The core console code checks this field when a console is added and
emits a warning if it's empty. In practice the warning is harmless for
uart(4), because the cn_name is filled in as soon as the device name is
known; which is when the device is enumerated.
To avoid the warning, to avoid possible complications caused by emitting
the warning without there (possibly) being a console selected yet and to
avoid complications when the UART isn't found during bus enumeration, we
just preset the cn_name field here to the name of the driver.
fact that access to RR0 does not need a prior write to the register
index because the index always reverts to 0 after the indexed register
has been accessed.
Typically when a RR or WR is to accessed, one programs the index (which
is a write to the control register), followed by a read or write to the
actual indexed register (a read pr write to the same control register).
When this non-atomic sequence is interrupted after having written the
index and low-level console I/O is done in that situation, the write to
program the index will actually write to the indexed register and nuke
state. This almost always yields a wedge.
By not programming the index register and instead just reading from RR0,
the worst case scenario is non-fatal. For if we don't actually read from
RR0 but some other register we get an invalid status, which may lead us
to conclude that the transit data register is empty when it's not or that
the receive data register contains data when it doesn't. Hence, we may
lose an output character or get a sporadic input character, but given
the situation this is a non-issue.
Full serialization is not possible due to the fact that this code needs
to work from DDB and before mutex initialization has happened.
In collaboration with: kris@, marius@
Tested by: kris@
MFC after: 1 day
X-MFC: 5.4-RELEASE candidate
a serial console anyway because input-device is set to keyboard and
output-device is set to screen but no keyboard is plugged in don't
assume that a device node for the input-device alias exists. While
this is true for RS232 keyboards (the node of the SCC and UART
respectively which controls the keyboard doesn't disappear when no
keyboard is plugged in) this assumption breaks for USB keyboards.
It's most likely also not true for PS/2 keyboards but OFW doesn't
reliably switch to a serial console when the potential keyboard is
a PS/2 one which isn't plugged in so this couldn't be verified
properly.
Reported by: Will Andrews <will@csociety.org>, obrien
MFC after: 1 week
with shared IRQs in case the bus code, MD interrupt code, etc. permits.
Together with sys/sparc64/sparc64/intr_machdep.c rev. 1.21 this fixes
an endless loop in uart_intr() when using the second NS16550 on the ISA
bus of sparc64 machines.
- Destroy the hardware mutex on detach and in case attaching fails.
Approved by: marcel
for nodes hanging off of Central (untested), FireHose (untested) and
PCI (tested) busses.
- Add an additional parameter to OF_decode_addr() which specifies the
index of the register bank to decode.
These should allow to eventually add support for the Z8530 hanging off of
FireHose to uart(4) and to write support for PCI-based graphics adapters.
Suggested by: tmm (back in '03)
The presence or absence of a keyboard does not change whether an
UART is designed as a keyboard port or not and thus whether we
can use the port as a TTY or not.
We now call sunkbd_attach() even when we didn't previously find
a keyboard. Emit a useful message stating that no keyboard was
found, but don't do anything else.
MFC after: 5 days
engineering the pending interrupt sources from the current
state of the controller. For channel A we can always read the
interrupt pending register (RR3). For channel B we can read
the interrupt vector register (RR2) because it contains the
modified vector and thus includes the interrupt source.
Since we currently need puc(4) for the Z8530, we know that
the interrupt handler for both channels will be called and
thus that RR3 will always be read at least once, even if ch A
has no pending interrupt.
NOTE: The modified interrupt vector has no value that represent
a lack of pending interrupt for channel B. That is, the
value read when no interrupts are pending is the same as the
value for the special receive condition. Fortunately, we don't
actually have to depend on that interrupt source. This does
mean that we need to properly handle the overflow condition,
when we read received character from the chip.
o The DSR signal is represented by the SYNC bit in the external
status register (RR0). We now properly track DSR.
o It's save to enable the external/status interrupt source. We
now get interrupts when line signals (DSR, DCD or CTS) change.
Problems fixes:
o interrupt storms.
o blocked open(2).
o lack of (hardware) flow control.
o unable to report DSR.
