[PATCH v5 08/12] net: stmmac: starfive_dmac: Add phy interface settings

[Samin Guo]

dwmac supports multiple modess. When working under rmii and rgmii,
you need to set different phy interfaces.

According to the dwmac document, when working in rmii, it needs to be
set to 0x4, and rgmii needs to be set to 0x1.

The phy interface needs to be set in syscon, the format is as follows:
starfive,syscon: <&syscon, offset, mask>

Signed-off-by: Samin Guo <samin.guo at starfivetech.com>
---
 .../ethernet/stmicro/stmmac/dwmac-starfive.c  | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
index 566378306f67..40fdd7036127 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
@@ -7,10 +7,15 @@
  *
  */
 
+#include <linux/mfd/syscon.h>
 #include <linux/of_device.h>
+#include <linux/regmap.h>
 
 #include "stmmac_platform.h"
 
+#define MACPHYC_PHY_INFT_RMII	0x4
+#define MACPHYC_PHY_INFT_RGMII	0x1
+
 struct starfive_dwmac {
 	struct device *dev;
 	struct clk *clk_tx;
@@ -53,6 +58,46 @@ static void starfive_eth_fix_mac_speed(void *priv, unsigned int speed)
 		dev_err(dwmac->dev, "failed to set tx rate %lu\n", rate);
 }
 
+static int starfive_dwmac_set_mode(struct plat_stmmacenet_data *plat_dat)
+{
+	struct starfive_dwmac *dwmac = plat_dat->bsp_priv;
+	struct of_phandle_args args;
+	struct regmap *regmap;
+	unsigned int reg, mask, mode;
+	int err;
+
+	switch (plat_dat->interface) {
+	case PHY_INTERFACE_MODE_RMII:
+		mode = MACPHYC_PHY_INFT_RMII;
+		break;
+
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+		mode = MACPHYC_PHY_INFT_RGMII;
+		break;
+
+	default:
+		dev_err(dwmac->dev, "Unsupported interface %d\n",
+			plat_dat->interface);
+	}
+
+	err = of_parse_phandle_with_fixed_args(dwmac->dev->of_node,
+					       "starfive,syscon", 2, 0, &args);
+	if (err) {
+		dev_dbg(dwmac->dev, "syscon reg not found\n");
+		return -EINVAL;
+	}
+
+	reg = args.args[0];
+	mask = args.args[1];
+	regmap = syscon_node_to_regmap(args.np);
+	of_node_put(args.np);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return regmap_update_bits(regmap, reg, mask, mode << __ffs(mask));
+}
+
 static int starfive_dwmac_probe(struct platform_device *pdev)
 {
 	struct plat_stmmacenet_data *plat_dat;
@@ -93,6 +138,7 @@ static int starfive_dwmac_probe(struct platform_device *pdev)
 	plat_dat->bsp_priv = dwmac;
 	plat_dat->dma_cfg->dche = true;
 
+	starfive_dwmac_set_mode(plat_dat);
 	err = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 	if (err) {
 		stmmac_remove_config_dt(pdev, plat_dat);
-- 
2.17.1