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