struct ti_sci_dev_ops {
 };
 
 /**
+ * struct ti_sci_clk_ops - Clock control operations
+ * @get_clock:	Request for activation of clock and manage by processor
+ *		- needs_ssc: 'true' if Spread Spectrum clock is desired.
+ *		- can_change_freq: 'true' if frequency change is desired.
+ *		- enable_input_term: 'true' if input termination is desired.
+ * @idle_clock:	Request for Idling a clock managed by processor
+ * @put_clock:	Release the clock to be auto managed by TISCI
+ * @is_auto:	Is the clock being auto managed
+ *		- req_state: state indicating if the clock is auto managed
+ * @is_on:	Is the clock ON
+ *		- req_state: if the clock is requested to be forced ON
+ *		- current_state: if the clock is currently ON
+ * @is_off:	Is the clock OFF
+ *		- req_state: if the clock is requested to be forced OFF
+ *		- current_state: if the clock is currently Gated
+ * @set_parent:	Set the clock source of a specific device clock
+ *		- parent_id: Parent clock identifier to set.
+ * @get_parent:	Get the current clock source of a specific device clock
+ *		- parent_id: Parent clock identifier which is the parent.
+ * @get_num_parents: Get the number of parents of the current clock source
+ *		- num_parents: returns the number of parent clocks.
+ * @get_best_match_freq: Find a best matching frequency for a frequency
+ *		range.
+ *		- match_freq: Best matching frequency in Hz.
+ * @set_freq:	Set the Clock frequency
+ * @get_freq:	Get the Clock frequency
+ *		- current_freq: Frequency in Hz that the clock is at.
+ *
+ * NOTE: for all these functions, the following parameters are generic in
+ * nature:
+ * -handle:	Pointer to TISCI handle as retrieved by *ti_sci_get_handle
+ * -did:	Device identifier this request is for
+ * -cid:	Clock identifier for the device for this request.
+ *		Each device has it's own set of clock inputs. This indexes
+ *		which clock input to modify.
+ * -min_freq:	The minimum allowable frequency in Hz. This is the minimum
+ *		allowable programmed frequency and does not account for clock
+ *		tolerances and jitter.
+ * -target_freq: The target clock frequency in Hz. A frequency will be
+ *		processed as close to this target frequency as possible.
+ * -max_freq:	The maximum allowable frequency in Hz. This is the maximum
+ *		allowable programmed frequency and does not account for clock
+ *		tolerances and jitter.
+ *
+ * Request for the clock - NOTE: the client MUST maintain integrity of
+ * usage count by balancing get_clock with put_clock. No refcounting is
+ * managed by driver for that purpose.
+ */
+struct ti_sci_clk_ops {
+	int (*get_clock)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+			 bool needs_ssc, bool can_change_freq,
+			 bool enable_input_term);
+	int (*idle_clock)(const struct ti_sci_handle *handle, u32 did, u8 cid);
+	int (*put_clock)(const struct ti_sci_handle *handle, u32 did, u8 cid);
+	int (*is_auto)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+		       bool *req_state);
+	int (*is_on)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+		     bool *req_state, bool *current_state);
+	int (*is_off)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+		      bool *req_state, bool *current_state);
+	int (*set_parent)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+			  u8 parent_id);
+	int (*get_parent)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+			  u8 *parent_id);
+	int (*get_num_parents)(const struct ti_sci_handle *handle, u32 did,
+			       u8 cid, u8 *num_parents);
+	int (*get_best_match_freq)(const struct ti_sci_handle *handle, u32 did,
+				   u8 cid, u64 min_freq, u64 target_freq,
+				   u64 max_freq, u64 *match_freq);
+	int (*set_freq)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+			u64 min_freq, u64 target_freq, u64 max_freq);
+	int (*get_freq)(const struct ti_sci_handle *handle, u32 did, u8 cid,
+			u64 *current_freq);
+};
+
+/**
  * struct ti_sci_ops - Function support for TI SCI
  * @dev_ops:	Device specific operations
+ * @clk_ops:	Clock specific operations
  */
 struct ti_sci_ops {
 	struct ti_sci_dev_ops dev_ops;
+	struct ti_sci_clk_ops clk_ops;
 };
 
 /**