kernel: add SFP support for Methode DM7052 NBASE-T module

Add support for Methode DM7052 NBASE-T module to OpenWRT. These
patches are taken from my "phy" branch, and will be sent for the
next kernel merge window.

Signed-off-by: Russell King <linux@armlinux.org.uk>
[jonas.gorski: move patches to pending, refresh patches]
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

1 files changed, 204 insertions, 0 deletions

diff --git a/target/linux/generic/pending-4.19/750-net-phylink-delay-MAC-configuration-for-copper-SFP-m.patch b/target/linux/generic/pending-4.19/750-net-phylink-delay-MAC-configuration-for-copper-SFP-m.patch
new file mode 100644
index 0000000000..358b9a1082
--- /dev/null
+++ b/target/linux/generic/pending-4.19/750-net-phylink-delay-MAC-configuration-for-copper-SFP-m.patch
@@ -0,0 +1,204 @@
+From eb514428f75bc67d12ff019c44a8f8ca9f33c54c Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Thu, 21 Nov 2019 17:42:49 +0000
+Subject: [PATCH 653/660] net: phylink: delay MAC configuration for copper SFP
+ modules
+
+Knowing whether we need to delay the MAC configuration because a module
+may have a PHY is useful to phylink to allow NBASE-T modules to work on
+systems supporting no more than 2.5G speeds.
+
+This commit allows us to delay such configuration until after the PHY
+has been probed by recording the parsed capabilities, and if the module
+may have a PHY, doing no more until the module_start() notification is
+called.  At that point, we either have a PHY, or we don't.
+
+We move the PHY-based setup a little later, and use the PHYs support
+capabilities rather than the EEPROM parsed capabilities to determine
+whether we can support the PHY.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+---
+ drivers/net/phy/phylink.c | 59 +++++++++++++++++++++++++++++++--------
+ drivers/net/phy/sfp-bus.c | 28 +++++++++++++++++++
+ include/linux/sfp.h       |  7 +++++
+ 3 files changed, 83 insertions(+), 11 deletions(-)
+
+--- a/drivers/net/phy/phylink.c
++++ b/drivers/net/phy/phylink.c
+@@ -72,6 +72,9 @@ struct phylink {
+ 	bool mac_link_dropped;
+ 
+ 	struct sfp_bus *sfp_bus;
++	bool sfp_may_have_phy;
++	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
++	u8 sfp_port;
+ };
+ 
+ static inline void linkmode_zero(unsigned long *dst)
+@@ -1633,7 +1636,7 @@ static void phylink_sfp_detach(void *ups
+ 	pl->netdev->sfp_bus = NULL;
+ }
+ 
+-static int phylink_sfp_config(struct phylink *pl, u8 mode, u8 port,
++static int phylink_sfp_config(struct phylink *pl, u8 mode,
+ 			      const unsigned long *supported,
+ 			      const unsigned long *advertising)
+ {
+@@ -1707,7 +1710,7 @@ static int phylink_sfp_config(struct phy
+ 			    phy_modes(config.interface));
+ 	}
+ 
+-	pl->link_port = port;
++	pl->link_port = pl->sfp_port;
+ 
+ 	if (changed && !test_bit(PHYLINK_DISABLE_STOPPED,
+ 				 &pl->phylink_disable_state))
+@@ -1720,15 +1723,20 @@ static int phylink_sfp_module_insert(voi
+ 				     const struct sfp_eeprom_id *id)
+ {
+ 	struct phylink *pl = upstream;
+-	__ETHTOOL_DECLARE_LINK_MODE_MASK(support) = { 0, };
+-	u8 port;
++	unsigned long *support = pl->sfp_support;
+ 
+ 	ASSERT_RTNL();
+ 
++	linkmode_zero(support);
+ 	sfp_parse_support(pl->sfp_bus, id, support);
+-	port = sfp_parse_port(pl->sfp_bus, id, support);
++	pl->sfp_port = sfp_parse_port(pl->sfp_bus, id, support);
+ 
+-	return phylink_sfp_config(pl, MLO_AN_INBAND, port, support, support);
++	/* If this module may have a PHY connecting later, defer until later */
++	pl->sfp_may_have_phy = sfp_may_have_phy(pl->sfp_bus, id);
++	if (pl->sfp_may_have_phy)
++		return 0;
++
++	return phylink_sfp_config(pl, MLO_AN_INBAND, support, support);
+ }
+ 
+ static int phylink_sfp_module_start(void *upstream)
+@@ -1736,10 +1744,19 @@ static int phylink_sfp_module_start(void
+ 	struct phylink *pl = upstream;
+ 
