[PATCH v2 0/2] GPIO: add single-register GPIO via CREG driver
From: Eugeniy Paltsev
Date: Tue Aug 28 2018 - 07:27:31 EST
Add single-register MMIO GPIO driver for complex cases where
only several fields in register belong to GPIO lines and each GPIO line
owns a field with different length and on/off value.
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
^ ^ register
(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
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 | 49 +++++
MAINTAINERS | 6 +
drivers/gpio/Kconfig | 9 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-creg-snps.c | 242 +++++++++++++++++++++
5 files changed, 307 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt
create mode 100644 drivers/gpio/gpio-creg-snps.c