net: stmmac: xgmac: Enable support for multiple Flexible PPS outputs

[ 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@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Furong Xu <0x1207@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
index 1913385df6856a26ad6915471bd7943de19aba44..880a75bf2eb1f03bd85e66a8eafd17b5b2e018c9 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
@@ -222,7 +222,7 @@
        ((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 c6c4d7948fe5f56dff0b3e516d86a218230e7abd..f30e08a106cbe608b085079d13c5db555fb12c17 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -1135,7 +1135,19 @@ 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));