* 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: Harald Geyer <harald@xxxxxxxxx>
---
drivers/iio/humidity/dht11.c | 40 ++++++++++++++++++++++++++++++++++------
1 file changed, 34 insertions(+), 6 deletions(-)
diff --git a/drivers/iio/humidity/dht11.c b/drivers/iio/humidity/dht11.c
index cd1477d..f0cb28c 100644
--- a/drivers/iio/humidity/dht11.c
+++ b/drivers/iio/humidity/dht11.c
@@ -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 ? 1 : 0;
}
@@ -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_real_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_real_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);
@@ -219,10 +244,13 @@ 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",
- dht11->num_edges);
+ dev_err(dht11->dev, "Only %d signal edges detected\n",
+ dht11->num_edges);
ret = -ETIMEDOUT;
}
if (ret < 0)
--
2.1.4
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