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Subject[PATCH v2 2/2] iio: dac: cio-dac: Cleanup indexing for DAC writes
Date
Simplify DAC write code by defining base member as u16 __iomem *; DAC
registers are 16-bit so this allows us to index each DAC channel
directly in a loop rather than calculating the offsets by multipling by
2 each time.

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
---
drivers/iio/dac/cio-dac.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/dac/cio-dac.c b/drivers/iio/dac/cio-dac.c
index 8080984dcb03..791dd999cf29 100644
--- a/drivers/iio/dac/cio-dac.c
+++ b/drivers/iio/dac/cio-dac.c
@@ -16,6 +16,7 @@
#include <linux/isa.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/types.h>

#define CIO_DAC_NUM_CHAN 16

@@ -37,11 +38,11 @@ MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses");
/**
* struct cio_dac_iio - IIO device private data structure
* @chan_out_states: channels' output states
- * @base: base port address of the IIO device
+ * @base: base memory address of the DAC device
*/
struct cio_dac_iio {
int chan_out_states[CIO_DAC_NUM_CHAN];
- void __iomem *base;
+ u16 __iomem *base;
};

static int cio_dac_read_raw(struct iio_dev *indio_dev,
@@ -61,7 +62,6 @@ static int cio_dac_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long mask)
{
struct cio_dac_iio *const priv = iio_priv(indio_dev);
- const unsigned int chan_addr_offset = 2 * chan->channel;

if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
@@ -71,7 +71,7 @@ static int cio_dac_write_raw(struct iio_dev *indio_dev,
return -EINVAL;

priv->chan_out_states[chan->channel] = val;
- iowrite16(val, priv->base + chan_addr_offset);
+ iowrite16(val, priv->base + chan->channel);

return 0;
}
@@ -117,7 +117,7 @@ static int cio_dac_probe(struct device *dev, unsigned int id)
indio_dev->name = dev_name(dev);

/* initialize DAC outputs to 0V */
- for (i = 0; i < 32; i += 2)
+ for (i = 0; i < CIO_DAC_NUM_CHAN; i++)
iowrite16(0, priv->base + i);

return devm_iio_device_register(dev, indio_dev);
--
2.36.1
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