+ 	/* If this SFP module has a PHY, start the PHY now. */
+-	if (pl->phydev)
++	if (pl->phydev) {
+ 		phy_start(pl->phydev);
+-		
+-	return 0;
++		return 0;
++	}
++
++	/* If the module may have a PHY but we didn't detect one we
++	 * need to configure the MAC here.
++	 */
++	if (!pl->sfp_may_have_phy)
++		return 0;
++
++	return phylink_sfp_config(pl, MLO_AN_INBAND,
++				  pl->sfp_support, pl->sfp_support);
+ }
+ 
+ static void phylink_sfp_module_stop(void *upstream)
+@@ -1773,10 +1790,30 @@ static void phylink_sfp_link_up(void *up
+ static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
+ {
+ 	struct phylink *pl = upstream;
+-	phy_interface_t interface = pl->link_config.interface;
++	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
++	__ETHTOOL_DECLARE_LINK_MODE_MASK(advertising);
++	phy_interface_t interface;
+ 	int ret;
+ 
+-	ret = phylink_attach_phy(pl, phy, pl->link_config.interface);
++	/*
++	 * This is the new way of dealing with flow control for PHYs,
++	 * as described by Timur Tabi in commit 529ed1275263 ("net: phy:
++	 * phy drivers should not set SUPPORTED_[Asym_]Pause") except
++	 * using our validate call to the MAC, we rely upon the MAC
++	 * clearing the bits from both supported and advertising fields.
++	 */
++	phy_support_asym_pause(phy);
++
++	ethtool_convert_legacy_u32_to_link_mode(supported, phy->supported);
++	ethtool_convert_legacy_u32_to_link_mode(advertising, phy->advertising);
++
++	/* Do the initial configuration */
++	ret = phylink_sfp_config(pl, ML_AN_INBAND, supported, advertising);
++	if (ret < 0)
++		return ret;
++
++	interface = pl->link_config.interface;
++	ret = phylink_attach_phy(pl, phy, interface);
+ 	if (ret < 0)
+ 		return ret;
+ 
+--- a/drivers/net/phy/sfp-bus.c
++++ b/drivers/net/phy/sfp-bus.c
+@@ -102,6 +102,7 @@ static const struct sfp_quirk *sfp_looku
+ 
+ 	return NULL;
+ }
++
+ /**
+  * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
+  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
+@@ -178,6 +179,33 @@ int sfp_parse_port(struct sfp_bus *bus,
+ EXPORT_SYMBOL_GPL(sfp_parse_port);
+ 
+ /**
++ * sfp_may_have_phy() - indicate whether the module may have a PHY
++ * @bus: a pointer to the &struct sfp_bus structure for the sfp module
++ * @id: a pointer to the module's &struct sfp_eeprom_id
++ *
++ * Parse the EEPROM identification given in @id, and return whether
++ * this module may have a PHY.
++ */
++bool sfp_may_have_phy(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
++{
++	if (id->base.e1000_base_t)
++		return true;
++
++	if (id->base.phys_id != SFF8024_ID_DWDM_SFP) {
++		switch (id->base.extended_cc) {
++		case SFF8024_ECC_10GBASE_T_SFI:
++		case SFF8024_ECC_10GBASE_T_SR:
++		case SFF8024_ECC_5GBASE_T:
++		case SFF8024_ECC_2_5GBASE_T:
++			return true;
++		}
++	}
++
++	return false;
++}
++EXPORT_SYMBOL_GPL(sfp_may_have_phy);
++
++/**
+  * sfp_parse_support() - Parse the eeprom id for supported link modes
+  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
+  * @id: a pointer to the module's &struct sfp_eeprom_id
+--- a/include/linux/sfp.h
++++ b/include/linux/sfp.h
+@@ -533,6 +533,7 @@ struct sfp_upstream_ops {
+ #if IS_ENABLED(CONFIG_SFP)
+ int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
+ 		   unsigned long *support);
++bool sfp_may_have_phy(struct sfp_bus *bus, const struct sfp_eeprom_id *id);
+ void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
+ 		       unsigned long *support);
+ phy_interface_t sfp_select_interface(struct sfp_bus *bus,
+@@ -556,6 +557,12 @@ static inline int sfp_parse_port(struct
+ 	return PORT_OTHER;
+ }
+ 
++static inline bool sfp_may_have_phy(struct sfp_bus *bus,
++				    const struct sfp_eeprom_id *id)
++{
++	return false;
++}
++
+ static inline void sfp_parse_support(struct sfp_bus *bus,
+ 				     const struct sfp_eeprom_id *id,
+ 				     unsigned long *support)