[PATCH 1/1] iio: use dmaengine_get_dma_device() instead of chan->device->dev
From: <hidden>
Date: 2026-09-17 20:37:15
Also in:
imx, linux-iio, lkml
Subsystem:
iio subsystem and drivers, microchip sama5d2-compatible adc driver, the rest · Maintainers:
Jonathan Cameron, Eugen Hristev, Linus Torvalds
From: Frank Li <Frank.Li@nxp.com> Replace direct dma_chan::device::dev access with the proper dmaengine_get_dma_device() accessor in IIO DMA consumers. chan->device->dev is not always the device used for DMA mapping. Some DMA engines support per-channel IOMMU mappings, so different channels may use different DMA devices. dmaengine_get_dma_device() returns the correct device for each channel. This also prepares for making the DMA engine provider data structures private. DMA consumers should not access DMA engine internals directly. Assisted-by: LLM Signed-off-by: Frank Li <Frank.Li@nxp.com> --- Cc: imx@lists.linux.dev Cc: vkoul@kernel.org --- drivers/iio/adc/at91-sama5d2_adc.c | 9 ++++++--- drivers/iio/adc/nxp-sar-adc.c | 2 +- drivers/iio/adc/stm32-adc.c | 10 ++++++---- drivers/iio/adc/stm32-dfsdm-adc.c | 4 ++-- drivers/iio/adc/ti_am335x_adc.c | 4 ++-- drivers/iio/buffer/industrialio-buffer-dmaengine.c | 5 +++-- 6 files changed, 20 insertions(+), 14 deletions(-)
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index e8a5285bb6d4f..0e7d07fb27ca7 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c@@ -2016,6 +2016,8 @@ static void at91_adc_dma_init(struct at91_adc_state *st) unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE * sample_size * 2, PAGE_SIZE); + struct device *dma_dev; + if (st->dma_st.dma_chan) return;
@@ -2026,7 +2028,8 @@ static void at91_adc_dma_init(struct at91_adc_state *st) goto dma_exit; } - st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev, + dma_dev = dmaengine_get_dma_device(st->dma_st.dma_chan); + st->dma_st.rx_buf = dma_alloc_coherent(dma_dev, pages * PAGE_SIZE, &st->dma_st.rx_dma_buf, GFP_KERNEL);
@@ -2054,7 +2057,7 @@ static void at91_adc_dma_init(struct at91_adc_state *st) return; dma_free_area: - dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE, + dma_free_coherent(dma_dev, pages * PAGE_SIZE, st->dma_st.rx_buf, st->dma_st.rx_dma_buf); dma_chan_disable: dma_release_channel(st->dma_st.dma_chan);
@@ -2078,7 +2081,7 @@ static void at91_adc_dma_disable(struct at91_adc_state *st) /* wait for all transactions to be terminated first*/ dmaengine_terminate_sync(st->dma_st.dma_chan); - dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE, + dma_free_coherent(dmaengine_get_dma_device(st->dma_st.dma_chan), pages * PAGE_SIZE, st->dma_st.rx_buf, st->dma_st.rx_dma_buf); dma_release_channel(st->dma_st.dma_chan); st->dma_st.dma_chan = NULL;
diff --git a/drivers/iio/adc/nxp-sar-adc.c b/drivers/iio/adc/nxp-sar-adc.c
index 894d3211b2838..2f716a2f97b80 100644
--- a/drivers/iio/adc/nxp-sar-adc.c
+++ b/drivers/iio/adc/nxp-sar-adc.c@@ -604,7 +604,7 @@ static void nxp_sar_adc_dma_cb(void *data) dma_buf = &info->dma_buf; dma_samples = (u32 *)dma_buf->buf; - dev_dma = info->dma_chan->device->dev; + dev_dma = dmaengine_get_dma_device(info->dma_chan); /* * DMA in some corner cases might have already be charged for
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 5c6c06b269be6..6aa672177970a 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c@@ -2456,6 +2456,7 @@ static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct dma_slave_config config = { }; + struct device *dma_dev; int ret; adc->dma_chan = dma_request_chan(dev, "rx");
@@ -2470,7 +2471,8 @@ static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev) return 0; } - adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, + dma_dev = dmaengine_get_dma_device(adc->dma_chan); + adc->rx_buf = dma_alloc_coherent(dma_dev, STM32_DMA_BUFFER_SIZE, &adc->rx_dma_buf, GFP_KERNEL); if (!adc->rx_buf) {
