Wiadomość napisana w dniu 2010-10-18, o godz. 19:36, przez Frank Wille:
Configuration file could look like this: clockport0 at mainbus addr 0xd80000 # A1200 mainboard clockport clockport* at zbus? # various Zorro clockports tduhc0 at clockport? # E3B SUBWAY USB ControllerThat looks like a good idea for me.But what is a Zorro clockport? Does it really exist? Do you have examples?
It is simply a clockport located on a Zorro card. Best known Zorro cards with clockports include Individual Computers Buddha and X-Surf. Clockports on a card usually have different base address than original A1200 clockport - this way it is possible to have more than one clockport device in a computer.
Match code for clockport at zbus should contain list of vendors and device IDs of cards carrying clockport, along with their default base adresses. It is not possible to "detect" a clockport in any other way. There is one disadvantage - we have to attach clockport layer to a card that already has some other driver attached, e.g. wdc at zbus in case of Buddha.
In some cases base address of such clockport is static, always the same, and in some cases it is configured dynamically. I think most clockports on Zorro cards are static, but I know at least one that is configurable - clockport on a Deneb USB controller. It is probably possible to change its base address via software.
By introducing this layer we move responsibility of knowing base adress from device driver to clockport layer. Therefore driver programmer does not have to worry about location of clockport and its address.
Best regards, Radoslaw Kujawa