Add single-register MMIO gpio driver for complex cases where
only several fields in register belong to GPIO and each GPIO
owns field with different length and on/off values.
Here is the example:
31 11 8 7 5 0 < bit number
| | | | | |
[ not used | gpio-1 | shift-1 | gpio-0 | shift-0 ] < 32 bit MMIO
^ ^
(3 bit) (2 bit)
| |
| |
| write 0x2 == set output to "1" (on)
| write 0x3 == set output to "0" (off)
|
write 0x1 == set output to "1" (on)
write 0x4 == set output to "0" (off)
This is different from gpio-reg, gpio-mmio and gpio-74xx-mmio:
* They all don't support cases when GPIO output register have
more than one bit per GPIO line.
* They don't support holes in MMIO register.
* They don't support cases when GPIO lines have different on/off
values.
This driver supports GPIOs via CREG on various Synopsys SoCs/boards.
Eugeniy Paltsev (2):
GPIO: add single-register gpio via creg driver
dt-bindings: Document the Synopsys GPIO via CREG bindings
.../devicetree/bindings/gpio/snps,creg-gpio.txt | 48 ++++
MAINTAINERS | 6 +
drivers/gpio/Kconfig | 9 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-creg-snps.c | 242 +++++++++++++++++++++
5 files changed, 306 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt
create mode 100644 drivers/gpio/gpio-creg-snps.c
--
2.14.4
