Commit e1d965ce authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Jonathan Cameron
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iio: dac: cio-dac: Cleanup indexing for DAC writes 



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: default avatarWilliam Breathitt Gray <william.gray@linaro.org>
Link: https://lore.kernel.org/r/d9dab6696af7eabb2d46f5cbc7871329f499c1c9.1657213745.git.william.gray@linaro.org


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 6cfd14c5

drivers/iio/dac/cio-dac.c

+5 −5
Original line number Diff line number Diff line
@@ -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);