[PATCH net-next v3 8/9] net: stmmac: mediatek: add support for TX clock output enable feature

[Louis-Alexis Eyraud]

The MT8189 SoC has in the Ethernet control 0 register from the
peripheral configuration (pericfg) an additional bit to enable the TX
clock signal output.

In preparation of MT8189 SoC support, add its definition, use in the
mt8195_set_interface callback, and a support flag in the platform
data.

Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@xxxxxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
index 4b2d5280f703..147e217b8662 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
@@ -44,6 +44,9 @@
 #define MT2712_RGMII_DLY_TXC_STAGE_DIV	550 /* 550ps per stage */
 #define MT2712_RGMII_DLY_TXC_MAX	17600 /* 32 x 550ps */
 
+/* Peri Configuration register for mt8189 */
+#define MT8189_CTRL0_TXC_OUT_OP_EN	BIT(20)
+
 /* Peri Configuration register for mt8195 */
 #define MT8195_PERI_ETH_CTRL_OFFSET	0xFD0
 
@@ -119,6 +122,7 @@ struct mediatek_dwmac_variant {
 	u16 rx_rgmii_delay_stage_div;
 	u16 tx_rgmii_delay_stage_div;
 	u8 dma_bit_mask;
+	bool mac_txclk_out_en;
 };
 
 /* list of clocks required for mac */
@@ -299,6 +303,9 @@ static int mt8195_set_interface(struct mediatek_dwmac_plat_data *plat,
 	/* MT8195 only support external PHY */
 	intf_val |= MT8195_EXT_PHY_MODE;
 
+	if (plat->variant->mac_txclk_out_en)
+		intf_val |= MT8189_CTRL0_TXC_OUT_OP_EN;
+
 	regmap_write(plat->peri_regmap,
 		     reg_offset + MT8195_PERI_ETH_CTRL0,
 		     intf_val);

-- 
2.56.0