zs(4): Convert to ttylock/ttyunlock.

in many device attach paths, allocate memory with M_WAITOK instead of M_NOWAIT
and remove code to handle failures that can no longer happen.

Fix panic due to inconsistent lock states of tty_lock in zsparam().
Tested on mac68k.

branches: 1.132.4;
As discussed on tech-kern: define a new tty internal state flag: TS_KERN_ONLY

Implement it in a few tty drivers. If this flag is set, the underlying
hardware is used by another driver and userland has no right to open
it. A few uses will appear soon in sys/dev/sun/sun{kbd,ms}.c.

branches: 1.131.12;
centralize the dialout/call unit macros.

Add d_discard to all struct cdevsw instances I could find.

All have been set to "nodiscard"; some should get a real implementation.

branches: 1.129.2;
Change (mostly mechanically) every cdevsw/bdevsw I can find to use
designated initializers.

I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.

branches: 1.128.4; 1.128.14; 1.128.18;
Rename ttymalloc() to tty_alloc(), and ttyfree() to tty_free() for
consistency. Remove some unnecessary malloc.h inclusions as well.

branches: 1.127.4; 1.127.6;
add two new functions for z8530tty: zs_chan_lock() and zs_chan_unlock(),
and use them instead of various spl's in the zs.c's.

reviewed by ad and martin.

struct device * -> device_t, no functional changes intended.

struct cfdata * -> cfdata_t, no functional changes intended.

Try to avoid zstty hangs on higher speed:

z8530sc.c:
Check pending interrupts in a loop until all requests are handled.
The old comments said it would cause horrible latency to sun3x floppy etc,
but serial ports should have higher priority than disks anyway.

z8530tty.c:
Don't enable and disable TX interrupts on each transmit start and completion
because it could cause possible race conditions.
Instead, set ZSWR0_RESET_TXINT on each TIE interrupt to clear the request
as other kbd drivers attached at zs(4).

Tested on cobalt, macppc, news68k, sparc, and sun3.

branches: 1.123.2; 1.123.10; 1.123.12; 1.123.16;
Make ntp, pmc, reboot, sysarch, time syscalls MPSAFE.

branches: 1.122.2;
Split softc and device_t for zsc(4) and its children.

XXX we should restructure MI APIs and make it really machine independent.

Remove a tty_lock for now - I know that this is wrong, but the whole
tty subsystem locking is not consistent and Andrew didn't have
time to come up (or guide to) the right fix.
This prevents machines with serial console on zs(4) from deadlocking on
first input.

branches: 1.120.2; 1.120.6;
Now that __HAVE_TIMECOUNTER and __HAVE_GENERIC_TODR are invariants,
remove the conditionals and the code associated with the undef case.

t_linesw->l_modem would ideally be called with tty_lock held, but before
that can happen someone needs to beat all the drivers into shape.

Don't recursively acquire tty_lock when zstty_softint() is called directly.

branches: 1.117.2; 1.117.6;
- Factor out too many copies of the same bit of tty code.
- Fix another tty signalling/wakeup problem.

zsstart, zstty_txsoft: don't acquire tty_lock, it's already held.

Merge tty changes from the vmlocking branch.

branches: 1.114.6; 1.114.8; 1.114.12; 1.114.14;
Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

branches: 1.113.2; 1.113.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.112.4;
More from Matt Fleming:

Adapt to KAUTH_DEVICE_TTY_PRIVSET and KAUTH_DEVICE_TTY_OPEN.

Adapt MD code to KAUTH_DEVICE_TTY_OPEN, batch #2 from Matt Fleming, thanks!

Also, add forgotten splx() calls in some places.

branches: 1.110.4; 1.110.6;
Remove unused variable to make it compile again.

- Use the LWP cached credentials where sane.
- Minor cosmetic changes.

merge FreeBSD timecounters from branch simonb-timecounters
- struct timeval time is gone
time.tv_sec -> time_second
- struct timeval mono_time is gone
mono_time.tv_sec -> time_uptime
- access to time via
{get,}{micro,nano,bin}time()
get* versions are fast but less precise
- support NTP nanokernel implementation (NTP API 4)
- further reading:
Timecounter Paper: http://phk.freebsd.dk/pubs/timecounter.pdf
NTP Nanokernel: http://www.eecis.udel.edu/~mills/ntp/html/kern.html

branches: 1.107.2;
integrate kauth.

- use M_NOWAIT rather than M_WAITOK for malloc(9) to allocate RX buffer
in zstty_attach()
- check a return value of the malloc(9)

Taken from com.c, and somehow this seems to fix PR port-sun2/32420 on tme.

Use device_cfdata().

Use device_unit().

branches: 1.103.2; 1.103.4;
Remove SET/CLR/ISSET macros.

branches: 1.102.4; 1.102.6; 1.102.8;
switch macppc to use the MI zstty driver.
add macppc's ZS_TXDMA hooks there.

merge ktrace-lwp.

Change the driver open function's conditional for overriding exclusive tty
use from checking the proc's uid to suser(9), and account for the use of
privileges. Noted by David Holland in PR kern/31126.

branches: 1.99.2;
Allow sparc64-style attachment of mouse and keyboard via zstty, needed for
wscons support.
Reviewed by uwe.

- add const
- avoid variable shadow

nuke trailing whitespace

de-__P

branches: 1.95.4; 1.95.6;
Define and use zsccf_channel as an alias for cf_loc[ZSCCF_CHANNEL].

Fix NTP PPSAPI support (enabled with "options PPS_SYNC"):

From PR kern/13702 from Charles Carvalho. Tested on alpha and
i386 with a Laipac TF10 PPS-capable GPS. The com.c change was
copied wholesale from Charles' z8530tty.c patch.

netbsd.org -> NetBSD.org

This was the last commit of this kind to src/sys, which is now totally
"NetBSD.org clean". Thanks for the patiance, and sorry for all the commits.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.91.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

More changes for providing lwpid for ktrace (sparc GENERIC built)

Provide locking required by the interrupt handlers running at IPL_SERIAL.

zs_shutdown: lower IPL before sleeping. Also note the fact that the
effectiveness of that very tsleep() call is dubious at best.

interrupt with two rs.

Fix signed/unsigned comparison warnings.

merge kqueue branch into -current

kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe

Add trailing ; to CFATTACH_DECL.

Use CFATTACH_DECL().

Declare all cfattach structures const.

Deal with the strange SCC wiring on TC IOASIC machines. Thanks to Bill
Studenmund and Jonathan Stone for useful comments.

Merge the gehenna-devsw branch into the trunk.

This merge changes the device switch tables from static array to
dynamically generated by config(8).

- All device switches is defined as a constant structure in device drivers.

