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From:   Hui Liu <hui.liu@mediatek.com>
To:     <robh+dt@kernel.org>, <jic23@kernel.org>, <lars@metafoo.de>,
        <pmeerw@pmeerw.net>
CC:     <srv_heupstream@mediatek.com>, <hui.liu@mediatek.com>,
        <zhiyong.tao@mediatek.com>, <chun-hung.wu@mediatek.com>,
        <yingjoe.chen@mediatek.com>, <seiya.wang@mediatek.com>,
        <ben.tseng@mediatek.com>, <matthias.bgg@gmail.com>,
        <s.hauer@pengutronix.de>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-iio@vger.kernel.org>, <linux-mediatek@lists.infradead.org>
Subject: [PATCH v2 1/1] iio: mtk-auxadc: update case IIO_CHAN_INFO_PROCESSED
Date:   Tue, 31 Aug 2021 13:42:07 +0800
Message-ID: <20210831054207.13236-2-hui.liu@mediatek.com>
In-Reply-To: <20210831054207.13236-1-hui.liu@mediatek.com>
References: <20210831054207.13236-1-hui.liu@mediatek.com>
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Convert raw data to processed data, the processed data is input voltage.

Signed-off-by: Hui Liu <hui.liu@mediatek.com>
---
 drivers/iio/adc/mt6577_auxadc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c
index 79c1dd68b909..d4fccd52ef08 100644
--- a/drivers/iio/adc/mt6577_auxadc.c
+++ b/drivers/iio/adc/mt6577_auxadc.c
@@ -82,6 +82,10 @@ static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
 	MT6577_AUXADC_CHANNEL(15),
 };
 
+/* For Voltage calculation */
+#define VOLTAGE_FULL_RANGE  1500	/* VA voltage */
+#define AUXADC_PRECISE      4096	/* 12 bits */
+
 static int mt_auxadc_get_cali_data(int rawdata, bool enable_cali)
 {
 	return rawdata;
@@ -191,6 +195,10 @@ static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
 		}
 		if (adc_dev->dev_comp->sample_data_cali)
 			*val = mt_auxadc_get_cali_data(*val, true);
+
+		/* Convert adc raw data to voltage: 0 - 1500 mV */
+		*val = *val * VOLTAGE_FULL_RANGE / AUXADC_PRECISE;
+
 		return IIO_VAL_INT;
 
 	default:
-- 
2.18.0