From f9c198c3ccaf90a1a265fb2ffa8d4b093c3b0784 Mon Sep 17 00:00:00 2001 From: Nuno Sá Date: Tue, 7 Oct 2025 10:15:22 +0100 Subject: iio: buffer-dma: support getting the DMA channel MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Implement the .get_dma_dev() callback for DMA buffers by returning the device that owns the DMA channel. This allows the core DMABUF infrastructure to properly map DMA buffers using the correct device, avoiding the need for bounce buffers on systems where memory is mapped above the 32-bit range. The function returns the DMA queue's device, which is the actual device responsible for DMA operations in buffer-dma implementations. Cc: stable@vger.kernel.org Reviewed-by: David Lechner Signed-off-by: Nuno Sá Signed-off-by: Jonathan Cameron --- drivers/iio/buffer/industrialio-buffer-dma.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/iio/buffer') diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c b/drivers/iio/buffer/industrialio-buffer-dma.c index ee294a775e8a..7a7a9d37339b 100644 --- a/drivers/iio/buffer/industrialio-buffer-dma.c +++ b/drivers/iio/buffer/industrialio-buffer-dma.c @@ -786,6 +786,12 @@ out_end_signalling: } EXPORT_SYMBOL_NS_GPL(iio_dma_buffer_enqueue_dmabuf, "IIO_DMA_BUFFER"); +struct device *iio_dma_buffer_get_dma_dev(struct iio_buffer *buffer) +{ + return iio_buffer_to_queue(buffer)->dev; +} +EXPORT_SYMBOL_NS_GPL(iio_dma_buffer_get_dma_dev, "IIO_DMA_BUFFER"); + void iio_dma_buffer_lock_queue(struct iio_buffer *buffer) { struct iio_dma_buffer_queue *queue = iio_buffer_to_queue(buffer); -- cgit v1.2.3