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 patches add hierarchical IRQ domain, one in IRQC driver and
another 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

v6->v7:
* Used devm_reset_control_get_exclusive() instead of
  devm_reset_control_get_exclusive_by_index()
* Included RB tag from Linus for patch 5/5
* Switched to newer version of populate_parent_alloc_arg() (patch depends
  on https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-p...
  patch/?id=178b7e21459e9a7e2a2c369711ef0cc9b1cfbcd7)

v5->v6:
* Fixed review comments pointed by Marc
* Included Ack from Rob

v4->v5:
* Updated commit message for patch 3/5
* Dropped interrupt-parent from and included RB tag from Geert
  for patch 4/5
* Implemented init_valid_mask() callback
* Dropped ngirq patch from previous series
* Dropped patches 4/7 and 5/7 from previous patch series will handle
  it separately.

v3->v4:
* Updated description for interrupts-cells property in patch #1
* Dropped the patch which overriding free callback in gpiolib
* Used devm helpers in patch#2
* Patch #4, #5 and #6 are newly added
* In patch #7 dropped using gpio offset as hwirq
* Implemented immutable GPIO in patch #7
* Implemented child_offset_to_irq() callback in patch #7

v2->v3:
* Updated description for interrupts-cells property in patch #1
* Included RB tag from Geert for binding patch
* Fixed review comments pointed by Geert, Biju and Sergei.

v1->v2:
* Included RB tag from Rob
* Fixed review comments pointed by Geert
* included GPIO driver changes

RFCV4 -> V1:
* Used unevaluatedProperties.
* Altered the sequence of reg property
* Set the parent type
* Used raw_spin_lock() instead of raw_spin_lock_irqsave()
* Simplified parsing IRQ map.
* Will send the GPIO and pinctrl changes as part of separate series

RFC 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/pa...
20220316200633.28974-1-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx/

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

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

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
  dt-bindings: pinctrl: renesas,rzg2l-pinctrl: Document the properties
    to handle GPIO IRQ
  pinctrl: renesas: pinctrl-rzg2l: Add IRQ domain to handle GPIO
    interrupt

 .../renesas,rzg2l-irqc.yaml                   | 133 ++++++
 .../pinctrl/renesas,rzg2l-pinctrl.yaml        |  15 +
 drivers/gpio/gpiolib.c                        |   9 +-
 drivers/irqchip/Kconfig                       |   8 +
 drivers/irqchip/Makefile                      |   1 +
 drivers/irqchip/irq-renesas-rzg2l.c           | 393 ++++++++++++++++++
 drivers/pinctrl/renesas/pinctrl-rzg2l.c       | 233 +++++++++++
 7 files changed, 789 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/renesas,rzg2l-irqc.yaml
 create mode 100644 drivers/irqchip/irq-renesas-rzg2l.c

-- 
2.25.1