net: stmmac: dwmac-imx: enable MAC propagation delay correction for i.MX8MP

As the i.MX8MP supports reading MAC propagation delay and correcting the
Hardware timestamp counter for additional delays [1], enable the feature
for this SoC.

This reduces phase error of the PPS output from the PTP Hardware Clock
from approx 150ns to 100ns.

[1] i.MX8MP Reference Manual, rev.1 Section 11.7.2.5.3 "Timestamp
correction"

Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
Link: https://lore.kernel.org/r/20230719-stmmac_correct_mac_delay-v3-2-61e63427735e@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
index 92e06a9..645a945 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
@@ -42,6 +42,7 @@
 
 struct imx_dwmac_ops {
        u32 addr_width;
+       u32 flags;
        bool mac_rgmii_txclk_auto_adj;
 
        int (*fix_soc_reset)(void *priv, void __iomem *ioaddr);
@@ -311,6 +312,9 @@ static int imx_dwmac_probe(struct platform_device *pdev)
                goto err_parse_dt;
        }
 
+       if (data->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
+               plat_dat->flags |= STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY;
+
        plat_dat->host_dma_width = dwmac->ops->addr_width;
        plat_dat->init = imx_dwmac_init;
        plat_dat->exit = imx_dwmac_exit;
@@ -350,6 +354,7 @@ static struct imx_dwmac_ops imx8mp_dwmac_data = {
        .addr_width = 34,
        .mac_rgmii_txclk_auto_adj = false,
        .set_intf_mode = imx8mp_set_intf_mode,
+       .flags = STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY,
 };
 
 static struct imx_dwmac_ops imx8dxl_dwmac_data = {