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Commit 94e65519 authored by Richard Weinberger's avatar Richard Weinberger Committed by Jonathan Cameron
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iio: dht11: IRQ fixes 



Since setting irq-enabled GPIOs into output state is not supported
by all GPIO controllers, we need to disable the irq while requesting
sensor data. As side effect we lose a tiny bit of functionality:
Some wiring problems can't be concluded from log messages anymore.

Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarHarald Geyer <harald@ccbib.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 004bc530

drivers/iio/humidity/dht11.c

+35 −27
Original line number Original line Diff line number Diff line
@@ -40,8 +40,12 @@ 




#define DHT11_DATA_VALID_TIME	2000000000  /* 2s in ns */

#define DHT11_DATA_VALID_TIME	2000000000  /* 2s in ns */





#define DHT11_EDGES_PREAMBLE 4

#define DHT11_EDGES_PREAMBLE 2

#define DHT11_BITS_PER_READ 40

#define DHT11_BITS_PER_READ 40

/*

 * Note that when reading the sensor actually 84 edges are detected, but

 * since the last edge is not significant, we only store 83:

 */

#define DHT11_EDGES_PER_READ (2*DHT11_BITS_PER_READ + DHT11_EDGES_PREAMBLE + 1)

#define DHT11_EDGES_PER_READ (2*DHT11_BITS_PER_READ + DHT11_EDGES_PREAMBLE + 1)





/* Data transmission timing (nano seconds) */

/* Data transmission timing (nano seconds) */
@@ -140,6 +144,27 @@ static int dht11_decode(struct dht11 *dht11, int offset) 
	return 0;

	return 0;

}

}





/*

 * IRQ handler called on GPIO edges

 */

static irqreturn_t dht11_handle_irq(int irq, void *data)

{

	struct iio_dev *iio = data;

	struct dht11 *dht11 = iio_priv(iio);



	/* TODO: Consider making the handler safe for IRQ sharing */

	if (dht11->num_edges < DHT11_EDGES_PER_READ && dht11->num_edges >= 0) {

		dht11->edges[dht11->num_edges].ts = iio_get_time_ns();

		dht11->edges[dht11->num_edges++].value =

						gpio_get_value(dht11->gpio);



		if (dht11->num_edges >= DHT11_EDGES_PER_READ)

			complete(&dht11->completion);

	}



	return IRQ_HANDLED;

}



static int dht11_read_raw(struct iio_dev *iio_dev,

static int dht11_read_raw(struct iio_dev *iio_dev,

			const struct iio_chan_spec *chan,

			const struct iio_chan_spec *chan,

			int *val, int *val2, long m)

			int *val, int *val2, long m)
@@ -160,8 +185,17 @@ static int dht11_read_raw(struct iio_dev *iio_dev, 
		if (ret)

		if (ret)

			goto err;

			goto err;





		ret = request_irq(dht11->irq, dht11_handle_irq,

				  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,

				  iio_dev->name, iio_dev);

		if (ret)

			goto err;



		ret = wait_for_completion_killable_timeout(&dht11->completion,

		ret = wait_for_completion_killable_timeout(&dht11->completion,

								 HZ);

								 HZ);



		free_irq(dht11->irq, iio_dev);



		if (ret == 0 && dht11->num_edges < DHT11_EDGES_PER_READ - 1) {

		if (ret == 0 && dht11->num_edges < DHT11_EDGES_PER_READ - 1) {

			dev_err(&iio_dev->dev,

			dev_err(&iio_dev->dev,

					"Only %d signal edges detected\n",

					"Only %d signal edges detected\n",
@@ -197,27 +231,6 @@ static const struct iio_info dht11_iio_info = { 
	.read_raw		= dht11_read_raw,

	.read_raw		= dht11_read_raw,

};

};





/*

 * IRQ handler called on GPIO edges

*/

static irqreturn_t dht11_handle_irq(int irq, void *data)

{

	struct iio_dev *iio = data;

	struct dht11 *dht11 = iio_priv(iio);



	/* TODO: Consider making the handler safe for IRQ sharing */

	if (dht11->num_edges < DHT11_EDGES_PER_READ && dht11->num_edges >= 0) {

		dht11->edges[dht11->num_edges].ts = iio_get_time_ns();

		dht11->edges[dht11->num_edges++].value =

						gpio_get_value(dht11->gpio);



		if (dht11->num_edges >= DHT11_EDGES_PER_READ)

			complete(&dht11->completion);

	}



	return IRQ_HANDLED;

}



static const struct iio_chan_spec dht11_chan_spec[] = {

static const struct iio_chan_spec dht11_chan_spec[] = {

	{ .type = IIO_TEMP,

	{ .type = IIO_TEMP,

		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), },

		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), },
@@ -260,11 +273,6 @@ static int dht11_probe(struct platform_device *pdev) 
		dev_err(dev, "GPIO %d has no interrupt\n", dht11->gpio);

		dev_err(dev, "GPIO %d has no interrupt\n", dht11->gpio);

		return -EINVAL;

		return -EINVAL;

	}

	}

	ret = devm_request_irq(dev, dht11->irq, dht11_handle_irq,

				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,

				pdev->name, iio);

	if (ret)

		return ret;





	dht11->timestamp = iio_get_time_ns() - DHT11_DATA_VALID_TIME - 1;

	dht11->timestamp = iio_get_time_ns() - DHT11_DATA_VALID_TIME - 1;

	dht11->num_edges = -1;

	dht11->num_edges = -1;