MFC r345405,345406,346228,346657,348195,348198: UART SPCR fixes.

r345405: Obey SPCR AccessWidth parameter.
r345406: Initialize uart_bus_space_mem on arm64.
r346228: Add quirk to ignore AccessWidth o

MFC r345405,345406,346228,346657,348195,348198: UART SPCR fixes.

r345405: Obey SPCR AccessWidth parameter.
r345406: Initialize uart_bus_space_mem on arm64.
r346228: Add quirk to ignore AccessWidth on PL011 UART.
r346657: Handle SPCR BaudRate = 0.
r348195: Extract arm64 SPCR code and make it MI; use on x86 too.
r348198: Fix for r348195.

This unbreaks the console on EC2 a1.* and *.metal instances.

Sponsored by: https://www.patreon.com/cperciva

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add snps IP uart support / genaralize UART

This is an amalgam of a patch by Doug Ambrisko to
generalize uart_acpi_find_device, imp moving the
ACPI table to uart_dev_ns8250.c and advice by jhb
to wor

add snps IP uart support / genaralize UART

This is an amalgam of a patch by Doug Ambrisko to
generalize uart_acpi_find_device, imp moving the
ACPI table to uart_dev_ns8250.c and advice by jhb
to work around a bug in the EPYC 3151 BIOS
(the BIOS incorrectly marks the serial ports as
disabled)

Reviewed by: imp
MFC after: 8 weeks
Differential Revision: https://reviews.freebsd.org/D16432

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sys/dev: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error

sys/dev: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

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Allow setting access-width for UART registers.

This is required for FDT's standard "reg-io-width" property
(similar to "reg-shift" property) found in many DTS files.

This fixes operation on Altera

Allow setting access-width for UART registers.

This is required for FDT's standard "reg-io-width" property
(similar to "reg-shift" property) found in many DTS files.

This fixes operation on Altera Arria 10 SOC Development Kit,
where standard ns8250 uart allows 4-byte access only.

Reviewed by: kan, marcel
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9785

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Restore uart PPS signal capture polarity to its historical norm, and add an
option to invert the polarity in software. Also add an option to capture
very narrow pulses by using the hardware's MSR del

Restore uart PPS signal capture polarity to its historical norm, and add an
option to invert the polarity in software. Also add an option to capture
very narrow pulses by using the hardware's MSR delta-bit capability of
latching line state changes.

This effectively reverts the mistake I made in r286595 which was based on
empirical measurements made on hardware using TTL-level signaling, in which
the logic levels are inverted from RS-232. Thus, this re-syncs the polarity
with the requirements of RFC 2783, which is writen in terms of RS-232
signaling.

Narrow-pulse mode uses the ability of most ns8250 and similar chips to
provide a delta indication in the modem status register. The hardware is
able to notice and latch the change when the pulse width is shorter than
interrupt latency, which results in the signal no longer being asserted by
time the interrupt service code runs. When running in this mode we get
notified only that "a pulse happened" so the driver synthesizes both an
ASSERT and a CLEAR event (with the same timestamp for each). When the pulse
width is about equal to the interrupt latency the driver may intermittantly
see both edges of the pulse. To prevent generating spurious events, the
driver implements a half-second lockout period after generating an event
before it will generate another.

Differential Revision: https://reviews.freebsd.org/D4477

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Allow the choice of PPS signal captured by uart(4) to be runtime-configured,
eliminating the need to build a custom kernel to use the CTS signal.

The historical UART_PPS_ON_CTS kernel option is stil

Allow the choice of PPS signal captured by uart(4) to be runtime-configured,
eliminating the need to build a custom kernel to use the CTS signal.

The historical UART_PPS_ON_CTS kernel option is still honored, but now it
can be overridden at runtime using a tunable to configure all uart devices
(hw.uart.pps_mode) or specific devices (dev.uart.#.pps_mode). The per-
device config is both a tunable and a writable sysctl.

This syncs the PPS capabilities of uart(4) with the enhancements recently
recently added to ucom(4) for capturing from USB serial devices.

Relnotes: yes

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Provide the tty-layer mutex when initializing the pps api. This allows
time_pps_fetch() to be used in blocking mode.

Also, don't init the pps api for system devices (consoles) that provide a
custom

Provide the tty-layer mutex when initializing the pps api. This allows
time_pps_fetch() to be used in blocking mode.

Also, don't init the pps api for system devices (consoles) that provide a
custom attach routine. The device may actually be a keyboard or other non-
tty device. If it wants to do pps processing (unlikely) it must handle
everything for itself. (In reality, only a sun keyboard uses a custom
attach routine, and it doesn't make a good pps device.)

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- Since r253161, uart_intr() abuses FILTER_SCHEDULE_THREAD for signaling
uart_bus_attach() during its test that 20 iterations weren't sufficient
for clearing all pending interrupts, assuming this

- Since r253161, uart_intr() abuses FILTER_SCHEDULE_THREAD for signaling
uart_bus_attach() during its test that 20 iterations weren't sufficient
for clearing all pending interrupts, assuming this means that hardware
is broken and doesn't deassert interrupts. However, under pressure, 20
iterations also can be insufficient for clearing all pending interrupts,
leading to a panic as intr_event_handle() tries to schedule an interrupt
handler not registered. Solve this by introducing a flag that is set in
test mode and otherwise restores pre-r253161 behavior of uart_intr(). The
approach of additionally registering uart_intr() as handler as suggested
in PR 194979 is not taken as that in turn would abuse special pccard and
pccbb handling code of intr_event_handle(). [1]
- Const'ify uart_driver_name.
- Fix some minor style bugs.

