kernel: backport support for clause 37 1000Base-X auto-negotiation

This patch is needed for clause 37 1000Base-X encoding used in many SFP modules.

Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>
Signed-off-by: René van Dorst <opensource@vdorst.com>

diff --git a/target/linux/generic/backport-5.4/750-v5.5-net-phy-add-support-for-clause-37-auto-negotiation.patch b/target/linux/generic/backport-5.4/750-v5.5-net-phy-add-support-for-clause-37-auto-negotiation.patch
new file mode 100644 (file)
index 0000000..da76523
--- /dev/null
+++ b/target/linux/generic/backport-5.4/750-v5.5-net-phy-add-support-for-clause-37-auto-negotiation.patch
@@ -0,0 +1,199 @@
+From fa6e98cee558622565c97924e922b97340aeabd8 Mon Sep 17 00:00:00 2001
+From: Heiner Kallweit <hkallweit1@gmail.com>
+Date: Tue, 22 Oct 2019 11:31:07 -0700
+Subject: [PATCH] net: phy: add support for clause 37 auto-negotiation
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This patch adds support for clause 37 1000Base-X auto-negotiation.
+
+Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
+Signed-off-by: Tao Ren <taoren@fb.com>
+Tested-by: René van Dorst <opensource@vdorst.com>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/phy/phy_device.c | 139 +++++++++++++++++++++++++++++++++++
+ include/linux/phy.h          |   4 +
+ 2 files changed, 143 insertions(+)
+
+diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
+index f1f60bd4865a..fa71998fea51 100644
+--- a/drivers/net/phy/phy_device.c
++++ b/drivers/net/phy/phy_device.c
+@@ -1607,6 +1607,40 @@ static int genphy_config_advert(struct phy_device *phydev)
+       return changed;
+ }
+ 
++/**
++ * genphy_c37_config_advert - sanitize and advertise auto-negotiation parameters
++ * @phydev: target phy_device struct
++ *
++ * Description: Writes MII_ADVERTISE with the appropriate values,
++ *   after sanitizing the values to make sure we only advertise
++ *   what is supported.  Returns < 0 on error, 0 if the PHY's advertisement
++ *   hasn't changed, and > 0 if it has changed. This function is intended
++ *   for Clause 37 1000Base-X mode.
++ */
++static int genphy_c37_config_advert(struct phy_device *phydev)
++{
++      u16 adv = 0;
++
++      /* Only allow advertising what this PHY supports */
++      linkmode_and(phydev->advertising, phydev->advertising,
++                   phydev->supported);
++
++      if (linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
++                            phydev->advertising))
++              adv |= ADVERTISE_1000XFULL;
++      if (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
++                            phydev->advertising))
++              adv |= ADVERTISE_1000XPAUSE;
++      if (linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
++                            phydev->advertising))
++              adv |= ADVERTISE_1000XPSE_ASYM;
++
++      return phy_modify_changed(phydev, MII_ADVERTISE,
++                                ADVERTISE_1000XFULL | ADVERTISE_1000XPAUSE |
++                                ADVERTISE_1000XHALF | ADVERTISE_1000XPSE_ASYM,
++                                adv);
++}
++
+ /**
+  * genphy_config_eee_advert - disable unwanted eee mode advertisement
+  * @phydev: target phy_device struct
+@@ -1715,6 +1749,54 @@ int __genphy_config_aneg(struct phy_device *phydev, bool changed)
+ }
+ EXPORT_SYMBOL(__genphy_config_aneg);
+ 
++/**
++ * genphy_c37_config_aneg - restart auto-negotiation or write BMCR
++ * @phydev: target phy_device struct
++ *
++ * Description: If auto-negotiation is enabled, we configure the
++ *   advertising, and then restart auto-negotiation.  If it is not
++ *   enabled, then we write the BMCR. This function is intended
++ *   for use with Clause 37 1000Base-X mode.
++ */
++int genphy_c37_config_aneg(struct phy_device *phydev)
++{
++      int err, changed;
++
++      if (phydev->autoneg != AUTONEG_ENABLE)
++              return genphy_setup_forced(phydev);
++
++      err = phy_modify(phydev, MII_BMCR, BMCR_SPEED1000 | BMCR_SPEED100,
++                       BMCR_SPEED1000);
