[RFC net-next PATCH 08/16] net: macb: Clean up macb_validate

[Sean Anderson <sean.anderson@seco.com>]

As the number of interfaces grows, the number of if statements grows
ever more unweildy. Clean everything up a bit by using a switch
statement. No functional change intended.

While we're on the subject, could someone clarify the relationship
between the various speed capabilities? What's the difference between
MACB_CAPS_GIGABIT_MODE_AVAILABLE, MACB_CAPS_HIGH_SPEED, MACB_CAPS_PCS,
and macb_is_gem()? Would there ever be a GEM without GIGABIT_MODE?
HIGH_SPEED without PCS? Why doesn't SGMII care if we're a gem (I think
this one is a bug, because it cares later on)?

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---

 drivers/net/ethernet/cadence/macb_main.c | 99 +++++++++++-------------
 1 file changed, 45 insertions(+), 54 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index e2730b3e1a57..18afa544b623 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -510,32 +510,55 @@ static void macb_validate(struct phylink_config *config,
 			  unsigned long *supported,
 			  struct phylink_link_state *state)
 {
+	bool one = state->interface == PHY_INTERFACE_MODE_NA;
 	struct net_device *ndev = to_net_dev(config->dev);
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
 	struct macb *bp = netdev_priv(ndev);
 
-	/* We only support MII, RMII, GMII, RGMII & SGMII. */
-	if (state->interface != PHY_INTERFACE_MODE_NA &&
-	    state->interface != PHY_INTERFACE_MODE_MII &&
-	    state->interface != PHY_INTERFACE_MODE_RMII &&
-	    state->interface != PHY_INTERFACE_MODE_GMII &&
-	    state->interface != PHY_INTERFACE_MODE_SGMII &&
-	    state->interface != PHY_INTERFACE_MODE_10GBASER &&
-	    !phy_interface_mode_is_rgmii(state->interface)) {
-		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
-		return;
-	}
-
-	if (!macb_is_gem(bp) &&
-	    (state->interface == PHY_INTERFACE_MODE_GMII ||
-	     phy_interface_mode_is_rgmii(state->interface))) {
-		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
-		return;
-	}
-
-	if (state->interface == PHY_INTERFACE_MODE_10GBASER &&
-	    !(bp->caps & MACB_CAPS_HIGH_SPEED &&
-	      bp->caps & MACB_CAPS_PCS)) {
+	switch (state->interface) {
+	case PHY_INTERFACE_MODE_NA:
+	case PHY_INTERFACE_MODE_10GBASER:
+		if (bp->caps & MACB_CAPS_HIGH_SPEED &&
+		    bp->caps & MACB_CAPS_PCS &&
+		    bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE) {
+			phylink_set(mask, 10000baseCR_Full);
+			phylink_set(mask, 10000baseER_Full);
+			phylink_set(mask, 10000baseKR_Full);
+			phylink_set(mask, 10000baseLR_Full);
+			phylink_set(mask, 10000baseLRM_Full);
+			phylink_set(mask, 10000baseSR_Full);
+			phylink_set(mask, 10000baseT_Full);
+		} else if (one) {
+			goto none;
+		}
+		if (one)
+			break;
+		fallthrough;
+	case PHY_INTERFACE_MODE_GMII:
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		if (!macb_is_gem(bp) && one)
+			goto none;
+		fallthrough;
+	case PHY_INTERFACE_MODE_SGMII:
+		if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE) {
+			phylink_set(mask, 1000baseT_Full);
+			phylink_set(mask, 1000baseX_Full);
+			if (!(bp->caps & MACB_CAPS_NO_GIGABIT_HALF))
+				phylink_set(mask, 1000baseT_Half);
+		}
+		fallthrough;
+	case PHY_INTERFACE_MODE_MII:
+	case PHY_INTERFACE_MODE_RMII:
+		phylink_set(mask, 10baseT_Half);
+		phylink_set(mask, 10baseT_Full);
+		phylink_set(mask, 100baseT_Half);
+		phylink_set(mask, 100baseT_Full);
+		break;
+	none:
+	default:
 		bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
 		return;
 	}
@@ -543,38 +566,6 @@ static void macb_validate(struct phylink_config *config,
 	phylink_set_port_modes(mask);
 	phylink_set(mask, Autoneg);
 	phylink_set(mask, Asym_Pause);
-
-	if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE &&
-	    (state->interface == PHY_INTERFACE_MODE_NA ||
-	     state->interface == PHY_INTERFACE_MODE_10GBASER)) {
-		phylink_set(mask, 10000baseCR_Full);
-		phylink_set(mask, 10000baseER_Full);
-		phylink_set(mask, 10000baseKR_Full);
-		phylink_set(mask, 10000baseLR_Full);
-		phylink_set(mask, 10000baseLRM_Full);
-		phylink_set(mask, 10000baseSR_Full);
-		phylink_set(mask, 10000baseT_Full);
-		if (state->interface != PHY_INTERFACE_MODE_NA)
-			goto out;
-	}
-
-	phylink_set(mask, 10baseT_Half);
-	phylink_set(mask, 10baseT_Full);
-	phylink_set(mask, 100baseT_Half);
-	phylink_set(mask, 100baseT_Full);
-
-	if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE &&
-	    (state->interface == PHY_INTERFACE_MODE_NA ||
-	     state->interface == PHY_INTERFACE_MODE_GMII ||
-	     state->interface == PHY_INTERFACE_MODE_SGMII ||
-	     phy_interface_mode_is_rgmii(state->interface))) {
-		phylink_set(mask, 1000baseT_Full);
-		phylink_set(mask, 1000baseX_Full);
-
-		if (!(bp->caps & MACB_CAPS_NO_GIGABIT_HALF))
-			phylink_set(mask, 1000baseT_Half);
-	}
-out:
 	bitmap_and(supported, supported, mask, __ETHTOOL_LINK_MODE_MASK_NBITS);
 	bitmap_and(state->advertising, state->advertising, mask,
 		   __ETHTOOL_LINK_MODE_MASK_NBITS);
-- 
2.25.1