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Commit af836d9a authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Greg Kroah-Hartman
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staging:iio:dac:ad5446: Fix 24bit transfers 



We currently only write 16 bit in case where we should write 24 bit. The spi message
length is calculated from the channel storage_size, but since the storage size
is only 16 bit we end up with the wrong value for devices which have power down
bits and thus a register with 24 bit. Since each store function knows how many
bytes it has to write just use the spi_write function from there instead of
going through the hassle of manually preparing a spi_message and keeping buffers
in the state struct.

Another advantage of this patch is that it will make implementing support for
similar I2C based DACs much easier.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Acked-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5ff6a99d

drivers/staging/iio/dac/ad5446.c

+25 −27
Original line number Diff line number Diff line
@@ -24,31 +24,40 @@ 


#include "ad5446.h"



static void ad5446_store_sample(struct ad5446_state *st, unsigned val)

static int ad5446_store_sample(struct ad5446_state *st, unsigned val)

{

	st->data.d16 = cpu_to_be16(val);

	__be16 data = cpu_to_be16(val);

	return spi_write(st->spi, &data, sizeof(data));

}



static void ad5660_store_sample(struct ad5446_state *st, unsigned val)

static int ad5660_store_sample(struct ad5446_state *st, unsigned val)

{

	uint8_t data[3];



	val |= AD5660_LOAD;

	st->data.d24[0] = (val >> 16) & 0xFF;

	st->data.d24[1] = (val >> 8) & 0xFF;

	st->data.d24[2] = val & 0xFF;

	data[0] = (val >> 16) & 0xFF;

	data[1] = (val >> 8) & 0xFF;

	data[2] = val & 0xFF;



	return spi_write(st->spi, data, sizeof(data));

}



static void ad5620_store_pwr_down(struct ad5446_state *st, unsigned mode)

static int ad5620_store_pwr_down(struct ad5446_state *st, unsigned mode)

{

	st->data.d16 = cpu_to_be16(mode << 14);

	__be16 data = cpu_to_be16(mode << 14);

	return spi_write(st->spi, &data, sizeof(data));

}



static void ad5660_store_pwr_down(struct ad5446_state *st, unsigned mode)

static int ad5660_store_pwr_down(struct ad5446_state *st, unsigned mode)

{

	unsigned val = mode << 16;

	uint8_t data[3];



	st->data.d24[0] = (val >> 16) & 0xFF;

	st->data.d24[1] = (val >> 8) & 0xFF;

	st->data.d24[2] = val & 0xFF;

	data[0] = (val >> 16) & 0xFF;

	data[1] = (val >> 8) & 0xFF;

	data[2] = val & 0xFF;



	return spi_write(st->spi, data, sizeof(data));

}



static ssize_t ad5446_write_powerdown_mode(struct device *dev,
@@ -111,11 +120,10 @@ static ssize_t ad5446_write_dac_powerdown(struct device *dev, 
	st->pwr_down = readin;



	if (st->pwr_down)

		st->chip_info->store_pwr_down(st, st->pwr_down_mode);

		ret = st->chip_info->store_pwr_down(st, st->pwr_down_mode);

	else

		st->chip_info->store_sample(st, st->cached_val);

		ret = st->chip_info->store_sample(st, st->cached_val);



	ret = spi_sync(st->spi, &st->msg);

	mutex_unlock(&indio_dev->mlock);



	return ret ? ret : len;
@@ -272,10 +280,8 @@ static int ad5446_write_raw(struct iio_dev *indio_dev, 
		val <<= chan->scan_type.shift;

		mutex_lock(&indio_dev->mlock);

		st->cached_val = val;

		if (!st->pwr_down) {

			st->chip_info->store_sample(st, val);

			ret = spi_sync(st->spi, &st->msg);

		}

		if (!st->pwr_down)

			ret = st->chip_info->store_sample(st, val);

		mutex_unlock(&indio_dev->mlock);

		break;

	default:
@@ -338,14 +344,6 @@ static int __devinit ad5446_probe(struct spi_device *spi) 
	indio_dev->channels = &st->chip_info->channel;

	indio_dev->num_channels = 1;



	/* Setup default message */



	st->xfer.tx_buf = &st->data;

	st->xfer.len = st->chip_info->channel.scan_type.storagebits / 8;



	spi_message_init(&st->msg);

	spi_message_add_tail(&st->xfer, &st->msg);



	switch (spi_get_device_id(spi)->driver_data) {

	case ID_AD5620_2500:

	case ID_AD5620_1250:

drivers/staging/iio/dac/ad5446.h

+2 −11
Original line number Diff line number Diff line
@@ -36,9 +36,6 @@ 
 * @reg:		supply regulator

 * @poll_work:		bottom half of polling interrupt handler

 * @vref_mv:		actual reference voltage used

 * @xfer:		default spi transfer

 * @msg:		default spi message

 * @data:		spi transmit buffer

 */



struct ad5446_state {
@@ -50,12 +47,6 @@ struct ad5446_state { 
	unsigned			cached_val;

	unsigned			pwr_down_mode;

	unsigned			pwr_down;

	struct spi_transfer		xfer;

	struct spi_message		msg;

	union {

		unsigned short		d16;

		unsigned char		d24[3];

	} data;

};



/**
@@ -69,8 +60,8 @@ struct ad5446_state { 
struct ad5446_chip_info {

	struct iio_chan_spec	channel;

	u16			int_vref_mv;

	void (*store_sample)	(struct ad5446_state *st, unsigned val);

	void (*store_pwr_down)	(struct ad5446_state *st, unsigned mode);

	int (*store_sample)	(struct ad5446_state *st, unsigned val);

	int (*store_pwr_down)	(struct ad5446_state *st, unsigned mode);

};



/**