From: David Shah <dave@ds0.me>
Date: Tue, 28 Apr 2020 14:14:27 +0000 (+0100)
Subject: Add RDIMM side-B inversion support
X-Git-Tag: 24jan2021_ls180~361^2~1
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=64b505156e41a12063a50b5884449ab972d6c02d;p=litex.git

Add RDIMM side-B inversion support

Signed-off-by: David Shah <dave@ds0.me>
---

diff --git a/litex/soc/software/bios/sdram.c b/litex/soc/software/bios/sdram.c
index 8d8ddfef..94df6316 100644
--- a/litex/soc/software/bios/sdram.c
+++ b/litex/soc/software/bios/sdram.c
@@ -269,6 +269,13 @@ void sdrwlon(void)
 	sdram_dfii_pi0_address_write(DDRX_MR1 | (1 << 7));
 	sdram_dfii_pi0_baddress_write(1);
 	command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
+
+#ifdef SDRAM_PHY_DDR4_RDIMM
+	sdram_dfii_pi0_address_write((DDRX_MR1 | (1 << 7)) ^ 0x2BF8) ;
+	sdram_dfii_pi0_baddress_write(1 ^ 0xF);
+	command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
+#endif
+
 	ddrphy_wlevel_en_write(1);
 }
 
@@ -277,6 +284,13 @@ void sdrwloff(void)
 	sdram_dfii_pi0_address_write(DDRX_MR1);
 	sdram_dfii_pi0_baddress_write(1);
 	command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
+
+#ifdef SDRAM_PHY_DDR4_RDIMM
+	sdram_dfii_pi0_address_write(DDRX_MR1 ^ 0x2BF8);
+	sdram_dfii_pi0_baddress_write(1 ^ 0xF);
+	command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
+#endif
+
 	ddrphy_wlevel_en_write(0);
 }
 
@@ -1158,6 +1172,12 @@ void sdrmrwr(char reg, int value) {
 	sdram_dfii_pi0_address_write(value);
 	sdram_dfii_pi0_baddress_write(reg);
 	command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
+
+#ifdef SDRAM_PHY_DDR4_RDIMM
+	sdram_dfii_pi0_address_write(value ^ 0x2BF8);
+	sdram_dfii_pi0_baddress_write(reg ^ 0xF);
+	command_p0(DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS);
+#endif
 }
 
 static void sdrmpron(char mpr)