[PATCH net-next v3 5/9] net: stmmac: mediatek: add RX/TX delay stage divider in platform data

From: Louis-Alexis Eyraud

Date: Fri Oct 16 2026 - 06:38:32 EST


In preparation of newer SoC support, that have like MT8189 SoC
different RX and TX internal delay stage steps than MT8188/MT8195, add
the RX and TX delay stage divider values in the variant platform data
and replace the hardcoded value uses in mt2712_set_delay and
mt8195_set_delay.

Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@xxxxxxxxxxxxx>
---
.../net/ethernet/stmicro/stmmac/dwmac-mediatek.c | 46 ++++++++++++++++++----
1 file changed, 38 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
index 596411d4a5b2..cb5bda53edb9 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
@@ -108,6 +108,10 @@ struct mediatek_dwmac_variant {

u32 rx_delay_max;
u32 tx_delay_max;
+ u16 rx_rmii_delay_stage_div;
+ u16 tx_rmii_delay_stage_div;
+ u16 rx_rgmii_delay_stage_div;
+ u16 tx_rgmii_delay_stage_div;
u8 dma_bit_mask;
};

@@ -146,14 +150,22 @@ static int mt2712_set_delay(struct mediatek_dwmac_plat_data *plat)
u32 fine_val = 0;

if (phy_interface_mode_is_rgmii(plat->phy_mode)) {
- rx_delay_stage_div = MT2712_RGMII_DLY_RXC_STAGE_DIV;
- tx_delay_stage_div = MT2712_RGMII_DLY_TXC_STAGE_DIV;
+ rx_delay_stage_div = plat->variant->rx_rgmii_delay_stage_div;
+ tx_delay_stage_div = plat->variant->tx_rgmii_delay_stage_div;
} else {
- rx_delay_stage_div = MT2712_RMII_DLY_RXC_STAGE_DIV;
- tx_delay_stage_div = MT2712_RMII_DLY_TXC_STAGE_DIV;
+ rx_delay_stage_div = plat->variant->rx_rmii_delay_stage_div;
+ tx_delay_stage_div = plat->variant->tx_rmii_delay_stage_div;
}
- rx_delay_stage_val = mac_delay->rx_delay / rx_delay_stage_div;
- tx_delay_stage_val = mac_delay->tx_delay / tx_delay_stage_div;
+
+ if (rx_delay_stage_div)
+ rx_delay_stage_val = mac_delay->rx_delay / rx_delay_stage_div;
+ else
+ rx_delay_stage_val = 0;
+
+ if (tx_delay_stage_div)
+ tx_delay_stage_val = mac_delay->tx_delay / tx_delay_stage_div;
+ else
+ tx_delay_stage_val = 0;

switch (plat->phy_mode) {
case PHY_INTERFACE_MODE_MII:
@@ -258,6 +270,10 @@ static const struct mediatek_dwmac_variant mt2712_gmac_variant = {
.num_clks = ARRAY_SIZE(mt2712_dwmac_clk_l),
.rx_delay_max = MT2712_RGMII_DLY_RXC_MAX,
.tx_delay_max = MT2712_RGMII_DLY_TXC_MAX,
+ .rx_rmii_delay_stage_div = MT2712_RMII_DLY_RXC_STAGE_DIV,
+ .tx_rmii_delay_stage_div = MT2712_RMII_DLY_TXC_STAGE_DIV,
+ .rx_rgmii_delay_stage_div = MT2712_RGMII_DLY_RXC_STAGE_DIV,
+ .tx_rgmii_delay_stage_div = MT2712_RMII_DLY_TXC_STAGE_DIV,
.dma_bit_mask = 33,
};

@@ -283,13 +299,25 @@ static int mt8195_set_interface(struct mediatek_dwmac_plat_data *plat,

static int mt8195_set_delay(struct mediatek_dwmac_plat_data *plat)
{
+ u16 rx_delay_stage_div = plat->variant->rx_rgmii_delay_stage_div;
+ u16 tx_delay_stage_div = plat->variant->tx_rgmii_delay_stage_div;
struct mac_delay_struct *mac_delay = &plat->mac_delay;
- u32 rx_delay_stage_val = mac_delay->rx_delay / MT8195_DLY_RXC_STAGE_DIV;
- u32 tx_delay_stage_val = mac_delay->tx_delay / MT8195_DLY_TXC_STAGE_DIV;
+ u32 rx_delay_stage_val;
+ u32 tx_delay_stage_val;
u32 gtxc_delay_val = 0;
u32 rmii_delay_val = 0;
u32 delay_val = 0;

+ if (rx_delay_stage_div)
+ rx_delay_stage_val = mac_delay->rx_delay / rx_delay_stage_div;
+ else
+ rx_delay_stage_val = 0;
+
+ if (tx_delay_stage_div)
+ tx_delay_stage_val = mac_delay->tx_delay / tx_delay_stage_div;
+ else
+ tx_delay_stage_val = 0;
+
switch (plat->phy_mode) {
case PHY_INTERFACE_MODE_MII:
delay_val |= FIELD_PREP(MT8195_DLY_TXC_ENABLE,
@@ -398,6 +426,8 @@ static const struct mediatek_dwmac_variant mt8195_gmac_variant = {
.num_clks = ARRAY_SIZE(mt8195_dwmac_clk_l),
.rx_delay_max = MT8195_DLY_RXC_MAX,
.tx_delay_max = MT8195_DLY_TXC_MAX,
+ .rx_rgmii_delay_stage_div = MT8195_DLY_RXC_STAGE_DIV,
+ .tx_rgmii_delay_stage_div = MT8195_DLY_TXC_STAGE_DIV,
.dma_bit_mask = 35,
};


--
2.56.0