firmware: arm_scmi: add initial support for clock protocol

The clock protocol is intended for management of clocks. It is used to
enable or disable clocks, and to set and get the clock rates. This
protocol provides commands to describe the protocol version, discover
various implementation specific attributes, describe a clock, enable
and disable a clock and get/set the rate of the clock synchronously or
asynchronously.

This patch adds initial support for the clock protocol.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 57d4b1c099e5..5a3092f05011 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -8,6 +8,7 @@
 #include <linux/types.h>
 
 #define SCMI_MAX_STR_SIZE	16
+#define SCMI_MAX_NUM_RATES	16
 
 /**
  * struct scmi_revision_info - version information structure
@@ -33,9 +34,49 @@ struct scmi_revision_info {
 	char sub_vendor_id[SCMI_MAX_STR_SIZE];
 };
 
+struct scmi_clock_info {
+	char name[SCMI_MAX_STR_SIZE];
+	bool rate_discrete;
+	union {
+		struct {
+			int num_rates;
+			u64 rates[SCMI_MAX_NUM_RATES];
+		} list;
+		struct {
+			u64 min_rate;
+			u64 max_rate;
+			u64 step_size;
+		} range;
+	};
+};
+
 struct scmi_handle;
 
 /**
+ * struct scmi_clk_ops - represents the various operations provided
+ *	by SCMI Clock Protocol
+ *
+ * @count_get: get the count of clocks provided by SCMI
+ * @info_get: get the information of the specified clock
+ * @rate_get: request the current clock rate of a clock
+ * @rate_set: set the clock rate of a clock
+ * @enable: enables the specified clock
+ * @disable: disables the specified clock
+ */
+struct scmi_clk_ops {
+	int (*count_get)(const struct scmi_handle *handle);
+
+	const struct scmi_clock_info *(*info_get)
+		(const struct scmi_handle *handle, u32 clk_id);
+	int (*rate_get)(const struct scmi_handle *handle, u32 clk_id,
+			u64 *rate);
+	int (*rate_set)(const struct scmi_handle *handle, u32 clk_id,
+			u32 config, u64 rate);
+	int (*enable)(const struct scmi_handle *handle, u32 clk_id);
+	int (*disable)(const struct scmi_handle *handle, u32 clk_id);
+};
+
+/**
  * struct scmi_perf_ops - represents the various operations provided
  *	by SCMI Performance Protocol
  *
@@ -77,13 +118,16 @@ struct scmi_perf_ops {
  * @dev: pointer to the SCMI device
  * @version: pointer to the structure containing SCMI version information
  * @perf_ops: pointer to set of performance protocol operations
+ * @clk_ops: pointer to set of clock protocol operations
  */
 struct scmi_handle {
 	struct device *dev;
 	struct scmi_revision_info *version;
 	struct scmi_perf_ops *perf_ops;
+	struct scmi_clk_ops *clk_ops;
 	/* for protocol internal use */
 	void *perf_priv;
+	void *clk_priv;
 };
 
 enum scmi_std_protocol {