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[85.148.52.161]) by smtp.gmail.com with ESMTPSA id n8sm7003659edb.5.2018.04.22.15.04.26 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 22 Apr 2018 15:04:27 -0700 (PDT) Date: Mon, 23 Apr 2018 00:04:24 +0200 From: David Veenstra To: jic23@kernel.org, lars@metafoo.de, pmeerw@pmeerw.net Cc: robh+dt@kernel.org, Michael.Hennerich@analog.com, knaack.h@gmx.de, linux-iio@vger.kernel.org, daniel.baluta@nxp.com, devel@driverdev.osuosl.org, devicetree@vger.kernel.org Subject: [PATCH v3 8/9] staging: iio: ad2s1200: Add scaling factor for angle channel Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A scaling factor of approximately 2 * Pi / (2^12 -1) is added, to scale the 12-bits angular position to radians. A return type of IIO_VAL_INT_PLUS_NANO is used, so that the scale of both the angle channel and angular velocity channel has 7 significant digits. Signed-off-by: David Veenstra --- Changes in v3: - A decimal approximation of the scale is used, instead of a fractional approximation. - Remove unneeded explanation of iio_convert_raw_to_processed. drivers/staging/iio/resolver/ad2s1200.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/staging/iio/resolver/ad2s1200.c b/drivers/staging/iio/resolver/ad2s1200.c index 3e1696e52c38..d2b62308b31d 100644 --- a/drivers/staging/iio/resolver/ad2s1200.c +++ b/drivers/staging/iio/resolver/ad2s1200.c @@ -60,6 +60,11 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev, switch (m) { case IIO_CHAN_INFO_SCALE: switch (chan->type) { + case IIO_ANGL: + /* 2 * Pi / (2^12 - 1) ~= 0.001534355 */ + *val = 0; + *val2 = 1534355; + return IIO_VAL_INT_PLUS_NANO; case IIO_ANGL_VEL: /* 2 * Pi ~= 6.283185 */ *val = 6; @@ -114,6 +119,7 @@ static const struct iio_chan_spec ad2s1200_channels[] = { .indexed = 1, .channel = 0, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), }, { .type = IIO_ANGL_VEL, .indexed = 1,