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, 94 insertions, 0 deletions

diff --git a/target/linux/generic/pending-4.19/753-net-sfp-add-support-for-Clause-45-PHYs.patch b/target/linux/generic/pending-4.19/753-net-sfp-add-support-for-Clause-45-PHYs.patch
new file mode 100644
index 0000000000..a710901690
--- /dev/null
+++ b/target/linux/generic/pending-4.19/753-net-sfp-add-support-for-Clause-45-PHYs.patch
@@ -0,0 +1,94 @@
+From 6df6709dc3d00e0bc948d45dfa8d8f18ba379c48 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Tue, 5 Nov 2019 11:56:18 +0000
+Subject: [PATCH 656/660] net: sfp: add support for Clause 45 PHYs
+
+Some SFP+ modules have a Clause 45 PHY onboard, which is accessible via
+the normal I2C address.  Detect 10G BASE-T PHYs which may have an
+accessible PHY and probe for it.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+---
+ drivers/net/phy/sfp.c | 44 +++++++++++++++++++++++++++++++++++++++----
+ 1 file changed, 40 insertions(+), 4 deletions(-)
+
+--- a/drivers/net/phy/sfp.c
++++ b/drivers/net/phy/sfp.c
+@@ -1326,12 +1326,12 @@ static void sfp_sm_phy_detach(struct sfp
+ 	sfp->mod_phy = NULL;
+ }
+ 
+-static void sfp_sm_probe_phy(struct sfp *sfp)
++static void sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
+ {
+ 	struct phy_device *phy;
+ 	int err;
+ 
+-	phy = mdiobus_scan(sfp->i2c_mii, SFP_PHY_ADDR);
++	phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
+ 	if (phy == ERR_PTR(-ENODEV)) {
+ 		dev_info(sfp->dev, "no PHY detected\n");
+ 		return;
+@@ -1341,6 +1341,13 @@ static void sfp_sm_probe_phy(struct sfp
+ 		return;
+ 	}
+ 
++	err = phy_device_register(phy);
++	if (err) {
++		phy_device_free(phy);
++		dev_err(sfp->dev, "phy_device_register failed: %d\n", err);
++		return;
++	}
++
+ 	err = sfp_add_phy(sfp->sfp_bus, phy);
+ 	if (err) {
+ 		phy_device_remove(phy);
+@@ -1411,10 +1418,32 @@ static void sfp_sm_fault(struct sfp *sfp
+ 	}
+ }
+ 
++/* Probe a SFP for a PHY device if the module supports copper - the PHY
++ * normally sits at I2C bus address 0x56, and may either be a clause 22
++ * or clause 45 PHY.
++ *
++ * Clause 22 copper SFP modules normally operate in Cisco SGMII mode with
++ * negotiation enabled, but some may be in 1000base-X - which is for the
++ * PHY driver to determine.
++ *
++ * Clause 45 copper SFP+ modules (10G) appear to switch their interface
++ * mode according to the negotiated line speed.
++ */
+ static void sfp_sm_probe_for_phy(struct sfp *sfp)
+ {
+-	if (sfp->id.base.e1000_base_t)
+-		sfp_sm_probe_phy(sfp);
++	switch (sfp->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:
++		sfp_sm_probe_phy(sfp, true);
++		break;
++
++	default:
++		if (sfp->id.base.e1000_base_t)
++			sfp_sm_probe_phy(sfp, false);
++		break;
++	}
+ }
+ 
+ static int sfp_module_parse_power(struct sfp *sfp)
+@@ -1474,6 +1503,13 @@ static int sfp_sm_mod_hpower(struct sfp
+ 		return -EAGAIN;
+ 	}
+ 
++	/* DM7052 reports as a high power module, responds to reads (with
++	 * all bytes 0xff) at 0x51 but does not accept writes.  In any case,
++	 * if the bit is already set, we're already in high power mode.
++	 */
++	if (!!(val & BIT(0)) == enable)
++		return 0;
++
+ 	if (enable)
+ 		val |= BIT(0);
+ 	else