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 4ef03d3287
("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 <sr@denx.de>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <yegorslists@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <yegorslists@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As the mctrl_gpio driver can be built as a module, it needs to have its
license specified with MODULE_LICENSE. Otherwise, it cannot access
required symbols exported through EXPORT_SYMBOL_GPL.
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To be able to make use of the mctrl-gpio helper from a module these
functions must be exported. This was forgotten in the commit introducing
support interrupt handling for these functions (while it was done for
mctrl_gpio_enable_ms, *sigh*).
Fixes: ce59e48fdb ("serial: mctrl_gpio: implement interrupt handling")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is done before adding more functionality to the init function with
the existing name. As this new functionality conflicts with stuff
drivers are required to implement themselves up to I want to convert
them one by one to make reviewing and reverting more easy in case I
broke something.
Once mctrl_gpio_init is there and all drivers are converted
mctrl_gpio_init_noauto can be removed again.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial driver updates from Greg KH:
"Here's the tty and serial driver patches for 4.2-rc1.
A number of individual driver updates, some code cleanups, and other
minor things, full details in the shortlog.
All have been in linux-next for a while with no reported issues"
* tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (152 commits)
Doc: serial-rs485.txt: update RS485 driver interface
Doc: tty.txt: remove mention of the BKL
MAINTAINERS: tty: add serial docs directory
serial: sprd: check for NULL after calling devm_clk_get
serial: 8250_pci: Correct uartclk for xr17v35x expansion chips
serial: 8250_pci: Add support for 12 port Exar boards
serial: 8250_uniphier: add bindings document for UniPhier UART
serial: core: cleanup in uart_get_baud_rate()
serial: stm32-usart: Add STM32 USART Driver
tty/serial: kill off set_irq_flags usage
tty: move linux/gsmmux.h to uapi
doc: dt: add documentation for nxp,lpc1850-uart
serial: 8250: add LPC18xx/43xx UART driver
serial: 8250_uniphier: add UniPhier serial driver
serial: 8250_dw: support ACPI platforms with integrated DMA engine
serial: of_serial: check the return value of clk_prepare_enable()
serial: of_serial: use devm_clk_get() instead of clk_get()
serial: earlycon: Add support for big-endian MMIO accesses
serial: sirf: use hrtimer for data rx
serial: sirf: correct the fifo empty_bit
...
There have been concerns that the function names gpiod_set_array() and
gpiod_get_array() might be confusing to users. One might expect
gpiod_get_array() to return array values, while it is actually the array
counterpart of gpiod_get(). To be consistent with the single descriptor API
we could rename gpiod_set_array() to gpiod_set_array_value(). This makes
some function names a bit lengthy: gpiod_set_raw_array_value_cansleep().
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The function mctrl_gpio_init returns failure if the assignment to any
member of the gpio array results in an error pointer. So there is no
need to check for such error values in the other functions.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of ignoring errors returned by devm_gpiod_get_index use
devm_gpiod_get_index_optional which results in slightly more strict
error handling which is good.
Also use the fourth parameter to devm_gpiod_get_index_optional to be
able to drop the explicit direction setting.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers using mctrl-gpio must not pass invalid values for struct
mctrl_gpios *. All drivers were fixed in this regard and so some checks
can go away or be simplified.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the serial_mctrl_gpio driver the first user of the new gpiod_set_array
function, which is now available in the linux-gpio devel tree.
All modem control output signals are now set simultaneously.
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch fixes COMPILE_TEST build of serial_mctrl_gpio module for
architectures with custom termios.h header.
sparc64:allmodconfig:
In file included from drivers/tty/serial/serial_mctrl_gpio.c:21:0:
include/uapi/asm-generic/termios.h:22:8: error: redefinition of 'struct termio'
./arch/sparc/include/uapi/asm/termbits.h:16:8: note: originally defined here
make[3]: *** [drivers/tty/serial/serial_mctrl_gpio.o] Error 1
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch add some helpers to control modem lines (CTS/RTS/DSR...) via
GPIO.
This will be useful for many boards which have a serial controller that
only handle CTS/RTS pins (or even just RX/TX).
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
