From: Renato Lui Geh <renatogeh@gmail.com>
Date: Sat, 16 Mar 2019 02:13:13 +0000 (-0300)
Subject: staging: iio: ad7780: add gain reading to ad778x
X-Git-Tag: v5.15~6451^2~149^2~55
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0149ba2d5b6d6799e6aeb1ae25773008745c1c5a;p=platform%2Fkernel%2Flinux-starfive.git

staging: iio: ad7780: add gain reading to ad778x

This patch adds a new functionality of reading gain values from the
ad778x chips. This value is stored in the chip's state struct and is
updated whenever a read or write call is performed on the driver.

Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---

diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
index 0968a69..abb30c1 100644
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -42,6 +42,8 @@
 #define AD7780_GAIN_MIDPOINT	64
 #define AD7780_FILTER_MIDPOINT	13350
 
+static const unsigned int ad778x_gain[2] = { 1, 128 };
+
 struct ad7780_chip_info {
 	struct iio_chan_spec	channel;
 	unsigned int		pattern_mask;
@@ -179,6 +181,9 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
 	    ((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
 		return -EIO;
 
+	if (chip_info->is_ad778x)
+		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
+
 	return 0;
 }