[PATCH RFC 0/2] pinctrl: Add support gpiod_to_irq

[PATCH RFC 0/2] pinctrl: Add support gpiod_to_irq

[Xianwei Zhao via B4 Relay]

Some users need to obtain an IRQ directly from a GPIO descriptor through gpiod_to_irq().
Add the required DT binding and implementation to support this use case.
Since this introduces a new DT property, the property is kept optional to
maintain compatibility with existing SoCs and DTS files.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
Xianwei Zhao (2):
      dt-bindings: pinctl: amlogic,pinctrl-a4: Add gpio irq property
      pinctrl: meson: amlogic-a4: support gpiod_to_irq

 .../bindings/pinctrl/amlogic,pinctrl-a4.yaml       |  5 ++
 drivers/pinctrl/meson/pinctrl-amlogic-a4.c         | 54 ++++++++++++++++++++++
 2 files changed, 59 insertions(+)
---
base-commit: 4ca496f6285e16d91751e5c84c6010e03285528c
change-id: 20260520-gpio-to-irq-be4797d2a23f

Best regards,
-- 
Xianwei Zhao <xianwei.zhao@amlogic.com>

[PATCH RFC 1/2] dt-bindings: pinctl: amlogic,pinctrl-a4: Add gpio irq property

[Xianwei Zhao via B4 Relay]

From: Xianwei Zhao <xianwei.zhao@amlogic.com>

Add the hw-irq property for each GPIO bank and enable interrupt-parent
for pinctrl so that gpiod_to_irq() can translate GPIO lines to IRQs.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
 Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml b/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml
index b69db1b95345..65ec9121300e 100644
--- a/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml
@@ -37,6 +37,8 @@ properties:
 
   ranges: true
 
+  interrupt-parent: true
+
 patternProperties:
   "^gpio@[0-9a-f]+$":
     type: object
@@ -65,6 +67,9 @@ patternProperties:
       gpio-ranges:
         maxItems: 1
 
+      hw-irq:
+        $ref: /schemas/types.yaml#/definitions/uint32
+
     required:
       - reg
       - reg-names

-- 
2.52.0

Re: [PATCH RFC 1/2] dt-bindings: pinctl: amlogic,pinctrl-a4: Add gpio irq property

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] The newly added `hw-irq` property is not marked as required for the GPIO banks, and the example is not updated.
- [Medium] The custom device tree property `hw-irq` lacks a vendor prefix.
- [Low] The newly added `hw-irq` property lacks a description field.
--

commit 779e29b8c4c1e37224d568880fcfcc77220c1d72
Author: Xianwei Zhao <xianwei.zhao@amlogic.com>

dt-bindings: pinctl: amlogic,pinctrl-a4: Add gpio irq property

Add the hw-irq property for each GPIO bank and enable interrupt-parent
for pinctrl so that gpiod_to_irq() can translate GPIO lines to IRQs.

> diff --git a/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml b/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml
> --- a/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml
> +++ b/Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml

[ ... ]

> @@ -65,6 +67,9 @@ patternProperties:
>        gpio-ranges:
>          maxItems: 1
>  
> +      hw-irq:
> +        $ref: /schemas/types.yaml#/definitions/uint32

[Severity: Medium]
Should this custom property have a vendor prefix to prevent namespace
collisions, such as amlogic,hw-irq? 

[Severity: Low]
Would it be helpful to include a description field here to document the
purpose and semantic usage of this new property?

> +
>      required:
>        - reg
>        - reg-names

[Severity: Medium]
The commit message indicates this property is added for each GPIO bank.
Should hw-irq be included in this required list under the 
patternProperties:^gpio@[0-9a-f]+$ node to ensure incomplete configurations
fail schema validation?

Additionally, the example at the bottom of the file doesn't seem to include
this new property:

examples:
  ...
    gpio@4240 {
        reg = <0 0x4240 0 0x40>, <0 0x4000 0 0x8>;
        reg-names = "gpio", "mux";
        gpio-controller;
        #gpio-cells = <2>;
        gpio-ranges = <&periphs_pinctrl 0 8 10>;
    };

Does the example section need to be updated to demonstrate the usage of the
newly added property?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260611-gpio-to-irq-v1-0-12201716f23f@amlogic.com?part=1

[PATCH RFC 2/2] pinctrl: meson: amlogic-a4: support gpiod_to_irq

[Xianwei Zhao via B4 Relay]

From: Xianwei Zhao <xianwei.zhao@amlogic.com>

Add the to_irq() callback implementation so that
gpiod_to_irq() can map GPIO lines to IRQs correctly.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
 drivers/pinctrl/meson/pinctrl-amlogic-a4.c | 54 ++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
index 5ae0c19d007d..663681887f35 100644
--- a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
+++ b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
@@ -10,6 +10,7 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
@@ -97,6 +98,8 @@ struct aml_gpio_bank {
 	struct regmap			*reg_gpio;
 	struct regmap			*reg_ds;
 	const struct multi_mux		*p_mux;
+	struct device_node		*of_irq;
+	u32				irq_start;
 };
 
 struct aml_pinctrl {
@@ -836,6 +839,32 @@ static int aml_pctl_parse_functions(struct device_node *np,
 	return 0;
 }
 
