From 7464850873714b888dbcfbbbffd4ad63bf64909c Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Thu, 21 Mar 2019 17:47:25 +0100 Subject: [PATCH] iio: adc: stm32-dfsdm: move dma slave config to start routine 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 Signed-off-by: Jonathan Cameron --- 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 818627fd5413..66e2ea038d9a 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,