From: Tien Hock Loh <redacted>

Adds a new device tree binding and driver for Altera soft GPIO IP.
The driver is able to do read/write and allows GPIO to be a interrupt
controller.

Tested on Altera GHRD on interrupt handling and IO.

v8:
Using for_each_set_bit
added const for struct definition
removed naggy pr_err
changed from
sort alpha header
remove unused macros
use fixed width data types instead of unsigned long
whitespace issue fixes
removed _relaxed function for better compatibility across different CPU
changed irq_create_mapping to platform_get_irq
updated implementation to use gpiochip_irqchip_add
reserve interrupt-cells number 2 in device tree binding for future use
remove confusing sections on devicetree bindings
Added tristate Kconfig help text

v7:
used dev_warn instead of pr_warn
clean up unnecesarry if else indentation

v6:
Added irq_startup and irq_shutdown
changed bitwise clamping style
cleanup bitwise operation to improve readability
change naming of mapped irqs from virq to mapped_irq

v5:
dispose irq_domain mapping correctly
update optional binding description in binding docs

v4:
added vendor prefix to devicetree binding for IP specific properties
using MMIO GPIO helper library instead of manually map PIO to memory
altera_gpio_chip inline struct documentation to kerneldoc
using dev_ print to print a better failure message

v2, v3:
Do not reference NO_IRQ
Updated irq_set_type to only allow the hardware configured irq type


Tien Hock Loh (2):
  drivers/gpio: Altera soft IP GPIO driver device tree binding
  drivers/gpio: Altera soft IP GPIO driver

 .../devicetree/bindings/gpio/gpio-altera.txt       |   43 ++
 MAINTAINERS                                        |    6 +
 drivers/gpio/Kconfig                               |    8 +
 drivers/gpio/Makefile                              |    1 +
 drivers/gpio/gpio-altera.c                         |  410 ++++++++++++++++++++
 5 files changed, 468 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-altera.txt
 create mode 100644 drivers/gpio/gpio-altera.c