On Mon, Jan 03, 2011 at 12:28:24PM +0100, Sebastian Andrzej Siewior wrote:
If you have a node describing a device, then it *must* have a
compatible value. Use the OF PCI binding to determine what the
compatible value should be something like:
compatible = "pciVVVV,DDDD,SSSS,ssss", "pciVVVV,DDDD"
See page 9 on this pdf: http://www.openbios.org/data/docs/bus.pci.pdf
The list of possible formats in the binding doc is long, but most of
them probably don't apply in your case (but include the other entries
if they do).
Also, since the i2c@15a00 is *not* an actual i2c bus, it should not be
named 'i2c@...'. Name it something like i2c-controller@15a00,0,0.
You'll also note that I added ',0,0' to the end of the address.
That's because the node address reflects the parent bus address format
which uses 3 cells in this case.
That depends. Are the child nodes separately memory mapped devices?
Or are all three controlled by a shared register bank in the
controller? If they are addressable (which they probably are) then
you need to use a ranges property to describe the translation from the
parent node to the child node. Since you say that the registers
define describe the bars, it probably makes sense to use a 2 cell
addressing scheme: one cell for the bar# and one cell for the offset
off the bar base address (which will be 0 for each I expect).
Something like this:
i2c-controller@15a00 {
compatible = "intel,<blah>", "pciVVVV,DDDD,SSSS,ssss", "pciVVVV,DDDD";
#address-cells = <2>;
#size-cells = <1>; // not 0! 0 is used for
// devices that cannot be
// memory mapped.
reg = <0x15a00 0x0 0x0 0x0>;
// Here's where the magic happens. Each entry in
// ranges describes how the parent pci address space
// (middle group of 3) is translated to the local
// address space (first group of 2) and the size of
// each range (last cell). In this particular case,
// the first cell of the local address is chosen to be
// 1:1 mapped to the BARs, and the second is the
// offset from be base of the BAR (which would be
// non-zero if you had 2 or more devices mapped off
// the same BAR)
//
// ranges allows the address mapping to be described
// in a way that the OS can interpret without
// requiring custom device driver code.
//
// This example assumes that each child node has it's
// own range of memory mapped registers.
ranges = <0 0 0x02000000 0 0xa0000000 0x1000>
<1 0 0x02000000 0 0xa0002000 0x1000>
<2 0 0x02000000 0 0xa0004000 0x1000>
i2c@0,0 {
#address-cells = <1>
#size-cells = <0>;
compatible = <need something here>;
reg = <1 0 0x1000>;
};
i2c@1,0 {
#address-cells = <1>;
#size-cells = <0>;
compatible = <need something here>;
reg = <1 0 0x1000>;
pcf8575@26 {
compatible = "ti,pcf8575";
reg = <0x26>;
};
};
i2c@2,0 {
#address-cells = <1>;
#size-cells = <0>;
compatible = <need something here>;
reg = <2 0 0x1000>;
pcf8575@26 {
compatible = "ti,pcf8575";
reg = <0x26>;
};
};
Correct.
g.
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