[RFC PATCH 05/16] firmware: arm_scmi: Expose information on configured transport

[Cristian Marussi]

Add a common descriptor to describe transport features and expose it via
the SCMI instance handle.

Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 12 ++++++++++++
 include/linux/scmi_protocol.h      | 20 ++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 8d356d4da0bd..8c5429529946 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1966,6 +1966,7 @@ static int scmi_probe(struct platform_device *pdev)
 	struct scmi_handle *handle;
 	const struct scmi_desc *desc;
 	struct scmi_info *info;
+	struct scmi_transport_info *trans;
 	struct device *dev = &pdev->dev;
 	struct device_node *child, *np = dev->of_node;
 
@@ -2023,6 +2024,17 @@ static int scmi_probe(struct platform_device *pdev)
 		dev_err(dev,
 			"Transport is not polling capable. Atomic mode not supported.\n");
 
+	trans = devm_kzalloc(dev, sizeof(*trans), GFP_KERNEL);
+	if (!trans)
+		return -ENOMEM;
+
+	of_property_read_string(dev->of_node, "compatible", &trans->compatible);
+	trans->is_atomic =
+		handle->is_transport_atomic(handle,
+					    &trans->atomic_threshold_us);
+	trans->max_rx_timeout_ms = info->desc->max_rx_timeout_ms;
+	handle->transport = trans;
+
 	/*
 	 * Trigger SCMI Base protocol initialization.
 	 * It's mandatory and won't be ever released/deinit until the
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index c5881d15f7d9..0b024d23a9b3 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -40,6 +40,24 @@ struct scmi_revision_info {
 	char sub_vendor_id[SCMI_MAX_STR_SIZE];
 };
 
+/**
+ * struct scmi_transport_info  - transport related information
+ *
+ * @compatible: Transport name picked from compatible string
+ * @is_atomic: True if the underlying transport can support atomic transactions
+ *	       and atomic mode is enabled.
+ * @atomic_threshold_us: Optional system wide DT-configured threshold, expressed
+ *			 in microseconds, for atomic operations.
+ * @max_rx_timeout_ms: configured maximum timeout in milliseconds for command
+ *		       replies.
+ */
+struct scmi_transport_info {
+	const char *compatible;
+	bool is_atomic;
+	unsigned int atomic_threshold_us;
+	unsigned int max_rx_timeout_ms;
+};
+
 struct scmi_clock_info {
 	char name[SCMI_MAX_STR_SIZE];
 	unsigned int enable_latency;
@@ -633,6 +651,7 @@ struct scmi_notify_ops {
  *
  * @dev: pointer to the SCMI device
  * @version: pointer to the structure containing SCMI version information
+ * @transport: pointer to the structure containing SCMI transport information
  * @devm_protocol_get: devres managed method to acquire a protocol and get specific
  *		       operations and a dedicated protocol handler
  * @devm_protocol_put: devres managed method to release a protocol
@@ -650,6 +669,7 @@ struct scmi_notify_ops {
 struct scmi_handle {
 	struct device *dev;
 	struct scmi_revision_info *version;
+	struct scmi_transport_info *transport;
 
 	const void __must_check *
 		(*devm_protocol_get)(struct scmi_device *sdev, u8 proto,
-- 
2.17.1