(ns8250 copied and s/ns8250/i8251/g), but there for linkage purposes.
Real code to follow, once I get past some boot issues on my pc98 boxes
with recent current.
It improves on sio(4) in the following areas:
o Fully newbusified to allow for memory mapped I/O. This is a must
for ia64 and sparc64,
o Machine dependent code to take full advantage of machine and firm-
ware specific ways to define serial consoles and/or debug ports.
o Hardware abstraction layer to allow the driver to be used with
various UARTs, such as the well-known ns8250 family of UARTs, the
Siemens sab82532 or the Zilog Z8530. This is especially important
for pc98 and sparc64 where it's common to have different UARTs,
o The notion of system devices to unkludge low-level consoles and
remote gdb ports and provides the mechanics necessary to support
the keyboard on sparc64 (which is UART based).
o The notion of a kernel interface so that a UART can be tied to
something other than the well-known TTY interface. This is needed
on sparc64 to present the user with a device and ioctl handling
suitable for a keyboard, but also allows us to cleanly hide an
UART when used as a debug port.
Following is a list of features and bugs/flaws specific to the ns8250
family of UARTs as compared to their support in sio(4):
o The uart(4) driver determines the FIFO size and automaticly takes
advantages of larger FIFOs and/or additional features. Note that
since I don't have sufficient access to 16[679]5x UARTs, hardware
flow control has not been enabled. This is almost trivial to do,
provided one can test. The downside of this is that broken UARTs
are more likely to not work correctly with uart(4). The need for
tunables or knobs may be large enough to warrant their creation.
o The uart(4) driver does not share the same bumpy history as sio(4)
and will therefore not provide the necessary hooks, tweaks, quirks
or work-arounds to deal with once common hardware. To that extend,
uart(4) supports a subset of the UARTs that sio(4) supports. The
question before us is whether the subset is sufficient for current
hardware.
o There is no support for multiport UARTs in uart(4). The decision
behind this is that uart(4) deals with one EIA RS232-C interface.
Packaging of multiple interfaces in a single chip or on a single
expansion board is beyond the scope of uart(4) and is now mostly
left for puc(4) to deal with. Lack of hardware made it impossible
to actually implement such a dependency other than is present for
the dual channel SAB82532 and Z8350 SCCs.
The current list of missing features is:
o No configuration capabilities. A set of tunables and sysctls is
being worked out. There are likely not going to be any or much
compile-time knobs. Such configuration does not fit well with
current hardware.
o No support for the PPS API. This is partly dependent on the
ability to configure uart(4) and partly dependent on having
sufficient information to implement it properly.
As usual, the manpage is present but lacks the attention the
software has gotten.
o Introduce PUC_PORT_TYPE_UART so that we can attach to uart(4),
o Introduce port sub-types (eg PUC_PORT_UART_NS8250, PUC_PORT_UART_Z8530)
to handle different hardware and determine resource sizes.
o Introduce two new IVARs: PUC_IVAR_SUBTYPE and PUC_IVAR_REGSHFT. Both
are used by uart(4) to get sufficient information to talk to the HW.
o Introduce PUC_FLAGS_ALTRES to tell puc(4) to try memory mapped I/O
if I/O port space cannot be allocated, or vice versa.
o Have ports of type PUC_PORT_TYPE_COM attach to uart(1) if attaching
to sio(4) fails (due to not having the sio driver).
o Put struct puc_device_description in struct puc_softc instead of
having a pointer to a device description in the softc. This allows
us to create device descriptions on the fly without having to use
malloc() or otherwise have them staticly defined.
o Move puc_find_description() from puc.c to puc_pci.c as it's specific
to PCI.
o Add EBUS and SBUS frontends for use on sparc64. Note that the P in
puc stands for PCI, so we kinda mess things up here. It's too soon
to worry about it though. We'll know what to do about it in time.
NOTE: This commit changes the behaviour of puc(4) to not quieten the
device probe and attach for child devices. The uart(4) driver provides
additional device description that is valuable to have.
For the floppy driver, use fdcontrol to manipulate density selection.
For the CD drivers, the 'a' and 'c' suffix is without actual effect and
any applications insisting on it can be satisfied with a symlink:
ln -s /dev/cd0 /dev/cd0a
Ongoing discussion may result in these pieces of code being removed before
the 5-stable branch as opposed to after.
such a card is ejected, we'd panic. Instead, just ignore it.
I should also add a sanity check in the FUNCID code as well, but this
isn't wrong since the check is cheap and happens infrequently.
and replace it with the more intuitive name PCIR_BARS.
- Add a PCIR_BAR(x) macro that returns the config space register offset of
the 32-bit BAR x.
MFC after: 3 days
switched from PCCARD_MEM_FOO to PCCARD_A_MEM_FOO, yet we didn't change
exca in all the right places. Do so now. Also use PCCARD_WIDTH_AUTO
rather than the magic cookie 0.
change also disables interrupts around non-S4 suspends whereas before we
did not do this. Our version of AcpiEnterSleepStateS4bios was almost
identical to the ACPICA version.
- Add a new PCIM_HDRTYPE constant for the field in PCIR_HDRTYPE that holds
the header type.
- Replace several magic numbers with appropriate constants for the header
type register and a couple of PCI_FUNCMAX.
- Merge to amd64 the fix to the i386 bridge code to skip devices with
unknown header types.
Requested by: imp (1, 2)
reading the CIS on some cards. However, not all just yet. This makes
at least some of the xircom cards that weren't working to work. It
doesn't make my home and away card work, however.
o Don't get the card offset wrong. This is the biggest hassle for
reading the CIS. The old code was just so wrong I can't believe that
it worked at all.
o Don't set the bit that allows/forces 16-bit memory access to the
memory. It is hard coded with 0x80.
o Don't need to slow down memory access with wait-states. OLDCARD didn't
need them and it doesn't hurt anything.
o remove bogus grousying in comment.