- The new grammer ``device-major'' is introduced to ``files''.

device-major <prefix> char <num> [block <num>] [<rules>]

- All device major numbers must be listed up in port dependent majors.<arch>
by using this grammer.

- Added the new naming convention.
The name of the device switch must be <prefix>_[bc]devsw for auto-generation
of device switch tables.

- The backward compatibility of loading block/character device
switch by LKM framework is broken. This is necessary to convert
from block/character device major to device name in runtime and vice versa.

- The restriction to assign device major by LKM is completely removed.
We don't need to reserve LKM entries for dynamic loading of device switch.

- In compile time, device major numbers list is packed into the kernel and
the LKM framework will refer it to assign device major number dynamically.

branches: 1.79.4;
Convert ioctl code to use EPASSTHROUGH instead of -1 or ENOTTY for
indicating an unhandled "command". ERESTART is -1, which can lead to
confusion. ERESTART has been moved to -3 and EPASSTHROUGH has been
placed at -4. No ioctl code should now return -1 anywhere. The
ioctl() system call is now properly restartable.

add/cleanup RCSID

branches: 1.77.2; 1.77.4;
add missing #include "opt_kgdb.h"

Add a flag to suppress SCC reset at attach time.

From Rafal K. Boni.

Add `l_poll' to `struct linesw' and provide an xxxpoll() entry point
in each tty driver to indirect through it.

This allows tty line-disciplines to handle poll(2) system calls.

Add some delay in zstty_attach() to wait previous console output
to complete before hardware initialization.

Add missing \n during probe if port is dedicated to kgdb

branches: 1.72.2;
Use the MI console magic sequence framework.

remove what looks to be a bit of leftover debug code.

Adapt to the new line discipline scheme.

Change tiocm_to_{com,zs}'s second argument to u_long to match with
the type in their caller.

Use device_lookup().

branches: 1.67.4;
Remove spurious splx() call.

Fix typos from last commit (callout).

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

Check for console input and output separately.
XXX - split input/output for /dev/console is not yet supported.

Add power management hooks.

Update user-level PPS-API to match -05 draft.
Change PPS_<xxx> ioctls to PPS_IOC_<xxx>.

branches: 1.61.2; 1.61.4;
Fix nanosecond/microsecond botch in PPSAPI:
remove bogus TIMESPEC_TO_TIMEVAL() after applying any {assert,clear} offset.

branches: 1.60.2;
Don't send any data upstream if we're not open yet.

branches: 1.59.2;
PPS support. Copied off of com.c support, with changes as DCD interupts
are only enabled if needed and if ok'd by MD layer.

Minor changes to tiocm code.

Redo the N previous changes, plus a couple of other things:
* Move the printf() delay to just after the printf(), where it actually makes
sense.
* Use zstty_stint() and zstty_softint() from zsparam(), to force an immediate
update of the carrier and flow control status. Abuse this in the attach and
open functions to defer all of that work. This insures that we don't lose
any status updates.
* Don't screw with register 1 when closing the console.
* Fix bugs in TIOCM??? (stay semicolon, clearing DTR while transmitting).
* Add comments in a couple of places.

Add the patch I floated on tech-kern. Andreas Eltrich <elchy@dahoam.de>
says it got pppd working for him.

Fix thinko in part of rev 1.53.

Thanks to Scott for pointing this out to me (I got his mail and figured out
this change before seeing the discussion on tech-kern) and to Charles for
the initial explanation.

Put back modem control ioctl's

Changes to deal with mac serial ports having clock sources on DCD or CTS.

- When doing a first open, don't enable receive & status interupts before
the MD layer has had a chance to set things up.
- Enable logic to only enable DCD/CTS interupts if we are looking for/
expecting interupts on those pins. Disable otherwise.
- in zs_param, only pass up the state of ZSRR0_DCD if we have enabled
interupts on that pin.

Henry Hotz (<hotz@jpl.nasa.gov>) and Greg walsh <gwalsh@artec.com> have
tried these changes to get certain printers from hanging at boot. They
work in a 1.3.2 kernel for Greg.

minor changes to console handling in zstty_attach():
-wait 20ms between printf() and reconfiguring the hardware
-set cn_tab->cn_dev here because this is the place where the real minor
number is known

kill the last remnants of __BROKEN_INDIRECT_CONFIG. (only the pica port
used it, and it's non-working and apparently slated for replacement.)

Oops. We do still need to set t_dev in the first open part of zsopen,
so we get ttyXX vs cuaXX right. Leave the initialization in attach.

Initialize the struct tty's t_dev field at attach rather than first open.
The attach routine calls zsparam if we're setting up the console, and
zsparam needs this field to tell which zstty to set up. Otherwise, we
set up zstty0 even if it's not the console!

Eliminate cs_heldchar. It is not necessary in my version of the driver.

Move the code to wait for carrier on a tty into a common function, since it
depends only on device-independent state bits.
Implement SunOS-style `dialout' devices.

Fix pasto.

Replace TS_WOPEN with t_wopen, per mail on tech-kern.

Fix bonehead error in previous change.

Similar changes to com driver:
Arrange to call com_break() and com_modem() at splserial().
It's simpler this way. Really.

Adjust for config changes.

Use a 1-character queue so polled console output can be deferred if
regular I/O has been scheduled.

Actually use TIOCFLAG_CDTRCTS.

Always leave DCD_IE and CTS_IE on for now. Needs more work in zsparam() to
make the optimization actually work right.

Leave the console running with or without DDB.

Slight optimization in soft input routine.

Set the ring size back to 2k.

Bug fixes:
* Carrier detect (TS_CARR_ON) is based on the actual DCD bit, even if it's
being ignored.
* Set TS_WOPEN early on in zsopen().
* Don't disable interrupts on the console during close if we have DDB.

Inert changes:
* Don't handle ZS_HWFLAG_NO_DCD here; the frontend does it.
* Deprecate `register'.
* Use SET(), CLR(), and ISSET().

More performance changes:
* Rototill receive handling; use a backpressure mechanism to prevent livelock.
* Output silo/ibuf overflow warnings at most once per minute, from a callout.
* When we exhaust the current transmit run, turn off transmit interrupts in
zstty_txint(), so we're fairly sure we don't get another one.

Fix serial console support (did not turn on CLOCAL).

Rearrange *param() slightly to eliminate a spl.
Also fix another comment regarding DTR.

Add another splserial()/splzs().

Minimize some spl regions slightly.

If we lose HFC, assert RTS.

Set the state of DCD_IE and CTS_IE based on what's in rr0_mask.

Correct a comment regarding our behaviour with DTR.

Fix minor omission; write back reg 1 earlier in zsopen().

Need some additional splzs() in zsopen(), and nuke one that's no longer
needed.

