ram: ast2600: Improve ddr4 timing and signal quality

Adjust the following settings to get better timing and signal quality.

1. write DQS/DQ delay
- 1e6e2304[0]
- 1e6e2304[15:8]

2. read DQS/DQ delay
- 0x1e6e0298[0]
- 0x1e6e0298[15:8]

3. CLK/CA timing
- 0x1e6e01a8[31]

4. Read and write termination
- change RTT_ROM from 40 ohm to 48 ohm (MR1[10:8])
- change RTT_PARK from disable to 48 ohm (MR5[8:6])
- change RTT_WR from 120 ohm to disable (MR2[11:9])
- change PHY ODT from 40 ohm to 80 ohm (0x1e6e0130[10:8])

Note1: Both DDR-PHY and DDR controller have their own registers for DDR4
Mode Registers (MR0~MR6).  This patch introduces macros to synchronize
the MR value on both sides.

Note2: the waveform meansurement can be found in item #21 of Aspeed
AST26x0 Application note (AP note).

Review-by: Ryan Chen <ryan_chen@aspeedtech.com>
Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>

1 files changed, 138 insertions, 25 deletions

diff --git a/drivers/ram/aspeed/sdram_ast2600.c b/drivers/ram/aspeed/sdram_ast2600.c
index b09232a304..bda02d0629 100644
--- a/drivers/ram/aspeed/sdram_ast2600.c
+++ b/drivers/ram/aspeed/sdram_ast2600.c
@@ -20,6 +20,119 @@
 #define DDR_PHY_TBL_CHG_ADDR            0xaeeddeea
 #define DDR_PHY_TBL_END                 0xaeededed
 
