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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Add busy detect quirk to list of console options

This change allows one to set the busy_detect flag
required by the synopsys UART at the loader prompt.
This is needed by the EPYC 3000 SoC.

This wil

Add busy detect quirk to list of console options

This change allows one to set the busy_detect flag
required by the synopsys UART at the loader prompt.
This is needed by the EPYC 3000 SoC.

This will give users a working console up to the point where getty is required:
hw.uart.console="mm:0xfedc9000,rs:2,bd:1"

Reviewed by: imp
MFC after: 4 weeks
Differential Revision: https://reviews.freebsd.org/D16399

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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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uart: detect 256-byte FIFOs

Submitted by: Zakary Nafziger <[email protected]>
Sponsored by: The FreeBSD Foundation

Make some UART consoles to not spin wait for data to be sent.

At least with Tx FIFO enabled it shows me ~10% reduction of verbose boot
time with serial console at 115200 baud.

Reviewed by: marcel
M

Make some UART consoles to not spin wait for data to be sent.

At least with Tx FIFO enabled it shows me ~10% reduction of verbose boot
time with serial console at 115200 baud.

Reviewed by: marcel
MFC after: 2 weeks

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Add support for UART found in the Ingenic XBurst system on chips.

These CPUs has non-standard UART enable bit hidden in the UART FIFO
Control Register.

Sponsored by: DARPA, AFRL

sys/dev: minor spelling fixes.

Most affect comments, very few have user-visible effects.

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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Add ns16550a compatible string in UART 8250 driver

Obtained from: Semihalf
Submitted by: Michal Stanek <[email protected]>
Sponsored by: Annapurna Labs
Approved by:

Add ns16550a compatible string in UART 8250 driver

Obtained from: Semihalf
Submitted by: Michal Stanek <[email protected]>
Sponsored by: Annapurna Labs
Approved by: cognet (mentor)
Reviewed by: imp, wma
Differential revision: https://reviews.freebsd.org/D5404

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UART: Fix spurious interrupts generated by ns8250 and lpc drivers:
- don't enable transmitter empty interrupt before filling TX FIFO.
- add missing uart_barrier() call in interrupt service routine

Fix busy-detect when using DesignWare UART

uart_dev_ns8250 now relies on compatible property instead of additional
'busy-detect' cell. All drivers with compatible = "snps,dw-apb-uart" have
busy dete

Fix busy-detect when using DesignWare UART

uart_dev_ns8250 now relies on compatible property instead of additional
'busy-detect' cell. All drivers with compatible = "snps,dw-apb-uart" have
busy detection turned on. DTS files of devices affected by the change
were modified and 'busy-detect' property was removed.

Reviewed by: andrew, ian, imp
Obtained from: Semihalf
Sponsored by: Stormshield
Submitted by: Bartosz Szczepanek <[email protected]>
Differential revision: https://reviews.freebsd.org/D4218

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Add compatibility string for dw-apb-uart in ns8250 driver

This compatibility string is used in .dts file of Armada38x
and isrequired for driver attachment.

Reviewed by: andrew, ian, imp
Obtained

Add compatibility string for dw-apb-uart in ns8250 driver

This compatibility string is used in .dts file of Armada38x
and isrequired for driver attachment.

Reviewed by: andrew, ian, imp
Obtained from: Semihalf
Sponsored by: Stormshield
Submitted by: Michal Stanek <[email protected]>
Differential revision: https://reviews.freebsd.org/D4216

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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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uart(4) - make the 8250 uart baudrate tolerance build time tweakable.

It turns out on a 16550 w/ a 25MHz SoC reference clock you get a little
over 3% error at 115200 baud, which causes this to fail.

uart(4) - make the 8250 uart baudrate tolerance build time tweakable.

It turns out on a 16550 w/ a 25MHz SoC reference clock you get a little
over 3% error at 115200 baud, which causes this to fail.

Just .. cope. Things cope these days.

Default to 30 (3.0%) as before, but allow UART_DEV_TOLERANCE_PCT to be
set at build time to change that.

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Actually check the DTS node value to enable the uart quirks.

Without this fix, you cannot disable the quirks by setting it to 0, just
the presence of the FDT node was enough to enable it.

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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Pull in r267961 and r267973 again. Fix for issues reported will follow.

Revert r267961, r267973:

These changes prevent sysctl(8) from returning proper output,
such as:

1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1

Revert r267961, r267973:

These changes prevent sysctl(8) from returning proper output,
such as:

1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory

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Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statica

Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after: 2 weeks
Sponsored by: Mellanox Technologies

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In uart_bus_grab(), use the ier_mask instead of a custom hack for XScale.

Suggested by: jmg

In the grab function, keep the bit 6 on in the IER, on XScale, using 0
turns the UART off, which is unfortunate if one want to use it as a console.

Introduce grab and ungrab upcalls. When the kernel desires to grab the
console, it calls the grab functions. These functions should turn off
the RX interrupts, and any others that interfere. This mak

Introduce grab and ungrab upcalls. When the kernel desires to grab the
console, it calls the grab functions. These functions should turn off
the RX interrupts, and any others that interfere. This makes mountroot
prompt work again. If there's more generalized need other than
prompting, many of these routines should be expanded to do those new
things.

Should have been part of r260889, but waasn't due to command line typo.

Reviewed by: bde (with reservations)

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Wait for DesignWare UART transfers completion before accessing line control

When using DW UART with BUSY detection it is necessary to wait
until all serial transfers are finished before manipulating

Wait for DesignWare UART transfers completion before accessing line control

When using DW UART with BUSY detection it is necessary to wait
until all serial transfers are finished before manipulating the
line control. LCR will not be affected when UART is busy.
In addition, if Divisor Latch Access Bit is being set in order to
modify UART divisors:
1. We will get BUSY interrupt if interrupts are enabled.
2. Because LCR will not be affected the THR and (even worse) IER
contents will be corrupted. This will lead to console hang.

Approved by: cognet (mentor)

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A final test with unmodified code has shown that a delay of 150ms
is not giving us a 100% success rate. Bump the delay to 200ms as
that seems to do the trick.

Note that during testing the delay was

A final test with unmodified code has shown that a delay of 150ms
is not giving us a 100% success rate. Bump the delay to 200ms as
that seems to do the trick.

Note that during testing the delay was added to uart_bus_attach()
in uart_core.c. While having the delay in a different place can
change the behaviour, it was not expected. Having to bump the
delay with another 50ms could therefore be an indication that
the problem can not be solved with delays.

Reported by: kevlo@
Tested by: kevlo@

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