[PATCH net-next v3 1/9] net: phylink: add interface to configure clause 22 PCS PHY

[Ioana Ciornei]

From: Russell King <rmk+ker...@armlinux.org.uk>

Add helper for clause 22 PCS configuration via the MII bus.
Apart from applying the advertisements, the pcs_config helper also sets
up the BMCR_ANENABLE depending on the in-band AN state.

Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
Signed-off-by: Ioana Ciornei <ioana.cior...@nxp.com>
---
Changes in v2:
 - none
Changes in v3:
 - none

 drivers/net/phy/phylink.c | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/phylink.h   |  3 +++
 2 files changed, 40 insertions(+)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 7ce787c227b3..f04ccdedda40 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2267,6 +2267,43 @@ int phylink_mii_c22_pcs_set_advertisement(struct 
mdio_device *pcs,
 }
 EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_set_advertisement);
 
+/**
+ * phylink_mii_c22_pcs_config() - configure clause 22 PCS
+ * @pcs: a pointer to a &struct mdio_device.
+ * @mode: link autonegotiation mode
+ * @interface: the PHY interface mode being configured
+ * @advertising: the ethtool advertisement mask
+ *
+ * Configure a Clause 22 PCS PHY with the appropriate negotiation
+ * parameters for the @mode, @interface and @advertising parameters.
+ * Returns negative error number on failure, zero if the advertisement
+ * has not changed, or positive if there is a change.
+ */
+int phylink_mii_c22_pcs_config(struct mdio_device *pcs, unsigned int mode,
+                              phy_interface_t interface,
+                              const unsigned long *advertising)
+{
+       bool changed;
+       u16 bmcr;
+       int ret;
+
+       ret = phylink_mii_c22_pcs_set_advertisement(pcs, interface,
+                                                   advertising);
+       if (ret < 0)
+               return ret;
+
+       changed = ret > 0;
+
+       bmcr = mode == MLO_AN_INBAND ? BMCR_ANENABLE : 0;
+       ret = mdiobus_modify(pcs->bus, pcs->addr, MII_BMCR,
+                            BMCR_ANENABLE, bmcr);
+       if (ret < 0)
+               return ret;
+
+       return changed ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_config);
+
 /**
  * phylink_mii_c22_pcs_an_restart() - restart 802.3z autonegotiation
  * @pcs: a pointer to a &struct mdio_device.
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index cc5b452a184e..d979832d0c71 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -410,6 +410,9 @@ void phylink_mii_c22_pcs_get_state(struct mdio_device *pcs,
 int phylink_mii_c22_pcs_set_advertisement(struct mdio_device *pcs,
                                          phy_interface_t interface,
                                          const unsigned long *advertising);
+int phylink_mii_c22_pcs_config(struct mdio_device *pcs, unsigned int mode,
+                              phy_interface_t interface,
+                              const unsigned long *advertising);
 void phylink_mii_c22_pcs_an_restart(struct mdio_device *pcs);
 
 void phylink_mii_c45_pcs_get_state(struct mdio_device *pcs,
-- 
2.25.1