+/**
+ * phyr030[18:16] - Ron PU (PHY side)
+ * phyr030[14:12] - Ron PD (PHY side)
+ *   b'000 : disable
+ *   b'001 : 240 ohm
+ *   b'010 : 120 ohm
+ *   b'011 : 80 ohm
+ *   b'100 : 60 ohm
+ *   b'101 : 48 ohm
+ *   b'110 : 40 ohm
+ *   b'111 : 34 ohm (default)
+ */
+#define PHY_RON				((0x7 << 16) | (0x7 << 12))
+
+/**
+ * phyr030[10:8] - ODT configuration (PHY side)
+ *   b'000 : ODT disabled
+ *   b'001 : 240 ohm
+ *   b'010 : 120 ohm
+ *   b'011 : 80 ohm (default)
+ *   b'100 : 60 ohm
+ *   b'101 : 48 ohm
+ *   b'110 : 40 ohm
+ *   b'111 : 34 ohm
+ */
+#define PHY_ODT				(0x3 << 8)
+
+/**
+ * MR1[2:1] output driver impedance
+ *   b'00 : 34 ohm (default)
+ *   b'01 : 48 ohm
+ */
+#define DRAM_RON			(0x0 << 1)
+
+/**
+ * DRAM ODT - synchronous ODT mode
+ *   RTT_WR: disable
+ *   RTT_NOM = RTT_PARK
+ *
+ * MR1[10:8] RTT_NOM
+ *   b'000 : RTT_NOM disable
+ *   b'001 : 60 ohm
+ *   b'010 : 120 ohm
+ *   b'011 : 40 ohm
+ *   b'100 : 240 ohm
+ *   b'101 : 48 ohm  (default)
+ *   b'110 : 80 ohm
+ *   b'111 : 34 ohm
+ *
+ * MR5[8:6] RTT_PARK
+ *   b'000 : RTT_PARK disable
+ *   b'001 : 60 ohm
+ *   b'010 : 120 ohm
+ *   b'011 : 40 ohm
+ *   b'100 : 240 ohm
+ *   b'101 : 48 ohm  (default)
+ *   b'110 : 80 ohm
+ *   b'111 : 34 ohm
+ *
+ * MR2[11:9] RTT_WR
+ *   b'000 : Dynamic ODT off  (default)
+ *   b'001 : 120 ohm
+ *   b'010 : 240 ohm
+ *   b'011 : Hi-Z
+ *   b'100 : 80 ohm
+ */
+#define RTT_WR				(0x0 << 9)
+#define RTT_NOM				(0x5 << 8)
+#define RTT_PARK			(0x5 << 6)
+
+/**
+ * MR6[6] VrefDQ training range
+ *   b'0 : range 1
+ *   b'1 : range 2 (default)
+ */
+#define VREFDQ_RANGE_2			BIT(6)
+
+/**
+ * Latency setting:
+ * AL = PL = 0 (hardware fixed setting)
+ * -> WL = AL + CWL + PL = CWL
+ * -> RL = AL + CL + PL = CL
+ */
+#define CONFIG_WL			9
+#define CONFIG_RL			12
+#define T_RDDATA_EN			((CONFIG_RL - 2) << 8)
+#define T_PHY_WRLAT			(CONFIG_WL - 2)
+
+/* MR0 */
+#define MR0_CL_12			(BIT(4) | BIT(2))
+#define MR0_WR12_RTP6			BIT(9)
+#define MR0_DLL_RESET			BIT(8)
+#define MR0_VAL				(MR0_CL_12 | MR0_WR12_RTP6 | MR0_DLL_RESET)
+
+/* MR1 */
+#define MR1_VAL				(0x0001 | RTT_NOM | DRAM_RON)
+
+/* MR2 */
+#define MR2_CWL_9			0
+#define MR2_VAL				(0x0000 | RTT_WR | MR2_CWL_9)
+
+/* MR3 ~ MR6 */
+#define MR3_VAL				0x0000
+#define MR4_VAL				0x0000
+#define MR5_VAL				(0x0400 | RTT_PARK)
+#define MR6_VAL				0x0400
+
+/**
+ * The offset value applied to the DDR PHY write data eye training result
+ * to fine-tune the write DQ/DQS alignment
+ */
+#define WR_DATA_EYE_OFFSET		(0x10 << 8)
+
 #if defined(CONFIG_ASPEED_DDR4_800)
 u32 ast2600_sdramphy_config[165] = {
 	0x1e6e0100,	// start address
@@ -35,7 +148,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x20000000,	// phyr024
 	0x00000008,	// phyr028
 	0x00000000,	// phyr02c
-	0x00077600,	// phyr030
+	(PHY_RON | PHY_ODT),	/* phyr030 */
 	0x00000000,	// phyr034
 	0x00000000,	// phyr038
 	0x20000000,	// phyr03c
@@ -44,18 +157,18 @@ u32 ast2600_sdramphy_config[165] = {
 	0x00002f07,	// phyr048
 	0x00003080,	// phyr04c
 	0x04000000,	// phyr050
-	0x00000200,	// phyr054
-	0x03140201,	// phyr058
-	0x04800000,	// phyr05c
-	0x0800044e,	// phyr060
+	((MR3_VAL << 16) | MR2_VAL),	/* phyr054 */
+	((MR0_VAL << 16) | MR1_VAL),	/* phyr058 */
+	((MR5_VAL << 16) | MR4_VAL),	/* phyr05c */
+	((0x0800 << 16) | MR6_VAL | VREFDQ_RANGE_2 | 0xe), /* phyr060 */
 	0x00000000,	// phyr064
 	0x00180008,	// phyr068
 	0x00e00400,	// phyr06c
 	0x00140206,	// phyr070
 	0x1d4c0000,	// phyr074
-	0x493e0107,	// phyr078
+	(0x493e0100 | T_PHY_WRLAT),	/* phyr078 */
 	0x08060404,	// phyr07c
-	0x90000a00,	// phyr080
+	(0x90000000 | T_RDDATA_EN),	/* phyr080 */
 	0x06420618,	// phyr084
