[PATCH RFC 3/9] gpio: lpc18xx: Make irq_chip immutable

From: Peng Fan (OSS)
Date: Fri May 09 2025 - 00:48:02 EST


From: Peng Fan <peng.fan@xxxxxxx>

Kernel warns about mutable irq_chips:
"not an immutable chip, please consider fixing!"

Constify lpc18xx_gpio_pin_ic, flag the irq_chip as IRQCHIP_IMMUTABLE,
add the new helper functions, and call the appropriate gpiolib functions.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
drivers/gpio/gpio-lpc18xx.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-lpc18xx.c b/drivers/gpio/gpio-lpc18xx.c
index ae6182cce7234166fe94ab0c8d5e07c11bb71101..a2e316d9350b736e8bb89c17845d70cc74481d1b 100644
--- a/drivers/gpio/gpio-lpc18xx.c
+++ b/drivers/gpio/gpio-lpc18xx.c
@@ -42,6 +42,7 @@ struct lpc18xx_gpio_pin_ic {
void __iomem *base;
struct irq_domain *domain;
struct raw_spinlock lock;
+ struct gpio_chip *gpio;
};

struct lpc18xx_gpio_chip {
@@ -74,6 +75,7 @@ static void lpc18xx_gpio_pin_ic_mask(struct irq_data *d)
{
struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
u32 type = irqd_get_trigger_type(d);
+ irq_hw_number_t hwirq = irqd_to_hwirq(d);

raw_spin_lock(&ic->lock);

@@ -88,12 +90,17 @@ static void lpc18xx_gpio_pin_ic_mask(struct irq_data *d)
raw_spin_unlock(&ic->lock);

irq_chip_mask_parent(d);
+
+ gpiochip_disable_irq(ic->gpio, hwirq);
}

static void lpc18xx_gpio_pin_ic_unmask(struct irq_data *d)
{
struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
u32 type = irqd_get_trigger_type(d);
+ irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+ gpiochip_enable_irq(ic->gpio, hwirq);

raw_spin_lock(&ic->lock);

@@ -149,13 +156,14 @@ static int lpc18xx_gpio_pin_ic_set_type(struct irq_data *d, unsigned int type)
return 0;
}

-static struct irq_chip lpc18xx_gpio_pin_ic = {
+static const struct irq_chip lpc18xx_gpio_pin_ic = {
.name = "LPC18xx GPIO pin",
.irq_mask = lpc18xx_gpio_pin_ic_mask,
.irq_unmask = lpc18xx_gpio_pin_ic_unmask,
.irq_eoi = lpc18xx_gpio_pin_ic_eoi,
.irq_set_type = lpc18xx_gpio_pin_ic_set_type,
- .flags = IRQCHIP_SET_TYPE_MASKED,
+ .flags = IRQCHIP_IMMUTABLE | IRQCHIP_SET_TYPE_MASKED,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
};

static int lpc18xx_gpio_pin_ic_domain_alloc(struct irq_domain *domain,
@@ -249,6 +257,7 @@ static int lpc18xx_gpio_pin_ic_probe(struct lpc18xx_gpio_chip *gc)
goto free_iomap;
}

+ ic->gpio = &gc->gpio;
gc->pin_ic = ic;

return 0;

--
2.37.1