On 1/12/22 19:11, Robert Hancock wrote:
The GEM controllers on ZynqMP were missing some initialization steps which
are required in some cases when using SGMII mode, which uses the PS-GTR
transceivers managed by the phy-zynqmp driver.
The GEM core appears to need a hardware-level reset in order to work
properly in SGMII mode in cases where the GT reference clock was not
present at initial power-on. This can be done using a reset mapped to
the zynqmp-reset driver in the device tree.
Also, when in SGMII mode, the GEM driver needs to ensure the PHY is
initialized and powered on when it is initializing.
Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx>
---
drivers/net/ethernet/cadence/macb_main.c | 47 +++++++++++++++++++++++-
1 file changed, 46 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index a363da928e8b..65b0360c487a 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -34,7 +34,9 @@
#include <linux/udp.h>
#include <linux/tcp.h>
#include <linux/iopoll.h>
+#include <linux/phy/phy.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include "macb.h"
/* This structure is only used for MACB on SiFive FU540 devices */
@@ -4455,6 +4457,49 @@ static int fu540_c000_init(struct platform_device *pdev)
return macb_init(pdev);
}
+static int zynqmp_init(struct platform_device *pdev)
+{
+ struct net_device *dev = platform_get_drvdata(pdev);
+ struct macb *bp = netdev_priv(dev);
+ int ret;
+
+ /* Fully reset GEM controller at hardware level using zynqmp-reset driver,
+ * if mapped in device tree.
+ */
+ ret = device_reset(&pdev->dev);
+ if (ret) {
+ dev_err_probe(&pdev->dev, ret, "failed to reset controller");
+ return ret;
+ }
+
+ if (bp->phy_interface == PHY_INTERFACE_MODE_SGMII) {
+ /* Ensure PS-GTR PHY device used in SGMII mode is ready */
+ struct phy *sgmii_phy = devm_phy_get(&pdev->dev, "sgmii-phy");
+
+ if (IS_ERR(sgmii_phy)) {
+ ret = PTR_ERR(sgmii_phy);
+ dev_err_probe(&pdev->dev, ret,
+ "failed to get PS-GTR PHY\n");
+ return ret;
+ }
+
+ ret = phy_init(sgmii_phy);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to init PS-GTR PHY: %d\n",
+ ret);
+ return ret;
+ }
I was playing with it recently on u-boot side and device reset should happen
between phy init and phy power on to finish calibration.
At least that's I was told and that's I use in u-boot driver.
Harini/Piyush: Please correct me if I am wrong.
Thanks,
Michal
