ata_channel.
- Add and use a CHAN_TO_WDC_REGS() macro to get the wdc_regs from an
ata_channel.
- Add and use a CHAN_TO_PCIIDE() macro to get the pciide_softc from an
ata_channel.
- Add and use a CHAN_TO_PCHAN() macro to get the pciide_channel from an
ata_channel. (This one just hides a cast, and is really just for
consistency with the others.)
wdc_regs structure, and array of which (indexed per channel) is pointed
to by struct wdc_softc.
- Move the resulting wdc_channel structure to atavar.h and rename it to
ata_channel. Rename the corresponding flags.
- Add a "ch_ndrive" member to struct ata_channel, which indicates the
maximum number of drives that can be present on the channel. For now,
this is always 2. Add an ATA_MAXDRIVES constant that places an upper
limit on this value, also currently 2.
in a different fashion. Individually, they have the same functionality,
but their layout is different. An example of such a chipset is
the Promise 203xx.
To be able to deal with this, transform the cmd and dma bus_space handles
into an array of handles, each seperately created with bus_space_subregion.
The code generated by using the extra indirection shouldn't change much,
since the extra indirection is negated by having the offset calculation
already done in bus_space_subregion. E.g.
bus_space_write_4(tag, handle, offset, value)
becomes
bus_space_write_4(tag, handles[offset], 0, value)
Reviewed by Manuel Bouyer. Tested on wdc_isa, wdc_pcmcia, viaide, piixide (i386)
and on cmdide (sparc64).
thorpej