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iio: adc: stm32-dfsdm: manage data resolution in trigger mode

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Add output sample resolution management in scan mode.
Add stm32_dfsdm_process_data() function to share sample
processing between continuous and trigger modes.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Olivier Moysan 2019-06-19 15:03:49 +02:00 committed by Jonathan Cameron
parent c6013bf50e
commit 102afde629
1 changed files with 28 additions and 13 deletions
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41
drivers/iio/adc/stm32-dfsdm-adc.c
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@ -779,6 +779,30 @@ static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
return 0;
}
static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc,
s32 *buffer)
{
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
struct stm32_dfsdm_filter_osr *flo = &fl->flo;
unsigned int i = adc->nconv;
s32 *ptr = buffer;
while (i--) {
/* Mask 8 LSB that contains the channel ID */
*ptr &= 0xFFFFFF00;
/* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */
if (*ptr > flo->max)
*ptr -= 1;
/*
* Samples from filter are retrieved with 23 bits resolution
* or less. Shift left to align MSB on 24 bits.
*/
*ptr <<= flo->lshift;
ptr++;
}
}
static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
@ -787,7 +811,9 @@ static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p)
int available = stm32_dfsdm_adc_dma_residue(adc);
while (available >= indio_dev->scan_bytes) {
u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi];
stm32_dfsdm_process_data(adc, buffer);
iio_push_to_buffers_with_timestamp(indio_dev, buffer,
pf->timestamp);
@ -806,8 +832,6 @@ static void stm32_dfsdm_dma_buffer_done(void *data)
{
struct iio_dev *indio_dev = data;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
struct stm32_dfsdm_filter_osr *flo = &fl->flo;
int available = stm32_dfsdm_adc_dma_residue(adc);
size_t old_pos;
@ -832,16 +856,7 @@ static void stm32_dfsdm_dma_buffer_done(void *data)
while (available >= indio_dev->scan_bytes) {
s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi];
/* Mask 8 LSB that contains the channel ID */
*buffer &= 0xFFFFFF00;
/* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */
if (*buffer > flo->max)
*buffer -= 1;
/*
* Samples from filter are retrieved with 23 bits resolution
* or less. Shift left to align MSB on 24 bits.
*/
*buffer <<= flo->lshift;
stm32_dfsdm_process_data(adc, buffer);
available -= indio_dev->scan_bytes;
adc->bufi += indio_dev->scan_bytes;