[RFC,v4,0/5] Renesas RZ/G2L IRQC support

Hi All,

The RZ/G2L Interrupt Controller is a front-end for the GIC found on
Renesas RZ/G2L SoC's with below pins:
- IRQ sense select for 8 external interrupts, mapped to 8 GIC SPI interrupts
- GPIO pins used as external interrupt input pins out of GPIOINT0-122 a
  maximum of only 32 can be mapped to 32 GIC SPI interrupts,
- NMI edge select.

                                                                _____________
                                                                |    GIC     |
                                                                |  ________  |
                                         ____________           | |        | |
NMI ------------------------------------>|          |  SPI0-479 | | GIC-600| |
                _______                  |          |------------>|        | |
                |      |                 |          |  PPI16-31 | |        | |
                |      | IRQ0-IRQ7       |   IRQC   |------------>|        | |
P0_P48_4 ------>| GPIO |---------------->|          |           | |________| |
                |      |GPIOINT0-122     |          |           |            |
                |      |---------------->| TINT0-31 |           |            |
                |______|                 |__________|           |____________|

The proposed RFC patches adds hierarchical IRQ domain one in IRQC driver and other in
pinctrl driver. Upon interrupt requests map the interrupt to GIC. Out of GPIOINT0-122
only 32 can be mapped to GIC SPI, this mapping is handled by the pinctrl and IRQC driver.

Cheers,
Prabhakar

Changes for v4:
* Used locking while RMW
* Now using interrupts property instead of interrupt-map
* Patch series depends on [0]
* Updated binding doc
* Fixed comments pointed by Andy

[0] https://patchwork.kernel.org/project/linux-renesas-soc/patch/
20220316200633.28974-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

Changes for v3:
-> Re-structured the driver as a hierarchical irq domain instead of chained
-> made use of IRQCHIP_* macros
-> dropped locking
-> Added support for IRQ0-7 interrupts
-> Introduced 2 new patches for GPIOLIB
-> Switched to using GPIOLIB for irqdomains in pinctrl

RFC v3: https://patchwork.kernel.org/project/linux-renesas-soc/cover/
20211110225808.16388-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

RFC v2: https://patchwork.kernel.org/project/linux-renesas-soc/cover/
20210921193028.13099-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

RFC v1: https://patchwork.kernel.org/project/linux-renesas-soc/cover/
20210803175109.1729-1-prabhakar.mahadev-lad.rj@bp.renesas.com/


Lad Prabhakar (5):
  dt-bindings: interrupt-controller: Add Renesas RZ/G2L Interrupt
    Controller
  irqchip: Add RZ/G2L IA55 Interrupt Controller driver
  gpio: gpiolib: Allow free() callback to be overridden
  gpio: gpiolib: Add ngirq member to struct gpio_irq_chip
  pinctrl: renesas: pinctrl-rzg2l: Add IRQ domain to handle GPIO
    interrupt

 .../renesas,rzg2l-irqc.yaml                   | 131 +++++
 drivers/gpio/gpiolib.c                        |  13 +-
 drivers/irqchip/Kconfig                       |   8 +
 drivers/irqchip/Makefile                      |   1 +
 drivers/irqchip/irq-renesas-rzg2l.c           | 462 ++++++++++++++++++
 drivers/pinctrl/renesas/pinctrl-rzg2l.c       | 205 ++++++++
 include/linux/gpio/driver.h                   |   8 +
 7 files changed, 823 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/renesas,rzg2l-irqc.yaml
 create mode 100644 drivers/irqchip/irq-renesas-rzg2l.c