diff mbox series

[v5,3/5] gpio: gpiolib: Allow free() callback to be overridden

Message ID 20220523174238.28942-4-prabhakar.mahadev-lad.rj@bp.renesas.com
State Superseded
Headers show
Series Renesas RZ/G2L IRQC support | expand

Commit Message

Prabhakar Mahadev Lad May 23, 2022, 5:42 p.m. UTC
Allow free() callback to be overridden from irq_domain_ops for
hierarchical chips.

This allows drivers to free up resources which are allocated during
child_to_parent_hwirq()/populate_parent_alloc_arg() callbacks.

On Renesas RZ/G2L platform a bitmap is maintained for TINT slots, a slot
is allocated in child_to_parent_hwirq() callback which is freed up in free
callback hence this override.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/gpio/gpiolib.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Comments

Linus Walleij May 24, 2022, 8:54 a.m. UTC | #1
On Mon, May 23, 2022 at 7:43 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:

> Allow free() callback to be overridden from irq_domain_ops for
> hierarchical chips.
>
> This allows drivers to free up resources which are allocated during
> child_to_parent_hwirq()/populate_parent_alloc_arg() callbacks.
>
> On Renesas RZ/G2L platform a bitmap is maintained for TINT slots, a slot
> is allocated in child_to_parent_hwirq() callback which is freed up in free
> callback hence this override.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

So that function today looks like this:

static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
{
        ops->activate = gpiochip_irq_domain_activate;
        ops->deactivate = gpiochip_irq_domain_deactivate;
        ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
        ops->free = irq_domain_free_irqs_common;

        /*
         * We only allow overriding the translate() function for
         * hierarchical chips, and this should only be done if the user
         * really need something other than 1:1 translation.
         */
        if (!ops->translate)
                ops->translate = gpiochip_hierarchy_irq_domain_translate;
}

(...)
-       ops->free = irq_domain_free_irqs_common;
(...)
> +       if (!ops->free)
> +               ops->free = irq_domain_free_irqs_common;

Marc Z is working on cleaning up the way that gpiolib is (ab)using
irqchips. We definitely need his ACK if we do things like this.
This doesn't look like one of the big offenders to me, but I want
to make sure we don't create new problems while Marc is trying
to solve the old ones.

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 690035124faa..8fcb9d23fea5 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1187,15 +1187,18 @@  static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
 	ops->activate = gpiochip_irq_domain_activate;
 	ops->deactivate = gpiochip_irq_domain_deactivate;
 	ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
-	ops->free = irq_domain_free_irqs_common;
 
 	/*
-	 * We only allow overriding the translate() function for
+	 * We only allow overriding the translate() and free() functions for
 	 * hierarchical chips, and this should only be done if the user
-	 * really need something other than 1:1 translation.
+	 * really need something other than 1:1 translation for translate()
+	 * callback and free if user wants to free up any resources which
+	 * were allocated during callbacks, for example populate_parent_alloc_arg.
 	 */
 	if (!ops->translate)
 		ops->translate = gpiochip_hierarchy_irq_domain_translate;
+	if (!ops->free)
+		ops->free = irq_domain_free_irqs_common;
 }
 
 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)