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/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

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Move Ti AM335x to dev/extres/clk framework.

Re-implement clocks for these SoC by using now standard extres/clk framework.
This is necessary for future expansion of these. The new implementation
is

Move Ti AM335x to dev/extres/clk framework.

Re-implement clocks for these SoC by using now standard extres/clk framework.
This is necessary for future expansion of these. The new implementation
is (due to the size of the patch) only the initial (minimum) version.
It will be updated/expanded with a subsequent set of particular patches.

This patch is also not tested on OMAP4 based boards (BeagleBone),
so all possible issues should be (and will be) fixed by ASAP once
identified.

Submited by: Oskar Holmlund ([email protected])
Differential Revision: https://reviews.freebsd.org/D25118

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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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Switch TI platform support code from using FreeBSD's custom-baked DTS
files to vendor-provided ones. It should make easier to adopt platform
code to new revisions of hardware and to use DTS overlays

Switch TI platform support code from using FreeBSD's custom-baked DTS
files to vendor-provided ones. It should make easier to adopt platform
code to new revisions of hardware and to use DTS overlays for various
Beaglebone extensions (shields/capes).

Original dts filenames were not changed, they're now wrappers over dts
files provided by TI. So make sure you update .dtb files on your
devices as part of kernel update

GPIO addressing was changed: instead of one global /dev/gpioc0 there
are per-bank instances of /dev/gpiocX. Each bank has 32 pins so for
instance pin 121 on /dev/gpioc0 in old addressing scheme is now pin 25
on /dev/gpioc3

On Pandaboard serial console devices was changed from /dev/ttyu0 to
/dev/ttyu2 so you'll have to update /etc/ttys to get login prompt
on serial port in multiuser mode. Single user mode serial console
should work as-is

Differential Revision: https://reviews.freebsd.org/D2146
Reviewed by: rpaulo, ian, Michal Meloun, Svatopluk Kraus

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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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Move the uart_class definitions and fdt compat data into the individual
uart implementations, and export them using the new linker-set mechanism.

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

Move the uart_class definitions and fdt compat data into the individual
uart implementations, and export them using the new linker-set mechanism.

Differential Revision: https://reviews.freebsd.org/D1993
Submitted by: Michal Meloun

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Add support for uarts other than the serial console in TI OMAP SoCs.

The TI uart hardware is ns16550-compatible, except that before it can
be used the clocks and power have to be enabled and a non-s

Add support for uarts other than the serial console in TI OMAP SoCs.

The TI uart hardware is ns16550-compatible, except that before it can
be used the clocks and power have to be enabled and a non-standard
mode control register has to be set to put the device in uart mode
(as opposed to irDa or other serial protocols). This adds the extra
code in an extension to the standard ns8250 probe routine, and the
rest of the driver is just the standard ns8250 code.

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