Nuke the special case of heldchange for reg 5. We don't use it for flow
control any more, and the speed of changing DTR isn't really an issue. Also,
the old code created a bug where zsparam() might have failed to set some
registers.

Yet more changes imported from com driver:
Change the interface to zs_hwiflow(); just have it use zst_rx_blocked.
Make zs_modem() a tiny bit faster.
Do RTS updates immediately; do not allow them to be held.

Make zst_tba a u_char *.

More changes taken from com driver:
Stop output as fast as possible when DCD is deasserted.
Do *not* automatically drop DTR when DCD is deasserted.
Only check for rr0 bits that we care about (DTR and DCD).

GC some unused bits.
Also, part of the previous was copied from the com driver, so DTRT.

Rearrange open sequence to make sure we catch all line status changes.
Make sure we turn on DTR and/or RTS as appropriate during open.
Rearrange close sequence so the tty is flushed before turning off interrupts.
Deal with `softcar' and the console device by silently asserting CLOCAL and
|HUPCL, as in com driver.
Do *not* fiddle with DTR when changing the line speed.
Make sure we update the tty's carrier status when CLOCAL or MDMBUF is changed.
Only change rr1 when we actually need to turn on or off TIE.

branches: 1.19.2;
Move the ttychars() call below the if-not-raw block.
(from Bill Studenmund)

spltty() does not drop the SPL; use splx() instead.

branches: 1.17.2;
use locator defines in "locators.h" to index cf_loc[]

KNF.

Tweak the KGDB glue slightly - do the printf here.

branches: 1.14.4;
New version of the z8530 driver that should permit the mac68k port
to use this instead of its own. Also fix warnings, etc.

Correct a problem with CRTSCTS flow control where output may fail to
restart if we get multiple status interrupts before the softintr()
routine gets a chance to run. The fix is to determine and accumulate
status line changes at the H/W interrupt level, and then check and zero
the accumulated changes when the softint() finally runs. Many thanks
to Bill Studenmund <wrstuden@loki.stanford.edu> for finding and fixing.

backout kprintf changes

- printf -> kprintf, sprintf -> ksprintf

tty stop functions really should return void, not int, and certainly not both.

Add tty_attach(), and fix a type mismatch.

branches: 1.8.4;
New version that handles hardware flow-control (CRTSCTS) at the input
to the ring (or silo). This eliminates ring overrun with crtscts.
Also handle deferred register changes earlier, and misc. cleanup.
Give credit to: Bill Studenmund and Ian Dall (Thanks!)

Rename cs_pclk_div16 to cs_brg_clk to clarify the fact that the
Baud Rate Generator (BRG) clock is not necessarily PCLK/16.

Make the ring size configurable in the tty driver.
Make the pseudo-interrupt functions return void.
Call the tty layer at spltty (to be safe).

Fix two bugs pointed out by Leo Weppelman:
(1) Did not initialize cs->cs_rr0 anywhere
(2) Have to read rr1 before the data it applies to

New device attachment scheme:

- split softc size and match/attach out from cfdriver into
a new struct cfattach.

- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.

Fix two bugs found by Bill Studenmund:
Driver can not use tp->t_sc for its own purposes
Attach should take the unit number from _dev.dv_unit

Eliminate remaining direct references to the z8530 chip
to allow the MD access functions to do delays, etc.

Reorganized, machine-independent z8530 driver, based on the sparc/sun3 zs.
Uses autoconfig to attach keyboard, mouse, or tty. (See z8530.doc)

in many device attach paths, allocate memory with M_WAITOK instead of M_NOWAIT
and remove code to handle failures that can no longer happen.

Fix panic due to inconsistent lock states of tty_lock in zsparam().
Tested on mac68k.

As discussed on tech-kern: define a new tty internal state flag: TS_KERN_ONLY

Implement it in a few tty drivers. If this flag is set, the underlying
hardware is used by another driver and userland has no right to open
it. A few uses will appear soon in sys/dev/sun/sun{kbd,ms}.c.

branches: 1.131.12;
centralize the dialout/call unit macros.

Add d_discard to all struct cdevsw instances I could find.

All have been set to "nodiscard"; some should get a real implementation.

branches: 1.129.2;
Change (mostly mechanically) every cdevsw/bdevsw I can find to use
designated initializers.

I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.

branches: 1.128.4; 1.128.14; 1.128.18;
Rename ttymalloc() to tty_alloc(), and ttyfree() to tty_free() for
consistency. Remove some unnecessary malloc.h inclusions as well.

branches: 1.127.4; 1.127.6;
add two new functions for z8530tty: zs_chan_lock() and zs_chan_unlock(),
and use them instead of various spl's in the zs.c's.

reviewed by ad and martin.

struct device * -> device_t, no functional changes intended.

struct cfdata * -> cfdata_t, no functional changes intended.

Try to avoid zstty hangs on higher speed:

z8530sc.c:
Check pending interrupts in a loop until all requests are handled.
The old comments said it would cause horrible latency to sun3x floppy etc,
but serial ports should have higher priority than disks anyway.

z8530tty.c:
Don't enable and disable TX interrupts on each transmit start and completion
because it could cause possible race conditions.
Instead, set ZSWR0_RESET_TXINT on each TIE interrupt to clear the request
as other kbd drivers attached at zs(4).

Tested on cobalt, macppc, news68k, sparc, and sun3.

branches: 1.123.2; 1.123.10; 1.123.12; 1.123.16;
Make ntp, pmc, reboot, sysarch, time syscalls MPSAFE.

branches: 1.122.2;
Split softc and device_t for zsc(4) and its children.

XXX we should restructure MI APIs and make it really machine independent.

Remove a tty_lock for now - I know that this is wrong, but the whole
tty subsystem locking is not consistent and Andrew didn't have
time to come up (or guide to) the right fix.
This prevents machines with serial console on zs(4) from deadlocking on
first input.

branches: 1.120.2; 1.120.6;
Now that __HAVE_TIMECOUNTER and __HAVE_GENERIC_TODR are invariants,
remove the conditionals and the code associated with the undef case.

t_linesw->l_modem would ideally be called with tty_lock held, but before
that can happen someone needs to beat all the drivers into shape.

Don't recursively acquire tty_lock when zstty_softint() is called directly.

branches: 1.117.2; 1.117.6;
- Factor out too many copies of the same bit of tty code.
- Fix another tty signalling/wakeup problem.

zsstart, zstty_txsoft: don't acquire tty_lock, it's already held.

Merge tty changes from the vmlocking branch.

branches: 1.114.6; 1.114.8; 1.114.12; 1.114.14;
Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

branches: 1.113.2; 1.113.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.112.4;
More from Matt Fleming:

Adapt to KAUTH_DEVICE_TTY_PRIVSET and KAUTH_DEVICE_TTY_OPEN.

