[PATCH net-next v4 09/10] net: stmmac: mediatek: add support for TX clock output enable feature

[Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>]

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@collabora.com>
---
 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 0426a0876956..8ee850791270 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
@@ -41,6 +41,9 @@
 #define MT2712_RGMII_DLY_STAGE_DIV	170 /* 170ps per stage */
 #define MT2712_RGMII_DELAY_MAX		5440 /* 32 x 170ps */
 
+/* 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
 
@@ -113,6 +116,7 @@ struct mediatek_dwmac_variant {
 	u16 rgmii_delay_stage_div;
 	u32 peri_eth_ctrl_offset;
 	u8 dma_bit_mask;
+	bool mac_txclk_out_en;
 };
 
 /* list of clocks required for mac */
@@ -307,6 +311,9 @@ 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