From 102afde62937de32758a023655ed90545c292245 Mon Sep 17 00:00:00 2001 From: Olivier Moysan Date: Wed, 19 Jun 2019 15:03:49 +0200 Subject: iio: adc: stm32-dfsdm: manage data resolution in trigger mode 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 Acked-by: Fabrice Gasnier Signed-off-by: Jonathan Cameron --- drivers/iio/adc/stm32-dfsdm-adc.c | 41 ++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) (limited to 'drivers/iio') diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 6b90a40882f2..5b19a88412a6 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -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; -- cgit v1.2.3