Adapt MD code to KAUTH_DEVICE_TTY_OPEN, batch #2 from Matt Fleming, thanks!

Also, add forgotten splx() calls in some places.

branches: 1.110.4; 1.110.6;
Remove unused variable to make it compile again.

- Use the LWP cached credentials where sane.
- Minor cosmetic changes.

merge FreeBSD timecounters from branch simonb-timecounters
- struct timeval time is gone
time.tv_sec -> time_second
- struct timeval mono_time is gone
mono_time.tv_sec -> time_uptime
- access to time via
{get,}{micro,nano,bin}time()
get* versions are fast but less precise
- support NTP nanokernel implementation (NTP API 4)
- further reading:
Timecounter Paper: http://phk.freebsd.dk/pubs/timecounter.pdf
NTP Nanokernel: http://www.eecis.udel.edu/~mills/ntp/html/kern.html

branches: 1.107.2;
integrate kauth.

- use M_NOWAIT rather than M_WAITOK for malloc(9) to allocate RX buffer
in zstty_attach()
- check a return value of the malloc(9)

Taken from com.c, and somehow this seems to fix PR port-sun2/32420 on tme.

Use device_cfdata().

Use device_unit().

branches: 1.103.2; 1.103.4;
Remove SET/CLR/ISSET macros.

branches: 1.102.4; 1.102.6; 1.102.8;
switch macppc to use the MI zstty driver.
add macppc's ZS_TXDMA hooks there.

merge ktrace-lwp.

Change the driver open function's conditional for overriding exclusive tty
use from checking the proc's uid to suser(9), and account for the use of
privileges. Noted by David Holland in PR kern/31126.

branches: 1.99.2;
Allow sparc64-style attachment of mouse and keyboard via zstty, needed for
wscons support.
Reviewed by uwe.

- add const
- avoid variable shadow

nuke trailing whitespace

de-__P

branches: 1.95.4; 1.95.6;
Define and use zsccf_channel as an alias for cf_loc[ZSCCF_CHANNEL].

Fix NTP PPSAPI support (enabled with "options PPS_SYNC"):

From PR kern/13702 from Charles Carvalho. Tested on alpha and
i386 with a Laipac TF10 PPS-capable GPS. The com.c change was
copied wholesale from Charles' z8530tty.c patch.

netbsd.org -> NetBSD.org

This was the last commit of this kind to src/sys, which is now totally
"NetBSD.org clean". Thanks for the patiance, and sorry for all the commits.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.91.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

More changes for providing lwpid for ktrace (sparc GENERIC built)

Provide locking required by the interrupt handlers running at IPL_SERIAL.

zs_shutdown: lower IPL before sleeping. Also note the fact that the
effectiveness of that very tsleep() call is dubious at best.

interrupt with two rs.

Fix signed/unsigned comparison warnings.

merge kqueue branch into -current

kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe

Add trailing ; to CFATTACH_DECL.

Use CFATTACH_DECL().

Declare all cfattach structures const.

Deal with the strange SCC wiring on TC IOASIC machines. Thanks to Bill
Studenmund and Jonathan Stone for useful comments.

Merge the gehenna-devsw branch into the trunk.

This merge changes the device switch tables from static array to
dynamically generated by config(8).

- All device switches is defined as a constant structure in device drivers.

- The new grammer ``device-major'' is introduced to ``files''.

device-major <prefix> char <num> [block <num>] [<rules>]

- All device major numbers must be listed up in port dependent majors.<arch>
by using this grammer.

- Added the new naming convention.
The name of the device switch must be <prefix>_[bc]devsw for auto-generation
of device switch tables.

- The backward compatibility of loading block/character device
switch by LKM framework is broken. This is necessary to convert
from block/character device major to device name in runtime and vice versa.

- The restriction to assign device major by LKM is completely removed.
We don't need to reserve LKM entries for dynamic loading of device switch.

- In compile time, device major numbers list is packed into the kernel and
the LKM framework will refer it to assign device major number dynamically.

branches: 1.79.4;
Convert ioctl code to use EPASSTHROUGH instead of -1 or ENOTTY for
indicating an unhandled "command". ERESTART is -1, which can lead to
confusion. ERESTART has been moved to -3 and EPASSTHROUGH has been
placed at -4. No ioctl code should now return -1 anywhere. The
ioctl() system call is now properly restartable.

add/cleanup RCSID

branches: 1.77.2; 1.77.4;
add missing #include "opt_kgdb.h"

Add a flag to suppress SCC reset at attach time.

From Rafal K. Boni.

Add `l_poll' to `struct linesw' and provide an xxxpoll() entry point
in each tty driver to indirect through it.

This allows tty line-disciplines to handle poll(2) system calls.

Add some delay in zstty_attach() to wait previous console output
to complete before hardware initialization.

Add missing \n during probe if port is dedicated to kgdb

branches: 1.72.2;
Use the MI console magic sequence framework.

remove what looks to be a bit of leftover debug code.

Adapt to the new line discipline scheme.

Change tiocm_to_{com,zs}'s second argument to u_long to match with
the type in their caller.

Use device_lookup().

branches: 1.67.4;
Remove spurious splx() call.

Fix typos from last commit (callout).

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

Check for console input and output separately.
XXX - split input/output for /dev/console is not yet supported.

Add power management hooks.

Update user-level PPS-API to match -05 draft.
Change PPS_<xxx> ioctls to PPS_IOC_<xxx>.

branches: 1.61.2; 1.61.4;
Fix nanosecond/microsecond botch in PPSAPI:
remove bogus TIMESPEC_TO_TIMEVAL() after applying any {assert,clear} offset.

branches: 1.60.2;
Don't send any data upstream if we're not open yet.

branches: 1.59.2;
PPS support. Copied off of com.c support, with changes as DCD interupts
are only enabled if needed and if ok'd by MD layer.

Minor changes to tiocm code.

Redo the N previous changes, plus a couple of other things:
* Move the printf() delay to just after the printf(), where it actually makes
sense.
* Use zstty_stint() and zstty_softint() from zsparam(), to force an immediate
update of the carrier and flow control status. Abuse this in the attach and
open functions to defer all of that work. This insures that we don't lose
any status updates.
* Don't screw with register 1 when closing the console.
* Fix bugs in TIOCM??? (stay semicolon, clearing DTR while transmitting).
* Add comments in a couple of places.

Add the patch I floated on tech-kern. Andreas Eltrich <elchy@dahoam.de>
says it got pppd working for him.

Fix thinko in part of rev 1.53.

Thanks to Scott for pointing this out to me (I got his mail and figured out
this change before seeing the discussion on tech-kern) and to Charles for
the initial explanation.

Put back modem control ioctl's

Changes to deal with mac serial ports having clock sources on DCD or CTS.

