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iio: ad7949: fix incorrect SPI xfer len 

This driver supports 14-bits and 16-bits devices. All of them have a 14-bit
configuration registers. All SPI trasfers, for reading AD conversion
results and for writing the configuration register, fit in two bytes.

The driver always uses 4-bytes xfers which seems at least pointless (maybe
even harmful). This patch trims the SPI xfer len and the buffer size to
two bytes.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Andrea Merello 2019-09-12 16:43:08 +02:00 committed by Jonathan Cameron
parent 0fe2f2b789
commit 348eb0b2c4
1 changed files with 3 additions and 3 deletions
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6
drivers/iio/adc/ad7949.c
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@ -54,7 +54,7 @@ struct ad7949_adc_chip {
u8 resolution;
u16 cfg;
unsigned int current_channel;
u32 buffer ____cacheline_aligned;
u16 buffer ____cacheline_aligned;
};
static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val,
@ -67,7 +67,7 @@ static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val,
struct spi_transfer tx[] = {
{
.tx_buf = &ad7949_adc->buffer,
.len = 4,
.len = 2,
.bits_per_word = bits_per_word,
},
};
@ -95,7 +95,7 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
struct spi_transfer tx[] = {
{
.rx_buf = &ad7949_adc->buffer,
.len = 4,
.len = 2,
.bits_per_word = bits_per_word,
},
};