dpaa2-mac: retrieve API version and detect features

Retrieve the API version running on the firmware and based on it detect
which features are available for usage.
The first one to be listed is the capability to change the MAC protocol
at runtime.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c

@@ -11,6 +11,28 @@
 #define phylink_to_dpaa2_mac(config) \
 	container_of((config), struct dpaa2_mac, phylink_config)
 
+#define DPMAC_PROTOCOL_CHANGE_VER_MAJOR		4
+#define DPMAC_PROTOCOL_CHANGE_VER_MINOR		8
+
+#define DPAA2_MAC_FEATURE_PROTOCOL_CHANGE	BIT(0)
+
+static int dpaa2_mac_cmp_ver(struct dpaa2_mac *mac,
+			     u16 ver_major, u16 ver_minor)
+{
+	if (mac->ver_major == ver_major)
+		return mac->ver_minor - ver_minor;
+	return mac->ver_major - ver_major;
+}
+
+static void dpaa2_mac_detect_features(struct dpaa2_mac *mac)
+{
+	mac->features = 0;
+
+	if (dpaa2_mac_cmp_ver(mac, DPMAC_PROTOCOL_CHANGE_VER_MAJOR,
+			      DPMAC_PROTOCOL_CHANGE_VER_MINOR) >= 0)
+		mac->features |= DPAA2_MAC_FEATURE_PROTOCOL_CHANGE;
+}
+
 static int phy_mode(enum dpmac_eth_if eth_if, phy_interface_t *if_mode)
 {
 	*if_mode = PHY_INTERFACE_MODE_NA;
@@ -359,6 +381,14 @@ int dpaa2_mac_open(struct dpaa2_mac *mac)
 		goto err_close_dpmac;
 	}
 
+	err = dpmac_get_api_version(mac->mc_io, 0, &mac->ver_major, &mac->ver_minor);
+	if (err) {
+		netdev_err(net_dev, "dpmac_get_api_version() = %d\n", err);
+		goto err_close_dpmac;
+	}
+
+	dpaa2_mac_detect_features(mac);
+
 	/* Find the device node representing the MAC device and link the device
 	 * behind the associated netdev to it.
 	 */

drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.h

@@ -17,6 +17,8 @@ struct dpaa2_mac {
 	struct net_device *net_dev;
 	struct fsl_mc_io *mc_io;
 	struct dpmac_attr attr;
+	u16 ver_major, ver_minor;
+	unsigned long features;
 
 	struct phylink_config phylink_config;
 	struct phylink *phylink;