[PATCH v5 11/16] firmware: scmi: add a check against availability of protocols

[AKASHI Takahiro]

Now that we have Base protocol support, we will be able to check if a given
protocol is really supported by the SCMI server (firmware).

Signed-off-by: AKASHI Takahiro <takahiro.aka...@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carri...@foss.st.com>
---
v3
* new; import this patch from my followup patch set
---
 drivers/firmware/scmi/scmi_agent-uclass.c | 41 +++++++++++++++++++++--
 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/scmi/scmi_agent-uclass.c 
b/drivers/firmware/scmi/scmi_agent-uclass.c
index b1a9c36310c1..6f585b96f740 100644
--- a/drivers/firmware/scmi/scmi_agent-uclass.c
+++ b/drivers/firmware/scmi/scmi_agent-uclass.c
@@ -38,6 +38,38 @@ static const struct error_code scmi_linux_errmap[] = {
        { .scmi = SCMI_PROTOCOL_ERROR, .errno = -EPROTO, },
 };
 
+/**
+ * scmi_protocol_is_supported - check availability of protocol
+ * @dev:       SCMI agent device
+ * @proto_id:  Identifier of protocol
+ *
+ * check if the protocol, @proto_id, is provided by the SCMI agent,
+ * @dev.
+ *
+ * Return:     0 on success, error code otherwise
+ */
+static bool scmi_protocol_is_supported(struct udevice *dev,
+                                      enum scmi_std_protocol proto_id)
+{
+       struct scmi_agent_priv *priv;
+       int i;
+
+       if (proto_id == SCMI_PROTOCOL_ID_BASE)
+               return true;
+
+       priv = dev_get_uclass_plat(dev);
+       if (!priv) {
+               dev_err(dev, "No priv data found\n");
+               return false;
+       }
+
+       for (i = 0; i < priv->num_protocols; i++)
+               if (priv->protocols[i] == proto_id)
+                       return true;
+
+       return false;
+}
+
 struct udevice *scmi_get_protocol(struct udevice *dev,
                                  enum scmi_std_protocol id)
 {
@@ -374,15 +406,18 @@ static int scmi_bind_protocols(struct udevice *dev)
                name = ofnode_get_name(node);
                switch (protocol_id) {
                case SCMI_PROTOCOL_ID_CLOCK:
-                       if (CONFIG_IS_ENABLED(CLK_SCMI))
+                       if (CONFIG_IS_ENABLED(CLK_SCMI) &&
+                           scmi_protocol_is_supported(dev, protocol_id))
                                drv = DM_DRIVER_GET(scmi_clock);
                        break;
                case SCMI_PROTOCOL_ID_RESET_DOMAIN:
-                       if (IS_ENABLED(CONFIG_RESET_SCMI))
+                       if (IS_ENABLED(CONFIG_RESET_SCMI) &&
+                           scmi_protocol_is_supported(dev, protocol_id))
                                drv = DM_DRIVER_GET(scmi_reset_domain);
                        break;
                case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
-                       if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI)) {
+                       if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI) &&
+                           scmi_protocol_is_supported(dev, protocol_id)) {
                                node = ofnode_find_subnode(node, "regulators");
                                if (!ofnode_valid(node)) {
                                        dev_err(dev, "no regulators node\n");
-- 
2.34.1