linux.git/drivers/tty/serial/serial_mctrl_gpio.c, branch v5.10.258

serial: mctrl_gpio: Check for NULL pointer

2019-10-07T11:21:54+00:00

When using mctrl_gpio_to_gpiod, it dereferences gpios into a single
requested GPIO.  This dereferencing can break if gpios is NULL,
so this patch adds a NULL check before dereferencing it.  If
gpios is NULL, this function will also return NULL.

Signed-off-by: Adam Ford 
Reviewed-by: Yegor Yefremov 
Link: https://lore.kernel.org/r/20191006163314.23191-1-aford173@gmail.com
Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: Use gpiod flags directly

2019-09-04T10:43:55+00:00

Description of the modem line control GPIOs contain a boolean type to set
direction of the line. Since GPIO library provides an enumerator type of flags,
we may utilize it and allow a bit more flexibility on the choice of the type of
the line parameters. It also removes an additional layer of value conversion.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Stefan Roese 
Reviewed-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/20190814140759.17486-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: Check if GPIO property exisits before requesting it

2019-06-21T08:18:43+00:00

This patch adds a check for the GPIOs property existence, before the
GPIO is requested. This fixes an issue seen when the 8250 mctrl_gpio
support is added (2nd patch in this patch series) on x86 platforms using
ACPI.

Here Mika's comments from 2016-08-09:

"
I noticed that with v4.8-rc1 serial console of some of our Broxton
systems does not work properly anymore. I'm able to see output but input
does not work.

I bisected it down to commit 4ef03d328769eddbfeca1f1c958fdb181a69c341
("tty/serial/8250: use mctrl_gpio helpers").

The reason why it fails is that in ACPI we do not have names for GPIOs
(except when _DSD is used) so we use the "idx" to index into _CRS GPIO
resources. Now mctrl_gpio_init_noauto() goes through a list of GPIOs
calling devm_gpiod_get_index_optional() passing "idx" of 0 for each. The
UART device in Broxton has following (simplified) ACPI description:

    Device (URT4)
    {
        ...
        Name (_CRS, ResourceTemplate () {
            GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly,
                    "\\_SB.GPO0", 0x00, ResourceConsumer)
            {
                0x003A
            }
            GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly,
                    "\\_SB.GPO0", 0x00, ResourceConsumer)
            {
                0x003D
            }
        })

In this case it finds the first GPIO (0x003A which happens to be RX pin
for that UART), turns it into GPIO which then breaks input for the UART
device. This also breaks systems with bluetooth connected to UART (those
typically have some GPIOs in their _CRS).

Any ideas how to fix this?

We cannot just drop the _CRS index lookup fallback because that would
break many existing machines out there so maybe we can limit this to
only DT enabled machines. Or alternatively probe if the property first
exists before trying to acquire the GPIOs (using
device_property_present()).
"

This patch implements the fix suggested by Mika in his statement above.

Signed-off-by: Stefan Roese 
Reviewed-by: Mika Westerberg 
Reviewed-by: Andy Shevchenko 
Tested-by: Yegor Yefremov 
Cc: Mika Westerberg 
Cc: Andy Shevchenko 
Cc: Yegor Yefremov 
Cc: Greg Kroah-Hartman 
Cc: Giulio Benetti 
Signed-off-by: Greg Kroah-Hartman

gpiolib: Pass array info to get/set array functions

2018-09-13T09:16:54+00:00

In order to make use of array info obtained from gpiod_get_array() and
speed up processing of arrays matching single GPIO chip layout, that
information must be passed to get/set array functions.  Extend the
functions' API with that additional parameter and update all users.
Pass NULL if a user builds an array itself from single GPIOs.

Cc: Jonathan Corbet 
Cc: Miguel Ojeda Sandonis 
Cc: Geert Uytterhoeven 
Cc: Sebastien Bourdelin 
Cc: Lukas Wunner 
Cc: Peter Korsgaard 
Cc: Peter Rosin 
Cc: Andrew Lunn 
Cc: Florian Fainelli 
Cc: "David S. Miller" 
Cc: Rojhalat Ibrahim 
Cc: Dominik Brodowski 
Cc: Russell King 
Cc: Kishon Vijay Abraham I 
Cc: Tony Lindgren 
Cc: Lars-Peter Clausen 
Cc: Michael Hennerich 
Cc: Jonathan Cameron 
Cc: Hartmut Knaack 
Cc: Peter Meerwald-Stadler 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Yegor Yefremov 
Cc: Uwe Kleine-König 
Signed-off-by: Janusz Krzysztofik 
Acked-by: Ulf Hansson 
Signed-off-by: Linus Walleij

gpiolib: Pass bitmaps, not integer arrays, to get/set array

2018-09-13T09:15:30+00:00

Most users of get/set array functions iterate consecutive bits of data,
usually a single integer, while processing array of results obtained
from, or building an array of values to be passed to those functions.
Save time wasted on those iterations by changing the functions' API to
accept bitmaps.

All current users are updated as well.

More benefits from the change are expected as soon as planned support
for accepting/passing those bitmaps directly from/to respective GPIO
chip callbacks if applicable is implemented.

