6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Furong Xu <0x1207@xxxxxxxxx>
[ Upstream commit db456d90a4c1b43b6251fa4348c8adc59b583274 ]
>From XGMAC Core 3.20 and later, each Flexible PPS has individual PPSEN bit
to select Fixed mode or Flexible mode. The PPSEN must be set, or it stays
in Fixed PPS mode by default.
XGMAC Core prior 3.20, only PPSEN0(bit 4) is writable. PPSEN{1,2,3} are
read-only reserved, and they are already in Flexible mode by default, our
new code always set PPSEN{1,2,3} do not make things worse ;-)
Fixes: 95eaf3cd0a90 ("net: stmmac: dwxgmac: Add Flexible PPS support")
Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx>
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Signed-off-by: Furong Xu <0x1207@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h | 2 +-
.../net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 14 +++++++++++++-
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
index 7a8f47e7b728b..a4e8b498dea96 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
@@ -259,7 +259,7 @@
((val) << XGMAC_PPS_MINIDX(x))
#define XGMAC_PPSCMD_START 0x2
#define XGMAC_PPSCMD_STOP 0x5
-#define XGMAC_PPSEN0 BIT(4)
+#define XGMAC_PPSENx(x) BIT(4 + (x) * 8)
#define XGMAC_PPSx_TARGET_TIME_SEC(x) (0x00000d80 + (x) * 0x10)
#define XGMAC_PPSx_TARGET_TIME_NSEC(x) (0x00000d84 + (x) * 0x10)
#define XGMAC_TRGTBUSY0 BIT(31)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index f352be269deb5..453e88b75be08 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -1178,7 +1178,19 @@ static int dwxgmac2_flex_pps_config(void __iomem *ioaddr, int index,
val |= XGMAC_PPSCMDx(index, XGMAC_PPSCMD_START);
val |= XGMAC_TRGTMODSELx(index, XGMAC_PPSCMD_START);
- val |= XGMAC_PPSEN0;
+
+ /* XGMAC Core has 4 PPS outputs at most.
+ *
+ * Prior XGMAC Core 3.20, Fixed mode or Flexible mode are selectable for
+ * PPS0 only via PPSEN0. PPS{1,2,3} are in Flexible mode by default,
+ * and can not be switched to Fixed mode, since PPSEN{1,2,3} are
+ * read-only reserved to 0.
+ * But we always set PPSEN{1,2,3} do not make things worse ;-)
+ *
+ * From XGMAC Core 3.20 and later, PPSEN{0,1,2,3} are writable and must
+ * be set, or the PPS outputs stay in Fixed PPS mode by default.
+ */
+ val |= XGMAC_PPSENx(index);
writel(cfg->start.tv_sec, ioaddr + XGMAC_PPSx_TARGET_TIME_SEC(index));
--
2.42.0