- When doing a first open, don't enable receive & status interupts before
the MD layer has had a chance to set things up.
- Enable logic to only enable DCD/CTS interupts if we are looking for/
expecting interupts on those pins. Disable otherwise.
- in zs_param, only pass up the state of ZSRR0_DCD if we have enabled
interupts on that pin.

Henry Hotz (<hotz@jpl.nasa.gov>) and Greg walsh <gwalsh@artec.com> have
tried these changes to get certain printers from hanging at boot. They
work in a 1.3.2 kernel for Greg.

minor changes to console handling in zstty_attach():
-wait 20ms between printf() and reconfiguring the hardware
-set cn_tab->cn_dev here because this is the place where the real minor
number is known

kill the last remnants of __BROKEN_INDIRECT_CONFIG. (only the pica port
used it, and it's non-working and apparently slated for replacement.)

Oops. We do still need to set t_dev in the first open part of zsopen,
so we get ttyXX vs cuaXX right. Leave the initialization in attach.

Initialize the struct tty's t_dev field at attach rather than first open.
The attach routine calls zsparam if we're setting up the console, and
zsparam needs this field to tell which zstty to set up. Otherwise, we
set up zstty0 even if it's not the console!

Eliminate cs_heldchar. It is not necessary in my version of the driver.

Move the code to wait for carrier on a tty into a common function, since it
depends only on device-independent state bits.
Implement SunOS-style `dialout' devices.

Fix pasto.

Replace TS_WOPEN with t_wopen, per mail on tech-kern.

Fix bonehead error in previous change.

Similar changes to com driver:
Arrange to call com_break() and com_modem() at splserial().
It's simpler this way. Really.

Adjust for config changes.

Use a 1-character queue so polled console output can be deferred if
regular I/O has been scheduled.

Actually use TIOCFLAG_CDTRCTS.

Always leave DCD_IE and CTS_IE on for now. Needs more work in zsparam() to
make the optimization actually work right.

Leave the console running with or without DDB.

Slight optimization in soft input routine.

Set the ring size back to 2k.

Bug fixes:
* Carrier detect (TS_CARR_ON) is based on the actual DCD bit, even if it's
being ignored.
* Set TS_WOPEN early on in zsopen().
* Don't disable interrupts on the console during close if we have DDB.

Inert changes:
* Don't handle ZS_HWFLAG_NO_DCD here; the frontend does it.
* Deprecate `register'.
* Use SET(), CLR(), and ISSET().

More performance changes:
* Rototill receive handling; use a backpressure mechanism to prevent livelock.
* Output silo/ibuf overflow warnings at most once per minute, from a callout.
* When we exhaust the current transmit run, turn off transmit interrupts in
zstty_txint(), so we're fairly sure we don't get another one.

Fix serial console support (did not turn on CLOCAL).

Rearrange *param() slightly to eliminate a spl.
Also fix another comment regarding DTR.

Add another splserial()/splzs().

Minimize some spl regions slightly.

If we lose HFC, assert RTS.

Set the state of DCD_IE and CTS_IE based on what's in rr0_mask.

Correct a comment regarding our behaviour with DTR.

Fix minor omission; write back reg 1 earlier in zsopen().

Need some additional splzs() in zsopen(), and nuke one that's no longer
needed.

Nuke the special case of heldchange for reg 5. We don't use it for flow
control any more, and the speed of changing DTR isn't really an issue. Also,
the old code created a bug where zsparam() might have failed to set some
registers.

Yet more changes imported from com driver:
Change the interface to zs_hwiflow(); just have it use zst_rx_blocked.
Make zs_modem() a tiny bit faster.
Do RTS updates immediately; do not allow them to be held.

Make zst_tba a u_char *.

More changes taken from com driver:
Stop output as fast as possible when DCD is deasserted.
Do *not* automatically drop DTR when DCD is deasserted.
Only check for rr0 bits that we care about (DTR and DCD).

GC some unused bits.
Also, part of the previous was copied from the com driver, so DTRT.

Rearrange open sequence to make sure we catch all line status changes.
Make sure we turn on DTR and/or RTS as appropriate during open.
Rearrange close sequence so the tty is flushed before turning off interrupts.
Deal with `softcar' and the console device by silently asserting CLOCAL and
|HUPCL, as in com driver.
Do *not* fiddle with DTR when changing the line speed.
Make sure we update the tty's carrier status when CLOCAL or MDMBUF is changed.
Only change rr1 when we actually need to turn on or off TIE.

branches: 1.19.2;
Move the ttychars() call below the if-not-raw block.
(from Bill Studenmund)

spltty() does not drop the SPL; use splx() instead.

branches: 1.17.2;
use locator defines in "locators.h" to index cf_loc[]

KNF.

Tweak the KGDB glue slightly - do the printf here.

branches: 1.14.4;
New version of the z8530 driver that should permit the mac68k port
to use this instead of its own. Also fix warnings, etc.

Correct a problem with CRTSCTS flow control where output may fail to
restart if we get multiple status interrupts before the softintr()
routine gets a chance to run. The fix is to determine and accumulate
status line changes at the H/W interrupt level, and then check and zero
the accumulated changes when the softint() finally runs. Many thanks
to Bill Studenmund <wrstuden@loki.stanford.edu> for finding and fixing.

backout kprintf changes

- printf -> kprintf, sprintf -> ksprintf

tty stop functions really should return void, not int, and certainly not both.

Add tty_attach(), and fix a type mismatch.

branches: 1.8.4;
New version that handles hardware flow-control (CRTSCTS) at the input
to the ring (or silo). This eliminates ring overrun with crtscts.
Also handle deferred register changes earlier, and misc. cleanup.
Give credit to: Bill Studenmund and Ian Dall (Thanks!)

Rename cs_pclk_div16 to cs_brg_clk to clarify the fact that the
Baud Rate Generator (BRG) clock is not necessarily PCLK/16.

Make the ring size configurable in the tty driver.
Make the pseudo-interrupt functions return void.
Call the tty layer at spltty (to be safe).

Fix two bugs pointed out by Leo Weppelman:
(1) Did not initialize cs->cs_rr0 anywhere
(2) Have to read rr1 before the data it applies to

New device attachment scheme:

- split softc size and match/attach out from cfdriver into
a new struct cfattach.

- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.

Fix two bugs found by Bill Studenmund:
Driver can not use tp->t_sc for its own purposes
Attach should take the unit number from _dev.dv_unit

Eliminate remaining direct references to the z8530 chip
to allow the MD access functions to do delays, etc.

Reorganized, machine-independent z8530 driver, based on the sparc/sun3 zs.
Uses autoconfig to attach keyboard, mouse, or tty. (See z8530.doc)

Fix panic due to inconsistent lock states of tty_lock in zsparam().
Tested on mac68k.

