amd-xgbe-phy: PHY KX/KR mode differences

The PHY requires different settings for the Decision Feedback Analyzer
(DFE) when running in KX mode vs. KR mode. Update the code to change
these settings when changing modes in order to provide a more stable
link.

Additionally, adjust the 10GbE PQ skew default setting to a more sane
value.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/devicetree/bindings/net/amd-xgbe-phy.txt b/Documentation/devicetree/bindings/net/amd-xgbe-phy.txt
index 33df3932168e1b8941a5de1565b1cf02f96fb551..8db32384a4866e56094aa96e86ac8765ccdf519c 100644 (file)
--- a/Documentation/devicetree/bindings/net/amd-xgbe-phy.txt
+++ b/Documentation/devicetree/bindings/net/amd-xgbe-phy.txt
@@ -27,6 +27,8 @@ property is used.
 - amd,serdes-cdr-rate: CDR rate speed selection
 - amd,serdes-pq-skew: PQ (data sampling) skew
 - amd,serdes-tx-amp: TX amplitude boost
+- amd,serdes-dfe-tap-config: DFE taps available to run
+- amd,serdes-dfe-tap-enable: DFE taps to enable
 
 Example:
        xgbe_phy@e1240800 {
@@ -41,4 +43,6 @@ Example:
                amd,serdes-cdr-rate = <2>, <2>, <7>;
                amd,serdes-pq-skew = <10>, <10>, <30>;
                amd,serdes-tx-amp = <15>, <15>, <10>;
+               amd,serdes-dfe-tap-config = <3>, <3>, <1>;
+               amd,serdes-dfe-tap-enable = <0>, <0>, <127>;
        };

diff --git a/drivers/net/phy/amd-xgbe-phy.c b/drivers/net/phy/amd-xgbe-phy.c
index 9e3af54c90102a2c113596d326d893670b7e6c24..32efbd48f32642ddabb21126384b0c21e160a403 100644 (file)
--- a/drivers/net/phy/amd-xgbe-phy.c
+++ b/drivers/net/phy/amd-xgbe-phy.c
@@ -92,6 +92,8 @@ MODULE_DESCRIPTION("AMD 10GbE (amd-xgbe) PHY driver");
 #define XGBE_PHY_CDR_RATE_PROPERTY     "amd,serdes-cdr-rate"
 #define XGBE_PHY_PQ_SKEW_PROPERTY      "amd,serdes-pq-skew"
 #define XGBE_PHY_TX_AMP_PROPERTY       "amd,serdes-tx-amp"
+#define XGBE_PHY_DFE_CFG_PROPERTY      "amd,serdes-dfe-tap-config"
+#define XGBE_PHY_DFE_ENA_PROPERTY      "amd,serdes-dfe-tap-enable"
 
 #define XGBE_PHY_SPEEDS                        3
 #define XGBE_PHY_SPEED_1000            0
@@ -177,10 +179,12 @@ MODULE_DESCRIPTION("AMD 10GbE (amd-xgbe) PHY driver");
 #define SPEED_10000_BLWC               0
 #define SPEED_10000_CDR                        0x7
 #define SPEED_10000_PLL                        0x1
-#define SPEED_10000_PQ                 0x1e
+#define SPEED_10000_PQ                 0x12
 #define SPEED_10000_RATE               0x0
 #define SPEED_10000_TXAMP              0xa
 #define SPEED_10000_WORD               0x7
+#define SPEED_10000_DFE_TAP_CONFIG     0x1
+#define SPEED_10000_DFE_TAP_ENABLE     0x7f
 
 #define SPEED_2500_BLWC                        1
 #define SPEED_2500_CDR                 0x2
@@ -189,6 +193,8 @@ MODULE_DESCRIPTION("AMD 10GbE (amd-xgbe) PHY driver");
 #define SPEED_2500_RATE                        0x1
 #define SPEED_2500_TXAMP               0xf
 #define SPEED_2500_WORD                        0x1
+#define SPEED_2500_DFE_TAP_CONFIG      0x3
+#define SPEED_2500_DFE_TAP_ENABLE      0x0
 
