Re: [PATCH v7 0/4] riscv: spacemit: add gpio support for K1 SoC

[Yixun Lan <dlan@gentoo.org>]

Hi Linus Walleij:

On 11:24 Wed 26 Feb     , Linus Walleij wrote:
> On Wed, Feb 26, 2025 at 2:01 AM Yixun Lan <dlan@gentoo.org> wrote:
> 
> > Current this v7 version work great with request irq from gpio, like:
> >         pin = devm_gpiod_get_optional(dev, "myirq", GPIOD_IN);
> >         irq = gpiod_to_irq(pin);
> >         devm_request_threaded_irq(dev, irq, ..)
> >
> > but have problem if request irq via of_irq_get(), something like this:
> > DT part
> >         mytst {
> >                 ..
> >                 interrupt-parent = <&gpio>;
> >                 interrupts = <1 28 IRQ_TYPE_EDGE_RISING>;
> >                 interrupt-names = "wakeup";
> >         }
> >
> > In source code
> >         irq = of_irq_get_byname(dev->of_node, "wakeup");
> >
> > I've made an attempt to patch gpiolib to support three cells "interrupts"
> > syntax, but still fail, it always get last gpio irqchip of four, thus using
> > the wrong pin (e.g: will always get 3 from gpiochips 0, 1, 2, 3)
> 
> Right, we need a proper patch to fix this.
> 
> Can you paste your patch so I can see if I can spot/fix
> the problem?
> 
> I think the irq cell parser needs to call out to
> of_node_instance_match() - or similar - as well.
do you have any suggestion where to implement this similar function?

I actually miss this logic, the patch here only support parsing
interrupts with 3 cells

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 679ed764cb14..9aa88c3fa485 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1454,6 +1454,10 @@ static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
 		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
 	}
 
+	if (is_of_node(fwspec->fwnode) && fwspec->param_count == 3) {
+		return irq_domain_translate_threecell(d, fwspec, hwirq, type);
+	}
+
 	/* This is for board files and others not using DT */
 	if (is_fwnode_irqchip(fwspec->fwnode)) {
 		int ret;
@@ -1758,7 +1762,8 @@ static const struct irq_domain_ops gpiochip_domain_ops = {
 	.map	= gpiochip_irq_map,
 	.unmap	= gpiochip_irq_unmap,
 	/* Virtually all GPIO irqchips are twocell:ed */
-	.xlate	= irq_domain_xlate_twocell,
+	/* FIXME: force switch to three cells */
+	.xlate	= irq_domain_xlate_threecell,
 };
 
 static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index e432b6a12a32..69a9540ec253 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -568,10 +568,18 @@ int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
 int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
 			const u32 *intspec, unsigned int intsize,
 			irq_hw_number_t *out_hwirq, unsigned int *out_type);
+int irq_domain_xlate_threecell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
 int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
 			const u32 *intspec, unsigned int intsize,
 			irq_hw_number_t *out_hwirq, unsigned int *out_type);
 
+int irq_domain_translate_threecell(struct irq_domain *d,
+				 struct irq_fwspec *fwspec,
+				 unsigned long *out_hwirq,
+				 unsigned int *out_type);
+
 int irq_domain_translate_twocell(struct irq_domain *d,
 				 struct irq_fwspec *fwspec,
 				 unsigned long *out_hwirq,
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index ec6d8e72d980..995e5e0ec2db 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1132,6 +1132,17 @@ int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
 }
 EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);
 
+int irq_domain_xlate_threecell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type)
+{
+	struct irq_fwspec fwspec;
+
+	of_phandle_args_to_fwspec(ctrlr, intspec, intsize, &fwspec);
+	return irq_domain_translate_threecell(d, &fwspec, out_hwirq, out_type);
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_threecell);
+
 /**
  * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
  * @d:		Interrupt domain involved in the translation
@@ -1216,6 +1227,19 @@ int irq_domain_translate_twocell(struct irq_domain *d,
 }
 EXPORT_SYMBOL_GPL(irq_domain_translate_twocell);
 
+int irq_domain_translate_threecell(struct irq_domain *d,
+				 struct irq_fwspec *fwspec,
+				 unsigned long *out_hwirq,
+				 unsigned int *out_type)
+{
+	if (WARN_ON(fwspec->param_count < 3))
+		return -EINVAL;
+	*out_hwirq = fwspec->param[1];
+	*out_type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_translate_threecell);
+
 int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
 			   int node, const struct irq_affinity_desc *affinity)
 {

-- 
Yixun Lan (dlan)
Gentoo Linux Developer
GPG Key ID AABEFD55