generic: replace mtk_sgmii patches with versions accepted upstream

Replace patches for MediaTek Ethernet driver SGMII/SerDes unit with
their corresponding upstream patches. Not all of the patches in our
tree went upstream as-is, some are slightly different implementations,
and they require the phylink_pcs helpers now made available.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.15/733-v6.3-16-net-ethernet-mtk_eth_soc-only-write-values-if-needed.patch b/target/linux/generic/backport-5.15/733-v6.3-16-net-ethernet-mtk_eth_soc-only-write-values-if-needed.patch
new file mode 100644
index 0000000000..0fabeea20c
--- /dev/null
+++ b/target/linux/generic/backport-5.15/733-v6.3-16-net-ethernet-mtk_eth_soc-only-write-values-if-needed.patch
@@ -0,0 +1,103 @@
+From 6e933a804c7db8be64f367f33e63cd7dcc302ebb Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Tue, 14 Mar 2023 00:34:45 +0000
+Subject: [PATCH 2/2] net: ethernet: mtk_eth_soc: only write values if needed
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Only restart auto-negotiation and write link timer if actually
+necessary. This prevents losing the link in case of minor
+changes.
+
+Fixes: 7e538372694b ("net: ethernet: mediatek: Re-add support SGMII")
+Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
+Tested-by: Bjørn Mork <bjorn@mork.no>
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/ethernet/mediatek/mtk_sgmii.c | 24 +++++++++++------------
+ 1 file changed, 12 insertions(+), 12 deletions(-)
+
+--- a/drivers/net/ethernet/mediatek/mtk_sgmii.c
++++ b/drivers/net/ethernet/mediatek/mtk_sgmii.c
+@@ -38,20 +38,16 @@ static int mtk_pcs_config(struct phylink
+ 			  const unsigned long *advertising,
+ 			  bool permit_pause_to_mac)
+ {
++	bool mode_changed = false, changed, use_an;
+ 	struct mtk_pcs *mpcs = pcs_to_mtk_pcs(pcs);
+ 	unsigned int rgc3, sgm_mode, bmcr;
+ 	int advertise, link_timer;
+-	bool changed, use_an;
+ 
+ 	advertise = phylink_mii_c22_pcs_encode_advertisement(interface,
+ 							     advertising);
+ 	if (advertise < 0)
+ 		return advertise;
+ 
+-	link_timer = phylink_get_link_timer_ns(interface);
+-	if (link_timer < 0)
+-		return link_timer;
+-
+ 	/* Clearing IF_MODE_BIT0 switches the PCS to BASE-X mode, and
+ 	 * we assume that fixes it's speed at bitrate = line rate (in
+ 	 * other words, 1000Mbps or 2500Mbps).
+@@ -77,13 +73,16 @@ static int mtk_pcs_config(struct phylink
+ 	}
+ 
+ 	if (use_an) {
+-		/* FIXME: Do we need to set AN_RESTART here? */
+-		bmcr = SGMII_AN_RESTART | SGMII_AN_ENABLE;
++		bmcr = SGMII_AN_ENABLE;
+ 	} else {
+ 		bmcr = 0;
+ 	}
+ 
+ 	if (mpcs->interface != interface) {
++		link_timer = phylink_get_link_timer_ns(interface);
++		if (link_timer < 0)
++			return link_timer;
++
+ 		/* PHYA power down */
+ 		regmap_update_bits(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL,
+ 				   SGMII_PHYA_PWD, SGMII_PHYA_PWD);
+@@ -101,16 +100,17 @@ static int mtk_pcs_config(struct phylink
+ 		regmap_update_bits(mpcs->regmap, mpcs->ana_rgc3,
+ 				   RG_PHY_SPEED_3_125G, rgc3);
+ 
++		/* Setup the link timer */
++		regmap_write(mpcs->regmap, SGMSYS_PCS_LINK_TIMER, link_timer / 2 / 8);
++
+ 		mpcs->interface = interface;
++		mode_changed = true;
+ 	}
+ 
+ 	/* Update the advertisement, noting whether it has changed */
+ 	regmap_update_bits_check(mpcs->regmap, SGMSYS_PCS_ADVERTISE,
+ 				 SGMII_ADVERTISE, advertise, &changed);
+ 
+-	/* Setup the link timer and QPHY power up inside SGMIISYS */
+-	regmap_write(mpcs->regmap, SGMSYS_PCS_LINK_TIMER, link_timer / 2 / 8);
+-
+ 	/* Update the sgmsys mode register */
+ 	regmap_update_bits(mpcs->regmap, SGMSYS_SGMII_MODE,
+ 			   SGMII_REMOTE_FAULT_DIS | SGMII_SPEED_DUPLEX_AN |
+@@ -118,7 +118,7 @@ static int mtk_pcs_config(struct phylink
+ 
+ 	/* Update the BMCR */
+ 	regmap_update_bits(mpcs->regmap, SGMSYS_PCS_CONTROL_1,
+-			   SGMII_AN_RESTART | SGMII_AN_ENABLE, bmcr);
++			   SGMII_AN_ENABLE, bmcr);
+ 
+ 	/* Release PHYA power down state
+ 	 * Only removing bit SGMII_PHYA_PWD isn't enough.
+@@ -132,7 +132,7 @@ static int mtk_pcs_config(struct phylink
+ 	usleep_range(50, 100);
+ 	regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, 0);
+ 
+-	return changed;
++	return changed || mode_changed;
+ }
+ 
+ static void mtk_pcs_restart_an(struct phylink_pcs *pcs)