+static struct device_node *aml_get_of_irq(struct device_node *np)
+{
+	struct device_node *of_irq;
+
+	of_irq = of_irq_find_parent(np);
+	if (of_irq && of_device_is_compatible(of_irq, "amlogic,meson-gpio-intc")) {
+		of_node_put(of_irq);
+		return of_irq;
+	}
+
+	if (of_irq)
+		of_node_put(of_irq);
+
+	return NULL;
+}
+
+static u32 aml_bank_irq(struct device_node *np)
+{
+	u32 hw_irq;
+
+	if (of_property_read_u32(np, "hw-irq", &hw_irq))
+		return U32_MAX;
+
+	return hw_irq;
+}
+
 static u32 aml_bank_pins(struct device_node *np)
 {
 	struct of_phandle_args of_args;
@@ -1003,6 +1032,27 @@ static int aml_gpio_get(struct gpio_chip *chip, unsigned int gpio)
 	return !!(val & BIT(bit));
 }
 
+static int aml_gpio_to_irq(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct aml_gpio_bank *bank = gpiochip_get_data(chip);
+	struct irq_fwspec fwspec;
+	int hwirq;
+
+	if (bank->irq_start == U32_MAX)
+		return -EINVAL;
+	if (!bank->of_irq)
+		return -EINVAL;
+
+	hwirq = gpio + bank->irq_start;
+
+	fwspec.fwnode = of_fwnode_handle(bank->of_irq);
+	fwspec.param_count = 2;
+	fwspec.param[0] = hwirq;
+	fwspec.param[1] = IRQ_TYPE_NONE;
+
+	return irq_create_fwspec_mapping(&fwspec);
+}
+
 static const struct gpio_chip aml_gpio_template = {
 	.request		= gpiochip_generic_request,
 	.free			= gpiochip_generic_free,
@@ -1012,6 +1062,7 @@ static const struct gpio_chip aml_gpio_template = {
 	.direction_input	= aml_gpio_direction_input,
 	.direction_output	= aml_gpio_direction_output,
 	.get_direction		= aml_gpio_get_direction,
+	.to_irq			= aml_gpio_to_irq,
 	.can_sleep		= true,
 };
 
@@ -1079,6 +1130,7 @@ static int aml_gpiolib_register_bank(struct aml_pinctrl *info,
 		bank->reg_ds = bank->reg_gpio;
 	}
 
+	bank->irq_start = aml_bank_irq(np);
 	bank->gpio_chip = aml_gpio_template;
 	bank->gpio_chip.base = -1;
 	bank->gpio_chip.ngpio = aml_bank_pins(np);
@@ -1154,6 +1206,8 @@ static int aml_pctl_probe_dt(struct platform_device *pdev,
 				pdesc->name = pin_names[j];
 				pdesc++;
 			}
+
+			info->banks[bank].of_irq = aml_get_of_irq(np);
 			bank++;
 		} else {
 			ret = aml_pctl_parse_functions(child, info,

-- 
2.52.0

Re: [PATCH RFC 2/2] pinctrl: meson: amlogic-a4: support gpiod_to_irq

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Premature `of_node_put()` in `aml_get_of_irq()` creates a dangling pointer, leading to a Use-After-Free.
--

commit 682e8ff8b51a310ddf41177d04828ab2fd8a5670
Author: Xianwei Zhao <xianwei.zhao@amlogic.com>

pinctrl: meson: amlogic-a4: support gpiod_to_irq

This patch adds the to_irq() callback implementation so that gpiod_to_irq()
can map GPIO lines to IRQs correctly.

> diff --git a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
> index 5ae0c19d007d7..663681887f35c 100644
> --- a/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
> +++ b/drivers/pinctrl/meson/pinctrl-amlogic-a4.c

[ ... ]

> @@ -836,6 +839,32 @@ static int aml_pctl_parse_functions(struct device_node *np,
>  	return 0;
>  }
>  
> +static struct device_node *aml_get_of_irq(struct device_node *np)
> +{
> +	struct device_node *of_irq;
> +
> +	of_irq = of_irq_find_parent(np);
> +	if (of_irq && of_device_is_compatible(of_irq, "amlogic,meson-gpio-intc")) {
> +		of_node_put(of_irq);
> +		return of_irq;

[Severity: High]
Does this premature of_node_put() call create a use-after-free risk?

of_irq_find_parent() returns a device node with an incremented reference
count. By calling of_node_put() before returning the pointer, the reference
is dropped while the pointer is still passed back and cached in bank->of_irq.

Later, aml_gpio_to_irq() dereferences this pointer:

    fwspec.fwnode = of_fwnode_handle(bank->of_irq);

If the device node is dynamically freed (for example, during Device Tree
overlay removal) between caching and use, this would lead to a
use-after-free. Should we retain the reference here until driver teardown
instead?

> +	}
> +
> +	if (of_irq)
> +		of_node_put(of_irq);
> +
> +	return NULL;
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260611-gpio-to-irq-v1-0-12201716f23f@amlogic.com?part=2