 #define SPEED_1000_BLWC                        1
 #define SPEED_1000_CDR                 0x2
@@ -197,16 +203,25 @@ MODULE_DESCRIPTION("AMD 10GbE (amd-xgbe) PHY driver");
 #define SPEED_1000_RATE                        0x3
 #define SPEED_1000_TXAMP               0xf
 #define SPEED_1000_WORD                        0x1
+#define SPEED_1000_DFE_TAP_CONFIG      0x3
+#define SPEED_1000_DFE_TAP_ENABLE      0x0
 
 /* SerDes RxTx register offsets */
+#define RXTX_REG6                      0x0018
 #define RXTX_REG20                     0x0050
+#define RXTX_REG22                     0x0058
 #define RXTX_REG114                    0x01c8
+#define RXTX_REG129                    0x0204
 
 /* SerDes RxTx register entry bit positions and sizes */
+#define RXTX_REG6_RESETB_RXD_INDEX     8
+#define RXTX_REG6_RESETB_RXD_WIDTH     1
 #define RXTX_REG20_BLWC_ENA_INDEX      2
 #define RXTX_REG20_BLWC_ENA_WIDTH      1
 #define RXTX_REG114_PQ_REG_INDEX       9
 #define RXTX_REG114_PQ_REG_WIDTH       7
+#define RXTX_REG129_RXDFE_CONFIG_INDEX 14
+#define RXTX_REG129_RXDFE_CONFIG_WIDTH 2
 
 /* Bit setting and getting macros
  *  The get macro will extract the current bit field value from within
@@ -333,6 +348,18 @@ static const u32 amd_xgbe_phy_serdes_tx_amp[] = {
        SPEED_10000_TXAMP,
 };
 
+static const u32 amd_xgbe_phy_serdes_dfe_tap_cfg[] = {
+       SPEED_1000_DFE_TAP_CONFIG,
+       SPEED_2500_DFE_TAP_CONFIG,
+       SPEED_10000_DFE_TAP_CONFIG,
+};
+
+static const u32 amd_xgbe_phy_serdes_dfe_tap_ena[] = {
+       SPEED_1000_DFE_TAP_ENABLE,
+       SPEED_2500_DFE_TAP_ENABLE,
+       SPEED_10000_DFE_TAP_ENABLE,
+};
+
 enum amd_xgbe_phy_an {
        AMD_XGBE_AN_READY = 0,
        AMD_XGBE_AN_PAGE_RECEIVED,
@@ -393,6 +420,8 @@ struct amd_xgbe_phy_priv {
        u32 serdes_cdr_rate[XGBE_PHY_SPEEDS];
        u32 serdes_pq_skew[XGBE_PHY_SPEEDS];
        u32 serdes_tx_amp[XGBE_PHY_SPEEDS];
+       u32 serdes_dfe_tap_cfg[XGBE_PHY_SPEEDS];
+       u32 serdes_dfe_tap_ena[XGBE_PHY_SPEEDS];
 
        /* Auto-negotiation state machine support */
        struct mutex an_mutex;
@@ -481,11 +510,16 @@ static void amd_xgbe_phy_serdes_complete_ratechange(struct phy_device *phydev)
                status = XSIR0_IOREAD(priv, SIR0_STATUS);
                if (XSIR_GET_BITS(status, SIR0_STATUS, RX_READY) &&
                    XSIR_GET_BITS(status, SIR0_STATUS, TX_READY))
-                       return;
+                       goto rx_reset;
        }
 
        netdev_dbg(phydev->attached_dev, "SerDes rx/tx not ready (%#hx)\n",
                   status);
+
+rx_reset:
+       /* Perform Rx reset for the DFE changes */
+       XRXTX_IOWRITE_BITS(priv, RXTX_REG6, RESETB_RXD, 0);
+       XRXTX_IOWRITE_BITS(priv, RXTX_REG6, RESETB_RXD, 1);
 }
 