Cc: Jonathan Corbet 
Cc: Miguel Ojeda Sandonis 
Cc: Sebastien Bourdelin 
Cc: Lukas Wunner 
Cc: Peter Korsgaard 
Cc: Peter Rosin 
Cc: Andrew Lunn 
Cc: Florian Fainelli 
Cc: "David S. Miller" 
Cc: Rojhalat Ibrahim 
Cc: Dominik Brodowski 
Cc: Russell King 
Cc: Kishon Vijay Abraham I 
Cc: Tony Lindgren 
Cc: Lars-Peter Clausen 
Cc: Michael Hennerich 
Cc: Jonathan Cameron 
Cc: Hartmut Knaack 
Cc: Peter Meerwald-Stadler 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Yegor Yefremov 
Cc: Uwe Kleine-König 
Signed-off-by: Janusz Krzysztofik 
Acked-by: Ulf Hansson 
Reviewed-by: Geert Uytterhoeven 
Tested-by: Geert Uytterhoeven 
Signed-off-by: Linus Walleij

tty: serial: Remove redundant license text

2017-11-08T12:08:12+00:00

Now that the SPDX tag is in all tty files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Jiri Slaby 
Cc: Eric Anholt 
Cc: Stefan Wahren 
Cc: Florian Fainelli 
Cc: Ray Jui 
Cc: Scott Branden 
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Joachim Eastwood 
Cc: Matthias Brugger 
Cc: Masahiro Yamada 
Cc: Tobias Klauser 
Cc: Russell King 
Cc: Vineet Gupta 
Cc: Richard Genoud 
Cc: Alexander Shiyan 
Cc: Baruch Siach 
Cc: Pat Gefre 
Cc: "Guilherme G. Piccoli" 
Cc: Jason Wessel 
Cc: Vladimir Zapolskiy 
Cc: Sylvain Lemieux 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Liviu Dudau 
Cc: Sudeep Holla 
Cc: Lorenzo Pieralisi 
Cc: Andy Gross 
Cc: David Brown 
Cc: "Andreas Färber" 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Kevin Cernekee 
Cc: Laxman Dewangan 
Cc: Thierry Reding 
Cc: Jonathan Hunter 
Cc: Barry Song 
Cc: Patrice Chotard 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: Chris Metcalf 
Cc: Peter Korsgaard 
Cc: Timur Tabi 
Cc: Tony Prisk 
Cc: Michal Simek 
Cc: "Sören Brinkmann" 
Signed-off-by: Greg Kroah-Hartman

tty: add SPDX identifiers to all remaining files in drivers/tty/

2017-11-08T12:08:12+00:00

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/tty files files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Jiri Slaby 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Chris Metcalf 
Cc: Jiri Kosina 
Cc: David Sterba 
Cc: James Hogan 
Cc: Rob Herring 
Cc: Eric Anholt 
Cc: Stefan Wahren 
Cc: Florian Fainelli 
Cc: Ray Jui 
Cc: Scott Branden 
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Joachim Eastwood 
Cc: Matthias Brugger 
Cc: Masahiro Yamada 
Cc: Tobias Klauser 
Cc: Russell King 
Cc: Vineet Gupta 
Cc: Richard Genoud 
Cc: Alexander Shiyan 
Cc: Baruch Siach 
Cc: "Maciej W. Rozycki" 
Cc: "Uwe Kleine-König" 
Cc: Pat Gefre 
Cc: "Guilherme G. Piccoli" 
Cc: Jason Wessel 
Cc: Vladimir Zapolskiy 
Cc: Sylvain Lemieux 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Liviu Dudau 
Cc: Sudeep Holla 
Cc: Lorenzo Pieralisi 
Cc: Andy Gross 
Cc: David Brown 
Cc: "Andreas Färber" 
Cc: Kevin Cernekee 
Cc: Laxman Dewangan 
Cc: Thierry Reding 
Cc: Jonathan Hunter 
Cc: Barry Song 
Cc: Patrice Chotard 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: "David S. Miller" 
Cc: Peter Korsgaard 
Cc: Timur Tabi 
Cc: Tony Prisk 
Cc: Michal Simek 
Cc: "Sören Brinkmann" 
Cc: Thomas Gleixner 
Cc: Kate Stewart 
Cc: Philippe Ombredanne 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: enable API usage only for initialized mctrl_gpios struct

2016-06-25T21:30:42+00:00

This workaround is needed for the cases, where mctrl_gpio API is used
before mctrl_gpio_init() was invoked. This happens in 8250 during
console initialization, as the driver sets DTR signal.

Signed-off-by: Yegor Yefremov 
Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: add modem control read routine

2016-06-25T21:30:42+00:00

mctrl_gpio_get_outputs() returns the state of following signals:

RTS, DTR

While defining the routine for reading outputs, fix the comment for
mctrl_gpio_get() routine as it returns only the state of the input
signals.

Signed-off-by: Yegor Yefremov 
Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: Drop support for out1-gpios and out2-gpios

2016-05-01T20:22:54+00:00

The OUT1 and OUT2 pins present on some legacy UARTs are basically GPIOs.
It doesn't make much sense to emulate GPIOs using other GPIOs, hence
drop support for that.

Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Peter Hurley 
Reviewed-by: Richard Genoud 
Reviewed-by: Yegor Yefremov 
Signed-off-by: Greg Kroah-Hartman