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authorJens Rottmann <JRottmann@LiPPERTembedded.de>2013-02-19 15:01:06 +0100
committerMarc Jones <marc.jones@se-eng.com>2013-03-06 19:07:28 +0100
commit3914a316c3d3ab1ba45fe33394f37aaefdc62d61 (patch)
tree2b8e8cc84bcd011a4fbda6574a99ae5206b45e33 /src/superio/smsc
parent069795a94716cdc5d5dbeed81d491004c3e6a58e (diff)
downloadcoreboot-3914a316c3d3ab1ba45fe33394f37aaefdc62d61.tar.xz
AMD SB800: don't switch clock from 14 to 48 MHz for smscsuperio
The power up default for the 14M_25M_48M_OSC switchable clock output ball of the SB800 chipset is 14 MHz. sb800/bootblock.c changes this to 48 MHz, which is the correct value for almost all SIOs. However, not for 'smscsuperio' (SMSC SCH311x), which needs the original 14 MHz and is not configurable for other clock speeds. A wrong SIO clock supply results in funny RS232 output (wrong bit speed) and non-working PS/2. We could switch back to 14 MHz in the mainboard's romstage.c, but then the clock frequency would change twice. The resulting short 48 MHz burst causes a handful of rubbish characters on RS232 on every boot until the SIO clock has stabilized again. This patch skips the SB800 clock switch if the SIO Kconfig requests 14 MHz. This does not affect any boards currently in the repository (yet). Change-Id: Icff41fd88dc41c08f3700ab4f786852f04eff2a4 Signed-off-by: Jens Rottmann <JRottmann@LiPPERTembedded.de> Reviewed-on: http://review.coreboot.org/2454 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Martin Roth <martin.roth@se-eng.com>
Diffstat (limited to 'src/superio/smsc')
-rw-r--r--src/superio/smsc/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/src/superio/smsc/Kconfig b/src/superio/smsc/Kconfig
index f863b3ed38..6aaa1127e9 100644
--- a/src/superio/smsc/Kconfig
+++ b/src/superio/smsc/Kconfig
@@ -44,6 +44,7 @@ config SUPERIO_SMSC_MEC1308
bool
config SUPERIO_SMSC_SMSCSUPERIO
bool
+ select SUPERIO_WANTS_14MHZ_CLOCK
config SUPERIO_SMSC_SIO1036
bool
config SUPERIO_SMSC_SCH4037