linux-kernel - [PATCH AUTOSEL 5.10 3/7] gpio: ixp4xx: Make irqchip immutable

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Date:   Wed, 21 Sep 2022 11:54:21 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Marc Zyngier <maz@...nel.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Sasha Levin <sashal@...nel.org>, linusw@...nel.org,
        kaloz@...nwrt.org, khalasa@...p.pl,
        linux-arm-kernel@...ts.infradead.org, linux-gpio@...r.kernel.org
Subject: [PATCH AUTOSEL 5.10 3/7] gpio: ixp4xx: Make irqchip immutable

From: Linus Walleij <linus.walleij@...aro.org>

[ Upstream commit 94e9bc73d85aa6ecfe249e985ff57abe0ab35f34 ]

This turns the IXP4xx GPIO irqchip into an immutable
irqchip, a bit different from the standard template due
to being hierarchical.

Tested on the IXP4xx which uses drivers/ata/pata_ixp4xx_cf.c
for a rootfs on compact flash with IRQs from this GPIO
block to the CF ATA controller.

Cc: Marc Zyngier <maz@...nel.org>
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
Acked-by: Marc Zyngier <maz@...nel.org>
Signed-off-by: Bartosz Golaszewski <brgl@...ev.pl>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpio/gpio-ixp4xx.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-ixp4xx.c b/drivers/gpio/gpio-ixp4xx.c
index b3b050604e0b..6bd047e2ca46 100644
--- a/drivers/gpio/gpio-ixp4xx.c
+++ b/drivers/gpio/gpio-ixp4xx.c
@@ -67,6 +67,14 @@ static void ixp4xx_gpio_irq_ack(struct irq_data *d)
 	__raw_writel(BIT(d->hwirq), g->base + IXP4XX_REG_GPIS);
 }
 
+static void ixp4xx_gpio_mask_irq(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+	irq_chip_mask_parent(d);
+	gpiochip_disable_irq(gc, d->hwirq);
+}
+
 static void ixp4xx_gpio_irq_unmask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
@@ -76,6 +84,7 @@ static void ixp4xx_gpio_irq_unmask(struct irq_data *d)
 	if (!(g->irq_edge & BIT(d->hwirq)))
 		ixp4xx_gpio_irq_ack(d);
 
+	gpiochip_enable_irq(gc, d->hwirq);
 	irq_chip_unmask_parent(d);
 }
 
@@ -153,12 +162,14 @@ static int ixp4xx_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
 }
 
-static struct irq_chip ixp4xx_gpio_irqchip = {
+static const struct irq_chip ixp4xx_gpio_irqchip = {
 	.name = "IXP4GPIO",
 	.irq_ack = ixp4xx_gpio_irq_ack,
-	.irq_mask = irq_chip_mask_parent,
+	.irq_mask = ixp4xx_gpio_mask_irq,
 	.irq_unmask = ixp4xx_gpio_irq_unmask,
 	.irq_set_type = ixp4xx_gpio_irq_set_type,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };
 
 static int ixp4xx_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
@@ -282,7 +293,7 @@ static int ixp4xx_gpio_probe(struct platform_device *pdev)
 	g->gc.owner = THIS_MODULE;
 
 	girq = &g->gc.irq;
-	girq->chip = &ixp4xx_gpio_irqchip;
+	gpio_irq_chip_set_chip(girq, &ixp4xx_gpio_irqchip);
 	girq->fwnode = g->fwnode;
 	girq->parent_domain = parent;
 	girq->child_to_parent_hwirq = ixp4xx_gpio_child_to_parent_hwirq;
-- 
2.35.1