[PATCH v2 3/3] usb: typec: tcpm: Introduce snk_vdo_v1 for SVDM version 1.0

[Kyle Tso]

The ID Header VDO and Product VDOs defined in USB PD Spec rev 2.0 and
rev 3.1 are quite different. Add an additional array snk_vdo_v1 and
send it as the response to the port partner if it only supports SVDM
version 1.0.

Signed-off-by: Kyle Tso <kyletso@xxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
changes since v1:
- add Acked-by tag
- merge the assignment to array element 1 into the for loop. No semantic
  code logic change.

 drivers/usb/typec/tcpm/tcpm.c | 40 ++++++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 617f48cdd90c..ebe490949fa0 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -401,6 +401,8 @@ struct tcpm_port {
 	unsigned int nr_src_pdo;
 	u32 snk_pdo[PDO_MAX_OBJECTS];
 	unsigned int nr_snk_pdo;
+	u32 snk_vdo_v1[VDO_MAX_OBJECTS];
+	unsigned int nr_snk_vdo_v1;
 	u32 snk_vdo[VDO_MAX_OBJECTS];
 	unsigned int nr_snk_vdo;
 
@@ -1589,18 +1591,16 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			 */
 			if ((port->data_role == TYPEC_DEVICE || svdm_version >= SVDM_VER_2_0) &&
 			    port->nr_snk_vdo) {
-				/*
-				 * Product Type DFP and Connector Type are not defined in SVDM
-				 * version 1.0 and shall be set to zero.
-				 */
-				if (svdm_version < SVDM_VER_2_0)
-					response[1] = port->snk_vdo[0] & ~IDH_DFP_MASK
-						      & ~IDH_CONN_MASK;
-				else
-					response[1] = port->snk_vdo[0];
-				for (i = 1; i <  port->nr_snk_vdo; i++)
-					response[i + 1] = port->snk_vdo[i];
-				rlen = port->nr_snk_vdo + 1;
+				if (svdm_version < SVDM_VER_2_0) {
+					for (i = 0; i < port->nr_snk_vdo_v1; i++)
+						response[i + 1] = port->snk_vdo_v1[i];
+					rlen = port->nr_snk_vdo_v1 + 1;
+
+				} else {
+					for (i = 0; i < port->nr_snk_vdo; i++)
+						response[i + 1] = port->snk_vdo[i];
+					rlen = port->nr_snk_vdo + 1;
+				}
 			}
 			break;
 		case CMD_DISCOVER_SVID:
@@ -5969,6 +5969,22 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
 			return ret;
 	}
 
+	/* If sink-vdos is found, sink-vdos-v1 is expected for backward compatibility. */
+	if (port->nr_snk_vdo) {
+		ret = fwnode_property_count_u32(fwnode, "sink-vdos-v1");
+		if (ret < 0)
+			return ret;
+		else if (ret == 0)
+			return -ENODATA;
+
+		port->nr_snk_vdo_v1 = min(ret, VDO_MAX_OBJECTS);
+		ret = fwnode_property_read_u32_array(fwnode, "sink-vdos-v1",
+						     port->snk_vdo_v1,
+						     port->nr_snk_vdo_v1);
+		if (ret < 0)
+			return ret;
+	}
+
 	return 0;
 }
 
-- 
2.32.0.rc0.204.g9fa02ecfa5-goog