On Mon, Oct 27, 2014 at 02:59:17PM +0100, Andrew Lunn wrote: > > So lets take a step back: For the Marvell chips, I have to provide both > > length > > and presence in devicetree or platform data. Presence seemed to be implied > > by > > length, so I used only a single property and variable to indicate both. > > Hi Guenter > > What i was thinking, is that you don't need length in device tree. The > datasheet specifies how big the EEPROM needs to be. > > However, i read the datasheet for the 6060, the only public datasheet > from Marvell. It does not work as i expected. Rather than being a > fixed list of register values, it is a variable length list of > command/value pairs. > > In this situation, yes, you do need the length in DT. > Correct. The 6352 supports "2K bit (93C56) or 4K bit (93C66) 4-wire EEPROM devices as well as 1K bit (24C01), 2K bit (24C02) or 4K bit (24C04) 2-wire EEPROM", so the length can be anything from 128 to 512 bytes.
> I had a quick look at some other switch chips. e.g. the RTL8100. It > has a fixed layout of its EEPROM, consisting of 0x80 bytes. In this > case, the switch driver could be hard coded with 0x80, and all DT > needs to indicate is if the EEPROM is present or not. > > So, what you have proposed will work. It is maybe not optimal in the > case of a well defined in the datasheet fixed size EEPROM, but it > still works. > > Acked-by: Andrew Lunn <[email protected]> > Thanks! Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
