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authorMichael Niewöhner <foss@mniewoehner.de>2022-06-20 21:22:27 +0200
committerMichael Niewöhner <foss@mniewoehner.de>2022-11-02 21:06:51 +0000
commit8998ab8b020d6711f56634880b26b2b908d1340c (patch)
treeb6dd3c229e3c431fcd5c12ec1e5b313c1376d2a0 /src
parent0ca534e059acc884aa999d727dcb67f76dd885ba (diff)
mb/clevo/l140cu: work around PECI staying high when idle, blocking s0ix
According to Intel doc# 575683 the PECI bus should be low when idle and is pulled up by clients with strong drive. However, for unknown reasons the bus stays high on this board, blocking s0ix entry. The PECI reference schematic in the ASPEED AST2400 BMC datasheet (actually not related to this board) says that a pull-down is *required* for the idle state. This might be just a requirement of this BMC, since this is nowhere documented in Intel datasheets, schematics or elsewhere. However, configuring a weak pull-down (20 k) on the PECI pad indeed solves this problem for now. Change-Id: Ib5a6b0ad3553c2cf795037d6a1982102bcb04644 Signed-off-by: Michael Niewöhner <foss@mniewoehner.de> Reviewed-on: https://review.coreboot.org/c/coreboot/+/68793 Reviewed-by: Angel Pons <th3fanbus@gmail.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src')
-rw-r--r--src/mainboard/clevo/cml-u/variants/l140cu/gpio.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c b/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c
index fb658dddd4..258f07698e 100644
--- a/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c
+++ b/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c
@@ -233,6 +233,9 @@ static const struct pad_config gpio_table[] = {
PAD_NC(GPP_H21, NONE),
PAD_NC(GPP_H22, UP_20K),
PAD_NC(GPP_H23, UP_20K),
+
+ /* ------- GPIO Group CPU ------- */
+ PAD_CFG_NF(PECI_IO, DN_20K, DEEP, NF1), /* PECI */
};
void variant_configure_gpios(void)