This change consists of two parts.
First, nctgpio now supports hardware access via an I/O port window if
it's configured by firmware. For instance, PC Engines firmware
v4.10.0.2 does that. This is faster than going through the Super I/O
configuration registers.
Second, nctgpio now caches values of bits that it controls. For
example, the driver does not need to access the hardware to determine if
a pin is an output or an input, or a state of an output. Also, the
driver makes use of the fact that the hardware preserves an output state
of a pin accross a switch to the input mode and back.
With this change I am able to use the 1-Wire bus over nctgpio whereas
previously the driver introduced too much latency to be compliant with
the relatively strict protocol timings.
superio0: <Nuvoton NCT5104D/NCT6102D/NCT6106D (rev. B+)> at port 0x2e-0x2f on isa0
gpio1: <Nuvoton GPIO controller> at GPIO ldn 0x07 on superio0
pcib0: allocated type 4 (0x220-0x226) for rid 0 of gpio1
gpiobus1: <GPIO bus> on gpio1
owc0: <GPIO attached one-wire bus> at pin 4 on gpiobus1
ow0: <1 Wire Bus> on owc0
ow0: romid 28:b2:9e:45:92:10:02:34: no driver
ow_temp0: <Advanced One Wire Temperature> romid 28:b2:9e:45:92:10:02:34 on ow0
MFC after: 4 weeks
This is where it logically belongs.
The change allows to drop a bunch of low lewel code.
Reviewed by: gonzo
MFC after: 19 days
Differential Revision: https://reviews.freebsd.org/D21980
That is, instead of the current GPIO00 - GPIO15 the names will be GPIO00
- GPIO07, GPIO10 - GPIO17. The first digit is a GPIO "bank" / group
number and the second one is a pin number within the bank. Alternative
view is that the pin names are changed from decimal numbering scheme to
octal one (as there are 8 pins per bank).
Discussed with: cem, gonzo
MFC after: 2 weeks
This driver thinks that the NCT_MAX_PIN index is a valid index in a few places
(nct_attach() for-loop, as well as NCT_IS_VALID_PIN()). Allocate room for
NCT_MAX_PIN as an index, that is, NCT_MAX_PIN + 1 elements.
Reported by: Coverity
CIDs: 1353806, 1353807, 1353808, 1353809, 1353810
Sponsored by: EMC / Isilon Storage Division
No functional change, only trivial cases are done in this sweep,
Drivers that can get further enhancements will be done independently.
Discussed in: freebsd-current
Make it compile only for i386/amd64 for now as it's been tested there.
It's quite possible it'll show up elsewhere and we can enable it
for other architectures later.
Tested:
* PC Engines APU1C4
Submitted by: Daniel Wyatt <daniel@dewyatt.com>
Reviewed by: adrian, loos
Differential Revision: https://reviews.freebsd.org/D5389
