Add rs485-rts-active-high property, this is a legacy property
used by 8250_omap.
This fixes the following make dt_binding_check warning:
Documentation/devicetree/bindings/serial/8250_omap.yaml:
rs485-rts-active-high: missing type definition
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/all/CAMuHMdUkPiA=o_QLyuwsTYW7y1ksCjHAqyNSHFx2QZ-dP-HGsQ@mail.gmail.com/
Fixes: 403e97d6ab ("dt-bindings: serial: 8250_omap: add rs485-rts-active-high")
Cc: stable <stable@kernel.org>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231019154834.41721-1-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a binding for a generic definition of an output GPIO that sets the
state of rs485-rx-during-tx. The idea is that the hardware already controls
the option receiving during sending before it gets to the signal receiving
hardware. The standard RS485 is a half-duplex bus that in most cases is
driven by an UART controller. The advantage of using this GPIO is that it
is independent of the capabilities of the UART core and the UART driver.
On the hardware side the interface to the bus is controlled by a transceiver,
that has a pin called RE (RX Enable) or similar, which connects the bus to
the RX signal of the UART controller. The GPIO can switch between two states
to control the RE pin via an electrical circuit:
- Active:
The RE pin is always active. The UART RX see everything on the bus and
therefore also what happens with the TX signal on the bus.
- Inactive:
The RE pin is always active, but during sending on the bus the pin RE is
inactive. So basically the receiving during sending is suppressed.
A possible circuit diagram could look like this:
┌──────────────────┐
│ RS485 │
TX ───────────────┤D │
│ Transceiver │
RTS ────┬──────────┤DE │
│ │ │
│ ┌─────┐ │ │
└─┤& │ │ │
│ ├──┤!RE │
!rx_during_tx_gpio ──────┤ │ │ │
└─────┘ │ │
│ │
RX ───────────────┤R │
│ │
└──────────────────┘
Here the RTS pin of the UART core is used to control TX via the transceiver
pin DE (Drive Enable). RE and rx_during_tx_gpio are active low.
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221202104127.122761-1-cniedermaier@dh-electronics.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Devicetree bindings document does not have to say in the title that
it is a "binding", but instead just describe the hardware.
Drop trailing "bindings" in various forms (also with trailing full
stop):
find Documentation/devicetree/bindings/ -type f -name '*.yaml' \
-not -name 'trivial-devices.yaml' \
-exec sed -i -e 's/^title: \(.*\) [bB]indings\?\.\?$/title: \1/' {} \;
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Matti Vaittinen <mazziesaccount@gmail.com> # ROHM
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # MMC
Acked-by: Stephen Boyd <sboyd@kernel.org> # clk
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> # input
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # media
Acked-by: Sebastian Reichel <sre@kernel.org> # power
Acked-by: Viresh Kumar <viresh.kumar@linaro.org> # cpufreq
Link: https://lore.kernel.org/r/20221216163815.522628-7-krzysztof.kozlowski@linaro.org
Signed-off-by: Rob Herring <robh@kernel.org>
Currently the documentation claims that a maximum of 1000 msecs is allowed
for RTS delays. However nothing actually checks the values read from device
tree/ACPI and so it is possible to set much higher values.
There is already a maximum of 100 ms enforced for RTS delays that are set
via the UART TIOCSRS485 ioctl. To be consistent with that use the same
limit for DT/ACPI values.
Although this change is visible to userspace the risk of breaking anything
when reducing the max delays from 1000 to 100 ms should be very low, since
100 ms is already a very high maximum for delays that are usually rather in
the usecs range.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20220710164442.2958979-7-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add polarity property for receiver enable. Some UARTs have separate
enable pins for tx (RTS or DE) and rx (RE). As most RS485 transceivers
have !RE pin, the default is active low in contrast to
rs485-rts-active-low that defaults to active high.
