uart(4): Honor hardware state of NS8250-class for tsw_busy

In 9750d9e5, I brought the equivalent of the TS_BUSY flag back in a
mostly hardware-agnostic way in order to fix tty_drain() and, thus,
TIO

uart(4): Honor hardware state of NS8250-class for tsw_busy

In 9750d9e5, I brought the equivalent of the TS_BUSY flag back in a
mostly hardware-agnostic way in order to fix tty_drain() and, thus,
TIOCDRAIN for UARTs with TX FIFOs. This proved to be sufficient for
fixing the regression reported. So in light of the release cycle of
FreeBSD 10.3, I decided that this change was be good enough for the
time being and opted to go with the smallest possible yet generic
(for all UARTs driven by uart(4)) solution addressing the problem at
hand.

However, at least for the NS8250-class the above isn't a complete
fix as these UARTs only trigger an interrupt when the TX FIFO became
empty. At this point, there still can be an outstanding character
left in the transmit shift register as indicated via the LSR. Thus,
this change adds the 3rd (besides the tty(4) and generic uart(4) bits)
part I had in my tree ever since, adding a uart_txbusy method to be
queried in addition for tsw_busy and hooking it up as appropriate
for the NS8250-class.

As it turns out, the exact equivalent of this 3rd part later on was
implemented for uftdi(4) in 9ad221a5.

While at it, explain the rational behind the deliberately missing
locking in uart_tty_busy() (also applying to the generic sc_txbusy
testing already present).

(cherry picked from commit 353e4c5a068d06b0d6dcfa9eb736ecb16e9eae45)

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sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

uart_dev_snps: Fix device probing

The "uart_bus_probe" function is used as a generic part of uart probe
logic. It returns a driver priority(negative number) if successful and
an error code otherwise

uart_dev_snps: Fix device probing

The "uart_bus_probe" function is used as a generic part of uart probe
logic. It returns a driver priority(negative number) if successful and
an error code otherwise.
Fix the error checking condition to account for that.
Also, while here return "BUS_PROBE_VENDOR", instead of "0".
This fixes uart on clearfog pro with recent DT.

PR: 266657
Reviewed by: mw
Obtained from: Semihalf
Differential Revision: https://reviews.freebsd.org/D36880

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Remove unused uart_devclass.

uart_dev_snps: Make ext_resources non-optional

EXT_RESOURCES have been introduced in 12-CURRENT and all supported
releases have it enabled in their kernel config.

MFC after: 1 month
Differenti

uart_dev_snps: Make ext_resources non-optional

EXT_RESOURCES have been introduced in 12-CURRENT and all supported
releases have it enabled in their kernel config.

MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D33828

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Remove "all rights reserved" from copyright for the file that Jared McNeill
own. He gave me permission to do this.

Update Armada 38x UART device tree binding

Recent changes in Linux updated Marvell Armada 38x
UART compatible string. As a result the FreeBSD driver
(uart_dev_snps) does not probe. This commit fixes

Update Armada 38x UART device tree binding

Recent changes in Linux updated Marvell Armada 38x
UART compatible string. As a result the FreeBSD driver
(uart_dev_snps) does not probe. This commit fixes the
situation, however not applying any functional modification
to the driver methods.

Approved by: re (kib)
Obtained from: Semihalf

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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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Now that we set the busy_detect bit in the bas to support setting it
for the console, set our override in the bas as well.

Tested by: emaste@

uart_snps: Add early printf support

Move the allwinner early printf support to the snps driver as it
should work with all implementation.
While here add instruction for enabling it on 64bits SoCs.

Do pass removing some write-only variables from the kernel.

This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(

Do pass removing some write-only variables from the kernel.

This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385

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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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Revert r314212 as it break Allwinner boards.

Reported by: manu

Use correct macro for Synopsys UART driver declaration.

EXTRES: Add OF node as argument to all <foo>_get_by_ofw_<bar>() functions.
In some cases, the driver must handle given properties located in
specific OF subnode. Instead of creating duplicate set of

EXTRES: Add OF node as argument to all <foo>_get_by_ofw_<bar>() functions.
In some cases, the driver must handle given properties located in
specific OF subnode. Instead of creating duplicate set of function, add
'node' as argument to existing functions, defaulting it to device OF node.

MFC after: 3 weeks

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Move support for Synopsys Designware APB UART out of ns8250 and into a
separate driver. Add support for activating clock and hwreset resources
for these devices when the EXT_RESOURCES option is prese

Move support for Synopsys Designware APB UART out of ns8250 and into a
separate driver. Add support for activating clock and hwreset resources
for these devices when the EXT_RESOURCES option is present.

Reviewed by: andrew, mmel, Emmanuel Vadot <[email protected]>
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D5749

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