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  1. Apr 08, 2016
    • Robert Jarzmik's avatar
      gpio: pxa: fix legacy non pinctrl aware builds · c4e5ffb6
      Robert Jarzmik authored 
      

In legacy pxa builds, ie. non device-tree and platform-data only builds,
pinctrl is not yet available. As a consequence, the pinctrl gpio
direction change function is a stub, returning always success.

In the current state, the gpio driver direction function believes the
pinctrl direction change was successful, and exits without actually
changing the gpio direction.

This patch changes the logic :
 - if the pinctrl direction function fails, gpio direction will report
   that failure
 - if the pinctrl direction function succeeds, gpio direction is changed
   by the gpio driver anyway.
   This is sub optimal in the pinctrl aware case, as the gpio direction
   will be changed twice: once by pinctrl function and another time by
   the gpio direction function.

Yet it should be acceptable in this form, as this is functional for all
pxa platforms (device-tree and platform-data), and moreover changing a
gpio direction is very very seldom, usually in machine initialization,
seldom in drivers probe, and an exception for ac97 reset bug.

Fixes: a770d946 ("gpio: pxa: add pin control gpio direction and request")
Reported-by: default avatarGuenter Roeck <guenter@roeck-us.net>
Tested-by: default avatarGuenter Roeck <guenter@roeck-us.net>
Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      c4e5ffb6
    • Dmitry Torokhov's avatar
      gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_* · 25487533
      Dmitry Torokhov authored 
      

When firmware does not use _DSD properties that allow properly name GPIO
resources, the kernel falls back on parsing _CRS resources, and will
return entries described as GpioInt() as general purpose GPIOs even
though they are meant to be used simply as interrupt sources for the
device:

Device (ETSA)
{
	Name (_HID, "ELAN0001")
	...

	Method(_CRS, 0x0, NotSerialized)
	{
		Name(BUF0,ResourceTemplate ()
		{
			I2CSerialBus(
				0x10,                     /* SlaveAddress */
				ControllerInitiated,      /* SlaveMode */
				400000,                   /* ConnectionSpeed */
				AddressingMode7Bit,       /* AddressingMode */
				"\\_SB.I2C1",             /* ResourceSource */
			)
			GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,,
				 "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX }
		} )
		Return (BUF0)
	}
...
}

This gives troubles with drivers such as Elan Touchscreen driver
(elants_i2c) that uses devm_gpiod_get to look up "reset" GPIO line and
decide whether the driver is responsible for powering up and resetting
the device, or firmware is. In the above case the lookup succeeds, we
map GPIO as output and later fail to request client->irq interrupt that
is mapped to the same GPIO.

Let's ignore resources described as GpioInt() while parsing _CRS when
requesting output GPIOs (but allow them when requesting GPIOD_ASIS or
GPIOD_IN as some drivers, such as i2c-hid, do request GPIO as input and
then map it to interrupt with gpiod_to_irq).

Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@chromium.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      25487533
  3. Apr 03, 2016
  5. Apr 02, 2016