[PATCH 0/4] More SD / GPS noise reduction

Andy Green andy at openmoko.com
Wed Jul 30 13:52:13 CEST 2008

The following series takes two actions to further reduce SD
Card access noise on GPS on GTA02.

 - use the minimum negotiated voltage for the SD Card,
   it is 2.7V for the shipping Sandisk card.  This reduces
   the power we put out by estimated 1.7dBm

 - when the GPS unit is powered, we dynamically reduce the
   clock rate to the SD Card.  By default we will reduce it
   by a factor of 8 (this can be overridden from kernel
   or ash commandlines), from 16MHz to 2MHz.  This also
   reduces the average energy on the SD Card lines by a
   factor of 8


Andy Green (4):

 arch/arm/mach-s3c2440/mach-gta02.c     |   22 ++++++++++++-----
 arch/arm/plat-s3c24xx/neo1973_pm_gps.c |   12 +++++++--
 drivers/mfd/glamo/glamo-core.c         |   15 +++++++++++-
 drivers/mfd/glamo/glamo-core.h         |    2 ++
 drivers/mfd/glamo/glamo-mci.c          |   41 ++++++++++++++++++++++++++------
 include/linux/glamofb.h                |    2 ++
 6 files changed, 76 insertions(+), 18 deletions(-)


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