From 10de21148f7d28c9e918aaee7cede74a7d506e24 Mon Sep 17 00:00:00 2001 From: Joseph Lo Date: Wed, 29 May 2019 16:21:36 +0800 Subject: memory: tegra: Add EMC scaling support code for Tegra210 This is the initial patch for Tegra210 EMC frequency scaling. It has the code to program various aspects of the EMC that are standardized, but it does not yet include the specific programming sequence needed for clock scaling. The driver is designed to support LPDDR4 SDRAM. Devices that use LPDDR4 need to perform training of the RAM before it can be used. Firmware will perform this training during early boot and pass a table of supported frequencies to the kernel via device tree. For the frequencies above 800 MHz, periodic retraining is needed to compensate for changes in timing. This periodic training will have to be performed until the frequency drops back to or below 800 MHz. This driver provides helpers used during this runtime retraining that will be used by the sequence specific code in a follow-up patch. Based on work by Peter De Schrijver . Signed-off-by: Joseph Lo Signed-off-by: Thierry Reding --- drivers/memory/tegra/mc.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/memory/tegra/mc.h') diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h index 957c6eb74ff9..afa3ba45c9e6 100644 --- a/drivers/memory/tegra/mc.h +++ b/drivers/memory/tegra/mc.h @@ -34,6 +34,7 @@ #define MC_EMEM_ARB_TIMING_W2W 0xbc #define MC_EMEM_ARB_TIMING_R2W 0xc0 #define MC_EMEM_ARB_TIMING_W2R 0xc4 +#define MC_EMEM_ARB_MISC2 0xc8 #define MC_EMEM_ARB_DA_TURNS 0xd0 #define MC_EMEM_ARB_DA_COVERS 0xd4 #define MC_EMEM_ARB_MISC0 0xd8 -- cgit v1.2.3