MFC after: 5 days
the address of a channel on a SCC, it returns 0 on failure. [1]
- Hardcode channel 1 for the keyboard on Z8530, the information present
in the Open Firmware device tree doesn't allow to determine this via
uart_cpu_channel(). This makes the keyboard (if one backs out rev. 1.5
of sys/dev/puc/puc_sbus.c and has both keyboard and mouse plugged in to
avoid the hang that revision works around) and consequently syscons(4)
on Ultra 2 work. There's a problem with the keyboard LEDs similar to
the one on Ultra 60 (LEDs don't get lit under X) though, instead of
lighting just a specific single one all get lit and can't be turned off
again. [1]
- Add comments about what uart_cpu_channel() and uart_cpu_getdev_keyboard()
do and their constraints.
- Improve the comments about what uart_cpu_getdev_[console,dbgport]() do,
they don't return an address (as in bus) but an Open Firmware package
handle.
Reviewed by: marcel (modulo the comments) [1]
- The claim in the commit log of rev. 1.11 of dev/uart/uart_cpu_sparc64.c
etc. that UARTs are the only relevant ISA devices on sparc64 turned out
to be false. While there are sparc64 models where UARTs are the only
devices on the ISA bus there are in fact also low-cost models where all
devices traditionally found on the EBus are hooked up to the ISA bus.
There are also models that use a mix between EBus and ISA devices with
things like an AT keyboard controller and other rather interesting
devices that we might want to support in the futute hook up to the ISA
bus.
In order to not need to add sparc64 specific device_identify methods to
all of the respective ISA drivers and also not add OFW specific code to
the common ISA code make the sparc64 ISA bus code fake up PnP devices so
most ISA drivers probe their devices without further changes.
Unfortunately Sun doesn't adhere to the ISA bindings defined in IEEE
1275-1994 for the properties of most of the ISA devices which would
allow to obtain the vendor and logical IDs from their properties. So we
we just use a simple table which maps the name properties to PnP IDs.
This could be done in a more sophisticated way but I courrently don't
see the need for this. [1]
- Add the children with fully mapped and specified resources (in the OFW
sense) similar to what is done in the EBus code for the IRQ resources
of the children as adjusting the resources and the resource list entries
respectively in isa_alloc_resource() as done perviously causes trouble
with drivers which use rman_get_start(), pass-through or allocate and
release resources multiple times, etc.
Adjusting the resources might be better off in a bus_activate_resource
method but the common ISA code currently doesn't allow for an
isa_activate_resource(). [2]
With this change:
- ppbus(4) and lpt(4) attach and work (modulo ECP mode, which requires
real ISADMA code but it currently only consists of stubs on sparc64).
- atkbdc(4) and atkbdc(4) attach, no further testing done.
- fdc(4) itself attaches but causes a hang while attaching fd0 also
when is DMA disabled, further work in fdc(4) is required here as e.g.
fd0 uses the address of fd1 on sparc64 (not sure if sparc64 supports
more than one floppy drive at all).
All of these drivers previously caused panics in the sparc64 ISA code.
- Minor changes, e.g. use __FBSDID, remove a dupe word in a comment and
declare one global variable which isn't used outside of isa.c static.
o dev/uart/uart_cpu_sparc64.c and modules/uart/Makefile:
- Remove the code for registering the UARTs on the ISA bus from the
sparc64 uart_cpu_identify() again and rely on probing them via PnP.
Original idea by: tmm [1]
No objections by: tmm [1], [2]
current baudrate setting. Use this ioctl() when we don't know the
baudrate of the sysdev (as represented by a 0 value). When the
ioctl() fails, e.g. when the backend hasn't implemented it or the
hardware doesn't provide the means to determine its current baudrate
setting, we invalidate the baudrate setting by setting it to -1.
None of the backends currently implement the new ioctl().
A baudrate we consider insane is silently replaced with 0. When the
baudrate is 0, we will not try to program the hardware. Instead we
leave the communication speed unaltered, maximizing the chance to
have a working console. Obviously this means we allow specifying a
0 baudrate for exactly that purpose.
and that can be used as an identify function for all kinds of busses on a
certain platform. Expect for sparc64 these are only stubs right now. [1]
- For sparc64, add code to its uart_cpu_identify() for registering the on-
board ISA UARTs and their resources based on information obtained from
Open Firmware.
It would be better if this would be done in the OFW ISA code. However, due
to the common FreeBSD ISA code and PNP-IDs not always being present in the
properties of the ISA nodes there seems to be no good way to implement that.
Therefore special casing UARTs as the sole really relevant ISA devices on
sparc64 seemed reasonable. [2]
Approved by: marcel
Discussed with: marcel [1], tmm [2]
Tested by: make universe
subset ("compatible", "device_type", "model" and "name") of the standard
properties in drivers for devices on Open Firmware supported busses. The
standard properties "reg", "interrupts" und "address" are not covered by
this interface because they are only of interest in the respective bridge
code. There's a remaining standard property "status" which is unclear how
to support properly but which also isn't used in FreeBSD at present.
