linux-kernel - [PATCH 3/5] pinctrl: apple-gpio: Make the irqchip immutable

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Message-Id: <20220223154405.54912-4-maz@kernel.org>
Date:   Wed, 23 Feb 2022 15:44:03 +0000
From:   Marc Zyngier <maz@...nel.org>
To:     linux-kernel@...r.kernel.org
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Thierry Reding <thierry.reding@...il.com>,
        Joey Gouly <joey.gouly@....com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Hector Martin <marcan@...can.st>,
        Sven Peter <sven@...npeter.dev>,
        Alyssa Rosenzweig <alyssa@...enzweig.io>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Andy Gross <agross@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-gpio@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-arm-msm@...r.kernel.org, kernel-team@...roid.com
Subject: [PATCH 3/5] pinctrl: apple-gpio: Make the irqchip immutable

Prevent gpiolib from messing with the irqchip by advertising
the irq_chip structure as immutable, making it const, and adding
the various calls that gpiolib relies upon.

Signed-off-by: Marc Zyngier <maz@...nel.org>
---
 drivers/pinctrl/pinctrl-apple-gpio.c | 30 ++++++++++++++++------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-apple-gpio.c b/drivers/pinctrl/pinctrl-apple-gpio.c
index 72f4dd2466e1..0ab5cc10f885 100644
--- a/drivers/pinctrl/pinctrl-apple-gpio.c
+++ b/drivers/pinctrl/pinctrl-apple-gpio.c
@@ -36,7 +36,6 @@ struct apple_gpio_pinctrl {
 
 	struct pinctrl_desc pinctrl_desc;
 	struct gpio_chip gpio_chip;
-	struct irq_chip irq_chip;
 	u8 irqgrps[];
 };
 
@@ -275,17 +274,21 @@ static unsigned int apple_gpio_irq_type(unsigned int type)
 
 static void apple_gpio_irq_mask(struct irq_data *data)
 {
-	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data));
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc);
 
 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
 	                   FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF));
+	gpiochip_disable_irq(gc, data->hwirq);
 }
 
 static void apple_gpio_irq_unmask(struct irq_data *data)
 {
-	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data));
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+	struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc);
 	unsigned int irqtype = apple_gpio_irq_type(irqd_get_trigger_type(data));
 
+	gpiochip_enable_irq(gc, data->hwirq);
 	apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE,
 	                   FIELD_PREP(REG_GPIOx_MODE, irqtype));
 }
@@ -343,13 +346,16 @@ static void apple_gpio_irq_handler(struct irq_desc *desc)
 	chained_irq_exit(chip, desc);
 }
 
-static struct irq_chip apple_gpio_irqchip = {
-	.name		= "Apple-GPIO",
-	.irq_startup	= apple_gpio_irq_startup,
-	.irq_ack	= apple_gpio_irq_ack,
-	.irq_mask	= apple_gpio_irq_mask,
-	.irq_unmask	= apple_gpio_irq_unmask,
-	.irq_set_type	= apple_gpio_irq_set_type,
+static const struct irq_chip apple_gpio_irqchip = {
+	.name			= "Apple-GPIO",
+	.irq_request_resources	= gpiochip_irq_reqres,
+	.irq_release_resources	= gpiochip_irq_relres,
+	.irq_startup		= apple_gpio_irq_startup,
+	.irq_ack		= apple_gpio_irq_ack,
+	.irq_mask		= apple_gpio_irq_mask,
+	.irq_unmask		= apple_gpio_irq_unmask,
+	.irq_set_type		= apple_gpio_irq_set_type,
+	.flags			= IRQCHIP_IMMUTABLE,
 };
 
 /* Probe & register */
@@ -360,8 +366,6 @@ static int apple_gpio_register(struct apple_gpio_pinctrl *pctl)
 	void **irq_data = NULL;
 	int ret;
 
-	pctl->irq_chip = apple_gpio_irqchip;
-
 	pctl->gpio_chip.label = dev_name(pctl->dev);
 	pctl->gpio_chip.request = gpiochip_generic_request;
 	pctl->gpio_chip.free = gpiochip_generic_free;
@@ -377,7 +381,7 @@ static int apple_gpio_register(struct apple_gpio_pinctrl *pctl)
 	if (girq->num_parents) {
 		int i;
 
-		girq->chip = &pctl->irq_chip;
+		girq->chip = (struct irq_chip *)&apple_gpio_irqchip;
 		girq->parent_handler = apple_gpio_irq_handler;
 
 		girq->parents = kmalloc_array(girq->num_parents,
-- 
2.30.2