PR: 194979 [1]
Reviewed by: marcel (earlier version)
MFC after: 3 days

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Add support for the uart classes to set their default register shift value.
This is needed with the pl011 driver. Before this change it would default
to a shift of 0, however the hardware places the

Add support for the uart classes to set their default register shift value.
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

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uart: add resume method and enable it for attachments on the most common
x86 buses

Otherwise the uart hardware could be in such a state after the resume
where IER is cleared and thus no interrupts a

uart: add resume method and enable it for attachments on the most common
x86 buses

Otherwise the uart hardware could be in such a state after the resume
where IER is cleared and thus no interrupts are generated.

This behavior is observed and tested with QEMU, so I am comitting this
change to help with my debugging.
There has been no feedback from users of serial ports on real hardware.

MFC after: 20 days

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MFC change 197721:
Fix RTS/CTS flow control, broken by the TTY overhaul. The new TTY
interface is fairly simple WRT dealing with flow control, but
needed 2 new RX buffer functions with "get-char-fro

MFC change 197721:
Fix RTS/CTS flow control, broken by the TTY overhaul. The new TTY
interface is fairly simple WRT dealing with flow control, but
needed 2 new RX buffer functions with "get-char-from-buf" separated
from "advance-buf-pointer" so that the pointer could be advanced
only when ttydisc_rint() succeeded.

Approved by: re (kib)

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Complete polled-mode operation by using a callout if the device will be
used in polled-mode. The callout invokes uart_intr, which rearms the timeout.
Implemented for bhyve, but generically useful for

Complete polled-mode operation by using a callout if the device will be
used in polled-mode. The callout invokes uart_intr, which rearms the timeout.
Implemented for bhyve, but generically useful for e.g. embedded bringup
when the interrupt controller hasn't been setup, or if it's not deemed
worthy to wire an interrupt line from a serial port.

Submitted by: neel
Reviewed by: marcel
Obtained from: NetApp
MFC after: 3 weeks

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Fix RTS/CTS flow control, broken by the TTY overhaul. The new TTY
interface is fairly simple WRT dealing with flow control, but
needed 2 new RX buffer functions with "get-char-from-buf" separated
fro

Fix RTS/CTS flow control, broken by the TTY overhaul. The new TTY
interface is fairly simple WRT dealing with flow control, but
needed 2 new RX buffer functions with "get-char-from-buf" separated
from "advance-buf-pointer" so that the pointer could be advanced
only when ttydisc_rint() succeeded.

MFC after: 1 week

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Don't expose the uart_ops structure directly, but instead have
it obtained through the uart_class structure. This allows us
to declare the uart_class structure as weak and as such allows
us to refere

Don't expose the uart_ops structure directly, but instead have
it obtained through the uart_class structure. This allows us
to declare the uart_class structure as weak and as such allows
us to reference it even when it's not compiled-in.
It also allows is to get the uart_ops structure by name, which
makes it possible to implement the dt tag handling in uart_getenv().
The side-effect of all this is that we're using the uart_class
structure more consistently which means that we now also have
access to the size of the bus space block needed by the hardware
when we map the bus space, eliminating any hardcoding.

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Implement the ipend() method of the serdev I/F.

Eliminate the sc_hasfifo flag from the softc. It was only used by
the NS8250 class driver. The UART has FIFOs if sc_rxfifosz>1, so
test for that instead.
While here properly initialize sc_rxfifosz an

Eliminate the sc_hasfifo flag from the softc. It was only used by
the NS8250 class driver. The UART has FIFOs if sc_rxfifosz>1, so
test for that instead.
While here properly initialize sc_rxfifosz and sc_txfifosz in the
case the UART doesn't have FIFOs.

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Add support for scc(4).

Replace our local UART_SIGMASK_* with the global SER_MASK_*.

MFp4:
Stop using our local UART_IPEND_* and instead use the global SER_INT_*
as defined in <sys/serial.h>.

Start each of the license/copyright comments with /*-, minor shuffle of lines

Add UART_IOCTL_BAUD to allow us to query the hardware about the
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(

Add UART_IOCTL_BAUD to allow us to query the hardware about the
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().

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Use generic tty code instead of (comparatively little) local copies.

Use the new serial port definitions for modemsignals.

Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.

Revert the introduction of iobase in struct uart_bas. Both the SAB82532
and the Z8530 drivers used the I/O address as a quick and dirty way to
determine which channel they operated on, but formalizin

Revert the introduction of iobase in struct uart_bas. Both the SAB82532
and the Z8530 drivers used the I/O address as a quick and dirty way to
determine which channel they operated on, but formalizing this by
introducing iobase is not a solution. How for example would a driver
know which channel it controls for a multi-channel UART that only has a
single I/O range?

Instead, add an explicit field, called chan, to struct uart_bas that
holds the channel within a device, or 0 otherwise. The chan field is
initialized both by the system device probing (i.e. a system console)
or it is passed down to uart_bus_probe() by any of the bus front-ends.
As such, it impacts all platforms and bus drivers and makes it a rather
large commit.

Remove the use of iobase in uart_cpu_eqres() for pc98. It is expected
that platforms have the capability to compare tag and handle pairs for
equality; as to determine whether two pairs access the same device or
not. The use of iobase for pc98 makes it impossible to formalize this
and turn it into a real newbus function later. This commit reverts
uart_cpu_eqres() for pc98 to an unimplemented function. It has to be
reimplemented using only the tag and handle fields in struct uart_bas.

Rewrite the SAB82532 and Z8530 drivers to use the chan field in struct
uart_bas. Remove the IS_CHANNEL_A and IS_CHANNEL_B macros. We don't
need to abstract anything anymore.

Discussed with: nyan
Tested on: i386, ia64, sparc64

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