1 files changed, 71 insertions, 20 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
index f184b00f5116..848e5c37746b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
@@ -68,10 +68,21 @@
  */
 #define PRG_ETH0_ADJ_SKEW		GENMASK(24, 20)
 
+#define PRG_ETH1			0x4
+
+/* Defined for adding a delay to the input RX_CLK for better timing.
+ * Each step is 200ps. These bits are used with external RGMII PHYs
+ * because RGMII RX only has the small window. cfg_rxclk_dly can
+ * adjust the window between RX_CLK and RX_DATA and improve the stability
+ * of "rx data valid".
+ */
+#define PRG_ETH1_CFG_RXCLK_DLY		GENMASK(19, 16)
+
 struct meson8b_dwmac;
 
 struct meson8b_dwmac_data {
 	int (*set_phy_mode)(struct meson8b_dwmac *dwmac);
+	bool has_prg_eth1_rgmii_rx_delay;
 };
 
 struct meson8b_dwmac {
@@ -82,7 +93,7 @@ struct meson8b_dwmac {
 	phy_interface_t			phy_mode;
 	struct clk			*rgmii_tx_clk;
 	u32				tx_delay_ns;
-	u32				rx_delay_ns;
+	u32				rx_delay_ps;
 	struct clk			*timing_adj_clk;
 };
 
@@ -268,32 +279,37 @@ static int meson8b_devm_clk_prepare_enable(struct meson8b_dwmac *dwmac,
 	return 0;
 }
 
-static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
+static int meson8b_init_rgmii_delays(struct meson8b_dwmac *dwmac)
 {
-	u32 tx_dly_config, rx_dly_config, delay_config;
+	u32 tx_dly_config, rx_adj_config, cfg_rxclk_dly, delay_config;
 	int ret;
 
+	rx_adj_config = 0;
+	cfg_rxclk_dly = 0;
 	tx_dly_config = FIELD_PREP(PRG_ETH0_TXDLY_MASK,
 				   dwmac->tx_delay_ns >> 1);
 
-	if (dwmac->rx_delay_ns == 2)
-		rx_dly_config = PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP;
-	else
-		rx_dly_config = 0;
+	if (dwmac->data->has_prg_eth1_rgmii_rx_delay)
+		cfg_rxclk_dly = FIELD_PREP(PRG_ETH1_CFG_RXCLK_DLY,
+					   dwmac->rx_delay_ps / 200);
+	else if (dwmac->rx_delay_ps == 2000)
+		rx_adj_config = PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP;
 
 	switch (dwmac->phy_mode) {
 	case PHY_INTERFACE_MODE_RGMII:
-		delay_config = tx_dly_config | rx_dly_config;
+		delay_config = tx_dly_config | rx_adj_config;
 		break;
 	case PHY_INTERFACE_MODE_RGMII_RXID:
 		delay_config = tx_dly_config;
+		cfg_rxclk_dly = 0;
 		break;
 	case PHY_INTERFACE_MODE_RGMII_TXID:
-		delay_config = rx_dly_config;
+		delay_config = rx_adj_config;
 		break;
 	case PHY_INTERFACE_MODE_RGMII_ID:
 	case PHY_INTERFACE_MODE_RMII:
 		delay_config = 0;
+		cfg_rxclk_dly = 0;
 		break;
 	default:
 		dev_err(dwmac->dev, "unsupported phy-mode %s\n",
@@ -301,7 +317,7 @@ static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
 		return -EINVAL;
 	}
 
-	if (rx_dly_config & PRG_ETH0_ADJ_ENABLE) {
+	if (delay_config & PRG_ETH0_ADJ_ENABLE) {
 		if (!dwmac->timing_adj_clk) {
 			dev_err(dwmac->dev,
 				"The timing-adjustment clock is mandatory for the RX delay re-timing\n");
@@ -323,6 +339,16 @@ static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
 				PRG_ETH0_ADJ_DELAY | PRG_ETH0_ADJ_SKEW,
 				delay_config);
 
