Commit a4e63554 authored by Alexander Stein's avatar Alexander Stein Committed by Linus Walleij
Browse files

gpio: mcp23s08: Add option to configure IRQ output polarity as active high 



Default is active low, but if property is specified in DT set INTPOL flag.

Signed-off-by: default avatarAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 0e9a5edf

Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt

+2 −0
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ Optional device specific properties: 
        occurred on. If it is not set, the interrupt are only generated for the

        bank they belong to.

        On devices with only one interrupt output this property is useless.

- microchip,irq-active-high: Sets the INTPOL flag in the IOCON register. This

        configures the IRQ output polarity as active high.



Example I2C (with interrupt):

gpiom1: gpio@20 {

drivers/gpio/gpio-mcp23s08.c

+23 −7
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ struct mcp23s08_ops { 


struct mcp23s08 {

	u8			addr;

	bool			irq_active_high;



	u16			cache[11];

	u16			irq_rise;
@@ -476,6 +477,7 @@ static int mcp23s08_irq_setup(struct mcp23s08 *mcp) 
{

	struct gpio_chip *chip = &mcp->chip;

	int err, irq, j;

	unsigned long irqflags = IRQF_ONESHOT | IRQF_SHARED;



	mutex_init(&mcp->irq_lock);
@@ -484,10 +486,13 @@ static int mcp23s08_irq_setup(struct mcp23s08 *mcp) 
	if (!mcp->irq_domain)

		return -ENODEV;



	if (mcp->irq_active_high)

		irqflags |= IRQF_TRIGGER_HIGH;

	else

		irqflags |= IRQF_TRIGGER_LOW;



	err = devm_request_threaded_irq(chip->dev, mcp->irq, NULL, mcp23s08_irq,

					IRQF_TRIGGER_LOW | IRQF_ONESHOT |

					IRQF_SHARED,

					dev_name(chip->dev), mcp);

					irqflags, dev_name(chip->dev), mcp);

	if (err != 0) {

		dev_err(chip->dev, "unable to request IRQ#%d: %d\n",

			mcp->irq, err);
@@ -589,6 +594,7 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, 


	mcp->data = data;

	mcp->addr = addr;

	mcp->irq_active_high = false;



	mcp->chip.direction_input = mcp23s08_direction_input;

	mcp->chip.get = mcp23s08_get;
@@ -648,14 +654,24 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, 
		goto fail;



	mcp->irq_controller = pdata->irq_controller;

	if (mcp->irq && mcp->irq_controller && (type == MCP_TYPE_017))

	if (mcp->irq && mcp->irq_controller) {

		mcp->irq_active_high = of_property_read_bool(mcp->chip.of_node,

				"microchip,irq-active-high");



		if (type == MCP_TYPE_017)

			mirror = pdata->mirror;

	}



	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror) {

	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror ||

	     mcp->irq_active_high) {

		/* mcp23s17 has IOCON twice, make sure they are in sync */

		status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));

		status |= IOCON_HAEN | (IOCON_HAEN << 8);

		if (mcp->irq_active_high)

			status |= IOCON_INTPOL | (IOCON_INTPOL << 8);

		else

			status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));



		if (mirror)

			status |= IOCON_MIRROR | (IOCON_MIRROR << 8);