[PATCH v4 2/2] net: stmmac: dwmac-imx: use platform specific reset for imx93 SoCs

[Shenwei Wang]

The patch addresses an issue with the reset logic on the i.MX93 SoC, which
requires configuration of the correct interface speed under RMII mode to
complete the reset. The patch implements a fix_soc_reset function and uses
it specifically for the i.MX93 SoCs.

Reviewed-by: Fabio Estevam <festevam at gmail.com>
Signed-off-by: Shenwei Wang <shenwei.wang at nxp.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-imx.c   | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
index ac8580f501e2..ebab2ced5422 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
@@ -37,10 +37,15 @@
 #define MX93_GPR_ENET_QOS_INTF_SEL_RGMII	(0x1 << 1)
 #define MX93_GPR_ENET_QOS_CLK_GEN_EN		(0x1 << 0)

+#define DMA_BUS_MODE			0x00001000
+#define DMA_BUS_MODE_SFT_RESET		(0x1 << 0)
+#define RMII_RESET_SPEED		(0x3 << 14)
+
 struct imx_dwmac_ops {
 	u32 addr_width;
 	bool mac_rgmii_txclk_auto_adj;

+	int (*fix_soc_reset)(void *priv, void __iomem *ioaddr);
 	int (*set_intf_mode)(struct plat_stmmacenet_data *plat_dat);
 };

@@ -207,6 +212,25 @@ static void imx_dwmac_fix_speed(void *priv, unsigned int speed)
 		dev_err(dwmac->dev, "failed to set tx rate %lu\n", rate);
 }

+static int imx_dwmac_mx93_reset(void *priv, void __iomem *ioaddr)
+{
+	u32 value = readl(ioaddr + DMA_BUS_MODE);
+	struct plat_stmmacenet_data *plat_dat = priv;
+
+	/* DMA SW reset */
+	value |= DMA_BUS_MODE_SFT_RESET;
+	writel(value, ioaddr + DMA_BUS_MODE);
+
+	if (plat_dat->interface == PHY_INTERFACE_MODE_RMII) {
+		usleep_range(100, 200);
+		writel(RMII_RESET_SPEED, ioaddr + MAC_CTRL_REG);
+	}
+
+	return readl_poll_timeout(ioaddr + DMA_BUS_MODE, value,
+				 !(value & DMA_BUS_MODE_SFT_RESET),
+				 10000, 1000000);
+}
+
 static int
 imx_dwmac_parse_dt(struct imx_priv_data *dwmac, struct device *dev)
 {
@@ -305,6 +329,8 @@ static int imx_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_dwmac_init;

+	dwmac->plat_dat->fix_soc_reset = dwmac->ops->fix_soc_reset;
+
 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 	if (ret)
 		goto err_drv_probe;
@@ -338,6 +364,7 @@ static struct imx_dwmac_ops imx93_dwmac_data = {
 	.addr_width = 32,
 	.mac_rgmii_txclk_auto_adj = true,
 	.set_intf_mode = imx93_set_intf_mode,
+	.fix_soc_reset = imx_dwmac_mx93_reset,
 };

 static const struct of_device_id imx_dwmac_match[] = {
--
2.34.1