debug-add-glamo-drive-strength-module-param.patch

Suggested-by: Werner Almesberger <werner@openmoko.org>

This patch allows users to control two additional settings
in Glamo MCI driver from kernel commandline or module
parameters.


First is Glamo drive strength on SD IOs including CLK.
This ranges from 0 (weakest) to 3 (strongest).

echo 0 > /sys/module/glamo_mci/parameters/sd_drive

(Changes to this take effect on next SD Card transaction)

or, from kernel commandline

glamo_mci.sd_drive=0

On tests here with 0 strength, communication to SD card
(shipped 512MB Sandisk) seemed fine, and a dd of 10MB
urandom had the same md5 when written to cache as after
a reboot.  I set the default to 2.


Second is whether we allow SD_CLK when the SD interface
is idle.

# stop the clock when we are idle (default)
echo 0 > /sys/module/glamo_mci/parameters/sd_idleclk

# run the SD clock all the time
echo 1 > /sys/module/glamo_mci/parameters/sd_idleclk

(changes take effect on next SD Card transaction)

From kernel commandline, eg:

glamo_mci.sd_idleclk=1

Normally you don't want to run the SD Clock all the time.


Signed-off-by: Andy Green <andy@openmoko.com>

0 files changed, 0 insertions, 0 deletions