[PATCH v2 3/4] usb: typec: Factor out non-PD fwnode properties

[Samuel Holland <samuel@xxxxxxxxxxxx>]

Basic programmable non-PD Type-C port controllers do not need the full
TCPM library, but they share the same devicetree binding and the same
typec_capability structure. Factor out a helper for parsing those
properties which map to fields in struct typec_capability, so the code
can be shared between TCPM and basic non-TCPM drivers.

Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---

Changes in v2:
 - Always put the return values from typec_find_* in a signed variable
   for error checking.

 drivers/usb/typec/class.c     | 52 +++++++++++++++++++++++++++++++++++
 drivers/usb/typec/tcpm/tcpm.c | 32 +--------------------
 include/linux/usb/typec.h     |  3 ++
 3 files changed, 56 insertions(+), 31 deletions(-)

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 45a6f0c807cb..b67ba9478c82 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -1894,6 +1894,58 @@ void *typec_get_drvdata(struct typec_port *port)
 }
 EXPORT_SYMBOL_GPL(typec_get_drvdata);
 
+int typec_get_fw_cap(struct typec_capability *cap,
+		     struct fwnode_handle *fwnode)
+{
+	const char *cap_str;
+	int ret;
+
+	/*
+	 * This fwnode has a "compatible" property, but is never populated as a
+	 * struct device. Instead we simply parse it to read the properties.
+	 * This it breaks fw_devlink=on. To maintain backward compatibility
+	 * with existing DT files, we work around this by deleting any
+	 * fwnode_links to/from this fwnode.
+	 */
+	fw_devlink_purge_absent_suppliers(fwnode);
+
+	cap->fwnode = fwnode;
+
+	ret = fwnode_property_read_string(fwnode, "power-role", &cap_str);
+	if (ret < 0)
+		return ret;
+
+	ret = typec_find_port_power_role(cap_str);
+	if (ret < 0)
+		return ret;
+	cap->type = ret;
+
+	/* USB data support is optional */
+	ret = fwnode_property_read_string(fwnode, "data-role", &cap_str);
+	if (ret == 0) {
+		ret = typec_find_port_data_role(cap_str);
+		if (ret < 0)
+			return ret;
+		cap->data = ret;
+	}
+
+	/* Get the preferred power role for a DRP */
+	if (cap->type == TYPEC_PORT_DRP) {
+		cap->prefer_role = TYPEC_NO_PREFERRED_ROLE;
+
+		ret = fwnode_property_read_string(fwnode, "try-power-role", &cap_str);
+		if (ret == 0) {
+			ret = typec_find_power_role(cap_str);
+			if (ret < 0)
+				return ret;
+			cap->prefer_role = ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(typec_get_fw_cap);
+
 /**
  * typec_port_register_altmode - Register USB Type-C Port Alternate Mode
  * @port: USB Type-C Port that supports the alternate mode
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 5fce795b69c7..8b58aa6e3509 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -5935,32 +5935,10 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
 	if (!fwnode)
 		return -EINVAL;
 
-	/*
-	 * This fwnode has a "compatible" property, but is never populated as a
-	 * struct device. Instead we simply parse it to read the properties.
-	 * This it breaks fw_devlink=on. To maintain backward compatibility
-	 * with existing DT files, we work around this by deleting any
-	 * fwnode_links to/from this fwnode.
-	 */
-	fw_devlink_purge_absent_suppliers(fwnode);
-
-	/* USB data support is optional */
-	ret = fwnode_property_read_string(fwnode, "data-role", &cap_str);
-	if (ret == 0) {
-		ret = typec_find_port_data_role(cap_str);
-		if (ret < 0)
-			return ret;
-		port->typec_caps.data = ret;
-	}
-
-	ret = fwnode_property_read_string(fwnode, "power-role", &cap_str);
+	ret = typec_get_fw_cap(&port->typec_caps, fwnode);
 	if (ret < 0)
 		return ret;
 
-	ret = typec_find_port_power_role(cap_str);
-	if (ret < 0)
-		return ret;
-	port->typec_caps.type = ret;
 	port->port_type = port->typec_caps.type;
 	port->pd_supported = !fwnode_property_read_bool(fwnode, "pd-disable");
 
@@ -5997,14 +5975,6 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
 	if (port->port_type == TYPEC_PORT_SRC)
 		return 0;
 
-	/* Get the preferred power role for DRP */
-	ret = fwnode_property_read_string(fwnode, "try-power-role", &cap_str);
-	if (ret < 0)
-		return ret;
-
-	port->typec_caps.prefer_role = typec_find_power_role(cap_str);
-	if (port->typec_caps.prefer_role < 0)
-		return -EINVAL;
 sink:
 	port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");
 
diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
index 7ba45a97eeae..fdf737d48b3b 100644
--- a/include/linux/usb/typec.h
+++ b/include/linux/usb/typec.h
@@ -295,6 +295,9 @@ int typec_set_mode(struct typec_port *port, int mode);
 
 void *typec_get_drvdata(struct typec_port *port);
 
+int typec_get_fw_cap(struct typec_capability *cap,
+		     struct fwnode_handle *fwnode);
+
 int typec_find_pwr_opmode(const char *name);
 int typec_find_orientation(const char *name);
 int typec_find_port_power_role(const char *name);
-- 
2.33.1