net: stmmac: dwmac-starfive: Add support for JH7100 SoC

Add a missing quirk to enable support for the StarFive JH7100 SoC.

Additionally, for greater flexibility in operation, allow using the
rgmii-rxid and rgmii-txid phy modes.
Co-developed-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/Kconfig

@@ -165,9 +165,9 @@ config DWMAC_STARFIVE
 	help
 	  Support for ethernet controllers on StarFive RISC-V SoCs
 
-	  This selects the StarFive platform specific glue layer support for
-	  the stmmac device driver. This driver is used for StarFive JH7110
-	  ethernet controller.
+	  This selects the StarFive platform specific glue layer support
+	  for the stmmac device driver. This driver is used for the
+	  StarFive JH7100 and JH7110 ethernet controllers.
 
 config DWMAC_STI
 	tristate "STi GMAC support"

drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c

@@ -19,9 +19,16 @@
 #define STARFIVE_DWMAC_PHY_INFT_RMII		0x4
 #define STARFIVE_DWMAC_PHY_INFT_FIELD		0x7U
 
+#define JH7100_SYSMAIN_REGISTER49_DLYCHAIN	0xc8
+
+struct starfive_dwmac_data {
+	unsigned int gtxclk_dlychain;
+};
+
 struct starfive_dwmac {
 	struct device *dev;
 	struct clk *clk_tx;
+	const struct starfive_dwmac_data *data;
 };
 
 static void starfive_dwmac_fix_mac_speed(void *priv, unsigned int speed, unsigned int mode)
@@ -67,6 +74,8 @@ static int starfive_dwmac_set_mode(struct plat_stmmacenet_data *plat_dat)
 
 	case PHY_INTERFACE_MODE_RGMII:
 	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
 		mode = STARFIVE_DWMAC_PHY_INFT_RGMII;
 		break;
 
@@ -89,6 +98,14 @@ static int starfive_dwmac_set_mode(struct plat_stmmacenet_data *plat_dat)
 	if (err)
 		return dev_err_probe(dwmac->dev, err, "error setting phy mode\n");
 
+	if (dwmac->data) {
+		err = regmap_write(regmap, JH7100_SYSMAIN_REGISTER49_DLYCHAIN,
+				   dwmac->data->gtxclk_dlychain);
+		if (err)
+			return dev_err_probe(dwmac->dev, err,
+					     "error selecting gtxclk delay chain\n");
+	}
+
 	return 0;
 }
 
@@ -114,6 +131,8 @@ static int starfive_dwmac_probe(struct platform_device *pdev)
 	if (!dwmac)
 		return -ENOMEM;
 
+	dwmac->data = device_get_match_data(&pdev->dev);
+
 	dwmac->clk_tx = devm_clk_get_enabled(&pdev->dev, "tx");
 	if (IS_ERR(dwmac->clk_tx))
 		return dev_err_probe(&pdev->dev, PTR_ERR(dwmac->clk_tx),
@@ -144,7 +163,12 @@ static int starfive_dwmac_probe(struct platform_device *pdev)
 	return stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 }
 
+static const struct starfive_dwmac_data jh7100_data = {
+	.gtxclk_dlychain = 4,
+};
+
 static const struct of_device_id starfive_dwmac_match[] = {
+	{ .compatible = "starfive,jh7100-dwmac", .data = &jh7100_data },
 	{ .compatible = "starfive,jh7110-dwmac" },
 	{ /* sentinel */ }
 };