[PATCH net-next v2 1/3] net: macb: fix SGMII with inband aneg disabled

[Charles Perry <charles.perry@microchip.com>]

Make it possible to connect a PHY which does not use inband
autoneg to a gem MAC using phylink's information.

The previous implementation relied on whether or not the link
was a fixed-link to disable SGMII autoneg. This commit extend
this to all link which are not configured for inband
autonegotiation.

Signed-off-by: Charles Perry <charles.perry@microchip.com>
---

Notes:
    Changes in v2:
      * Move my notes to the cover letter
      * Remove the spinlock in macb_pcs_config
      * Keep the comment about the PCSSEL register

 drivers/net/ethernet/cadence/macb_main.c | 36 +++++++++++++-----------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index f72270a39d25..f4250e76cef0 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -574,6 +574,26 @@ static int macb_pcs_config(struct phylink_pcs *pcs,
 			   const unsigned long *advertising,
 			   bool permit_pause_to_mac)
 {
+	struct macb *bp = container_of(pcs, struct macb, phylink_sgmii_pcs);
+	u32 old, new;
+
+	old = gem_readl(bp, PCSANADV);
+	new = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
+	if (new != -EINVAL && old != new)
+		gem_writel(bp, PCSANADV, new);
+
+	/* Disable AN if it's not to be used, enable otherwise.
+	 * Must be written after PCSSEL is set in NCFGR which is done in
+	 * macb_mac_config(), otherwise writes will not take effect.
+	 */
+	old = gem_readl(bp, PCSCNTRL);
+	if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
+		new = old | BMCR_ANENABLE;
+	else
+		new = old & ~BMCR_ANENABLE;
+	if (old != new)
+		gem_writel(bp, PCSCNTRL, new);
+
 	return 0;
 }
 
@@ -628,22 +648,6 @@ static void macb_mac_config(struct phylink_config *config, unsigned int mode,
 	if (old_ncr ^ ncr)
 		macb_or_gem_writel(bp, NCR, ncr);
 
-	/* Disable AN for SGMII fixed link configuration, enable otherwise.
-	 * Must be written after PCSSEL is set in NCFGR,
-	 * otherwise writes will not take effect.
-	 */
-	if (macb_is_gem(bp) && state->interface == PHY_INTERFACE_MODE_SGMII) {
-		u32 pcsctrl, old_pcsctrl;
-
-		old_pcsctrl = gem_readl(bp, PCSCNTRL);
-		if (mode == MLO_AN_FIXED)
-			pcsctrl = old_pcsctrl & ~GEM_BIT(PCSAUTONEG);
-		else
-			pcsctrl = old_pcsctrl | GEM_BIT(PCSAUTONEG);
-		if (old_pcsctrl != pcsctrl)
-			gem_writel(bp, PCSCNTRL, pcsctrl);
-	}
-
 	spin_unlock_irqrestore(&bp->lock, flags);
 }
 
-- 
2.47.3