ASUS P4SC-E Board Enable / IT8707F support

[Mattias Mattsson]

Hi,

The attached patch adds board enable for the ASUS P4SC-E board. It
does this by setting bits 3..2 of register 0x24 on the super i/o chip,
while keeping bit 3 of register 0x23 set while manipulating the first
register. I have no idea what this actually means since no public
datasheet is available, but this is how the vendor BIOS does it.

Tested on a P4SC-E with SST 39SF020A flash. Probe, read, erase, write
all work. Matching on NB/SB.

lspci/superio output:
http://www.flashrom.org/pipermail/flashrom/2010-July/004090.html

The ITE IT8707F chip seems to have been manufactured exclusively for ASUS:
http://lists.lm-sensors.org/pipermail/lm-sensors/2002-October/001260.html

In the past (before it's release) the IT8707F was listed on the ITE website:
http://web.archive.org/web/20000510121435/http://www.ite.com.tw/productInfo/...

By looking through some ASUS manuals I have found that at least 17
ASUS boards is using this chip:

P4S133/-VM
P4S333/-FX/-M/-VF/-VM
P4S533/-E/-VM
P4SC/-E/-EA ("Terminator P4" barebone series)
P4SDR-VM
P4SE/U2
P4SGL-VM

The vendor BIOS of these boards all use the same super i/o flash
enable code described above.

The following boards additionally clears bit 6 of IDX F4, LDN 7 in the
flash enabling routine: P4S133, P4S333, P4S533, P4S533-E, P4SE,
P4SE/U2. (Not included in this patch since I don't own any of these.)

Many thanks to Reinder de Haan for help with reverse engineering this!

Signed-off-by: Mattias Mattsson

[Uwe Hermann]

> +static int it8707f_write_enable(uint8_t port)
> +{
> uint8_t tmp;
> w836xx_ext_enter(port);
> tmp = sio_read(port, 0x23);
> tmp |= 8;

Please consider (1 << 3) for better readability.

Acked-by: Uwe Hermann

Uwe.

[Mattias Mattsson]

On Mon, Sep 13, 2010 at 20:29, Uwe Hermann  wrote:
> > +static int it8707f_write_enable(uint8_t port)
> > +{
> > uint8_t tmp;
> > w836xx_ext_enter(port);
> > tmp = sio_read(port, 0x23);
> > tmp |= 8;
>
> Please consider (1 << 3) for better readability.

Fixed. Also added some comments.
> Acked-by: Uwe Hermann

Thanks, r1161

-mattias