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Commit ab4b6496 authored by Harald Geyer's avatar Harald Geyer Committed by Jonathan Cameron
Browse files

iio: dht11: Improve logging 



* Unify log messages
* Add more DEBUG messages

Apparently this driver is working unreliably on some platforms that I can't
test. Therefore I want an easy way for bug reporters to provide useful
information without making the driver too chatty by default.

Signed-off-by: default avatarHarald Geyer <harald@ccbib.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent ff5c37e3

drivers/iio/humidity/dht11.c

+34 −6
Original line number Diff line number Diff line
@@ -96,6 +96,24 @@ struct dht11 { 
	struct {s64 ts; int value; }	edges[DHT11_EDGES_PER_READ];

};



#ifdef CONFIG_DYNAMIC_DEBUG

/*

 * dht11_edges_print: show the data as actually received by the

 *                    driver.

 */

static void dht11_edges_print(struct dht11 *dht11)

{

	int i;



	dev_dbg(dht11->dev, "%d edges detected:\n", dht11->num_edges);

	for (i = 1; i < dht11->num_edges; ++i) {

		dev_dbg(dht11->dev, "%d: %lld ns %s\n", i,

			dht11->edges[i].ts - dht11->edges[i - 1].ts,

			dht11->edges[i - 1].value ? "high" : "low");

	}

}

#endif /* CONFIG_DYNAMIC_DEBUG */



static unsigned char dht11_decode_byte(char *bits)

{

	unsigned char ret = 0;
@@ -119,8 +137,12 @@ static int dht11_decode(struct dht11 *dht11, int offset) 
	for (i = 0; i < DHT11_BITS_PER_READ; ++i) {

		t = dht11->edges[offset + 2 * i + 2].ts -

			dht11->edges[offset + 2 * i + 1].ts;

		if (!dht11->edges[offset + 2 * i + 1].value)

			return -EIO;  /* lost synchronisation */

		if (!dht11->edges[offset + 2 * i + 1].value) {

			dev_dbg(dht11->dev,

				"lost synchronisation at edge %d\n",

				offset + 2 * i + 1);

			return -EIO;

		}

		bits[i] = t > DHT11_THRESHOLD;

	}
@@ -130,8 +152,10 @@ static int dht11_decode(struct dht11 *dht11, int offset) 
	temp_dec = dht11_decode_byte(&bits[24]);

	checksum = dht11_decode_byte(&bits[32]);



	if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum)

	if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum) {

		dev_dbg(dht11->dev, "invalid checksum\n");

		return -EIO;

	}



	dht11->timestamp = ktime_get_boot_ns();

	if (hum_int < 20) {  /* DHT22 */
@@ -182,6 +206,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev, 
	mutex_lock(&dht11->lock);

	if (dht11->timestamp + DHT11_DATA_VALID_TIME < ktime_get_boot_ns()) {

		timeres = ktime_get_resolution_ns();

		dev_dbg(dht11->dev, "current timeresolution: %dns\n", timeres);

		if (timeres > DHT11_MIN_TIMERES) {

			dev_err(dht11->dev, "timeresolution %dns too low\n",

				timeres);
@@ -219,9 +244,12 @@ static int dht11_read_raw(struct iio_dev *iio_dev, 


		free_irq(dht11->irq, iio_dev);



#ifdef CONFIG_DYNAMIC_DEBUG

		dht11_edges_print(dht11);

#endif



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

			dev_err(&iio_dev->dev,

				"Only %d signal edges detected\n",

			dev_err(dht11->dev, "Only %d signal edges detected\n",

				dht11->num_edges);

			ret = -ETIMEDOUT;

		}