fix(scmi): add parameter for plat_scmi_clock_rates_array

Pass "start_idx" to plat_scmi_clock_rates_array.
This parameter is required to obtain the rate table
a second time.

Signed-off-by: XiaoDong Huang <derrick.huang@rock-chips.com>
Change-Id: I97c6751e7d34c839ced8f22bddc39fb534978cc4

drivers/scmi-msg/clock.c

@@ -37,7 +37,8 @@ const char *plat_scmi_clock_get_name(unsigned int agent_id __unused,
 int32_t plat_scmi_clock_rates_array(unsigned int agent_id __unused,
 				    unsigned int scmi_id __unused,
 				    unsigned long *rates __unused,
-				    size_t *nb_elts __unused)
+				    size_t *nb_elts __unused,
+				    uint32_t start_idx __unused)
 {
 	return SCMI_NOT_SUPPORTED;
 }
@@ -298,7 +299,7 @@ static void scmi_clock_describe_rates(struct scmi_msg *msg)
 
 	/* Platform may support array rate description */
 	status = plat_scmi_clock_rates_array(msg->agent_id, clock_id, NULL,
-					     &nb_rates);
+					     &nb_rates, 0);
 	if (status == SCMI_SUCCESS) {
 		/* Currently 12 cells mex, so it's affordable for the stack */
 		unsigned long plat_rates[RATES_ARRAY_SIZE_MAX / RATE_DESC_SIZE];
@@ -307,7 +308,8 @@ static void scmi_clock_describe_rates(struct scmi_msg *msg)
 		size_t rem_nb = nb_rates - in_args->rate_index - ret_nb;
 
 		status =  plat_scmi_clock_rates_array(msg->agent_id, clock_id,
-						      plat_rates, &ret_nb);
+						      plat_rates, &ret_nb,
+						      in_args->rate_index);
 		if (status == SCMI_SUCCESS) {
 			write_rate_desc_array_in_buffer(msg->out + sizeof(p2a),
 							plat_rates, ret_nb);

include/drivers/scmi-msg.h

@@ -113,10 +113,12 @@ const char *plat_scmi_clock_get_name(unsigned int agent_id,
  * @scmi_id: SCMI clock ID
  * @rates: If NULL, function returns, else output rates array
  * @nb_elts: Array size of @rates.
+ * @start_idx: Start index of rates array
  * Return an SCMI compliant error code
  */
 int32_t plat_scmi_clock_rates_array(unsigned int agent_id, unsigned int scmi_id,
-				    unsigned long *rates, size_t *nb_elts);
+				    unsigned long *rates, size_t *nb_elts,
+				    uint32_t start_idx);
 
 /*
  * Get clock possible rate as range with regular steps in Hertz

plat/st/stm32mp1/stm32mp1_scmi.c

@@ -260,7 +260,8 @@ const char *plat_scmi_clock_get_name(unsigned int agent_id,
 }
 
 int32_t plat_scmi_clock_rates_array(unsigned int agent_id, unsigned int scmi_id,
-				    unsigned long *array, size_t *nb_elts)
+				    unsigned long *array, size_t *nb_elts,
+				    uint32_t start_idx)
 {
 	struct stm32_scmi_clk *clock = find_clock(agent_id, scmi_id);
 
@@ -272,6 +273,10 @@ int32_t plat_scmi_clock_rates_array(unsigned int agent_id, unsigned int scmi_id,
 		return SCMI_DENIED;
 	}
 
+	if (start_idx > 0) {
+		return SCMI_OUT_OF_RANGE;
+	}
+
 	if (array == NULL) {
 		*nb_elts = 1U;
 	} else if (*nb_elts == 1U) {