[PATCH v2 0/6] pinctrl: rzg2l: Fix releasing of IRQ and status reported in pinmux-pins

[Prabhakar <prabhakar.csengg@xxxxxxxxx>]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Hi All,

This patch series aims to fix the reporting of pin status in the
`pinmux-pins` file and properly free up the IRQ line when using a GPIO
pin as an interrupt via the `interrupts`/`interrupts-extended` property.

Testing on SMARC RZ/G2L:
------------------------
	keys {
		compatible = "gpio-keys";

		key-1 {
			interrupt-parent = <&pinctrl>;
			gpios = <&pinctrl RZG2L_GPIO(41, 0) GPIO_ACTIVE_HIGH>;
			linux,code = <KEY_1>;
			label = "USER_SW1";
			wakeup-source;
			debounce-interval = <20>;
		};

		key-3 {
			interrupts-extended = <&pinctrl RZG2L_GPIO(43, 1) IRQ_TYPE_EDGE_RISING>;
			linux,code = <KEY_3>;
			label = "USER_SW3";
			wakeup-source;
			debounce-interval = <20>;
		};
	};

Before this patch series, the pin status was incorrectly reported in the
`pinmux-pins` file, and the IRQ was not released. As seen below, `P43_1` is
reported as `UNCLAIMED`, and after unloading the `gpio_keys` module, the
IRQ is not released, unlike `P41_0`, which was used via the `gpios` property.
---------------------------------------------------------------------------------
root@smarc-rzg2l:~# cat /proc/interrupts | grep pinctrl
 78:          1          0 11030000.pinctrl  17 Edge      1-003d
 91:          0          0 11030000.pinctrl 345 Edge      USER_SW3
 92:          0          0 11030000.pinctrl 328 Edge      USER_SW1
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep 41_0
 gpio-840 (P41_0               |USER_SW1            ) in  lo IRQ
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep 43_1
 gpio-857 (P43_1               |interrupt           ) in  lo IRQ
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep 43_1
pin 345 (P43_1): UNCLAIMED
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep 41_0
pin 328 (P41_0): GPIO 11030000.pinctrl:840
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/91
/sys/kernel/debug/irq/irqs/91
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/92
/sys/kernel/debug/irq/irqs/92
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# lsmod
Module                  Size  Used by
gpio_keys              20480  0
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# modprobe -r gpio_keys
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# cat /proc/interrupts | grep pinctrl
 78:          1          0 11030000.pinctrl  17 Edge      1-003d
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep 41_0
 gpio-840 (P41_0               )
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep 43_1
 gpio-857 (P43_1               )
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep 41_0
pin 328 (P41_0): UNCLAIMED
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep 43_1
pin 345 (P43_1): UNCLAIMED
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/91
/sys/kernel/debug/irq/irqs/91
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/92
ls: /sys/kernel/debug/irq/irqs/92: No such file or directory
root@smarc-rzg2l:~#
root@smarc-rzg2l:~#


After applying this patch series, the pin status is correctly reported in
the `pinmux-pins` file, and the IRQ is properly released. As shown below,
the status for pin `P43_1` is now reported correctly, and the IRQ is now
released, unlike in the previous logs above.
---------------------------------------------------------------------------
root@smarc-rzg2l:~# cat /proc/interrupts | grep pinctrl
 78:          1          0 11030000.pinctrl  17 Edge      1-003d
 91:          0          0 11030000.pinctrl 345 Edge      USER_SW3
 92:          0          0 11030000.pinctrl 328 Edge      USER_SW1
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep 41_0
 gpio-840 (P41_0               |USER_SW1            ) in  lo IRQ
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep 43_1
 gpio-857 (P43_1               |interrupt           ) in  lo IRQ
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep P43_1
pin 345 (P43_1): GPIO 11030000.pinctrl:857
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep P41_0
pin 328 (P41_0): GPIO 11030000.pinctrl:840
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/91
/sys/kernel/debug/irq/irqs/91
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/92
/sys/kernel/debug/irq/irqs/92
root@smarc-rzg2l:~# lsmod
Module                  Size  Used by
gpio_keys              20480  0
root@smarc-rzg2l:~# modprobe -r gpio_keys
root@smarc-rzg2l:~# cat /proc/interrupts | grep pinctrl
 78:          1          0 11030000.pinctrl  17 Edge      1-003d
root@smarc-rzg2l:~#
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep P43_1
 gpio-857 (P43_1               )
root@smarc-rzg2l:~# cat /sys/kernel/debug/gpio | grep P41_0
 gpio-840 (P41_0               )
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep P43_1
pin 345 (P43_1): UNCLAIMED
root@smarc-rzg2l:~# cat /sys/kernel/debug/pinctrl/11030000.pinctrl-pinctrl-rzg2l/pinmux-pins | grep P41_0
pin 328 (P41_0): UNCLAIMED
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/91
ls: /sys/kernel/debug/irq/irqs/91: No such file or directory
root@smarc-rzg2l:~# ls /sys/kernel/debug/irq/irqs/92
ls: /sys/kernel/debug/irq/irqs/92: No such file or directory
root@smarc-rzg2l:~#

Note:
- On RZ/G3S SMARC, prior to this patch series, we hogged the GPIO pins as
  inputs before using them as GPIO interrupts via the
  `interrupts`/`interrupts-extended` property. These patches do not break
  older DTBs, i.e., functionality remains the same. However, after
  unloading the `gpio_keys` module, the `pinmux-pins` file in sysfs
  reports the pin as UNCLAIMED.

v1->v2
- Fixed build warning
- Collected RB tag from Linus fr patch 5/6
- Dropped patch 2/7 from v1 series

v1: https://lore.kernel.org/all/20241017113942.139712-1-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx/

Cheers,
Prabhakar

Lad Prabhakar (6):
  arm64: dts: renesas: rzg3s-smarc: Drop hogging of GPIO pins
  pinctrl: renesas: rzg2l: Release all the virq's in free callback
  pinctrl: renesas: rzg2l: Reorder function call in rzg2l_gpio_free()
  pinctrl: renesas: rzg2l: Drop calling rzg2l_gpio_request()
  pinctrl: pinmux: Introduce API to check if a pin is requested
  pinctrl: renesas: pinctrl-rzg2l: Override
    irq_request/release_resources

 .../boot/dts/renesas/rzg3s-smarc-som.dtsi     |  18 ---
 arch/arm64/boot/dts/renesas/rzg3s-smarc.dtsi  |  21 ----
 drivers/pinctrl/pinmux.c                      |  14 +++
 drivers/pinctrl/pinmux.h                      |   6 +
 drivers/pinctrl/renesas/pinctrl-rzg2l.c       | 111 ++++++++++--------
 5 files changed, 79 insertions(+), 91 deletions(-)

-- 
2.43.0