+	meson8b_dwmac_mask_bits(dwmac, PRG_ETH1, PRG_ETH1_CFG_RXCLK_DLY,
+				cfg_rxclk_dly);
+
+	return 0;
+}
+
+static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
+{
+	int ret;
+
 	if (phy_interface_mode_is_rgmii(dwmac->phy_mode)) {
 		/* only relevant for RMII mode -> disable in RGMII mode */
 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
@@ -406,16 +432,30 @@ static int meson8b_dwmac_probe(struct platform_device *pdev)
 				 &dwmac->tx_delay_ns))
 		dwmac->tx_delay_ns = 2;
 
-	/* use 0ns as fallback since this is what most boards actually use */
-	if (of_property_read_u32(pdev->dev.of_node, "amlogic,rx-delay-ns",
-				 &dwmac->rx_delay_ns))
-		dwmac->rx_delay_ns = 0;
+	/* RX delay defaults to 0ps since this is what many boards use */
+	if (of_property_read_u32(pdev->dev.of_node, "rx-internal-delay-ps",
+				 &dwmac->rx_delay_ps)) {
+		if (!of_property_read_u32(pdev->dev.of_node,
+					  "amlogic,rx-delay-ns",
+					  &dwmac->rx_delay_ps))
+			/* convert ns to ps */
+			dwmac->rx_delay_ps *= 1000;
+	}
 
-	if (dwmac->rx_delay_ns != 0 && dwmac->rx_delay_ns != 2) {
-		dev_err(&pdev->dev,
-			"The only allowed RX delays values are: 0ns, 2ns");
-		ret = -EINVAL;
-		goto err_remove_config_dt;
+	if (dwmac->data->has_prg_eth1_rgmii_rx_delay) {
+		if (dwmac->rx_delay_ps > 3000 || dwmac->rx_delay_ps % 200) {
+			dev_err(dwmac->dev,
+				"The RGMII RX delay range is 0..3000ps in 200ps steps");
+			ret = -EINVAL;
+			goto err_remove_config_dt;
+		}
+	} else {
+		if (dwmac->rx_delay_ps != 0 && dwmac->rx_delay_ps != 2000) {
+			dev_err(dwmac->dev,
+				"The only allowed RGMII RX delays values are: 0ps, 2000ps");
+			ret = -EINVAL;
+			goto err_remove_config_dt;
+		}
 	}
 
 	dwmac->timing_adj_clk = devm_clk_get_optional(dwmac->dev,
@@ -425,6 +465,10 @@ static int meson8b_dwmac_probe(struct platform_device *pdev)
 		goto err_remove_config_dt;
 	}
 
+	ret = meson8b_init_rgmii_delays(dwmac);
+	if (ret)
+		goto err_remove_config_dt;
+
 	ret = meson8b_init_rgmii_tx_clk(dwmac);
 	if (ret)
 		goto err_remove_config_dt;
@@ -453,10 +497,17 @@ err_remove_config_dt:
 
 static const struct meson8b_dwmac_data meson8b_dwmac_data = {
 	.set_phy_mode = meson8b_set_phy_mode,
+	.has_prg_eth1_rgmii_rx_delay = false,
 };
 
 static const struct meson8b_dwmac_data meson_axg_dwmac_data = {
 	.set_phy_mode = meson_axg_set_phy_mode,
+	.has_prg_eth1_rgmii_rx_delay = false,
+};
+
+static const struct meson8b_dwmac_data meson_g12a_dwmac_data = {
+	.set_phy_mode = meson_axg_set_phy_mode,
+	.has_prg_eth1_rgmii_rx_delay = true,
 };
 
 static const struct of_device_id meson8b_dwmac_match[] = {
@@ -478,7 +529,7 @@ static const struct of_device_id meson8b_dwmac_match[] = {
 	},
 	{
 		.compatible = "amlogic,meson-g12a-dwmac",
-		.data = &meson_axg_dwmac_data,
+		.data = &meson_g12a_dwmac_data,
 	},
 	{ }
 };