From 474a7c51cecfd2e37b315da9cfb25607f3ad84f1 Mon Sep 17 00:00:00 2001 From: Matt DeVillier Date: Tue, 7 Feb 2017 22:07:56 -0600 Subject: google/rambi: add explicit pull-down for ram-id Some variants need the internal pull resistor on GPIO_SSUS_40 set explicitly to pull down rather than disabling the pull, in order for the ram-id to be read correctly via GPIO. Correct this by adding a function to enable and set the internal pull and define its use as needed in the board's variant.h. Chromium source: branch: firmware-gnawty-5216.239.B /src/soc/intel/baytrail/baytrail/gpio.h#418 /src/mainboard/google/gnawty/romstage.c#60 Test: boot 4GB Candy board and observe correct RAM id, amount detected Change-Id: I8823c27385f4422184b5afa57f6048f7ff2a25ab Signed-off-by: Matt DeVillier Reviewed-on: https://review.coreboot.org/18309 Tested-by: build bot (Jenkins) Reviewed-by: Nico Huber Reviewed-by: Paul Menzel --- src/mainboard/google/rambi/romstage.c | 5 ++++- src/mainboard/google/rambi/variants/candy/include/variant/variant.h | 1 + .../google/rambi/variants/glimmer/include/variant/variant.h | 1 + src/mainboard/google/rambi/variants/gnawty/include/variant/variant.h | 2 ++ 4 files changed, 8 insertions(+), 1 deletion(-) (limited to 'src/mainboard') diff --git a/src/mainboard/google/rambi/romstage.c b/src/mainboard/google/rambi/romstage.c index d8ba001efa..25fe85952b 100644 --- a/src/mainboard/google/rambi/romstage.c +++ b/src/mainboard/google/rambi/romstage.c @@ -32,7 +32,10 @@ static void *get_spd_pointer(char *spd_file_content, int total_spds, int *dual) ssus_disable_internal_pull(GPIO_SSUS_37_PAD); ssus_disable_internal_pull(GPIO_SSUS_38_PAD); ssus_disable_internal_pull(GPIO_SSUS_39_PAD); -#ifdef GPIO_SSUS_40_PAD +#ifdef GPIO_SSUS_40_PAD_USE_PULLDOWN + /* To prevent floating pin on shipped systems. */ + ssus_enable_internal_pull(GPIO_SSUS_40_PAD, PAD_PULL_DOWN | PAD_PU_20K); +#elif defined (GPIO_SSUS_40_PAD) ssus_disable_internal_pull(GPIO_SSUS_40_PAD); #endif ram_id |= (ssus_get_gpio(GPIO_SSUS_37_PAD) << 0); diff --git a/src/mainboard/google/rambi/variants/candy/include/variant/variant.h b/src/mainboard/google/rambi/variants/candy/include/variant/variant.h index 0c58ceefa2..fe4c475825 100644 --- a/src/mainboard/google/rambi/variants/candy/include/variant/variant.h +++ b/src/mainboard/google/rambi/variants/candy/include/variant/variant.h @@ -38,5 +38,6 @@ static const uint32_t dual_channel_config = #define GPIO_SSUS_38_PAD 50 #define GPIO_SSUS_39_PAD 58 #define GPIO_SSUS_40_PAD 52 +#define GPIO_SSUS_40_PAD_USE_PULLDOWN #endif diff --git a/src/mainboard/google/rambi/variants/glimmer/include/variant/variant.h b/src/mainboard/google/rambi/variants/glimmer/include/variant/variant.h index 0ea42c52e9..59d5ee1f6d 100644 --- a/src/mainboard/google/rambi/variants/glimmer/include/variant/variant.h +++ b/src/mainboard/google/rambi/variants/glimmer/include/variant/variant.h @@ -38,5 +38,6 @@ static const uint32_t dual_channel_config = #define GPIO_SSUS_38_PAD 50 #define GPIO_SSUS_39_PAD 58 #define GPIO_SSUS_40_PAD 52 +#define GPIO_SSUS_40_PAD_USE_PULLDOWN #endif diff --git a/src/mainboard/google/rambi/variants/gnawty/include/variant/variant.h b/src/mainboard/google/rambi/variants/gnawty/include/variant/variant.h index 9bac7bc89e..bd79c982ed 100644 --- a/src/mainboard/google/rambi/variants/gnawty/include/variant/variant.h +++ b/src/mainboard/google/rambi/variants/gnawty/include/variant/variant.h @@ -33,5 +33,7 @@ static const uint32_t dual_channel_config = #define GPIO_SSUS_37_PAD 57 #define GPIO_SSUS_38_PAD 50 #define GPIO_SSUS_39_PAD 58 +#define GPIO_SSUS_40_PAD 52 +#define GPIO_SSUS_40_PAD_USE_PULLDOWN #endif -- cgit v1.2.3