iio: hx711: fix bug in reset functionality

PATCH Superseded Andreas Klinger 1 participant 1 message Nov 28, 2017

Subsystems (2)

IIO Avia HX711 Analog digital converter IIO driver

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Andreas Klinger

author maintainer

2017-11-28 12:57 UTC #0 lore raw

PATCH 2/2 iio: hx711: fix bug in reset functionality

return value in hx711_reset() should indicate status of dout otherwise the calling function is reporting an error als false positive

wait up to 1 second until the device is in normal state;
by changing the channel on every trigger event it turned out that the former 100 ms are not enough for waiting until the device is in normal mode

Signed-off-by Andreas Klinger <[email protected]>

---
 drivers/iio/adc/hx711.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

drivers/iio/adc/hx711.c +6 -7

index d773fd69a76d..eabd2e66aca3 100644
@@ -153,15 +153,16 @@ static int hx711_wait_for_ready(struct hx711_data *hx711_data)
 	int i, val;
 
 	/*
-	 * a maximum reset cycle time of 56 ms was measured.
-	 * we round it up to 100 ms
+	 * in some rare cases the reset takes quite a long time
+	 * especially when the channel is changed.
+	 * Allow up to one second for it
 	 */
 	for (i = 0; i < 100; i++) {
 		val = gpiod_get_value(hx711_data->gpiod_dout);
 		if (!val)
 			break;
-		/* sleep at least 1 ms */
-		msleep(1);
+		/* sleep at least 10 ms */
+		msleep(10);
 	}
 	if (val)
 		return -EIO;

@@ -203,9 +204,7 @@ static int hx711_reset(struct hx711_data *hx711_data)
 		 * after a dummy read we need to wait vor readiness
 		 * for not mixing gain pulses with the clock
 		 */
-		ret = hx711_wait_for_ready(hx711_data);
-		if (ret)
-			return ret;
+		val = hx711_wait_for_ready(hx711_data);
 	}
 
 	return val;

Signature · 4 lines

2.1.4


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