diff options
| author | Andy Green <andy@openmoko.com> | 2008-11-19 17:09:56 +0000 |
|---|---|---|
| committer | Andy Green <agreen@pads.home.warmcat.com> | 2008-11-19 17:09:56 +0000 |
| commit | f92e8c8670f21d25f4e3c575b394c6312c659e39 (patch) | |
| tree | 5b970cf779a85fea9da07ae5d62379a8cf6edf83 /arch/arm/plat-s3c24xx/Makefile | |
| parent | e06346a8baf9c3340299930a8ea8586e1f0a729c (diff) | |
introduce-BANKCON-meddling-sysfs.patch
A few questions have been flying around about how optimal
our waitstates are for various things including Glamo.
This patch introduces new sysfs nodes
/sys/devices/platform/neo1973-memconfig.0/BANKCON0
...
/sys/devices/platform/neo1973-memconfig.0/BANKCON7
If you cat them you get translated info about bus speed on
that chip select, eg,
# cat /sys/devices/platform/neo1973-memconfig.0/BANKCON1
BANKCON1 = 0x00000A40
Type = ROM / SRAM
PMC = normal (1 data)
Tacp = 2 clocks
Tcah = 0 clocks
Tcoh = 1 clock
Tacc = 3 clocks
Tcos = 1 clock
Tacs = 0 clocks
You can write them in hex too
# echo 0x200 > /sys/devices/platform/neo1973-memconfig.0/BANKCON1
The write format for BANKCON0 - 5 looks like this
b1..b0 PMC Page Mode Config
b3..b2 Tacp Page Mode Access Cycle
b5..b4 Tcah Address hold after CS deasserted
b7..b6 Tcoh CS hold after OE deasserted
b10..b8 Tacc Access Cycle Period
b12..b11 Tcos CS setup before OE asserted
b14..b13 Tacs Address setup before CS asserted
BANKCON 6 and 7 have two extra bits
b16..b15 MT Memory type (00=ROM/SRAM, 11=DRAM)
If it's ROM/SRAM, the rest of the bits are as described above.
For DRAM
b1..b0 SCAN Column address number
b3..b2 RAS to CAS delay
The patch is intended to let people experiement on their own. But
of course you will crash things for sure if the timing is wrong, and
you can also trash SD Card data if you make Glamo unstable, so remove
it or remount ro first. Other horrible things are possible, but
because the settings aren't sticky, you should always be able to
recover by either normal reboot usually or at worst NOR boot and then
dfu. Most likely you will just crash your session and have to reboot
if your settings are bad, but consider yourself warned bad things are
possible. :-)
Signed-off-by: Andy Green <andy@openmoko.com>
Diffstat (limited to 'arch/arm/plat-s3c24xx/Makefile')
| -rw-r--r-- | arch/arm/plat-s3c24xx/Makefile | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/plat-s3c24xx/Makefile b/arch/arm/plat-s3c24xx/Makefile index 0a56561a975..fafd153374f 100644 --- a/arch/arm/plat-s3c24xx/Makefile +++ b/arch/arm/plat-s3c24xx/Makefile @@ -49,4 +49,5 @@ obj-$(CONFIG_MACH_NEO1973) += neo1973_version.o \ neo1973_pm_gps.o \ neo1973_pm_bt.o \ neo1973_shadow.o \ - neo1973_pm_resume_reason.o + neo1973_pm_resume_reason.o \ + neo1973_memconfig.o |