[Linux-stm32] [PATCH] net: stmmac: Fix PTP ref clock for Tegra234

[Jon Hunter]

Since commit 030ce919e114 ("net: stmmac: make sure that ptp_rate is not
0 before configuring timestamping") was added the following error is
observed on Tegra234:

 ERR KERN tegra-mgbe 6800000.ethernet eth0: Invalid PTP clock rate
 WARNING KERN tegra-mgbe 6800000.ethernet eth0: PTP init failed

It turns out that the Tegra234 device-tree binding defines the PTP ref
clock name as 'ptp-ref' and not 'ptp_ref' and the above commit now
exposes this and that the PTP clock is not configured correctly.

Ideally, we would rename the PTP ref clock for Tegra234 to fix this but
this will break backward compatibility with existing device-tree blobs.
Therefore, fix this by using the name 'ptp-ref' for devices that are
compatible with 'nvidia,tegra234-mgbe'.

Fixes: d8ca113724e7 ("net: stmmac: tegra: Add MGBE support")
Signed-off-by: Jon Hunter <jonathanh at nvidia.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index b80c1efdb323..f82a7d55ea0a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -635,8 +635,12 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 	}
 	clk_prepare_enable(plat->pclk);
 
+	if (of_device_is_compatible(np, "nvidia,tegra234-mgbe"))
+		plat->clk_ptp_ref = devm_clk_get(&pdev->dev, "ptp-ref");
+	else
+		plat->clk_ptp_ref = devm_clk_get(&pdev->dev, "ptp_ref");
+
 	/* Fall-back to main clock in case of no PTP ref is passed */
-	plat->clk_ptp_ref = devm_clk_get(&pdev->dev, "ptp_ref");
 	if (IS_ERR(plat->clk_ptp_ref)) {
 		plat->clk_ptp_rate = clk_get_rate(plat->stmmac_clk);
 		plat->clk_ptp_ref = NULL;
-- 
2.43.0