As discussed on tech-kern: define a new tty internal state flag: TS_KERN_ONLY

Implement it in a few tty drivers. If this flag is set, the underlying
hardware is used by another driver and userland has no right to open
it. A few uses will appear soon in sys/dev/sun/sun{kbd,ms}.c.

branches: 1.131.12;
centralize the dialout/call unit macros.

Add d_discard to all struct cdevsw instances I could find.

All have been set to "nodiscard"; some should get a real implementation.

branches: 1.129.2;
Change (mostly mechanically) every cdevsw/bdevsw I can find to use
designated initializers.

I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.

branches: 1.128.4; 1.128.14; 1.128.18;
Rename ttymalloc() to tty_alloc(), and ttyfree() to tty_free() for
consistency. Remove some unnecessary malloc.h inclusions as well.

branches: 1.127.4; 1.127.6;
add two new functions for z8530tty: zs_chan_lock() and zs_chan_unlock(),
and use them instead of various spl's in the zs.c's.

reviewed by ad and martin.

struct device * -> device_t, no functional changes intended.

struct cfdata * -> cfdata_t, no functional changes intended.

Try to avoid zstty hangs on higher speed:

z8530sc.c:
Check pending interrupts in a loop until all requests are handled.
The old comments said it would cause horrible latency to sun3x floppy etc,
but serial ports should have higher priority than disks anyway.

z8530tty.c:
Don't enable and disable TX interrupts on each transmit start and completion
because it could cause possible race conditions.
Instead, set ZSWR0_RESET_TXINT on each TIE interrupt to clear the request
as other kbd drivers attached at zs(4).

Tested on cobalt, macppc, news68k, sparc, and sun3.

branches: 1.123.2; 1.123.10; 1.123.12; 1.123.16;
Make ntp, pmc, reboot, sysarch, time syscalls MPSAFE.

branches: 1.122.2;
Split softc and device_t for zsc(4) and its children.

XXX we should restructure MI APIs and make it really machine independent.

Remove a tty_lock for now - I know that this is wrong, but the whole
tty subsystem locking is not consistent and Andrew didn't have
time to come up (or guide to) the right fix.
This prevents machines with serial console on zs(4) from deadlocking on
first input.

branches: 1.120.2; 1.120.6;
Now that __HAVE_TIMECOUNTER and __HAVE_GENERIC_TODR are invariants,
remove the conditionals and the code associated with the undef case.

t_linesw->l_modem would ideally be called with tty_lock held, but before
that can happen someone needs to beat all the drivers into shape.

Don't recursively acquire tty_lock when zstty_softint() is called directly.

branches: 1.117.2; 1.117.6;
- Factor out too many copies of the same bit of tty code.
- Fix another tty signalling/wakeup problem.

zsstart, zstty_txsoft: don't acquire tty_lock, it's already held.

Merge tty changes from the vmlocking branch.

branches: 1.114.6; 1.114.8; 1.114.12; 1.114.14;
Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

branches: 1.113.2; 1.113.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.112.4;
More from Matt Fleming:

Adapt to KAUTH_DEVICE_TTY_PRIVSET and KAUTH_DEVICE_TTY_OPEN.

Adapt MD code to KAUTH_DEVICE_TTY_OPEN, batch #2 from Matt Fleming, thanks!

Also, add forgotten splx() calls in some places.

branches: 1.110.4; 1.110.6;
Remove unused variable to make it compile again.

- Use the LWP cached credentials where sane.
- Minor cosmetic changes.

merge FreeBSD timecounters from branch simonb-timecounters
- struct timeval time is gone
time.tv_sec -> time_second
- struct timeval mono_time is gone
mono_time.tv_sec -> time_uptime
- access to time via
{get,}{micro,nano,bin}time()
get* versions are fast but less precise
- support NTP nanokernel implementation (NTP API 4)
- further reading:
Timecounter Paper: http://phk.freebsd.dk/pubs/timecounter.pdf
NTP Nanokernel: http://www.eecis.udel.edu/~mills/ntp/html/kern.html

branches: 1.107.2;
integrate kauth.

- use M_NOWAIT rather than M_WAITOK for malloc(9) to allocate RX buffer
in zstty_attach()
- check a return value of the malloc(9)

Taken from com.c, and somehow this seems to fix PR port-sun2/32420 on tme.

Use device_cfdata().

Use device_unit().

branches: 1.103.2; 1.103.4;
Remove SET/CLR/ISSET macros.

branches: 1.102.4; 1.102.6; 1.102.8;
switch macppc to use the MI zstty driver.
add macppc's ZS_TXDMA hooks there.

merge ktrace-lwp.

Change the driver open function's conditional for overriding exclusive tty
use from checking the proc's uid to suser(9), and account for the use of
privileges. Noted by David Holland in PR kern/31126.

branches: 1.99.2;
Allow sparc64-style attachment of mouse and keyboard via zstty, needed for
wscons support.
Reviewed by uwe.

- add const
- avoid variable shadow

nuke trailing whitespace

de-__P

branches: 1.95.4; 1.95.6;
Define and use zsccf_channel as an alias for cf_loc[ZSCCF_CHANNEL].

Fix NTP PPSAPI support (enabled with "options PPS_SYNC"):

From PR kern/13702 from Charles Carvalho. Tested on alpha and
i386 with a Laipac TF10 PPS-capable GPS. The com.c change was
copied wholesale from Charles' z8530tty.c patch.

netbsd.org -> NetBSD.org

This was the last commit of this kind to src/sys, which is now totally
"NetBSD.org clean". Thanks for the patiance, and sorry for all the commits.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.91.2;
Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

More changes for providing lwpid for ktrace (sparc GENERIC built)

Provide locking required by the interrupt handlers running at IPL_SERIAL.

zs_shutdown: lower IPL before sleeping. Also note the fact that the
effectiveness of that very tsleep() call is dubious at best.

interrupt with two rs.

Fix signed/unsigned comparison warnings.

merge kqueue branch into -current

kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe

Add trailing ; to CFATTACH_DECL.

Use CFATTACH_DECL().

Declare all cfattach structures const.

Deal with the strange SCC wiring on TC IOASIC machines. Thanks to Bill
Studenmund and Jonathan Stone for useful comments.

Merge the gehenna-devsw branch into the trunk.

This merge changes the device switch tables from static array to
dynamically generated by config(8).

- All device switches is defined as a constant structure in device drivers.

- The new grammer ``device-major'' is introduced to ``files''.

device-major <prefix> char <num> [block <num>] [<rules>]

- All device major numbers must be listed up in port dependent majors.<arch>
by using this grammer.

- Added the new naming convention.
The name of the device switch must be <prefix>_[bc]devsw for auto-generation
of device switch tables.

