Subject: [PATCH net-next A 4/5] sfp: improve support for direct-attach copper cables

From: Russell King <[email-masked]>
Date: Fri, 29 Dec 2017 12:15:28 +0000

Improve the support for direct-attach copper so that we avoid kernel
warning messages, and report the appropriate PORT_DA type to userspace.
Direct Attach cables can use a number of protocols depending on their
range of speeds.

Signed-off-by: Russell King <[email-masked]>
---
 drivers/net/phy/sfp-bus.c | 51 ++++++++++++++++++++++++++++++++++++++++-------
 include/linux/sfp.h       | 36 ++++++++++++++++++++++++++++++++-
 2 files changed, 79 insertions(+), 8 deletions(-)

diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 6c05acd5b1d4..bdc4bb3c8288 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -57,21 +57,19 @@ int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 	case SFP_CONNECTOR_MT_RJ:
 	case SFP_CONNECTOR_MU:
 	case SFP_CONNECTOR_OPTICAL_PIGTAIL:
-		if (support)
-			phylink_set(support, FIBRE);
 		port = PORT_FIBRE;
 		break;
 
 	case SFP_CONNECTOR_RJ45:
-		if (support)
-			phylink_set(support, TP);
 		port = PORT_TP;
 		break;
 
+	case SFP_CONNECTOR_COPPER_PIGTAIL:
+		port = PORT_DA;
+		break;
+
 	case SFP_CONNECTOR_UNSPEC:
 		if (id->base.e1000_base_t) {
-			if (support)
-				phylink_set(support, TP);
 			port = PORT_TP;
 			break;
 		}
@@ -80,7 +78,6 @@ int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 	case SFP_CONNECTOR_MPO_1X12:
 	case SFP_CONNECTOR_MPO_2X16:
 	case SFP_CONNECTOR_HSSDC_II:
-	case SFP_CONNECTOR_COPPER_PIGTAIL:
 	case SFP_CONNECTOR_NOSEPARATE:
 	case SFP_CONNECTOR_MXC_2X16:
 		port = PORT_OTHER;
@@ -92,6 +89,18 @@ int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 		break;
 	}
 
+	if (support) {
+		switch (port) {
+		case PORT_FIBRE:
+			phylink_set(support, FIBRE);
+			break;
+
+		case PORT_TP:
+			phylink_set(support, TP);
+			break;
+		}
+	}
+
 	return port;
 }
 EXPORT_SYMBOL_GPL(sfp_parse_port);
@@ -143,6 +152,11 @@ phy_interface_t sfp_parse_interface(struct sfp_bus *bus,
 		break;
 
 	default:
+		if (id->base.e1000_base_cx) {
+			iface = PHY_INTERFACE_MODE_1000BASEX;
+			break;
+		}
+
 		iface = PHY_INTERFACE_MODE_NA;
 		dev_err(bus->sfp_dev,
 			"SFP module encoding does not support 8b10b nor 64b66b\n");
@@ -208,6 +222,29 @@ void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 	    br_min <= 1300 && br_max >= 1200)
 		phylink_set(support, 1000baseX_Full);
 
+	/* For active or passive cables, select the link modes
+	 * based on the bit rates and the cable compliance bytes.
+	 */
+	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
+		/* This may look odd, but some manufacturers use 12000MBd */
+		if (br_min <= 12000 && br_max >= 10300)
+			phylink_set(support, 10000baseCR_Full);
+		if (br_min <= 3200 && br_max >= 3100)
+			phylink_set(support, 2500baseX_Full);
+		if (br_min <= 1300 && br_max >= 1200)
+			phylink_set(support, 1000baseX_Full);
+	}
+	if (id->base.sfp_ct_passive) {
+		if (id->base.passive.sff8431_app_e)
+			phylink_set(support, 10000baseCR_Full);
+	}
+	if (id->base.sfp_ct_active) {
+		if (id->base.active.sff8431_app_e ||
+		    id->base.active.sff8431_lim) {
+			phylink_set(support, 10000baseCR_Full);
+		}
+	}
+
 	switch (id->base.extended_cc) {
 	case 0x00: /* Unspecified */
 		break;
diff --git a/include/linux/sfp.h b/include/linux/sfp.h
index 0c5c5f6ae1ec..e724d5a3dd80 100644
--- a/include/linux/sfp.h
+++ b/include/linux/sfp.h
@@ -165,7 +165,41 @@ struct sfp_eeprom_base {
 	char vendor_rev[4];
 	union {
 		__be16 optical_wavelength;
-		u8 cable_spec;
+		__be16 cable_compliance;
+		struct {
+#if defined __BIG_ENDIAN_BITFIELD
+			u8 reserved60_2:6;
+			u8 fc_pi_4_app_h:1;
+			u8 sff8431_app_e:1;
+			u8 reserved61:8;
+#elif defined __LITTLE_ENDIAN_BITFIELD
+			u8 sff8431_app_e:1;
+			u8 fc_pi_4_app_h:1;
+			u8 reserved60_2:6;
+			u8 reserved61:8;
+#else
+#error Unknown Endian
+#endif
+		} __packed passive;
+		struct {
+#if defined __BIG_ENDIAN_BITFIELD
+			u8 reserved60_4:4;
+			u8 fc_pi_4_lim:1;
+			u8 sff8431_lim:1;
+			u8 fc_pi_4_app_h:1;
+			u8 sff8431_app_e:1;
+			u8 reserved61:8;
+#elif defined __LITTLE_ENDIAN_BITFIELD
+			u8 sff8431_app_e:1;
+			u8 fc_pi_4_app_h:1;
+			u8 sff8431_lim:1;
+			u8 fc_pi_4_lim:1;
+			u8 reserved60_4:4;
+			u8 reserved61:8;
+#else
+#error Unknown Endian
+#endif
+		} __packed active;
 	} __packed;
 	u8 reserved62;
 	u8 cc_base;
-- 
2.7.4