This ofw_bus kobj-interface allows to replace the various (ebus_get_node(),
ofw_pci_get_node(), etc.) and partially inconsistent (central_get_type()
vs. sbus_get_device_type(), etc.) existing IVAR ones with a common one.
This in turn allows to simplify and remove code-duplication in drivers for
devices that can hang off of more than one OFW supported bus.
- Convert the sparc64 Central, EBus, FHC, PCI and SBus bus drivers and the
drivers for their children to use the ofw_bus kobj-interface. The IVAR-
interfaces of the Central, EBus and FHC are entirely replaced by this. The
PCI bus driver used its own kobj-interface and now also uses the ofw_bus
one. The IVARs special to the SBus, e.g. for retrieving the burst size,
remain.
Beware: this causes an ABI-breakage for modules of drivers which used the
IVAR-interfaces, i.e. esp(4), hme(4), isp(4) and uart(4), which need to be
recompiled.
The style-inconsistencies introduced in some of the bus drivers will be
fixed by tmm@ in a generic clean-up of the respective drivers later (he
requested to add the changes in the "new" style).
- Convert the powerpc MacIO bus driver and the drivers for its children to
use the ofw_bus kobj-interface. This invloves removing the IVARs related
to the "reg" property which were unused and a leftover from the NetBSD
origini of the code. There's no ABI-breakage caused by this because none
of these driver are currently built as modules.
There are other powerpc bus drivers which can be converted to the ofw_bus
kobj-interface, e.g. the PCI bus driver, which should be done together
with converting powerpc to use the OFW PCI code from sparc64.
- Make the SBus and FHC front-end of zs(4) and the sparc64 eeprom(4) take
advantage of the ofw_bus kobj-interface and simplify them a bit.
Reviewed by: grehan, tmm
Approved by: re (scottl)
Discussed with: tmm
Tested with: Sun AX1105, AXe, Ultra 2, Ultra 60; PPC cross-build on i386
with it that need to be understood better before they can be resolved.
This takes time and time is already in short supply.
Reported & tested by: glebius@
future:
rename ttyopen() -> tty_open() and ttyclose() -> tty_close().
We need the ttyopen() and ttyclose() for the new generic cdevsw
functions for tty devices in order to have consistent naming.
o Call kdb_enter() instead of breakpoint().
o Call kdb_alt_break() instead of db_alt_break().
o Make debugging code conditional upon KDB instead of DDB.
does not reliably prevent the triggering of interrupts for all supported
configurations. Thus, the FIFO size probe could cause an interrupt,
which could lead to an interrupt storm in the shared interrupt case.
To prevent this, change ns8250_bus_probe() to use the overflow bit in
the line status register instead of the RX ready bit in the interrupt
identification register to detect whether the FIFO has filled up.
This allows us to clear all bits in the interrupt enable register during
the probe, which should prevent interrupts reliably.
Additionally, the detected FIFO size may be a bit more accurate, because
the overflow bit is only set when the FIFO did actually fill up, while
interrupts would trigger a bit early.
Reviewed and tested on a lot of hardware by: marcel
not as a pending interrupt status, but as a matter of status quo.
Consequently, when there's no data to be transmitted the condition
is not cleared and uart_intr() is stuck in an infinite loop trying
to clear the UART_IPEND_TXIDLE status.
The z8530_bus_ipend() function is changed to return idle only once
after having sent any data.
The root cause for this problem is that we cannot use the interrupt
status bits of the SCC itself. The register that holds the interrupt
status can only be accessed by channel A and holds the status for
both channels. Using the interrupt status register would complicate
the driver because we need to synchronize access to the SCC between
the channels.
Elementary testing: marius
"... uart_cpu_sparc64.c currently only looks at /options if ttyX is
the selected console. However, there's one case where it should
additionally look at /chosen. If "keyboard" is the selected input-
device and "screen" the output-device (both via /options) but the
keyboard is unplugged, OF automatically switches to ttya for the
console. It even prints a line telling so on "screen". Solaris
respects this behaviour and uses ttya as the console in this case
and people probably expect FreeBSD to do the same (it's also very
handy to temporarily switch consoles)..."
Submitted by: Marius Strobl <marius@alchemy.franken.de>
Has no doubt the change is correct: marcel
