Commit Graph

7 Commits

Author SHA1 Message Date
Claudiu Beznea
7a94b83a7d ARM: at91: pm: fix DDR recalibration when resuming from backup and self-refresh
On SAMA7G5, when resuming from backup and self-refresh, the bootloader
performs DDR PHY recalibration by restoring the value of ZQ0SR0 (stored
in RAM by Linux before going to backup and self-refresh). It has been
discovered that the current procedure doesn't work for all possible values
that might go to ZQ0SR0 due to hardware bug. The workaround to this is to
avoid storing some values in ZQ0SR0. Thus Linux will read the ZQ0SR0
register and cache its value in RAM after processing it (using
modified_gray_code array). The bootloader will restore the processed value.

Fixes: d2d4716d83 ("ARM: at91: pm: save ddr phy calibration data to securam")
Suggested-by: Frederic Schumacher <frederic.schumacher@microchip.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220826083927.3107272-4-claudiu.beznea@microchip.com
2022-08-31 10:28:18 +03:00
Claudiu Beznea
a02875c4cb 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: f0bbf17958 ("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
2022-08-31 10:27:57 +03:00
Claudiu Beznea
9584e7263e ARM: at91: PM: add cpu idle support for sama7g5
Add CPU idle support for SAMA7G5. Support will make use of PMC_CPU_RATIO
register to divide the CPU clock by 16 before switching it to idle and
use automatic self-refresh option of DDR controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220113144900.906370-5-claudiu.beznea@microchip.com
2022-02-25 12:36:25 +01:00
Claudiu Beznea
9a0775c9cd ARM: at91: ddr: fix typo to align with datasheet naming
Fix typo on UDDRC_PWRCTL.SELFREF_SW bitmask to align with datasheet
naming.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220113144900.906370-4-claudiu.beznea@microchip.com
2022-02-25 12:36:25 +01:00
Claudiu Beznea
55614e682a ARM: at91: ddr: align macro definitions
Align all macro definitions.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220113144900.906370-3-claudiu.beznea@microchip.com
2022-02-25 12:36:25 +01:00
Claudiu Beznea
dc3005703f ARM: at91: ddr: remove CONFIG_SOC_SAMA7 dependency
Remove CONFIG_SOC_SAMA7 dependency to avoid having #ifdef preprocessor
directives in driver code (arch/arm/mach-at91/pm.c). This prepares the
code for next commits.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220113144900.906370-2-claudiu.beznea@microchip.com
2022-02-25 12:36:25 +01:00
Claudiu Beznea
d8c7983f31 ARM: at91: ddr: add registers definitions for sama7g5's ddr
Add registers and bits definitions for SAMA7G5's UDDRC and DDR3PHY.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20210415105010.569620-12-claudiu.beznea@microchip.com
2021-07-19 14:32:12 +02:00