gpio: dt-bindings: add ibm,ppc4xx-gpio binding
This patch adds binding information for IBM/AMCC/APM GPIO
Controllers of the PowerPC 4XX series and compatible SoCs.
The "PowerPC 405EP Embedded Processor Data Sheet" has the
following to say about the GPIO controllers: "
- Controller functions and GPIO registers are programmed
and accessed via memory-mapped OPB bus master accesses
- All GPIOs are pin-shared with other functions. DCRs control
whether a particular pin that has GPIO capabilities acts
as a GPIO or is used for another purpose.
- Each GPIO outputs is separately programmable to emulate
an open-drain driver (i.e. drives to zero, threestated if
output bit is 1)
"
The ppc4xx_gpio.c driver is part of the platform/sysdev drivers
in arch/powerpc/sysdev.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
1 file changed