 	0x00001002,	// phyr088
 	0x05701016,	// phyr08c
@@ -94,7 +207,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x20202020,	// phyr09c
 	0x20202020,	// phyr0a0
 	0x00002020,	// phyr0a4
-	0x80000000,	// phyr0a8
+	0x00000000,	/* phyr0a8 */
 	0x00000001,	// phyr0ac
 	0xaeeddeea,	// change address
 	0x1e6e0318,	// new address
@@ -154,7 +267,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x20202020,	// phyr170
 	0xaeeddeea,	// change address
 	0x1e6e0298,	// new address
-	0x20200800,	// phyr198
+	0x20200000,	/* phyr198 */
 	0x20202020,	// phyr19c
 	0x20202020,	// phyr1a0
 	0x20202020,	// phyr1a4
@@ -177,7 +290,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x00002020,	// phyr1e8
 	0xaeeddeea,	// change address
 	0x1e6e0304,	// new address
-	0x00000800,	// phyr204
+	(0x00000001 | WR_DATA_EYE_OFFSET), /* phyr204 */
 	0xaeeddeea,	// change address
 	0x1e6e027c,	// new address
 	0x4e400000,	// phyr17c
@@ -203,7 +316,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x20000000,	// phyr024
 	0x00000008,	// phyr028
 	0x00000000,	// phyr02c
-	0x00077600,	// phyr030
+	(PHY_RON | PHY_ODT),	/* phyr030 */
 	0x00000000,	// phyr034
 	0x00000000,	// phyr038
 	0x20000000,	// phyr03c
@@ -212,18 +325,18 @@ u32 ast2600_sdramphy_config[165] = {
 	0x00002f07,	// phyr048
 	0x00003080,	// phyr04c
 	0x04000000,	// phyr050
-	0x00000200,	// phyr054
-	0x03140501,	// phyr058-rtt:40
-	0x04800000,	// phyr05c
-	0x0800044e,	// phyr060
+	((MR3_VAL << 16) | MR2_VAL),	/* phyr054 */
+	((MR0_VAL << 16) | MR1_VAL),	/* phyr058 */
+	((MR5_VAL << 16) | MR4_VAL),	/* phyr05c */
+	((0x0800 << 16) | MR6_VAL | VREFDQ_RANGE_2 | 0xe), /* phyr060 */
 	0x00000000,	// phyr064
 	0x00180008,	// phyr068
 	0x00e00400,	// phyr06c
 	0x00140206,	// phyr070
 	0x1d4c0000,	// phyr074
-	0x493e0107,	// phyr078
+	(0x493e0100 | T_PHY_WRLAT),	/* phyr078 */
 	0x08060404,	// phyr07c
-	0x90000a00,	// phyr080
+	(0x90000000 | T_RDDATA_EN),	/* phyr080 */
 	0x06420c30,	// phyr084
 	0x00001002,	// phyr088
 	0x05701016,	// phyr08c
@@ -256,13 +369,13 @@ u32 ast2600_sdramphy_config[165] = {
 	0x00000000,	// phyr200
 	0xaeeddeea,	// change address
 	0x1e6e0194,	// new address
-	0x801112e0,	// phyr094 - bit12=1,15=0,- write window is ok
+	0x801112e0,	// phyr094
 	0xaeeddeea,	// change address
 	0x1e6e019c,	// new address
 	0x20202020,	// phyr09c
 	0x20202020,	// phyr0a0
 	0x00002020,	// phyr0a4
-	0x80000000,	// phyr0a8
+	0x00000000,	/* phyr0a8 */
 	0x00000001,	// phyr0ac
 	0xaeeddeea,	// change address
 	0x1e6e0318,	// new address
@@ -322,7 +435,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x20202020,	// phyr170
 	0xaeeddeea,	// change address
 	0x1e6e0298,	// new address
-	0x20200800,	// phyr198
+	0x20200000,	/* phyr198 */
 	0x20202020,	// phyr19c
 	0x20202020,	// phyr1a0
 	0x20202020,	// phyr1a4
@@ -345,7 +458,7 @@ u32 ast2600_sdramphy_config[165] = {
 	0x00002020,	// phyr1e8
 	0xaeeddeea,	// change address
 	0x1e6e0304,	// new address
-	0x00000800,	// phyr204
+	(0x00000001 | WR_DATA_EYE_OFFSET), /* phyr204 */
 	0xaeeddeea,	// change address
 	0x1e6e027c,	// new address
 	0x4e400000,	// phyr17c
@@ -388,10 +501,10 @@ u32 ast2600_sdramphy_config[165] = {
  * AC timing and SDRAM mode register setting
  * for real chip are derived from the model GDDR4-1600
  */
-#define DDR4_MR01_MODE	0x03010510
-#define DDR4_MR23_MODE	0x00000000
-#define DDR4_MR45_MODE	0x04000000
-#define DDR4_MR6_MODE	0x00000400
+#define DDR4_MR01_MODE	((MR1_VAL << 16) | MR0_VAL)
+#define DDR4_MR23_MODE	((MR3_VAL << 16) | MR2_VAL)
+#define DDR4_MR45_MODE	((MR5_VAL << 16) | MR4_VAL)
+#define DDR4_MR6_MODE	MR6_VAL
 #define DDR4_TRFC_1600	0x467299f1
 #define DDR4_TRFC_1333	0x3a5f80c9
 #define DDR4_TRFC_800	0x23394c78