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Message-Id: <20200416205428.437503-3-alexandre.belloni@bootlin.com>
Date: Thu, 16 Apr 2020 22:54:28 +0200
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: Hartmut Knaack <knaack.h@....de>,
Lars-Peter Clausen <lars@...afoo.de>,
Peter Meerwald-Stadler <pmeerw@...erw.net>,
Gregory CLEMENT <gregory.clement@...tlin.com>,
linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org,
Alexandre Belloni <alexandre.belloni@...tlin.com>
Subject: [PATCH v2 2/2] iio: adc: ti-ads8344: optimize consumption
Set the clock mode only once, at probe time and then keep the ADC powered
down between conversions.
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
---
drivers/iio/adc/ti-ads8344.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c
index abe4b56c847c..40e7a9eee189 100644
--- a/drivers/iio/adc/ti-ads8344.c
+++ b/drivers/iio/adc/ti-ads8344.c
@@ -72,7 +72,7 @@ static const struct iio_chan_spec ads8344_channels[] = {
};
static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
- bool differential)
+ bool differential, u8 clock)
{
struct spi_device *spi = adc->spi;
int ret;
@@ -81,7 +81,7 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
if (!differential)
adc->tx_buf |= ADS8344_SINGLE_END;
adc->tx_buf |= ADS8344_CHANNEL(channel);
- adc->tx_buf |= ADS8344_CLOCK_INTERNAL;
+ adc->tx_buf |= clock;
ret = spi_write(spi, &adc->tx_buf, 1);
if (ret)
@@ -106,7 +106,7 @@ static int ads8344_read_raw(struct iio_dev *iio,
case IIO_CHAN_INFO_RAW:
mutex_lock(&adc->lock);
*value = ads8344_adc_conversion(adc, channel->scan_index,
- channel->differential);
+ channel->differential, 0);
mutex_unlock(&adc->lock);
if (*value < 0)
return *value;
@@ -161,6 +161,11 @@ static int ads8344_probe(struct spi_device *spi)
if (ret)
return ret;
+ /* Do a dummy read and set external clock mode */
+ ret = ads8344_adc_conversion(adc, 0, 0, ADS8344_CLOCK_INTERNAL);
+ if (ret < 0)
+ return ret;
+
spi_set_drvdata(spi, indio_dev);
ret = iio_device_register(indio_dev);
--
2.25.2
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