From: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
[ Upstream commit cef8cdc0d0e7c701fe4dcfba4ed3fd25d28a6020 ]
Do not soft reset AC DLL as controller is buggy and this operation my
introduce glitches in the controller leading to undefined behavior.
Fixes: f0bbf17958e8 ("ARM: at91: pm: add self-refresh support for sama7g5")
Depends-on: a02875c4cbd6 ("ARM: at91: pm: fix self-refresh for sama7g5")
Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221026124114.985876-2-claudiu.beznea@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/arm/mach-at91/pm_suspend.S | 7 ++++++-
include/soc/at91/sama7-ddr.h | 5 ++++-
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index 65cfcc19a936..2f0a370a1309 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -169,10 +169,15 @@ sr_ena_2:
cmp tmp1, #UDDRC_STAT_SELFREF_TYPE_SW
bne sr_ena_2
- /* Put DDR PHY's DLL in bypass mode for non-backup modes. */
+ /* Disable DX DLLs for non-backup modes. */
cmp r7, #AT91_PM_BACKUP
beq sr_ena_3
+ /* Do not soft reset the AC DLL. */
+ ldr tmp1, [r3, DDR3PHY_ACDLLCR]
+ bic tmp1, tmp1, DDR3PHY_ACDLLCR_DLLSRST
+ str tmp1, [r3, DDR3PHY_ACDLLCR]
+
/* Disable DX DLLs. */
ldr tmp1, [r3, #DDR3PHY_DX0DLLCR]
orr tmp1, tmp1, #DDR3PHY_DXDLLCR_DLLDIS
diff --git a/include/soc/at91/sama7-ddr.h b/include/soc/at91/sama7-ddr.h
index f203f34dba12..cac3f9cd25f9 100644
--- a/include/soc/at91/sama7-ddr.h
+++ b/include/soc/at91/sama7-ddr.h
@@ -26,7 +26,10 @@
#define DDR3PHY_PGSR (0x0C) /* DDR3PHY PHY General Status Register */
#define DDR3PHY_PGSR_IDONE (1 << 0) /* Initialization Done */
-#define DDR3PHY_ACIOCR (0x24) /* DDR3PHY AC I/O Configuration Register */
+#define DDR3PHY_ACDLLCR (0x14) /* DDR3PHY AC DLL Control Register */
+#define DDR3PHY_ACDLLCR_DLLSRST (1 << 30) /* DLL Soft Reset */
+
+#define DDR3PHY_ACIOCR (0x24) /* DDR3PHY AC I/O Configuration Register */
#define DDR3PHY_ACIOCR_CSPDD_CS0 (1 << 18) /* CS#[0] Power Down Driver */
#define DDR3PHY_ACIOCR_CKPDD_CK0 (1 << 8) /* CK[0] Power Down Driver */
#define DDR3PHY_ACIORC_ACPDD (1 << 3) /* AC Power Down Driver */
--
2.35.1
