Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Const'ify scc_driver_name.

With rev 1.24 of sys/powerpc/powermac/macio.c, we now get a
total of 6 interrupt resources for scc(4) on macio(4). This
is 3 per channel, of which the 1st of each channel is the
interrupt associated with the SCC. The other 2 are for DMA
operation.
Change scc_bfe_attach() to accept an argument that's the
number of interrupts per channel (ipc) and change each bus
front-end (bfe) to pass that argument through a wrapper
for the device_attach method.

For now, we only allocate the 1st interrupt of each channel
to perserve behaviour.

Support for Freescale QUad Integrated Communications Controller.

The QUICC engine is found on various Freescale parts including MPC85xx, and
provides multiple generic time-division serial channel resources, which are in
turn muxed/demuxed by the Serial Communications Controller (SCC).

Along with core QUICC/SCC functionality a uart(4)-compliant device driver is
provided which allows for serial ports over QUICC/SCC.

Approved by: cognet (mentor)
Obtained from: Juniper
MFp4: e500

Add method enabled() to the SCC interface. This method can be used
by driver backends to mark individual channels as enabled or not.
The default implementation of this method always mark channels as
enabled.
This method is currently not used, but is added with the PowerQUICC
in mind where the 2nd SCC channel can be disabled.

Pass the RID from the bus frontends to the core probe function.
Currently all RIDs are 0, but for PCI devices this typically
isn't the case. This change is made with future PCI support in
mind.

o break newbus api: add a new argument of type driver_filter_t to
bus_setup_intr()

o add an int return code to all fast handlers

o retire INTR_FAST/IH_FAST

For more info: http://docs.freebsd.org/cgi/getmsg.cgi?fetch=465712+0+current/freebsd-current

Reviewed by: many
Approved by: re@

The Z8530 on the MacIO has an interrupt per channel. Deal with this
by having interrupt resource variables per channel. We don't set up
different interrupt handlers per channel, though.

Add a MacIO bus attachment. The Z8530 as present in the Mac needs
a different register shift and is fed by a different clock than
we use for UltraSPARC hardware. To deal with this, the regshft and
rclk fields in the class structure are removed and bus frontends
now pass the right regshft and rclk to the probe function where
they're put in the BAS and passed in to subordinate drivers.

Add scc(4), a driver for serial communications controllers. These
controllers typically have multiple channels and support a number
of serial communications protocols. The scc(4) driver is itself
an umbrella driver that delegates the control over each channel
and mode to a subordinate driver (like uart(4)).
The scc(4) driver supports the Siemens SAB 82532 and the Zilog
Z8530 and replaces puc(4) for these devices.