[RFC v6 0/3] gpio: add DT support for memory-mapped GPIOs

From: Christian Lamparter
Date: Sun May 01 2016 - 08:19:13 EST

This patch series adds device tree support for generic memory-mapped GPIOs.
The GPIO library already allows drivers and architecture support code to
reuse generic code for managing a GPIO chip. Currently, a developer has
to create a platform device "basic-mmio-gpio" and attach a bgpio_pdata
platform data structure to make use of it. However, for architectures
which rely on the device tree to enumerate devices, creating custom
platform devices is another extra step that can be avoided by having
direct support via a device tree binding.

I initially came across this patch [0] from Ãlvaro FernÃndez Rojas,
while looking for an easy way to add support for the GPIO of my
WD MyBook Live [1] (APM82181 - ppc464). His generic approach patch
allowed me to easily get the GPIO (and the connected LEDs,
buttons, gpiohogs, etc.) up and running. Even thought, Mr. Fernandez
initially developed it for his work on the brcm63xx [2].

The drivers for gpio-clps711x, gpio-ge, gpio-moxart and gpio-ts4800
are now part of the gpio-mmio.c driver. The old driver files have
been removed and the Kconfig, Makefile entries have been updated

And finally, the most important stat about the series:
>>> 333 insertions(+), 411 deletions(-) <<<
It still removes more lines than it adds!

Thanks! (Please keep me in the CC)

[0] <https://patchwork.ozlabs.org/patch/422121/>
[1] <https://github.com/chunkeey/MBL-openwrt>
[2] <https://wiki.openwrt.org/doc/hardware/soc/soc.broadcom.bcm63xx>


v5 -> v6:
- rewrote bindings and driver patch to fit the wd,mbl-gpio
- unified parser code for gpio-ge, gpio-moxart and gpio-ts4800
- fixed gpio chip's base being overwritten with bogus "0"
- fixed compat driver crash when reload gpio-generic.ko module
- dropped already applied patches from the series
- rebased code on linus' devel tree
- moved dt bindings patch to the top of the series

v4 -> v5:
- reverted rename of gpio-mmio.c back to gpio-generic.c
- fixed Andy Shevchenko's comments
- consolidated changes from clps711x, gpio-ge, gpio-moxart and
gpio-ts4800 into one patch.

v3 -> v4:
- renamed gpio-generic.c to gpio-mmio.c
- changed compat. string to "linux,gpio-mmio"
- integrated Cirrus clps711x driver
- integrated GE FGPA gpio-ge driver
- integrated MOXA ART GPIO driver
- integrated TS4800 gpio driver
- reshuffled patches, reworded commits, fixed spelling errors, etc.

Christian Lamparter (2):
gpio: dt-bindings: add wd,mbl-gpio bindings
gpio: move clps711x, moxart, ts4800 and gpio-ge into gpio-mmio

Ãlvaro FernÃndez Rojas (1):
gpio: mmio: add DT support for memory-mapped GPIOs

.../devicetree/bindings/gpio/wd,mbl-gpio.txt | 38 +++
drivers/gpio/Kconfig | 43 +--
drivers/gpio/Makefile | 4 -
drivers/gpio/gpio-clps711x.c | 91 -------
drivers/gpio/gpio-ge.c | 114 --------
drivers/gpio/gpio-mmio.c | 289 ++++++++++++++++++++-
drivers/gpio/gpio-moxart.c | 84 ------
drivers/gpio/gpio-ts4800.c | 81 ------
8 files changed, 333 insertions(+), 411 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/wd,mbl-gpio.txt
delete mode 100644 drivers/gpio/gpio-clps711x.c
delete mode 100644 drivers/gpio/gpio-ge.c
delete mode 100644 drivers/gpio/gpio-moxart.c
delete mode 100644 drivers/gpio/gpio-ts4800.c