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staging:iio:dac:ad5446: Fix 24bit transfers

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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: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lars-Peter Clausen
2012-04-25 09:44:54 +02:00
committed by Greg Kroah-Hartman
parent 5ff6a99d7c
commit af836d9a38
2 changed files with 27 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/staging/iio/dac/ad5446.c
+25 -27
View File
@@ -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
View File
@@ -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);
};
/**