interrupt controller.
The latter is required for INTRNG, because of the hardware erratum
workaround installed by the linux folks into the imx6 FDT data, which remaps
an ethernet interrupt to the gpio device. In the non-INTRNG world we
intercept the call to map the interrupt and map it back to the ethernet
hardware (because we don't need linux's workaround), but in the INTRNG world
we lose the hookpoint where that remapping was happening, but we gain the
ability to work the way linux does by having the gpio driver dispatch the
interrupt.
the name the function will have when the new ARM_INTRNG code is integrated,
and doing this rename first will make it easier to toggle the new interrupt
handling code on/off with a config option for debugging.
Make it clearer what each one means in the comments that define them.
IIC_BUSBSY was used in many places to mean two different things, either
"someone else has reserved the bus so you have to wait until they're done"
or "the signal level on the bus was not in the state I expected before/after
issuing some command".
Now IIC_BUSERR is used consistantly to refer to protocol/signaling errors,
and IIC_BUSBSY refers to ownership/reservation of the bus.
one specific problem: the driver didn't check for ACK/NAK after writing a
slave address byte to the bus, and some slaves signal that they are busy
(such as when completing an internal write to flash memory) by sending a
NAK in response to being addressed.
While working on that problem I discovered that the driver's handling of
error conditions in general didn't match the state transition diagram in
the reference manual, and making that right resulted in a lot of code
reorganization.
Along the way various other changes also happened...
- Remove a mutex that wasn't protecting anything.
- Remove some mystery DELAY()s, document the few that remain.
- Use pause_sbt(9) to yield the processor for the bulk of the time it
takes to transfer each byte rather than busy-polling the whole time.
- Disable the controller when no transfers are in progress; since we
don't operate in slave mode, there's no reason to run the hardware.
- Remove a bunch of unecessary code from probe().
Also, follow the rules from watchdog(9) about what values to return in
various situations (especially, don't touch *error when asked to set a
non-zero timeout that isn't achievable on the hardware).
Also, move the READ/WRITE bus space access macros from the header into the
source file, and rename them to RD2/WR2 to make it clear they're 16-bit
accessors. (READ/WRITE just don't seem like good names to be in a public
header file.)
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
This is needed with the pl011 driver. Before this change it would default
to a shift of 0, however the hardware places the registers at 4-byte
addresses meaning the value should be 2.
This patch fixes this for the pl011 when configured using the fdt. The
other drivers have a default value of 0 to keep this a no-op.
MFC after: 1 week
uart implementations, and export them using the new linker-set mechanism.
Differential Revision: https://reviews.freebsd.org/D1993
Submitted by: Michal Meloun
o Digital Audio Multiplexer (AUDMUX)
o Smart Direct Memory Access Controller (SDMA)
o Synchronous Serial Interface (SSI)
Disable by default as it depends on SDMA firmware.
Sponsored by: Machdep, Inc.
The current support for controlling i2c bus speed is an inconsistant mess.
There are 4 symbolic speed values defined, UNKNOWN, SLOW, FAST, FASTEST.
It seems to be universally assumed that SLOW means the standard 100KHz
rate from the original spec. Nothing ever calls iicbus_reset() with a
speed of FAST, although some drivers would treat it as the 400KHz standard
speed. Mostly iicbus_reset() is called with the speed set to UNKNOWN or
FASTEST, and there's really no telling what any individual driver will do
with those.
The speed of an i2c bus is limited by the speed of the slowest device on
the bus. This means that generally the bus speed needs to be configured
based on the board/system and the components within it. Historically for
i2c we've configured with device hints. Newer systems use FDT data and it
documents a clock-frequency property for i2c busses. Hobbyists and
developers are likely to want on the fly changes. These changes provide
all 3 methods, but do not require any existing drivers to change to use
the new facilities.
This adds an iicbus method, iicbus_get_frequency(dev, speed) that gets the
frequency for the requested symbolic speed. If the symbolic speed is SLOW
or if there is no speed configured for the bus, the returned value is
100KHz, always. Otherwise, if bus speed is configured by hints, fdt,
tunable, or sysctl, that speed is returned. It also adds a helper
function, iicbus_init_frequency() that any bus driver subclassed from
iicbus can initialize the frequency from some other source of info.
Initial driver implementations are provided for Freescale and TI.
Differential Revision: https://reviews.freebsd.org/D1174
PR: 195009
I originally overlooked a couple flag bits defined in the fdt binding docs.
One flag suppresses the pad configuration (pullup/pulldown/etc). The other
one requires that the SION (set input on) flag be set in the mux register.
Also, it appears from the data involved that if the input register
address in the config tuple is zero, there is no input configuration. The
old code was writing to register zero, which contains a collection of misc
control bits (having nothing to do with input configuration) that probably
shouldn't get overwritten arbitrarily. The bindings doc doesn't explictly
mention this.
unit 0.
It seems that this 'simplification' was copied to all GPIO drivers in tree.
This fix a bug where a GPIO controller could fail to attach its children
(gpioc and gpiobus) if another GPIO driver attach first.
workaround for an imx6 chip erratum. Linux works around the bug with
changes in fdt data that we can't currently handle, so to enable running
with standard vendor-supplied fdt data, this watches for an attempt to map
the gpio1_6 interrupt and remaps it back to the standard ethernet interrupt.
This can be undone when the intrng project is completed and our gpio drivers
can also be interrupt controllers.
for, or that are required to run the chip (such as busses). Turn off all
the devices we don't yet have drivers for.
Some day we will have a fully functional imx6 clock driver so that we can
manage clocks based on fdt data. This will have to do until then.
timecounter resolution is available, so ask for a 1 GHz frequency. It
won't actually get one that fast, but that'll get the fastest available
clock and use a divisor of 1 (probably 132 or 66mhz on current hardware).
bus_new_pass() handler so it doesn't happen until BUS_PASS_CPU. This allows
the anatop driver to outbid the generic simplebus driver (which the FDT
data describes as compatible).
Some day when we handle power regulators, this driver may actually
become a functional simplebus and attach the regulators as children, as
described in the FDT data.
