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| author | Claudiu Beznea <claudiu.beznea@microchip.com> | 2022-08-26 11:39:20 +0300 |
|---|---|---|
| committer | Claudiu Beznea <claudiu.beznea@microchip.com> | 2022-08-31 10:27:57 +0300 |
| commit | a02875c4cbd6f3d2f33d70cc158a19ef02d4b84f (patch) | |
| tree | b535c15dc44af5758e70a53d16a7896b41eb6a0b /include | |
| parent | f04445fa099668ca1c9889c48e309f49740f92f0 (diff) | |
| download | linux-a02875c4cbd6f3d2f33d70cc158a19ef02d4b84f.tar.gz | |
ARM: at91: pm: fix self-refresh for sama7g5
It has been discovered that on some parts, from time to time, self-refresh
procedure doesn't work as expected. Debugging and investigating it proved
that disabling AC DLL introduce glitches in RAM controllers which
leads to unexpected behavior. This is confirmed as a hardware bug. DLL
bypass disables 3 DLLs: 2 DX DLLs and AC DLL. Thus, keep only DX DLLs
disabled. This introduce 6mA extra current consumption on VDDCORE when
switching to any ULP mode or standby mode but the self-refresh procedure
still works.
Fixes: f0bbf17958e8 ("ARM: at91: pm: add self-refresh support for sama7g5")
Suggested-by: Frederic Schumacher <frederic.schumacher@microchip.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Tested-by: Cristian Birsan <cristian.birsan@microchip.com>
Link: https://lore.kernel.org/r/20220826083927.3107272-3-claudiu.beznea@microchip.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/soc/at91/sama7-ddr.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/soc/at91/sama7-ddr.h b/include/soc/at91/sama7-ddr.h index 9e17247474fa..2706bc48c076 100644 --- a/include/soc/at91/sama7-ddr.h +++ b/include/soc/at91/sama7-ddr.h @@ -39,6 +39,10 @@ #define DDR3PHY_ZQ0SR0 (0x188) /* ZQ status register 0 */ +#define DDR3PHY_DX0DLLCR (0x1CC) /* DDR3PHY DATX8 DLL Control Register */ +#define DDR3PHY_DX1DLLCR (0x20C) /* DDR3PHY DATX8 DLL Control Register */ +#define DDR3PHY_DXDLLCR_DLLDIS (1 << 31) /* DLL Disable */ + /* UDDRC */ #define UDDRC_STAT (0x04) /* UDDRC Operating Mode Status Register */ #define UDDRC_STAT_SELFREF_TYPE_DIS (0x0 << 4) /* SDRAM is not in Self-refresh */ |