Corey Osgood wrote:
I'm working on vt8237 smbus in v3, and I had a quick question, mostly
for Rudolf Marek and Bari, but feel free to jump in with your 2 cents:
u8 smbus_read_byte(u16 dimm, u8 offset, u16 smbus_io_base)
{
u8 val;
printk(BIOS_SPEW, "SMBus Read from DIMM %1x at address 0x%4x\n",
dimm, offset);
smbus_reset(smbus_io_base);
/* Clear host data port. */
outb(0x00, smbus_io_base + SMBHSTDAT0);
//SMBUS_DELAY();
smbus_wait_until_ready(smbus_io_base);
dimm = (dimm << 1) | 1;
outb(dimm, smbus_io_base + SMBXMITADD);
The dimm = (dimm << 1) | 1 is something that came from a via southbridge
porting guide (NOT the one for the vt8237r, I don't have that one). With
it, my spd addresses are 0x50, 0x51, etc, without it, they'd be 0xa1,
0xa3, etc. Which would be preferred? Do you think we'd ever need a 0xa0
or 0xa2 address?
My 2cents.
I have never really cared for the <<1. I prefer the more normal IO
address. Most platform specs I have seen indicate the spd device at
0xA0, 0xA2, etc.
Marc
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Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:[EMAIL PROTECTED]
http://www.amd.com/embeddedprocessors
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