@@ -2490,7 +2492,7 @@ static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev) return 0; err_free: - dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, + dma_free_coherent(dma_dev, STM32_DMA_BUFFER_SIZE, adc->rx_buf, adc->rx_dma_buf); err_release: dma_release_channel(adc->dma_chan);
@@ -2617,7 +2619,7 @@ static int stm32_adc_probe(struct platform_device *pdev) err_dma_disable: if (adc->dma_chan) { - dma_free_coherent(adc->dma_chan->device->dev, + dma_free_coherent(dmaengine_get_dma_device(adc->dma_chan), STM32_DMA_BUFFER_SIZE, adc->rx_buf, adc->rx_dma_buf); dma_release_channel(adc->dma_chan);
@@ -2640,7 +2642,7 @@ static void stm32_adc_remove(struct platform_device *pdev) pm_runtime_put_noidle(&pdev->dev); iio_triggered_buffer_cleanup(indio_dev); if (adc->dma_chan) { - dma_free_coherent(adc->dma_chan->device->dev, + dma_free_coherent(dmaengine_get_dma_device(adc->dma_chan), STM32_DMA_BUFFER_SIZE, adc->rx_buf, adc->rx_dma_buf); dma_release_channel(adc->dma_chan);
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index 00f05e167afc9..674767da3ac37 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c@@ -1484,7 +1484,7 @@ static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev) struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); if (adc->dma_chan) { - dma_free_coherent(adc->dma_chan->device->dev, + dma_free_coherent(dmaengine_get_dma_device(adc->dma_chan), DFSDM_DMA_BUFFER_SIZE, adc->rx_buf, adc->dma_buf); dma_release_channel(adc->dma_chan);
@@ -1504,7 +1504,7 @@ static int stm32_dfsdm_dma_request(struct device *dev, return ret; } - adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, + adc->rx_buf = dma_alloc_coherent(dmaengine_get_dma_device(adc->dma_chan), DFSDM_DMA_BUFFER_SIZE, &adc->dma_buf, GFP_KERNEL); if (!adc->rx_buf) {
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index 1516dd332f905..e53c839e87ef3 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c@@ -548,7 +548,7 @@ static int tiadc_request_dma(struct platform_device *pdev, } /* RX buffer */ - dma->buf = dma_alloc_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE, + dma->buf = dma_alloc_coherent(dmaengine_get_dma_device(dma->chan), DMA_BUFFER_SIZE, &dma->addr, GFP_KERNEL); if (!dma->buf) goto err;
@@ -688,7 +688,7 @@ static void tiadc_remove(struct platform_device *pdev) u32 step_en; if (dma->chan) { - dma_free_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE, + dma_free_coherent(dmaengine_get_dma_device(dma->chan), DMA_BUFFER_SIZE, dma->buf, dma->addr); dma_release_channel(dma->chan); }
diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 559880e0cad72..b9f8b5b3aa6b6 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c@@ -254,6 +254,7 @@ static const struct iio_dev_attr *iio_dmaengine_buffer_attrs[] = { */ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct dma_chan *chan) { + struct device *dma_dev = dmaengine_get_dma_device(chan); struct dmaengine_buffer *dmaengine_buffer; unsigned int width, src_width, dest_width; struct dma_slave_caps caps;
@@ -281,9 +282,9 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct dma_chan *chan) INIT_LIST_HEAD(&dmaengine_buffer->active); dmaengine_buffer->chan = chan; dmaengine_buffer->align = width; - dmaengine_buffer->max_size = dma_get_max_seg_size(chan->device->dev); + dmaengine_buffer->max_size = dma_get_max_seg_size(dma_dev); - iio_dma_buffer_init(&dmaengine_buffer->queue, chan->device->dev, + iio_dma_buffer_init(&dmaengine_buffer->queue, dma_dev, &iio_dmaengine_default_ops); dmaengine_buffer->queue.buffer.attrs = iio_dmaengine_buffer_attrs;
--
2.43.0