firmware: arm_scmi: Allow transport properties for multiple instances

Default SCMI transport properties values can be overridden with devicetree
provided descriptors; in order to support multiple SCMI instances, make the
properties-update happen on a per-instance copy of the original transport
descriptor.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Message-Id: <20241203193544.3895173-1-cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Author: cris-ma

drivers/firmware/arm_scmi/common.h

@@ -442,7 +442,7 @@ struct scmi_transport_core_operations {
  */
 struct scmi_transport {
 	struct device *supplier;
-	struct scmi_desc *desc;
+	struct scmi_desc desc;
 	struct scmi_transport_core_operations **core_ops;
 };
 
@@ -468,7 +468,7 @@ static int __tag##_probe(struct platform_device *pdev)			       \
 	device_set_of_node_from_dev(&spdev->dev, dev);			       \
 									       \
 	strans.supplier = dev;						       \
-	strans.desc = &(__desc);					       \
+	memcpy(&strans.desc, &(__desc), sizeof(strans.desc));		       \
 	strans.core_ops = &(__core_ops);				       \
 									       \
 	ret = platform_device_add_data(spdev, &strans, sizeof(strans));	       \

drivers/firmware/arm_scmi/driver.c

@@ -3028,7 +3028,7 @@ static const struct scmi_desc *scmi_transport_setup(struct device *dev)
 	int ret;
 
 	trans = dev_get_platdata(dev);
-	if (!trans || !trans->desc || !trans->supplier || !trans->core_ops)
+	if (!trans || !trans->supplier || !trans->core_ops)
 		return NULL;
 
 	if (!device_link_add(dev, trans->supplier, DL_FLAG_AUTOREMOVE_CONSUMER)) {
@@ -3043,33 +3043,33 @@ static const struct scmi_desc *scmi_transport_setup(struct device *dev)
 	dev_info(dev, "Using %s\n", dev_driver_string(trans->supplier));
 
 	ret = of_property_read_u32(dev->of_node, "arm,max-rx-timeout-ms",
-				   &trans->desc->max_rx_timeout_ms);
+				   &trans->desc.max_rx_timeout_ms);
 	if (ret && ret != -EINVAL)
 		dev_err(dev, "Malformed arm,max-rx-timeout-ms DT property.\n");
 
 	ret = of_property_read_u32(dev->of_node, "arm,max-msg-size",
-				   &trans->desc->max_msg_size);
+				   &trans->desc.max_msg_size);
 	if (ret && ret != -EINVAL)
 		dev_err(dev, "Malformed arm,max-msg-size DT property.\n");
 
 	ret = of_property_read_u32(dev->of_node, "arm,max-msg",
-				   &trans->desc->max_msg);
+				   &trans->desc.max_msg);
 	if (ret && ret != -EINVAL)
 		dev_err(dev, "Malformed arm,max-msg DT property.\n");
 
 	dev_info(dev,
 		 "SCMI max-rx-timeout: %dms / max-msg-size: %dbytes / max-msg: %d\n",
-		 trans->desc->max_rx_timeout_ms, trans->desc->max_msg_size,
-		 trans->desc->max_msg);
+		 trans->desc.max_rx_timeout_ms, trans->desc.max_msg_size,
+		 trans->desc.max_msg);
 
 	/* System wide atomic threshold for atomic ops .. if any */
 	if (!of_property_read_u32(dev->of_node, "atomic-threshold-us",
-				  &trans->desc->atomic_threshold))
+				  &trans->desc.atomic_threshold))
 		dev_info(dev,
 			 "SCMI System wide atomic threshold set to %u us\n",
-			 trans->desc->atomic_threshold);
+			 trans->desc.atomic_threshold);
 
-	return trans->desc;
+	return &trans->desc;
 }
 
 static int scmi_probe(struct platform_device *pdev)