kernel: mt7530: add support for in-band managed link

Add support for in-band managed link status to support SFP cage
connected to port 5 of the MT7531 switch on the Bananapi BPi-R3.

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

diff --git a/target/linux/generic/pending-5.15/731-net-dsa-mt7530-add-support-for-in-band-link-status.patch b/target/linux/generic/pending-5.15/731-net-dsa-mt7530-add-support-for-in-band-link-status.patch
new file mode 100644 (file)
index 0000000..8196f19
--- /dev/null
+++ b/target/linux/generic/pending-5.15/731-net-dsa-mt7530-add-support-for-in-band-link-status.patch
@@ -0,0 +1,123 @@
+From 8e18c5fef75debfae3531fbd6901f3bf317d91ed Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Fri, 9 Sep 2022 04:28:43 +0100
+Subject: [PATCH] net: dsa: mt7530: add support for in-band link status
+To: linux-mediatek@lists.infradead.org,
+    netdev@vger.kernel.org
+Cc: Russell King <linux@armlinux.org.uk>,
+    Sean Wang <sean.wang@mediatek.com>,
+    Landen Chao <Landen.Chao@mediatek.com>,
+    DENG Qingfang <dqfext@gmail.com>,
+    Andrew Lunn <andrew@lunn.ch>,
+    Vivien Didelot <vivien.didelot@gmail.com>,
+    Florian Fainelli <f.fainelli@gmail.com>,
+    Vladimir Oltean <olteanv@gmail.com>,
+    David S. Miller <davem@davemloft.net>,
+    Eric Dumazet <edumazet@google.com>,
+    Jakub Kicinski <kuba@kernel.org>,
+    Paolo Abeni <pabeni@redhat.com>,
+    Matthias Brugger <matthias.bgg@gmail.com>,
+    Philipp Zabel <p.zabel@pengutronix.de>
+
+Read link status from SGMII PCS for in-band managed 2500Base-X and
+1000Base-X connection on a MAC port of the MT7531. This is needed to
+get the SFP cage working which is connected to SGMII interface of
+port 5 of the MT7531 switch IC on the Bananapi BPi-R3 board.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/net/dsa/mt7530.c | 48 +++++++++++++++++++++++++++++-----------
+ 1 file changed, 35 insertions(+), 13 deletions(-)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -2703,9 +2703,6 @@ mt7531_mac_config(struct dsa_switch *ds,
+       case PHY_INTERFACE_MODE_NA:
+       case PHY_INTERFACE_MODE_1000BASEX:
+       case PHY_INTERFACE_MODE_2500BASEX:
+-              if (phylink_autoneg_inband(mode))
+-                      return -EINVAL;
+-
+               return mt7531_sgmii_setup_mode_force(priv, port, interface);
+       default:
+               return -EINVAL;
+@@ -2781,13 +2778,6 @@ unsupported:
+               return;
+       }
+ 
+-      if (phylink_autoneg_inband(mode) &&
+-          state->interface != PHY_INTERFACE_MODE_SGMII) {
+-              dev_err(ds->dev, "%s: in-band negotiation unsupported\n",
+-                      __func__);
+-              return;
+-      }
+-
+       mcr_cur = mt7530_read(priv, MT7530_PMCR_P(port));
+       mcr_new = mcr_cur;
+       mcr_new &= ~PMCR_LINK_SETTINGS_MASK;
+@@ -2924,6 +2914,9 @@ static void mt753x_phylink_get_caps(stru
+       config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
+                                  MAC_10 | MAC_100 | MAC_1000FD;
+ 
++      if ((priv->id == ID_MT7531) && mt753x_is_mac_port(port))
++              config->mac_capabilities |= MAC_2500FD;
++
+       /* This driver does not make use of the speed, duplex, pause or the
+        * advertisement in its mac_config, so it is safe to mark this driver
+        * as non-legacy.
+@@ -3019,16 +3012,43 @@ mt7531_sgmii_pcs_get_state_an(struct mt7
+       return 0;
+ }
+ 
++static void
++mt7531_sgmii_pcs_get_state_inband(struct mt7530_priv *priv, int port,
++                                struct phylink_link_state *state)
++{
++      unsigned int val;
++
++      val = mt7530_read(priv, MT7531_PCS_CONTROL_1(port));
++      state->link = !!(val & MT7531_SGMII_LINK_STATUS);
++      if (!state->link)
++              return;
++
++      if (state->interface == PHY_INTERFACE_MODE_2500BASEX)
++              state->speed = SPEED_2500;
++      else
++              state->speed = SPEED_1000;
++
++      state->duplex = DUPLEX_FULL;
++      state->pause = 0;
++}
++
+ static void mt7531_pcs_get_state(struct phylink_pcs *pcs,
+                                struct phylink_link_state *state)
+ {
+       struct mt7530_priv *priv = pcs_to_mt753x_pcs(pcs)->priv;
+       int port = pcs_to_mt753x_pcs(pcs)->port;
++      unsigned int val;
+ 
+-      if (state->interface == PHY_INTERFACE_MODE_SGMII)
++      if (state->interface == PHY_INTERFACE_MODE_SGMII) {
+               mt7531_sgmii_pcs_get_state_an(priv, port, state);
+-      else
+-              state->link = false;
++              return;
++      } else if ((state->interface == PHY_INTERFACE_MODE_1000BASEX) ||
++                 (state->interface == PHY_INTERFACE_MODE_2500BASEX)) {
++              mt7531_sgmii_pcs_get_state_inband(priv, port, state);
++              return;
++      }
++
++      state->link = false;
+ }
+ 
+ static int mt753x_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
+@@ -3069,6 +3089,8 @@ mt753x_setup(struct dsa_switch *ds)
+               priv->pcs[i].pcs.ops = priv->info->pcs_ops;
+               priv->pcs[i].priv = priv;
+               priv->pcs[i].port = i;
++              if (mt753x_is_mac_port(i))
++                      priv->pcs[i].pcs.poll = 1;
+       }
+ 
+       ret = priv->info->sw_setup(ds);