[PATCH] net: ti: am65-cpsw-nuss: Use dedicated port mode control registers

[Andreas Dannenberg]

The different CPSW sub-system Ethernet ports have different PHY mode
control registers. In order to allow the modes to get configured
independently only the register for the port in question must be
accessed, otherwise we would just be re-configuring the mode for port 1,
while leaving all others at their power-on defaults. Fix this issue by
adding a port-number based offset to the mode control base register
address based on the fact that the control registers for the different
ports are spaced exactly 0x4 bytes apart.

Fixes: 9d0dca1199d1 ("net: ethernet: ti: Introduce am654 gigabit eth switch subsystem driver")
Signed-off-by: Andreas Dannenberg <dannenberg at ti.com>
Reviewed-by: Siddharth Vadapalli <s-vadapalli at ti.com>
---
Driver changes bench-tested on an SK-AM62 EVM by iterating through
different variations of RGMII and RMII modes for CPSW ports 1 and 2 and
checking operation as well as CTRL_ENET1_CTRL and CTRL_ENET2_CTRL
control register contents from the U-Boot command line via 'md.l'.
Testing was done on top of today's 'next' branch.

 drivers/net/ti/am65-cpsw-nuss.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ti/am65-cpsw-nuss.c b/drivers/net/ti/am65-cpsw-nuss.c
index f674b0baa3..523a4c9f91 100644
--- a/drivers/net/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ti/am65-cpsw-nuss.c
@@ -223,6 +223,8 @@ out:
 	return phy->link;
 }
 
+#define AM65_GMII_SEL_PORT_OFFS(x)	(0x4 * ((x) - 1))
+
 #define AM65_GMII_SEL_MODE_MII		0
 #define AM65_GMII_SEL_MODE_RMII		1
 #define AM65_GMII_SEL_MODE_RGMII	2
@@ -233,11 +235,12 @@ static void am65_cpsw_gmii_sel_k3(struct am65_cpsw_priv *priv,
 				  phy_interface_t phy_mode, int slave)
 {
 	struct am65_cpsw_common	*common = priv->cpsw_common;
+	fdt_addr_t gmii_sel = common->gmii_sel + AM65_GMII_SEL_PORT_OFFS(slave);
 	u32 reg;
 	u32 mode = 0;
 	bool rgmii_id = false;
 
-	reg = readl(common->gmii_sel);
+	reg = readl(gmii_sel);
 
 	dev_dbg(common->dev, "old gmii_sel: %08x\n", reg);
 
@@ -273,9 +276,9 @@ static void am65_cpsw_gmii_sel_k3(struct am65_cpsw_priv *priv,
 	reg = mode;
 	dev_dbg(common->dev, "gmii_sel PHY mode: %u, new gmii_sel: %08x\n",
 		phy_mode, reg);
-	writel(reg, common->gmii_sel);
+	writel(reg, gmii_sel);
 
-	reg = readl(common->gmii_sel);
+	reg = readl(gmii_sel);
 	if (reg != mode)
 		dev_err(common->dev,
 			"gmii_sel PHY mode NOT SET!: requested: %08x, gmii_sel: %08x\n",
-- 
2.34.1