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Commit 7bf0d7f6 authored by Baolin Wang's avatar Baolin Wang Committed by Linus Walleij
Browse files

gpio: eic: Add edge trigger emulation for EIC 



The Spreadtrum debounce EIC and latch EIC can not support edge trigger,
but most GPIO users (like gpio-key driver) only use the edge trigger,
thus the EIC driver need add some support to emulate the edge trigger
to satisfy this requirement.

Signed-off-by: default avatarBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent df42a02d

drivers/gpio/gpio-eic-sprd.c

+73 −0
Original line number Diff line number Diff line
@@ -300,6 +300,7 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) 
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);

	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);

	u32 offset = irqd_to_hwirq(data);

	int state;



	switch (sprd_eic->type) {

	case SPRD_EIC_DEBOUNCE:
@@ -310,6 +311,17 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) 
		case IRQ_TYPE_LEVEL_LOW:

			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);

			break;

		case IRQ_TYPE_EDGE_RISING:

		case IRQ_TYPE_EDGE_FALLING:

		case IRQ_TYPE_EDGE_BOTH:

			state = sprd_eic_get(chip, offset);

			if (state)

				sprd_eic_update(chip, offset,

						SPRD_EIC_DBNC_IEV, 0);

			else

				sprd_eic_update(chip, offset,

						SPRD_EIC_DBNC_IEV, 1);

			break;

		default:

			return -ENOTSUPP;

		}
@@ -324,6 +336,17 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) 
		case IRQ_TYPE_LEVEL_LOW:

			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);

			break;

		case IRQ_TYPE_EDGE_RISING:

		case IRQ_TYPE_EDGE_FALLING:

		case IRQ_TYPE_EDGE_BOTH:

			state = sprd_eic_get(chip, offset);

			if (state)

				sprd_eic_update(chip, offset,

						SPRD_EIC_LATCH_INTPOL, 0);

			else

				sprd_eic_update(chip, offset,

						SPRD_EIC_LATCH_INTPOL, 1);

			break;

		default:

			return -ENOTSUPP;

		}
@@ -405,6 +428,55 @@ static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type) 
	return 0;

}



static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq,

				    unsigned int offset)

{

	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);

	struct irq_data *data = irq_get_irq_data(irq);

	u32 trigger = irqd_get_trigger_type(data);

	int state, post_state;



	/*

	 * The debounce EIC and latch EIC can only support level trigger, so we

	 * can toggle the level trigger to emulate the edge trigger.

	 */

	if ((sprd_eic->type != SPRD_EIC_DEBOUNCE &&

	     sprd_eic->type != SPRD_EIC_LATCH) ||

	    !(trigger & IRQ_TYPE_EDGE_BOTH))

		return;



	sprd_eic_irq_mask(data);

	state = sprd_eic_get(chip, offset);



retry:

	switch (sprd_eic->type) {

	case SPRD_EIC_DEBOUNCE:

		if (state)

			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);

		else

			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);

		break;

	case SPRD_EIC_LATCH:

		if (state)

			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);

		else

			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);

		break;

	default:

		sprd_eic_irq_unmask(data);

		return;

	}



	post_state = sprd_eic_get(chip, offset);

	if (state != post_state) {

		dev_warn(chip->parent, "EIC level was changed.\n");

		state = post_state;

		goto retry;

	}



	sprd_eic_irq_unmask(data);

}



static int sprd_eic_match_chip_by_type(struct gpio_chip *chip, void *data)

{

	enum sprd_eic_type type = *(enum sprd_eic_type *)data;
@@ -448,6 +520,7 @@ static void sprd_eic_handle_one_type(struct gpio_chip *chip) 
					bank * SPRD_EIC_PER_BANK_NR + n);



			generic_handle_irq(girq);

			sprd_eic_toggle_trigger(chip, girq, n);

		}

	}

}