 static int amd_xgbe_phy_xgmii_mode(struct phy_device *phydev)
@@ -534,6 +568,10 @@ static int amd_xgbe_phy_xgmii_mode(struct phy_device *phydev)
                           priv->serdes_blwc[XGBE_PHY_SPEED_10000]);
        XRXTX_IOWRITE_BITS(priv, RXTX_REG114, PQ_REG,
                           priv->serdes_pq_skew[XGBE_PHY_SPEED_10000]);
+       XRXTX_IOWRITE_BITS(priv, RXTX_REG129, RXDFE_CONFIG,
+                          priv->serdes_dfe_tap_cfg[XGBE_PHY_SPEED_10000]);
+       XRXTX_IOWRITE(priv, RXTX_REG22,
+                     priv->serdes_dfe_tap_ena[XGBE_PHY_SPEED_10000]);
 
        amd_xgbe_phy_serdes_complete_ratechange(phydev);
 
@@ -586,6 +624,10 @@ static int amd_xgbe_phy_gmii_2500_mode(struct phy_device *phydev)
                           priv->serdes_blwc[XGBE_PHY_SPEED_2500]);
        XRXTX_IOWRITE_BITS(priv, RXTX_REG114, PQ_REG,
                           priv->serdes_pq_skew[XGBE_PHY_SPEED_2500]);
+       XRXTX_IOWRITE_BITS(priv, RXTX_REG129, RXDFE_CONFIG,
+                          priv->serdes_dfe_tap_cfg[XGBE_PHY_SPEED_2500]);
+       XRXTX_IOWRITE(priv, RXTX_REG22,
+                     priv->serdes_dfe_tap_ena[XGBE_PHY_SPEED_2500]);
 
        amd_xgbe_phy_serdes_complete_ratechange(phydev);
 
@@ -638,6 +680,10 @@ static int amd_xgbe_phy_gmii_mode(struct phy_device *phydev)
                           priv->serdes_blwc[XGBE_PHY_SPEED_1000]);
        XRXTX_IOWRITE_BITS(priv, RXTX_REG114, PQ_REG,
                           priv->serdes_pq_skew[XGBE_PHY_SPEED_1000]);
+       XRXTX_IOWRITE_BITS(priv, RXTX_REG129, RXDFE_CONFIG,
+                          priv->serdes_dfe_tap_cfg[XGBE_PHY_SPEED_1000]);
+       XRXTX_IOWRITE(priv, RXTX_REG22,
+                     priv->serdes_dfe_tap_ena[XGBE_PHY_SPEED_1000]);
 
        amd_xgbe_phy_serdes_complete_ratechange(phydev);
 
@@ -1668,6 +1714,38 @@ static int amd_xgbe_phy_probe(struct phy_device *phydev)
                       sizeof(priv->serdes_tx_amp));
        }
 
+       if (device_property_present(phy_dev, XGBE_PHY_DFE_CFG_PROPERTY)) {
+               ret = device_property_read_u32_array(phy_dev,
+                                                    XGBE_PHY_DFE_CFG_PROPERTY,
+                                                    priv->serdes_dfe_tap_cfg,
+                                                    XGBE_PHY_SPEEDS);
+               if (ret) {
+                       dev_err(dev, "invalid %s property\n",
+                               XGBE_PHY_DFE_CFG_PROPERTY);
+                       goto err_sir1;
+               }
+       } else {
+               memcpy(priv->serdes_dfe_tap_cfg,
+                      amd_xgbe_phy_serdes_dfe_tap_cfg,
+                      sizeof(priv->serdes_dfe_tap_cfg));
+       }
+
+       if (device_property_present(phy_dev, XGBE_PHY_DFE_ENA_PROPERTY)) {
+               ret = device_property_read_u32_array(phy_dev,
+                                                    XGBE_PHY_DFE_ENA_PROPERTY,
+                                                    priv->serdes_dfe_tap_ena,
+                                                    XGBE_PHY_SPEEDS);
+               if (ret) {
+                       dev_err(dev, "invalid %s property\n",
+                               XGBE_PHY_DFE_ENA_PROPERTY);
+                       goto err_sir1;
+               }
+       } else {
+               memcpy(priv->serdes_dfe_tap_ena,
+                      amd_xgbe_phy_serdes_dfe_tap_ena,
+                      sizeof(priv->serdes_dfe_tap_ena));
+       }
+
        phydev->priv = priv;
 
        if (!priv->adev || acpi_disabled)