[PATCH 3/7] firmware: arm_scmi: Add Clock check for extended config support

[Cristian Marussi]

SCMI v3.2 added support to set/get Clock custom OEM types; such support is
conditionally present, though, depending on an extended config attribute
bit possibly advertised by the platform server on a per-domain base.

Add a check to verify if OEM types are supported before allowing any kind
of OEM-specific get/set operation and also a check around all Clock v3.2
features.

Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
base-commit: 7dd3d11f4dac301e958f00e18db4901a35cefc70
---
 drivers/firmware/arm_scmi/clock.c | 33 +++++++++++++++++++++++++------
 include/linux/scmi_protocol.h     |  1 +
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 959e48aba1b5..9d80ad95b467 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -54,6 +54,7 @@ struct scmi_msg_resp_clock_attributes {
 #define SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(x)	((x) & BIT(30))
 #define SUPPORTS_EXTENDED_NAMES(x)		((x) & BIT(29))
 #define SUPPORTS_PARENT_CLOCK(x)		((x) & BIT(28))
+#define SUPPORTS_EXTENDED_CONFIG(x)		((x) & BIT(27))
 #define SUPPORTS_GET_PERMISSIONS(x)		((x) & BIT(1))
 	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
 	__le32 clock_enable_latency;
@@ -372,10 +373,14 @@ static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
 			clk->rate_changed_notifications = true;
 		if (SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(attributes))
 			clk->rate_change_requested_notifications = true;
-		if (SUPPORTS_PARENT_CLOCK(attributes))
-			scmi_clock_possible_parents(ph, clk_id, clk);
-		if (SUPPORTS_GET_PERMISSIONS(attributes))
-			scmi_clock_get_permissions(ph, clk_id, clk);
+		if (PROTOCOL_REV_MAJOR(version) >= 0x3) {
+			if (SUPPORTS_PARENT_CLOCK(attributes))
+				scmi_clock_possible_parents(ph, clk_id, clk);
+			if (SUPPORTS_GET_PERMISSIONS(attributes))
+				scmi_clock_get_permissions(ph, clk_id, clk);
+			if (SUPPORTS_EXTENDED_CONFIG(attributes))
+				clk->extended_config = true;
+		}
 	}
 
 	return ret;
@@ -684,7 +689,7 @@ scmi_clock_get_parent(const struct scmi_protocol_handle *ph, u32 clk_id,
 	return ret;
 }
 
-/* For SCMI clock v2.1 and onwards */
+/* For SCMI clock v3.0 and onwards */
 static int
 scmi_clock_config_set_v2(const struct scmi_protocol_handle *ph, u32 clk_id,
 			 enum clk_state state, u8 oem_type, u32 oem_val,
@@ -757,7 +762,7 @@ static int scmi_clock_disable(const struct scmi_protocol_handle *ph, u32 clk_id,
 				    NULL_OEM_TYPE, 0, atomic);
 }
 
-/* For SCMI clock v2.1 and onwards */
+/* For SCMI clock v3.0 and onwards */
 static int
 scmi_clock_config_get_v2(const struct scmi_protocol_handle *ph, u32 clk_id,
 			 u8 oem_type, u32 *attributes, bool *enabled,
@@ -844,6 +849,14 @@ static int scmi_clock_config_oem_set(const struct scmi_protocol_handle *ph,
 				     bool atomic)
 {
 	struct clock_info *ci = ph->get_priv(ph);
+	struct scmi_clock_info *clk;
+
+	clk = scmi_clock_domain_lookup(ci, clk_id);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	if (!clk->extended_config)
+		return -EOPNOTSUPP;
 
 	return ci->clock_config_set(ph, clk_id, CLK_STATE_UNCHANGED,
 				    oem_type, oem_val, atomic);
@@ -854,6 +867,14 @@ static int scmi_clock_config_oem_get(const struct scmi_protocol_handle *ph,
 				     u32 *attributes, bool atomic)
 {
 	struct clock_info *ci = ph->get_priv(ph);
+	struct scmi_clock_info *clk;
+
+	clk = scmi_clock_domain_lookup(ci, clk_id);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	if (!clk->extended_config)
+		return -EOPNOTSUPP;
 
 	return ci->clock_config_get(ph, clk_id, oem_type, attributes,
 				    NULL, oem_val, atomic);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 0cc40af5519a..caeca3f51be2 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -50,6 +50,7 @@ struct scmi_clock_info {
 	bool state_ctrl_forbidden;
 	bool rate_ctrl_forbidden;
 	bool parent_ctrl_forbidden;
+	bool extended_config;
 	union {
 		struct {
 			int num_rates;
-- 
2.43.0