[PATCH v2 03/11] staging:iio:dac:ad5446: Fix 24bit transfers
Lars-Peter Clausen
lars at metafoo.de
Wed Apr 25 07:44:54 UTC 2012
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 at metafoo.de>
Acked-by: Jonathan Cameron <jic23 at kernel.org>
---
drivers/staging/iio/dac/ad5446.c | 52 ++++++++++++++++++--------------------
drivers/staging/iio/dac/ad5446.h | 13 ++--------
2 files changed, 27 insertions(+), 38 deletions(-)
diff --git a/drivers/staging/iio/dac/ad5446.c b/drivers/staging/iio/dac/ad5446.c
index 0da5c6c..2ce6b5b 100644
--- a/drivers/staging/iio/dac/ad5446.c
+++ b/drivers/staging/iio/dac/ad5446.c
@@ -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];
+
+ data[0] = (val >> 16) & 0xFF;
+ data[1] = (val >> 8) & 0xFF;
+ data[2] = val & 0xFF;
- st->data.d24[0] = (val >> 16) & 0xFF;
- st->data.d24[1] = (val >> 8) & 0xFF;
- st->data.d24[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:
diff --git a/drivers/staging/iio/dac/ad5446.h b/drivers/staging/iio/dac/ad5446.h
index 4ea3476..f9fff71 100644
--- a/drivers/staging/iio/dac/ad5446.h
+++ b/drivers/staging/iio/dac/ad5446.h
@@ -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);
};
/**
--
1.7.9.5
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