Commit a8173820 authored by Maulik Shah's avatar Maulik Shah Committed by Linus Walleij
Browse files

gpio: gpiolib: Allow GPIO IRQs to lazy disable 



With 'commit 461c1a7d ("gpiolib: override irq_enable/disable")' gpiolib
overrides irqchip's irq_enable and irq_disable callbacks. If irq_disable
callback is implemented then genirq takes unlazy path to disable irq.

Underlying irqchip may not want to implement irq_disable callback to lazy
disable irq when client drivers invokes disable_irq(). By overriding
irq_disable callback, gpiolib ends up always unlazy disabling IRQ.

Allow gpiolib to lazy disable IRQs by overriding irq_disable callback only
if irqchip implemented irq_disable. In cases where irq_disable is not
implemented irq_mask is overridden. Similarly override irq_enable callback
only if irqchip implemented irq_enable otherwise irq_unmask is overridden.

Fixes: 461c1a7d ("gpiolib: override irq_enable/disable")
Signed-off-by: default avatarMaulik Shah <mkshah@codeaurora.org>
Tested-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/1590253873-11556-2-git-send-email-mkshah@codeaurora.org


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent a34d5e56

drivers/gpio/gpiolib.c

+36 −19
Original line number Diff line number Diff line
@@ -2471,32 +2471,37 @@ static void gpiochip_irq_relres(struct irq_data *d) 
	gpiochip_relres_irq(gc, d->hwirq);

}



static void gpiochip_irq_mask(struct irq_data *d)

{

	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);



	if (gc->irq.irq_mask)

		gc->irq.irq_mask(d);

	gpiochip_disable_irq(gc, d->hwirq);

}



static void gpiochip_irq_unmask(struct irq_data *d)

{

	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);



	gpiochip_enable_irq(gc, d->hwirq);

	if (gc->irq.irq_unmask)

		gc->irq.irq_unmask(d);

}



static void gpiochip_irq_enable(struct irq_data *d)

{

	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);



	gpiochip_enable_irq(gc, d->hwirq);

	if (gc->irq.irq_enable)

	gc->irq.irq_enable(d);

	else

		gc->irq.chip->irq_unmask(d);

}



static void gpiochip_irq_disable(struct irq_data *d)

{

	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);



	/*

	 * Since we override .irq_disable() we need to mimic the

	 * behaviour of __irq_disable() in irq/chip.c.

	 * First call .irq_disable() if it exists, else mimic the

	 * behaviour of mask_irq() which calls .irq_mask() if

	 * it exists.

	 */

	if (gc->irq.irq_disable)

	gc->irq.irq_disable(d);

	else if (gc->irq.chip->irq_mask)

		gc->irq.chip->irq_mask(d);

	gpiochip_disable_irq(gc, d->hwirq);

}
@@ -2521,10 +2526,22 @@ static void gpiochip_set_irq_hooks(struct gpio_chip *gc) 
			  "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");

		return;

	}

	gc->irq.irq_enable = irqchip->irq_enable;



	if (irqchip->irq_disable) {

		gc->irq.irq_disable = irqchip->irq_disable;

	irqchip->irq_enable = gpiochip_irq_enable;

		irqchip->irq_disable = gpiochip_irq_disable;

	} else {

		gc->irq.irq_mask = irqchip->irq_mask;

		irqchip->irq_mask = gpiochip_irq_mask;

	}



	if (irqchip->irq_enable) {

		gc->irq.irq_enable = irqchip->irq_enable;

		irqchip->irq_enable = gpiochip_irq_enable;

	} else {

		gc->irq.irq_unmask = irqchip->irq_unmask;

		irqchip->irq_unmask = gpiochip_irq_unmask;

	}

}



/**

include/linux/gpio/driver.h

+13 −0
Original line number Diff line number Diff line
@@ -253,6 +253,19 @@ struct gpio_irq_chip { 
	 * Store old irq_chip irq_disable callback

	 */

	void		(*irq_disable)(struct irq_data *data);

	/**

	 * @irq_unmask:

	 *

	 * Store old irq_chip irq_unmask callback

	 */

	void		(*irq_unmask)(struct irq_data *data);



	/**

	 * @irq_mask:

	 *

	 * Store old irq_chip irq_mask callback

	 */

	void		(*irq_mask)(struct irq_data *data);

};



/**

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