linux-iio.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 1/4] staging: iio: isl29018: add documentation about the infrared suppression
@ 2016-10-07  0:48 Brian Masney
  2016-10-07  0:48 ` [PATCH 2/4] staging: iio: isl29018: document device tree bindings Brian Masney
                   ` (3 more replies)
  0 siblings, 4 replies; 11+ messages in thread
From: Brian Masney @ 2016-10-07  0:48 UTC (permalink / raw)
  To: jic23; +Cc: gregkh, linux-iio, devel

Add documentation from the ISL29018 Data Sheet (FN6619.4, Oct 8, 2012)
about the infrared suppression that can be controlled
with the proximity_on_chip_ambient_infrared_suppression sysfs attribute.

Signed-off-by: Brian Masney <masneyb@onstation.org>
---
 drivers/staging/iio/light/isl29018.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/staging/iio/light/isl29018.c b/drivers/staging/iio/light/isl29018.c
index 51226bd..52bfb1cb 100644
--- a/drivers/staging/iio/light/isl29018.c
+++ b/drivers/staging/iio/light/isl29018.c
@@ -307,6 +307,24 @@ static ssize_t in_illuminance_integration_time_available_show
 	return len;
 }
 
+/*
+ * From ISL29018 Data Sheet (FN6619.4, Oct 8, 2012) regarding the
+ * infrared suppression:
+ *
+ *   Proximity Sensing Scheme: Bit 7. This bit programs the function
+ * of the proximity detection. Logic 0 of this bit, Scheme 0, makes
+ * full n (4, 8, 12, 16) bits (unsigned) proximity detection. The range
+ * of Scheme 0 proximity count is from 0 to 2^n. Logic 1 of this bit,
+ * Scheme 1, makes n-1 (3, 7, 11, 15) bits (2's complementary)
+ * proximity_less_ambient detection. The range of Scheme 1
+ * proximity count is from -2^(n-1) to 2^(n-1) . The sign bit is extended
+ * for resolutions less than 16. While Scheme 0 has wider dynamic
+ * range, Scheme 1 proximity detection is less affected by the
+ * ambient IR noise variation.
+ *
+ * 0 Sensing IR from LED and ambient
+ * 1 Sensing IR from LED with ambient IR rejection
+ */
 static ssize_t proximity_on_chip_ambient_infrared_suppression_show
 			(struct device *dev, struct device_attribute *attr,
 			 char *buf)
-- 
2.5.5

^ permalink raw reply related	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2016-10-09 10:39 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-10-07  0:48 [PATCH 1/4] staging: iio: isl29018: add documentation about the infrared suppression Brian Masney
2016-10-07  0:48 ` [PATCH 2/4] staging: iio: isl29018: document device tree bindings Brian Masney
2016-10-09  8:48   ` Jonathan Cameron
2016-10-07  0:48 ` [PATCH 3/4] staging: iio: isl29018: rename Kconfig variable to match existing light drivers in mainline Brian Masney
2016-10-09 10:33   ` Jonathan Cameron
2016-10-07  0:48 ` [PATCH 4/4] staging: iio: isl29018: move out of staging Brian Masney
2016-10-09  9:45   ` Jonathan Cameron
2016-10-09 10:35     ` Brian Masney
2016-10-09 10:39       ` Jonathan Cameron
2016-10-09  8:43 ` [PATCH 1/4] staging: iio: isl29018: add documentation about the infrared suppression Jonathan Cameron
2016-10-09  8:51   ` Jonathan Cameron

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).