[v3,5/8] net: stmmac: dwmac-meson8b: Add the PRG_ETH0_ADJ_* bits
diff mbox series

Message ID 20200512211103.530674-6-martin.blumenstingl@googlemail.com
State Accepted
Commit c92d1d2311a0513d8f7f8311f5c2b1d7e78005a0
Headers show
  • dwmac-meson8b Ethernet RX delay configuration
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Commit Message

Martin Blumenstingl May 12, 2020, 9:11 p.m. UTC
The PRG_ETH0_ADJ_* are used for applying the RGMII RX delay. The public
datasheets only have very limited description for these registers, but
Jianxin Pan provided more detailed documentation from an (unnamed)
Amlogic engineer. Add the PRG_ETH0_ADJ_* bits along with the improved

Suggested-by: Jianxin Pan <jianxin.pan@amlogic.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
 .../ethernet/stmicro/stmmac/dwmac-meson8b.c   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff mbox series

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
index 1d7526ee09dd..70075628c58e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
@@ -48,6 +48,27 @@ 
+/* Bypass (= 0, the signal from the GPIO input directly connects to the
+ * internal sampling) or enable (= 1) the internal logic for RXEN and RXD[3:0]
+ * timing tuning.
+ */
+#define PRG_ETH0_ADJ_ENABLE		BIT(13)
+/* Controls whether the RXEN and RXD[3:0] signals should be aligned with the
+ * input RX rising/falling edge and sent to the Ethernet internals. This sets
+ * the automatically delay and skew automatically (internally).
+ */
+#define PRG_ETH0_ADJ_SETUP		BIT(14)
+/* An internal counter based on the "timing-adjustment" clock. The counter is
+ * cleared on both, the falling and rising edge of the RX_CLK. This selects the
+ * delay (= the counter value) when to start sampling RXEN and RXD[3:0].
+ */
+#define PRG_ETH0_ADJ_DELAY		GENMASK(19, 15)
+/* Adjusts the skew between each bit of RXEN and RXD[3:0]. If a signal has a
+ * large input delay, the bit for that signal (RXEN = bit 0, RXD[3] = bit 1,
+ * ...) can be configured to be 1 to compensate for a delay of about 1ns.
+ */
+#define PRG_ETH0_ADJ_SKEW		GENMASK(24, 20)
 struct meson8b_dwmac;