++      if (err)
++              return err;
++
++      changed = genphy_c37_config_advert(phydev);
++      if (changed < 0) /* error */
++              return changed;
++
++      if (!changed) {
++              /* Advertisement hasn't changed, but maybe aneg was never on to
++               * begin with?  Or maybe phy was isolated?
++               */
++              int ctl = phy_read(phydev, MII_BMCR);
++
++              if (ctl < 0)
++                      return ctl;
++
++              if (!(ctl & BMCR_ANENABLE) || (ctl & BMCR_ISOLATE))
++                      changed = 1; /* do restart aneg */
++      }
++
++      /* Only restart aneg if we are advertising something different
++       * than we were before.
++       */
++      if (changed > 0)
++              return genphy_restart_aneg(phydev);
++
++      return 0;
++}
++EXPORT_SYMBOL(genphy_c37_config_aneg);
++
+ /**
+  * genphy_aneg_done - return auto-negotiation status
+  * @phydev: target phy_device struct
+@@ -1886,6 +1968,63 @@ int genphy_read_status(struct phy_device *phydev)
+ }
+ EXPORT_SYMBOL(genphy_read_status);
+ 
++/**
++ * genphy_c37_read_status - check the link status and update current link state
++ * @phydev: target phy_device struct
++ *
++ * Description: Check the link, then figure out the current state
++ *   by comparing what we advertise with what the link partner
++ *   advertises. This function is for Clause 37 1000Base-X mode.
++ */
++int genphy_c37_read_status(struct phy_device *phydev)
++{
++      int lpa, err, old_link = phydev->link;
++
++      /* Update the link, but return if there was an error */
++      err = genphy_update_link(phydev);
++      if (err)
++              return err;
++
++      /* why bother the PHY if nothing can have changed */
++      if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
++              return 0;
++
++      phydev->duplex = DUPLEX_UNKNOWN;
++      phydev->pause = 0;
++      phydev->asym_pause = 0;
++
++      if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
++              lpa = phy_read(phydev, MII_LPA);
++              if (lpa < 0)
++                      return lpa;
++
++              linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
++                               phydev->lp_advertising, lpa & LPA_LPACK);
++              linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
++                               phydev->lp_advertising, lpa & LPA_1000XFULL);
++              linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT,
++                               phydev->lp_advertising, lpa & LPA_1000XPAUSE);
++              linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
++                               phydev->lp_advertising,
++                               lpa & LPA_1000XPAUSE_ASYM);
++
++              phy_resolve_aneg_linkmode(phydev);
++      } else if (phydev->autoneg == AUTONEG_DISABLE) {
++              int bmcr = phy_read(phydev, MII_BMCR);
++
++              if (bmcr < 0)
++                      return bmcr;
++
++              if (bmcr & BMCR_FULLDPLX)
++                      phydev->duplex = DUPLEX_FULL;
++              else
++                      phydev->duplex = DUPLEX_HALF;
++      }
++
++      return 0;
++}
++EXPORT_SYMBOL(genphy_c37_read_status);
++
+ /**
+  * genphy_soft_reset - software reset the PHY via BMCR_RESET bit
+  * @phydev: target phy_device struct
+diff --git a/include/linux/phy.h b/include/linux/phy.h
+index 9a0e981df502..78436d58ce7c 100644
+--- a/include/linux/phy.h
++++ b/include/linux/phy.h
+@@ -1106,6 +1106,10 @@ int genphy_read_mmd_unsupported(struct phy_device *phdev, int devad,
+ int genphy_write_mmd_unsupported(struct phy_device *phdev, int devnum,
+                                u16 regnum, u16 val);
+ 
++/* Clause 37 */
++int genphy_c37_config_aneg(struct phy_device *phydev);
++int genphy_c37_read_status(struct phy_device *phydev);
++
+ /* Clause 45 PHY */
+ int genphy_c45_restart_aneg(struct phy_device *phydev);
+ int genphy_c45_check_and_restart_aneg(struct phy_device *phydev, bool restart);