Jean Delvare wrote: >Hi Frank, > > > >>The patch works BUT... >>The PCF8584 device is a bridge, not a hardware monitor. One of the >>other I2C device types could very well be behind it such as a sound >>chip. Maybe we could add a BRIDGE type or have it as a I2C_CLASS_ALL >>device. This is just a suggestion - like I said, the patch works for >>me. >> >> > >The PCF8584 is an I2C master, as I understand it. It's as much of a >bridge as every other I2C or SMBus master is. The idea of a bridge class >doesn't make any sense to me. A class is meant to isolate chip drivers >from bus drivers. As such, class definitions are carried by bus drivers >and checked by chip drivers. This doesn't leave any room for a bridge >class unless I'm missing something obvious. > >Setting class to I2C_CLASS_ALL would somehow defeat our attempt to >isolate different types of I2C busses. It's better to add classes when >it is found that we actually need them. > >That being said, I don't know exactly where the PCF8584 is found and >what the Elektor is. Care to tell me what kind of hardware your are >playing with? > >Thanks, > > In my application the PCF8584 is located on the ISA bus from the cpu's south bridge. I have a Cypress CPLD doing the ISA address decoding and chip selects. From the list I sent earlier, you can see that I chain several sensors on this I2C bus. The one part I didn't include in my list earlier is a X24165 EEPROM device (going obsolete and being replaced by X4165) of which I have four installed. I have a driver for this part but it is not completely tested so I have not submitted it for consideration. FYI - I don't know where the elektor name came from. I understand and agree with your comments about isolating chip drivers from bus drivers. My point is since the Elektor is just a bus master, it does not know what class of chips might be placed on its bus just that they are I2C. The only analogy I can think of is saying a PCI Bridge/Master chip is of class "video" because there is a video device on its bus. There may also be an ethernet device, sound device, etc. This is where my comment comes from that the use of the Elektor driver/module does not define that only hardware monitor chips/devices are located on the bus. Yes is capable of communicating with hardware monitor chips but it can also communicate with other classes such as eeprom and sound. Thanks
