Commit 417b0f8d authored by Potin Lai's avatar Potin Lai Committed by Bartosz Golaszewski
Browse files

gpio: pca953x: Add support for level-triggered interrupts 



Adds support for level-triggered interrupts in the PCA953x GPIO
expander driver. Previously, the driver only supported edge-triggered
interrupts, which could lead to missed events in scenarios where an
interrupt condition persists until it is explicitly cleared.

By enabling level-triggered interrupts, the driver can now detect and
respond to sustained interrupt conditions more reliably.

Signed-off-by: default avatarPotin Lai <potin.lai.pt@gmail.com>
Link: https://lore.kernel.org/r/20250409-gpio-pca953x-level-triggered-irq-v3-1-7f184d814934@gmail.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 73dc041f

drivers/gpio/gpio-pca953x.c

+27 −5
Original line number Diff line number Diff line
@@ -215,6 +215,8 @@ struct pca953x_chip { 
	DECLARE_BITMAP(irq_stat, MAX_LINE);

	DECLARE_BITMAP(irq_trig_raise, MAX_LINE);

	DECLARE_BITMAP(irq_trig_fall, MAX_LINE);

	DECLARE_BITMAP(irq_trig_level_high, MAX_LINE);

	DECLARE_BITMAP(irq_trig_level_low, MAX_LINE);

#endif

	atomic_t wakeup_path;
@@ -774,6 +776,8 @@ static void pca953x_irq_bus_sync_unlock(struct irq_data *d) 
	pca953x_read_regs(chip, chip->regs->direction, reg_direction);



	bitmap_or(irq_mask, chip->irq_trig_fall, chip->irq_trig_raise, gc->ngpio);

	bitmap_or(irq_mask, irq_mask, chip->irq_trig_level_high, gc->ngpio);

	bitmap_or(irq_mask, irq_mask, chip->irq_trig_level_low, gc->ngpio);

	bitmap_complement(reg_direction, reg_direction, gc->ngpio);

	bitmap_and(irq_mask, irq_mask, reg_direction, gc->ngpio);
@@ -791,13 +795,15 @@ static int pca953x_irq_set_type(struct irq_data *d, unsigned int type) 
	struct device *dev = &chip->client->dev;

	irq_hw_number_t hwirq = irqd_to_hwirq(d);



	if (!(type & IRQ_TYPE_EDGE_BOTH)) {

	if (!(type & IRQ_TYPE_SENSE_MASK)) {

		dev_err(dev, "irq %d: unsupported type %d\n", d->irq, type);

		return -EINVAL;

	}



	assign_bit(hwirq, chip->irq_trig_fall, type & IRQ_TYPE_EDGE_FALLING);

	assign_bit(hwirq, chip->irq_trig_raise, type & IRQ_TYPE_EDGE_RISING);

	assign_bit(hwirq, chip->irq_trig_level_low, type & IRQ_TYPE_LEVEL_LOW);

	assign_bit(hwirq, chip->irq_trig_level_high, type & IRQ_TYPE_LEVEL_HIGH);



	return 0;

}
@@ -810,6 +816,8 @@ static void pca953x_irq_shutdown(struct irq_data *d) 


	clear_bit(hwirq, chip->irq_trig_raise);

	clear_bit(hwirq, chip->irq_trig_fall);

	clear_bit(hwirq, chip->irq_trig_level_low);

	clear_bit(hwirq, chip->irq_trig_level_high);

}



static void pca953x_irq_print_chip(struct irq_data *data, struct seq_file *p)
@@ -840,6 +848,7 @@ static bool pca953x_irq_pending(struct pca953x_chip *chip, unsigned long *pendin 
	DECLARE_BITMAP(cur_stat, MAX_LINE);

	DECLARE_BITMAP(new_stat, MAX_LINE);

	DECLARE_BITMAP(trigger, MAX_LINE);

	DECLARE_BITMAP(edges, MAX_LINE);

	int ret;



	ret = pca953x_read_regs(chip, chip->regs->input, cur_stat);
@@ -857,13 +866,26 @@ static bool pca953x_irq_pending(struct pca953x_chip *chip, unsigned long *pendin 


	bitmap_copy(chip->irq_stat, new_stat, gc->ngpio);



	if (bitmap_empty(chip->irq_trig_level_high, gc->ngpio) &&

	    bitmap_empty(chip->irq_trig_level_low, gc->ngpio)) {

		if (bitmap_empty(trigger, gc->ngpio))

			return false;

	}



	bitmap_and(cur_stat, chip->irq_trig_fall, old_stat, gc->ngpio);

	bitmap_and(old_stat, chip->irq_trig_raise, new_stat, gc->ngpio);

	bitmap_or(new_stat, old_stat, cur_stat, gc->ngpio);

	bitmap_and(pending, new_stat, trigger, gc->ngpio);

	bitmap_or(edges, old_stat, cur_stat, gc->ngpio);

	bitmap_and(pending, edges, trigger, gc->ngpio);



	bitmap_and(cur_stat, new_stat, chip->irq_trig_level_high, gc->ngpio);

	bitmap_and(cur_stat, cur_stat, chip->irq_mask, gc->ngpio);

	bitmap_or(pending, pending, cur_stat, gc->ngpio);



	bitmap_complement(cur_stat, new_stat, gc->ngpio);

	bitmap_and(cur_stat, cur_stat, reg_direction, gc->ngpio);

	bitmap_and(old_stat, cur_stat, chip->irq_trig_level_low, gc->ngpio);

	bitmap_and(old_stat, old_stat, chip->irq_mask, gc->ngpio);

	bitmap_or(pending, pending, old_stat, gc->ngpio);



	return !bitmap_empty(pending, gc->ngpio);

}