- The backward compatibility of loading block/character device
switch by LKM framework is broken. This is necessary to convert
from block/character device major to device name in runtime and vice versa.

- The restriction to assign device major by LKM is completely removed.
We don't need to reserve LKM entries for dynamic loading of device switch.

- In compile time, device major numbers list is packed into the kernel and
the LKM framework will refer it to assign device major number dynamically.

branches: 1.79.4;
Convert ioctl code to use EPASSTHROUGH instead of -1 or ENOTTY for
indicating an unhandled "command". ERESTART is -1, which can lead to
confusion. ERESTART has been moved to -3 and EPASSTHROUGH has been
placed at -4. No ioctl code should now return -1 anywhere. The
ioctl() system call is now properly restartable.

add/cleanup RCSID

branches: 1.77.2; 1.77.4;
add missing #include "opt_kgdb.h"

Add a flag to suppress SCC reset at attach time.

From Rafal K. Boni.

Add `l_poll' to `struct linesw' and provide an xxxpoll() entry point
in each tty driver to indirect through it.

This allows tty line-disciplines to handle poll(2) system calls.

Add some delay in zstty_attach() to wait previous console output
to complete before hardware initialization.

Add missing \n during probe if port is dedicated to kgdb

branches: 1.72.2;
Use the MI console magic sequence framework.

remove what looks to be a bit of leftover debug code.

Adapt to the new line discipline scheme.

Change tiocm_to_{com,zs}'s second argument to u_long to match with
the type in their caller.

Use device_lookup().

branches: 1.67.4;
Remove spurious splx() call.

Fix typos from last commit (callout).

New callout mechanism with two major improvements over the old
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.

The old timeout()/untimeout() API has been removed from the kernel.

Check for console input and output separately.
XXX - split input/output for /dev/console is not yet supported.

Add power management hooks.

Update user-level PPS-API to match -05 draft.
Change PPS_<xxx> ioctls to PPS_IOC_<xxx>.

branches: 1.61.2; 1.61.4;
Fix nanosecond/microsecond botch in PPSAPI:
remove bogus TIMESPEC_TO_TIMEVAL() after applying any {assert,clear} offset.

branches: 1.60.2;
Don't send any data upstream if we're not open yet.

branches: 1.59.2;
PPS support. Copied off of com.c support, with changes as DCD interupts
are only enabled if needed and if ok'd by MD layer.

Minor changes to tiocm code.

Redo the N previous changes, plus a couple of other things:
* Move the printf() delay to just after the printf(), where it actually makes
sense.
* Use zstty_stint() and zstty_softint() from zsparam(), to force an immediate
update of the carrier and flow control status. Abuse this in the attach and
open functions to defer all of that work. This insures that we don't lose
any status updates.
* Don't screw with register 1 when closing the console.
* Fix bugs in TIOCM??? (stay semicolon, clearing DTR while transmitting).
* Add comments in a couple of places.

Add the patch I floated on tech-kern. Andreas Eltrich <elchy@dahoam.de>
says it got pppd working for him.

Fix thinko in part of rev 1.53.

Thanks to Scott for pointing this out to me (I got his mail and figured out
this change before seeing the discussion on tech-kern) and to Charles for
the initial explanation.

Put back modem control ioctl's

Changes to deal with mac serial ports having clock sources on DCD or CTS.

- When doing a first open, don't enable receive & status interupts before
the MD layer has had a chance to set things up.
- Enable logic to only enable DCD/CTS interupts if we are looking for/
expecting interupts on those pins. Disable otherwise.
- in zs_param, only pass up the state of ZSRR0_DCD if we have enabled
interupts on that pin.

Henry Hotz (<hotz@jpl.nasa.gov>) and Greg walsh <gwalsh@artec.com> have
tried these changes to get certain printers from hanging at boot. They
work in a 1.3.2 kernel for Greg.

minor changes to console handling in zstty_attach():
-wait 20ms between printf() and reconfiguring the hardware
-set cn_tab->cn_dev here because this is the place where the real minor
number is known

kill the last remnants of __BROKEN_INDIRECT_CONFIG. (only the pica port
used it, and it's non-working and apparently slated for replacement.)

Oops. We do still need to set t_dev in the first open part of zsopen,
so we get ttyXX vs cuaXX right. Leave the initialization in attach.

Initialize the struct tty's t_dev field at attach rather than first open.
The attach routine calls zsparam if we're setting up the console, and
zsparam needs this field to tell which zstty to set up. Otherwise, we
set up zstty0 even if it's not the console!

Eliminate cs_heldchar. It is not necessary in my version of the driver.

Move the code to wait for carrier on a tty into a common function, since it
depends only on device-independent state bits.
Implement SunOS-style `dialout' devices.

Fix pasto.

Replace TS_WOPEN with t_wopen, per mail on tech-kern.

Fix bonehead error in previous change.

Similar changes to com driver:
Arrange to call com_break() and com_modem() at splserial().
It's simpler this way. Really.

Adjust for config changes.

Use a 1-character queue so polled console output can be deferred if
regular I/O has been scheduled.

Actually use TIOCFLAG_CDTRCTS.

Always leave DCD_IE and CTS_IE on for now. Needs more work in zsparam() to
make the optimization actually work right.

Leave the console running with or without DDB.

Slight optimization in soft input routine.

Set the ring size back to 2k.

Bug fixes:
* Carrier detect (TS_CARR_ON) is based on the actual DCD bit, even if it's
being ignored.
* Set TS_WOPEN early on in zsopen().
* Don't disable interrupts on the console during close if we have DDB.

Inert changes:
* Don't handle ZS_HWFLAG_NO_DCD here; the frontend does it.
* Deprecate `register'.
* Use SET(), CLR(), and ISSET().

More performance changes:
* Rototill receive handling; use a backpressure mechanism to prevent livelock.
* Output silo/ibuf overflow warnings at most once per minute, from a callout.
* When we exhaust the current transmit run, turn off transmit interrupts in
zstty_txint(), so we're fairly sure we don't get another one.

Fix serial console support (did not turn on CLOCAL).

Rearrange *param() slightly to eliminate a spl.
Also fix another comment regarding DTR.

Add another splserial()/splzs().

Minimize some spl regions slightly.

If we lose HFC, assert RTS.

Set the state of DCD_IE and CTS_IE based on what's in rr0_mask.

Correct a comment regarding our behaviour with DTR.

Fix minor omission; write back reg 1 earlier in zsopen().

Need some additional splzs() in zsopen(), and nuke one that's no longer
needed.

Nuke the special case of heldchange for reg 5. We don't use it for flow
control any more, and the speed of changing DTR isn't really an issue. Also,
the old code created a bug where zsparam() might have failed to set some
registers.

