mvebu: SFP backports for GPON modules

This backports the following upstream Linux patches
  net: sfp: add mode quirk for GPON module Ubiquiti U-Fiber Instant
  net: sfp: relax bitrate-derived mode check
  net: sfp: cope with SFPs that set both LOS normal and LOS inverted
for 5.4 for mvebu platform.

This fixes GPON modules:
  Ubiquiti U-Fiber Instant SFP GPON
  VSOL V2801F
  CarlitoxxPro CPGOS03-0490 v2.0

Signed-off-by: Marek Behún <marek.behun@nic.cz>

3 files changed, 101 insertions, 7 deletions

diff --git a/target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch b/target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch
new file mode 100644
index 0000000000..fbbaae1d2b
--- /dev/null
+++ b/target/linux/generic/backport-5.4/768-net-sfp-cope-with-SFPs-that-set-both-LOS-normal-and-.patch
@@ -0,0 +1,94 @@
+From da5bc1832b325b15e4cca3b63861ecf48be870ef Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Sun, 10 Jan 2021 10:58:32 +0000
+Subject: [PATCH] net: sfp: cope with SFPs that set both LOS normal and LOS
+ inverted
+
+The SFP MSA defines two option bits in byte 65 to indicate how the
+Rx_LOS signal on SFP pin 8 behaves:
+
+bit 2 - Loss of Signal implemented, signal inverted from standard
+        definition in SFP MSA (often called "Signal Detect").
+bit 1 - Loss of Signal implemented, signal as defined in SFP MSA
+        (often called "Rx_LOS").
+
+Clearly, setting both bits results in a meaningless situation: it would
+mean that LOS is implemented in both the normal sense (1 = signal loss)
+and inverted sense (0 = signal loss).
+
+Unfortunately, there are modules out there which set both bits, which
+will be initially interpret as "inverted" sense, and then, if the LOS
+signal changes state, we will toggle between LINK_UP and WAIT_LOS
+states.
+
+Change our LOS handling to give well defined behaviour: only interpret
+these bits as meaningful if exactly one is set, otherwise treat it as
+if LOS is not implemented.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Link: https://lore.kernel.org/r/E1kyYQa-0004iR-CU@rmk-PC.armlinux.org.uk
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ drivers/net/phy/sfp.c | 36 ++++++++++++++++++++++--------------
+ 1 file changed, 22 insertions(+), 14 deletions(-)
+
+--- a/drivers/net/phy/sfp.c
++++ b/drivers/net/phy/sfp.c
+@@ -1430,15 +1430,19 @@ static void sfp_sm_link_down(struct sfp
+ 
+ static void sfp_sm_link_check_los(struct sfp *sfp)
+ {
+-	unsigned int los = sfp->state & SFP_F_LOS;
++	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
++	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
++	__be16 los_options = sfp->id.ext.options & (los_inverted | los_normal);
++	bool los = false;
+ 
+ 	/* If neither SFP_OPTIONS_LOS_INVERTED nor SFP_OPTIONS_LOS_NORMAL
+-	 * are set, we assume that no LOS signal is available.
++	 * are set, we assume that no LOS signal is available. If both are
++	 * set, we assume LOS is not implemented (and is meaningless.)
+ 	 */
+-	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED))
+-		los ^= SFP_F_LOS;
+-	else if (!(sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL)))
+-		los = 0;
++	if (los_options == los_inverted)
++		los = !(sfp->state & SFP_F_LOS);
++	else if (los_options == los_normal)
++		los = !!(sfp->state & SFP_F_LOS);
+ 
+ 	if (los)
+ 		sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
+@@ -1448,18 +1452,22 @@ static void sfp_sm_link_check_los(struct
+ 
+ static bool sfp_los_event_active(struct sfp *sfp, unsigned int event)
+ {
+-	return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
+-		event == SFP_E_LOS_LOW) ||
+-	       (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
+-		event == SFP_E_LOS_HIGH);
++	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
++	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
++	__be16 los_options = sfp->id.ext.options & (los_inverted | los_normal);
++
++	return (los_options == los_inverted && event == SFP_E_LOS_LOW) ||
++	       (los_options == los_normal && event == SFP_E_LOS_HIGH);
+ }
+ 
+ static bool sfp_los_event_inactive(struct sfp *sfp, unsigned int event)
+ {
+-	return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
+-		event == SFP_E_LOS_HIGH) ||
+-	       (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
+-		event == SFP_E_LOS_LOW);
++	const __be16 los_inverted = cpu_to_be16(SFP_OPTIONS_LOS_INVERTED);
++	const __be16 los_normal = cpu_to_be16(SFP_OPTIONS_LOS_NORMAL);
++	__be16 los_options = sfp->id.ext.options & (los_inverted | los_normal);
++
++	return (los_options == los_inverted && event == SFP_E_LOS_HIGH) ||
++	       (los_options == los_normal && event == SFP_E_LOS_LOW);
+ }
+ 
+ static void sfp_sm_fault(struct sfp *sfp, unsigned int next_state, bool warn)
diff --git a/target/linux/generic/backport-5.4/852-v5.10-0001-net-sfp-VSOL-V2801F-CarlitoxxPro-CPGOS03-0490-v2.0-w.patch b/target/linux/generic/backport-5.4/852-v5.10-0001-net-sfp-VSOL-V2801F-CarlitoxxPro-CPGOS03-0490-v2.0-w.patch
index 1901054a10..39f4b273ae 100644
--- a/target/linux/generic/backport-5.4/852-v5.10-0001-net-sfp-VSOL-V2801F-CarlitoxxPro-CPGOS03-0490-v2.0-w.patch
+++ b/target/linux/generic/backport-5.4/852-v5.10-0001-net-sfp-VSOL-V2801F-CarlitoxxPro-CPGOS03-0490-v2.0-w.patch
@@ -68,7 +68,7 @@ Signed-off-by: David S. Miller <davem@davemloft.net>
  
