[PATCH] net: stmmac: dwmac-meson8b: add calibration registers

[PATCH] net: stmmac: dwmac-meson8b: add calibration registers

[Martin Blumenstingl]

The Amlogic dwmac Ethernet IP glue has two registers:
- PRG_ETH0 with various configuration bits
- PRG_ETH1 with various calibration and information related bits

Add the register definitions with comments from different drivers in
Amlogic's vendor u-boot and Linux.

The most important part is PRG_ETH1_AUTO_CALI_IDX_VAL which is needed on
G12A (and later: G12B, SM1) with RGMII PHYs. Ethernet is only working up
to 100Mbit/s speeds if u-boot does not initialize these bits correctly.
On 1Gbit/s links no traffic is flowing (similar to when the RGMII delays
are set incorrectly). The logic to write this register will be added
later.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 .../ethernet/stmicro/stmmac/dwmac-meson8b.c   | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
index 5afcf05bbf9c..9a898d2a1e08 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c
@@ -69,6 +69,34 @@
  */
 #define PRG_ETH0_ADJ_SKEW		GENMASK(24, 20)
 
+#define PRG_ETH0_START_CALIBRATION	BIT(25)
+
+/* 0: falling edge, 1: rising edge */
+#define PRG_ETH0_TEST_EDGE		BIT(26)
+
+/* Select one signal from {RXDV, RXD[3:0]} to calibrate */
+#define PRG_ETH0_SIGNAL_TO_CALIBRATE	GENMASK(29, 27)
+
+#define PRG_ETH1			0x4
+
+/* Signal switch position in 1ns resolution */
+#define PRG_ETH1_SIGNAL_SWITCH_POSITION	GENMASK(4, 0)
+
+/* RXC (RX clock) length in 1ns resolution */
+#define PRG_ETH1_RX_CLK_LENGTH		GENMASK(9, 5)
+
+#define PRG_ETH1_CALI_WAITING_FOR_EVENT	BIT(10)
+
+#define PRG_ETH1_SIGNAL_UNDER_TEST	GENMASK(13, 11)
+
+/* 0: falling edge, 1: rising edge */
+#define PRG_ETH1_RESULT_EDGE		BIT(14)
+
+#define PRG_ETH1_RESULT_IS_VALID	BIT(15)
+
+/* undocumented - only valid on G12A and later */
+#define PRG_ETH1_AUTO_CALI_IDX_VAL	GENMASK(19, 16)
+
 struct meson8b_dwmac;
 
 struct meson8b_dwmac_data {
-- 
2.28.0


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Re: [PATCH] net: stmmac: dwmac-meson8b: add calibration registers

[David Miller]

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date: Fri, 25 Sep 2020 23:56:29 +0200

> The Amlogic dwmac Ethernet IP glue has two registers:
> - PRG_ETH0 with various configuration bits
> - PRG_ETH1 with various calibration and information related bits
> 
> Add the register definitions with comments from different drivers in
> Amlogic's vendor u-boot and Linux.
> 
> The most important part is PRG_ETH1_AUTO_CALI_IDX_VAL which is needed on
> G12A (and later: G12B, SM1) with RGMII PHYs. Ethernet is only working up
> to 100Mbit/s speeds if u-boot does not initialize these bits correctly.
> On 1Gbit/s links no traffic is flowing (similar to when the RGMII delays
> are set incorrectly). The logic to write this register will be added
> later.
> 
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

Please add these definitions alongside actual uses of them.

Thank you.

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