Yet more changes imported from com driver:
Change the interface to zs_hwiflow(); just have it use zst_rx_blocked.
Make zs_modem() a tiny bit faster.
Do RTS updates immediately; do not allow them to be held.

Make zst_tba a u_char *.

More changes taken from com driver:
Stop output as fast as possible when DCD is deasserted.
Do *not* automatically drop DTR when DCD is deasserted.
Only check for rr0 bits that we care about (DTR and DCD).

GC some unused bits.
Also, part of the previous was copied from the com driver, so DTRT.

Rearrange open sequence to make sure we catch all line status changes.
Make sure we turn on DTR and/or RTS as appropriate during open.
Rearrange close sequence so the tty is flushed before turning off interrupts.
Deal with `softcar' and the console device by silently asserting CLOCAL and
|HUPCL, as in com driver.
Do *not* fiddle with DTR when changing the line speed.
Make sure we update the tty's carrier status when CLOCAL or MDMBUF is changed.
Only change rr1 when we actually need to turn on or off TIE.

branches: 1.19.2;
Move the ttychars() call below the if-not-raw block.
(from Bill Studenmund)

spltty() does not drop the SPL; use splx() instead.

branches: 1.17.2;
use locator defines in "locators.h" to index cf_loc[]

KNF.

Tweak the KGDB glue slightly - do the printf here.

branches: 1.14.4;
New version of the z8530 driver that should permit the mac68k port
to use this instead of its own. Also fix warnings, etc.

Correct a problem with CRTSCTS flow control where output may fail to
restart if we get multiple status interrupts before the softintr()
routine gets a chance to run. The fix is to determine and accumulate
status line changes at the H/W interrupt level, and then check and zero
the accumulated changes when the softint() finally runs. Many thanks
to Bill Studenmund <wrstuden@loki.stanford.edu> for finding and fixing.

backout kprintf changes

- printf -> kprintf, sprintf -> ksprintf

tty stop functions really should return void, not int, and certainly not both.

Add tty_attach(), and fix a type mismatch.

branches: 1.8.4;
New version that handles hardware flow-control (CRTSCTS) at the input
to the ring (or silo). This eliminates ring overrun with crtscts.
Also handle deferred register changes earlier, and misc. cleanup.
Give credit to: Bill Studenmund and Ian Dall (Thanks!)

Rename cs_pclk_div16 to cs_brg_clk to clarify the fact that the
Baud Rate Generator (BRG) clock is not necessarily PCLK/16.

Make the ring size configurable in the tty driver.
Make the pseudo-interrupt functions return void.
Call the tty layer at spltty (to be safe).

Fix two bugs pointed out by Leo Weppelman:
(1) Did not initialize cs->cs_rr0 anywhere
(2) Have to read rr1 before the data it applies to

New device attachment scheme:

- split softc size and match/attach out from cfdriver into
a new struct cfattach.

- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.

Fix two bugs found by Bill Studenmund:
Driver can not use tp->t_sc for its own purposes
Attach should take the unit number from _dev.dv_unit

Eliminate remaining direct references to the z8530 chip
to allow the MD access functions to do delays, etc.

Reorganized, machine-independent z8530 driver, based on the sparc/sun3 zs.
Uses autoconfig to attach keyboard, mouse, or tty. (See z8530.doc)

As discussed on tech-kern: define a new tty internal state flag: TS_KERN_ONLY

Implement it in a few tty drivers. If this flag is set, the underlying
hardware is used by another driver and userland has no right to open
it. A few uses will appear soon in sys/dev/sun/sun{kbd,ms}.c.

branches: 1.131.12;
centralize the dialout/call unit macros.

Add d_discard to all struct cdevsw instances I could find.

All have been set to "nodiscard"; some should get a real implementation.

branches: 1.129.2;
Change (mostly mechanically) every cdevsw/bdevsw I can find to use
designated initializers.

I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.

branches: 1.128.4; 1.128.14; 1.128.18;
Rename ttymalloc() to tty_alloc(), and ttyfree() to tty_free() for
consistency. Remove some unnecessary malloc.h inclusions as well.

branches: 1.127.4; 1.127.6;
add two new functions for z8530tty: zs_chan_lock() and zs_chan_unlock(),
and use them instead of various spl's in the zs.c's.

reviewed by ad and martin.

struct device * -> device_t, no functional changes intended.

struct cfdata * -> cfdata_t, no functional changes intended.

Try to avoid zstty hangs on higher speed:

z8530sc.c:
Check pending interrupts in a loop until all requests are handled.
The old comments said it would cause horrible latency to sun3x floppy etc,
but serial ports should have higher priority than disks anyway.

z8530tty.c:
Don't enable and disable TX interrupts on each transmit start and completion
because it could cause possible race conditions.
Instead, set ZSWR0_RESET_TXINT on each TIE interrupt to clear the request
as other kbd drivers attached at zs(4).

Tested on cobalt, macppc, news68k, sparc, and sun3.

branches: 1.123.2; 1.123.10; 1.123.12; 1.123.16;
Make ntp, pmc, reboot, sysarch, time syscalls MPSAFE.

branches: 1.122.2;
Split softc and device_t for zsc(4) and its children.

XXX we should restructure MI APIs and make it really machine independent.

Remove a tty_lock for now - I know that this is wrong, but the whole
tty subsystem locking is not consistent and Andrew didn't have
time to come up (or guide to) the right fix.
This prevents machines with serial console on zs(4) from deadlocking on
first input.

branches: 1.120.2; 1.120.6;
Now that __HAVE_TIMECOUNTER and __HAVE_GENERIC_TODR are invariants,
remove the conditionals and the code associated with the undef case.

t_linesw->l_modem would ideally be called with tty_lock held, but before
that can happen someone needs to beat all the drivers into shape.

Don't recursively acquire tty_lock when zstty_softint() is called directly.

branches: 1.117.2; 1.117.6;
- Factor out too many copies of the same bit of tty code.
- Fix another tty signalling/wakeup problem.

zsstart, zstty_txsoft: don't acquire tty_lock, it's already held.

Merge tty changes from the vmlocking branch.

branches: 1.114.6; 1.114.8; 1.114.12; 1.114.14;
Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

branches: 1.113.2; 1.113.4;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.112.4;
More from Matt Fleming:

Adapt to KAUTH_DEVICE_TTY_PRIVSET and KAUTH_DEVICE_TTY_OPEN.

Adapt MD code to KAUTH_DEVICE_TTY_OPEN, batch #2 from Matt Fleming, thanks!

Also, add forgotten splx() calls in some places.

branches: 1.110.4; 1.110.6;
Remove unused variable to make it compile again.

- Use the LWP cached credentials where sane.
- Minor cosmetic changes.