Re: [LinuxBIOS] MCP55 LinuxBIOS with USB debug

[Lu, Yinghai]

If you have smbus hub,

You may need to use

smbus_send_byte(hub_address, hub_channel);

or

smbus_write_byte(hub_address, hub_channel);

the code is same as CK804's, and the code is verified with Tyan S4881
and 4885.

For PCA9556/PCA9516

static inline void activate_spd_rom(const struct mem_controller *ctrl)

{

#define SMBUS_HUB 0x18

unsigned device=(ctrl->channel0[0])>>8;

smbus_write_byte(SMBUS_HUB, 0x01, device);

smbus_write_byte(SMBUS_HUB,0x03, 0);

}

YH

________________________________

From: [e-mail]
[mailto:[e-mail]] On Behalf Of bxshi
Sent: Monday, January 22, 2007 11:04 PM
To: [e-mail]
Cc: [e-mail]
Subject: Re: [LinuxBIOS] MCP55 LinuxBIOS with USB debug

Dr. Lu,

In mcp55_smbus.h

static int do_smbus_send_byte(unsigned smbus_io_base, unsigned device,
unsigned char val)
{

.....

outb(0, smbus_io_base + SMBHSTCMD);

.....

}

I wonder why you write 0 to SMBHSTCMD ?  if we are using a smbus_hub , I
think we should write the channel number  we want to enable to this
register. for example , if my memory controller is on channel 2 , we
should write  outb(2,smbus_io_base+SMBHSTCMD).

So could that be changed to    outb(val,smbus_io_base + SMBHSTCMD) ?

Thanks

bxshi

[LinuxBIOS] MCP55 LinuxBIOS with USB debug

[bxshi]

You may need to use
> smbus_send_byte(hub_address, hub_channel);
>
> or
>
> smbus_write_byte(hub_address, hub_channel);

smbus_write_byte may need three parametres, smbus_write_byte(device ,address
,val).
for PCA9545 to enable one channel need four steps ,

1. outb(hub_address, base_io+02)
2. outb(hub_channel, base_io +03)
3. outb(0x04, base_io + 00)
4. test  inb(base_io+01)

it is a little different from PCA9556/PCA9557. as I look at the code , use
smbus_write_byte may not make pca9545 work .
use smbus_send_byte(device,val) , I get the output:

No memory for this cpu
No memory

so I change below
outb(val, smbus_io_base + SMBHSTCMD);
then everything works fine.
so I think smbus_send_byte(device,val) ,device should be the HUB_ADDRESS ,
and val is the HUB_CHANNEL. is it right?

bxshi