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From: "Stefan Brüns" <stefan.bruens@rwth-aachen.de>
To: <linux-iio@vger.kernel.org>
Cc: "Rob Herring" <robh@kernel.org>,
	"Peter Meerwald-Stadler" <pmeerw@pmeerw.net>,
	"Stefan Brüns" <stefan.bruens@rwth-aachen.de>,
	linux-kernel@vger.kernel.org,
	"Manivannan Sadhasivam" <manivannanece23@gmail.com>,
	"Lars-Peter Clausen" <lars@metafoo.de>,
	"Jonathan Cameron" <jic23@kernel.org>,
	"Hartmut Knaack" <knaack.h@gmx.de>
Subject: [PATCH v3 2/4] iio: light: vl6180: Avoid readback of integration time register
Date: Sun, 24 Sep 2017 23:59:18 +0200	[thread overview]
Message-ID: <1d9dd709-84d1-4778-becb-2cda99032763@rwthex-w2-a.rwth-ad.de> (raw)
In-Reply-To: <20170924215920.7465-1-stefan.bruens@rwth-aachen.de>

Instead of reading the value from the register on each query, store the
set value.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

---

Changes in v3:
- Use IIO_VAL_FRACTIONAL for integration time return value

Changes in v2: None

 drivers/iio/light/vl6180.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/light/vl6180.c b/drivers/iio/light/vl6180.c
index 3b6351b89ce7..9b056c83a90a 100644
--- a/drivers/iio/light/vl6180.c
+++ b/drivers/iio/light/vl6180.c
@@ -86,6 +86,7 @@
 struct vl6180_data {
 	struct i2c_client *client;
 	struct mutex lock;
+	unsigned int als_it_ms;
 };
 
 enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX };
@@ -306,13 +307,11 @@ static int vl6180_read_raw(struct iio_dev *indio_dev,
 
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_INT_TIME:
-		ret = vl6180_read_word(data->client, VL6180_ALS_IT);
-		if (ret < 0)
-			return ret;
-		*val = 0; /* 1 count = 1ms (0 = 1ms) */
-		*val2 = (ret + 1) * 1000; /* convert to seconds */
+		*val = data->als_it_ms;
+		*val2 = 1000;
+
+		return IIO_VAL_FRACTIONAL;
 
-		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_LIGHT:
@@ -401,6 +400,9 @@ static int vl6180_set_it(struct vl6180_data *data, int val, int val2)
 
 	ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1);
 
+	if (ret >= 0)
+		data->als_it_ms = it_ms;
+
 fail:
 	vl6180_hold(data, false);
 	mutex_unlock(&data->lock);
@@ -471,6 +473,7 @@ static int vl6180_init(struct vl6180_data *data)
 		return ret;
 
 	/* ALS integration time: 100ms */
+	data->als_it_ms = 100;
 	ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100);
 	if (ret < 0)
 		return ret;
-- 
2.14.1

  parent reply	other threads:[~2017-09-24 22:00 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20170924215920.7465-1-stefan.bruens@rwth-aachen.de>
2017-09-24 21:59 ` [PATCH v3 1/4] iio: light: vl6180: Move range check to integration time setter, cleanup Stefan Brüns
2017-09-30 20:21   ` Jonathan Cameron
2017-09-24 21:59 ` Stefan Brüns [this message]
2017-09-30 20:23   ` [PATCH v3 2/4] iio: light: vl6180: Avoid readback of integration time register Jonathan Cameron
2017-09-24 21:59 ` [PATCH v3 3/4] iio: light: vl6180: Cleanup als_gain lookup, avoid register readback Stefan Brüns
2017-09-30 20:29   ` Jonathan Cameron
2017-09-24 21:59 ` [PATCH v3 4/4] iio: light: vl6180: Correct ALS scale for non-default gain/integration time Stefan Brüns
2017-09-30 20:31   ` Jonathan Cameron

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