newbus ioport usage

[Nate Lawson]

On Mon, 26 Jan 2004, M. Warner Losh wrote:
> In message: <20040126172211.J30603 at root.org>
>             Nate Lawson <nate at root.org> writes:
> : On Mon, 26 Jan 2004, M. Warner Losh wrote:
> : > In message: <20040126165523.W30461 at root.org>
> : >             Nate Lawson <nate at root.org> writes:
> : > : Ok, I'm doing the set/alloc and it works.  However, one weird thing.  If I
> : > : allocate all ports at boot time, it succeeds.  My driver goes through
> : > : multiple release/allocate cycles and it all works as expected.  However if
> : > : I boot and attach to only one of the registers, subsequent attempts to
> : > : attach the second one fail.  The resources are 2 IO ports, 0x101c and
> : > : 0x101d.  Both are 1 byte.
> : >
> : > Deos devinfo -r show any cause for the problem?  Maybe you aren't
> : > releasing them properly?  Also, why not allocate them as a block of 2?
> :
> : I'll look into that.  I can't allocate them in one block as they come and
> : go, based on system state.  In one state, one is available and in another,
> : both are available.  If I boot while only one is available and then you
> : plug in the AC adapter, new ones appear.  This is acpi, btw.
>
> Ummm, wouldn't they both always be allocated to the driver, even if
> you could only talk to one of them at any given time?

No, the object you evaluate for a list of registers changes dynamically at
runtime.  The _CST method returns one of the below objects, depending on
AC adapter state.  If you evaluate it at boot and get CST1, you have no
info about CST2, which you might get later.

            Name (CST1, Package (0x02) {
                Package (0x04) {
                    ResourceTemplate () {
                        Register (FFixedHW, 0x08, 0x00, 0x0000000000000000)
                    },
                }
            })
            Name (CST2, Package (0x03) {
                Package (0x04) {
                    ResourceTemplate () {
                        Register (FFixedHW, 0x08, 0x00, 0x0000000000000000)
                    },
                },

                Package (0x04) {
                    ResourceTemplate () {
                        Register (SystemIO, 0x08, 0x00, 0x0000000000001014)
                    },
                }
            })

-Nate