Re: [PATCH v2 4/8] iio: adc: stm32-dfsdm: move dma slave config to start routine

Jonathan Cameron
2019-03-24T16:45:15Z

On Thu, 21 Mar 2019 17:47:25 +0100
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> Move DMA slave configuration to start routine: depending on regular or
> injected mode is in use, DMA needs to read resp. RDATAR or JDATAR.
> This is precursor patch to introduce injected mode (used for scan).
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>

Applied, thanks,

Jonathan
> ---
> drivers/iio/adc/stm32-dfsdm-adc.c | 31 +++++++++++--------------------
> 1 file changed, 11 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> index 818627f..66e2ea0 100644
> --- a/drivers/iio/adc/stm32-dfsdm-adc.c
> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
> @@ -556,6 +556,11 @@ static void stm32_dfsdm_audio_dma_buffer_done(void *data)
> static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
> {
> struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
> + struct dma_slave_config config = {
> + .src_addr = (dma_addr_t)adc->dfsdm->phys_base +
> + DFSDM_RDATAR(adc->fl_id),
> + .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
> + };
> struct dma_async_tx_descriptor *desc;
> dma_cookie_t cookie;
> int ret;
> @@ -566,6 +571,10 @@ static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
> dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
> adc->buf_sz, adc->buf_sz / 2);
>
> + ret = dmaengine_slave_config(adc->dma_chan, &config);
> + if (ret)
> + return ret;
> +
> /* Prepare a DMA cyclic transaction */
> desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
> adc->dma_buf,
> @@ -925,12 +934,6 @@ static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
> static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
> {
> struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
> - struct dma_slave_config config = {
> - .src_addr = (dma_addr_t)adc->dfsdm->phys_base +
> - DFSDM_RDATAR(adc->fl_id),
> - .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
> - };
> - int ret;
>
> adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
> if (!adc->dma_chan)
> @@ -940,23 +943,11 @@ static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
> DFSDM_DMA_BUFFER_SIZE,
> &adc->dma_buf, GFP_KERNEL);
> if (!adc->rx_buf) {
> - ret = -ENOMEM;
> - goto err_release;
> + dma_release_channel(adc->dma_chan);
> + return -ENOMEM;
> }
>
> - ret = dmaengine_slave_config(adc->dma_chan, &config);
> - if (ret)
> - goto err_free;
> -
> return 0;
> -
> -err_free:
> - dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
> - adc->rx_buf, adc->dma_buf);
> -err_release:
> - dma_release_channel(adc->dma_chan);
> -
> - return ret;
> }
>
> static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,