  		msgs[1].len = this_len;
  
-@@ -1569,6 +1579,28 @@ static int sfp_sm_mod_hpower(struct sfp
+@@ -1577,6 +1587,28 @@ static int sfp_sm_mod_hpower(struct sfp
  	return 0;
  }
  
@@ -97,7 +97,7 @@ Signed-off-by: David S. Miller <davem@davemloft.net>
  static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
  {
  	/* SFP module inserted - read I2C data */
-@@ -1577,14 +1609,20 @@ static int sfp_sm_mod_probe(struct sfp *
+@@ -1585,14 +1617,20 @@ static int sfp_sm_mod_probe(struct sfp *
  	u8 check;
  	int ret;
  
@@ -120,7 +120,7 @@ Signed-off-by: David S. Miller <davem@davemloft.net>
  		dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
  		return -EAGAIN;
  	}
-@@ -1612,6 +1650,21 @@ static int sfp_sm_mod_probe(struct sfp *
+@@ -1620,6 +1658,21 @@ static int sfp_sm_mod_probe(struct sfp *
  		}
  	}
  
diff --git a/target/linux/generic/backport-5.4/852-v5.10-0002-net-sfp-add-workaround-for-Realtek-RTL8672-and-RTL96.patch b/target/linux/generic/backport-5.4/852-v5.10-0002-net-sfp-add-workaround-for-Realtek-RTL8672-and-RTL96.patch
index 27ae97cee7..8c95284280 100644
--- a/target/linux/generic/backport-5.4/852-v5.10-0002-net-sfp-add-workaround-for-Realtek-RTL8672-and-RTL96.patch
+++ b/target/linux/generic/backport-5.4/852-v5.10-0002-net-sfp-add-workaround-for-Realtek-RTL8672-and-RTL96.patch
@@ -102,7 +102,7 @@ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  	err = sfp_read(sfp, true, 0, &sfp->diag, sizeof(sfp->diag));
  	if (err < 0) {
  		if (sfp->hwmon_tries--) {
-@@ -1579,26 +1585,30 @@ static int sfp_sm_mod_hpower(struct sfp
+@@ -1587,26 +1593,30 @@ static int sfp_sm_mod_hpower(struct sfp
  	return 0;
  }
  
@@ -149,7 +149,7 @@ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  }
  
  static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
-@@ -1609,11 +1619,11 @@ static int sfp_sm_mod_probe(struct sfp *
+@@ -1617,11 +1627,11 @@ static int sfp_sm_mod_probe(struct sfp *
  	u8 check;
  	int ret;
  
@@ -165,7 +165,7 @@ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  
  	ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base));
  	if (ret < 0) {
-@@ -1627,6 +1637,33 @@ static int sfp_sm_mod_probe(struct sfp *
+@@ -1635,6 +1645,33 @@ static int sfp_sm_mod_probe(struct sfp *
  		return -EAGAIN;
  	}
  
@@ -199,7 +199,7 @@ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  	/* Cotsworks do not seem to update the checksums when they
  	 * do the final programming with the final module part number,
  	 * serial number and date code.
-@@ -1650,9 +1687,6 @@ static int sfp_sm_mod_probe(struct sfp *
+@@ -1658,9 +1695,6 @@ static int sfp_sm_mod_probe(struct sfp *
  		}
  	}