Cc: devicetree@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220426122448.38997-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to add meta-schema checks for additional/unevaluatedProperties
being present, all schema need to make this explicit. As common/shared
schema are included by other schemas, they should always allow for
additionalProperties.
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201005183830.486085-5-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Here is the tty and serial driver updates for 5.8-rc1
Nothing huge at all, just a lot of little serial driver fixes, updates
for new devices and features, and other small things. Full details are
in the shortlog.
Note, you will get a conflict merging with your tree in the
Documentation/devicetree/bindings/serial/rs485.yaml file, but it should
be pretty obvious what to do. If not, I'm sure Rob will clean it all up
afterwards :)
All of these have been in linux-next with no issues for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXtzpCg8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ylRxACgjGtOKPjahONL4lWd0F8ZYEcyw7sAn34woBCO
BDUV3kolrRQ4OYNJWsHP
=TvqG
-----END PGP SIGNATURE-----
Merge tag 'tty-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here is the tty and serial driver updates for 5.8-rc1
Nothing huge at all, just a lot of little serial driver fixes, updates
for new devices and features, and other small things. Full details are
in the shortlog.
All of these have been in linux-next with no issues for a while"
* tag 'tty-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (67 commits)
tty: serial: qcom_geni_serial: Add 51.2MHz frequency support
tty: serial: imx: clear Ageing Timer Interrupt in handler
serial: 8250_fintek: Add F81966 Support
sc16is7xx: Add flag to activate IrDA mode
dt-bindings: sc16is7xx: Add flag to activate IrDA mode
serial: 8250: Support rs485 bus termination GPIO
serial: 8520_port: Fix function param documentation
dt-bindings: serial: Add binding for rs485 bus termination GPIO
vt: keyboard: avoid signed integer overflow in k_ascii
serial: 8250: Enable 16550A variants by default on non-x86
tty: hvc_console, fix crashes on parallel open/close
serial: imx: Initialize lock for non-registered console
sc16is7xx: Read the LSR register for basic device presence check
sc16is7xx: Allow sharing the IRQ line
sc16is7xx: Use threaded IRQ
sc16is7xx: Always use falling edge IRQ
tty: n_gsm: Fix bogus i++ in gsm_data_kick
tty: n_gsm: Remove unnecessary test in gsm_print_packet()
serial: stm32: add no_console_suspend support
tty: serial: fsl_lpuart: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
...
Commit e8759ad17d ("serial: uapi: Add support for bus termination")
introduced the ability to enable rs485 bus termination from user space.
So far the feature is only used by a single driver, 8250_exar.c, using a
hardcoded GPIO pin specific to Siemens IOT2040 products.
Provide for a more generic solution by allowing specification of an
rs485 bus termination GPIO pin in the device tree. An upcoming commit
implements support for this pin for any 8250 driver. The binding is
used in device trees of the "Revolution Pi" PLCs offered by KUNBUS.
[Heiko Stuebner converted the binding to YAML, hence his Signed-off-by.]
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/4f4411895dc52c846f766e7f7207ec412c4811b6.1589811297.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
json-schema versions draft7 and earlier have a weird behavior in that
any keywords combined with a '$ref' are ignored (silently). The correct
form was to put a '$ref' under an 'allOf'. This behavior is now changed
in the 2019-09 json-schema spec and '$ref' can be mixed with other
keywords. The json-schema library doesn't yet support this, but the
tooling now does a fixup for this and either way works.
This has been a constant source of review comments, so let's change this
treewide so everyone copies the simpler syntax.
Scripted with ruamel.yaml with some manual fixups. Some minor whitespace
changes from the script.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for I2C
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio
Reviewed-by: Stephen Boyd <sboyd@kernel.org> # clock
Signed-off-by: Rob Herring <robh@kernel.org>
Fix various inconsistencies in schema indentation. Most of these are
list indentation which should be 2 spaces more than the start of the
enclosing keyword. This doesn't matter functionally, but affects running
scripts which do transforms on the schema files.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Rob Herring <robh@kernel.org>
