kernel/drivers/iio/buffer/industrialio-buffer-dma.c, branch linux-6.18.y

iio: buffer-dma: support getting the DMA channel

2025-10-13T07:38:08Z

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

iio: buffer-dma: Fix docstrings

2025-03-04T14:49:31Z

Fix a typo in the docstring of iio_dma_buffer_read() and fix what looks like a copy-and-paste error in the iio_dma_buffer_write() docstring. Signed-off-by: Folker Schwesinger Reviewed-by: Nuno Sá Link: https://patch.msgid.link/D83IPSTKYWNB.1PUBV1530XI86@folker-schwesinger.de Signed-off-by: Jonathan Cameron

module: Convert symbol namespace to string literal

2024-12-02T19:34:44Z

Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS$([^)]*)$/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)$([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)$/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)$([^,]+), ([^)]+)$/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada Signed-off-by: Peter Zijlstra (Intel) Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH Signed-off-by: Linus Torvalds

iio: buffer-dma: Move exports into IIO_DMA_BUFFER namespace

2024-08-03T09:13:43Z

Avoid unnecessary pollution of the global symbol namespace and move global APIs into a specific namespace. Import that into the places that use them Signed-off-by: Nuno Sa Link: https://patch.msgid.link/20240726-dev-iio-dma-buf-mod-namespace-v1-1-8877cfe7f68e@analog.com Signed-off-by: Jonathan Cameron

iio: buffer-dma: Enable support for DMABUFs

2024-06-30T10:29:24Z

Implement iio_dma_buffer_attach_dmabuf(), iio_dma_buffer_detach_dmabuf() and iio_dma_buffer_transfer_dmabuf(), which can then be used by the IIO DMA buffer implementations. Signed-off-by: Paul Cercueil Co-developed-by: Nuno Sa Signed-off-by: Nuno Sa Link: https://patch.msgid.link/20240620122726.41232-5-paul@crapouillou.net Signed-off-by: Jonathan Cameron

iio: buffer-dma: Enable buffer write support

2024-04-20T14:36:41Z

Adding write support to the buffer-dma code is easy - the write() function basically needs to do the exact same thing as the read() function: dequeue a block, read or write the data, enqueue the block when entirely processed. Therefore, the iio_buffer_dma_read() and the new iio_buffer_dma_write() now both call a function iio_buffer_dma_io(), which will perform this task. Note that we preemptively reset block->bytes_used to the buffer's size in iio_dma_buffer_request_update(), as in the future the iio_dma_buffer_enqueue() function won't reset it. Signed-off-by: Paul Cercueil Reviewed-by: Alexandru Ardelean Signed-off-by: Nuno Sa Link: https://lore.kernel.org/r/20240419-iio-backend-axi-dac-v4-3-5ca45b4de294@analog.com Signed-off-by: Jonathan Cameron

iio: buffer-dma: Rename iio_dma_buffer_data_available()

2024-04-20T14:36:41Z

Change its name to iio_dma_buffer_usage(), as this function can be used both for the .data_available and the .space_available callbacks. Signed-off-by: Paul Cercueil Signed-off-by: Nuno Sa Link: https://lore.kernel.org/r/20240419-iio-backend-axi-dac-v4-2-5ca45b4de294@analog.com Signed-off-by: Jonathan Cameron

iio: buffer-dma: split iio_dma_buffer_fileio_free() function

2023-12-21T11:30:59Z

This change splits the logic into a separate function, which will be re-used later. Signed-off-by: Alexandru Ardelean Cc: Alexandru Ardelean Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20231219175009.65482-3-paul@crapouillou.net Signed-off-by: Jonathan Cameron

iio: buffer-dma: Get rid of outgoing queue

2023-12-21T11:28:47Z

The buffer-dma code was using two queues, incoming and outgoing, to manage the state of the blocks in use. While this totally works, it adds some complexity to the code, especially since the code only manages 2 blocks. It is much easier to just check each block's state manually, and keep a counter for the next block to dequeue. Since the new DMABUF based API wouldn't use the outgoing queue anyway, getting rid of it now makes the upcoming changes simpler. With this change, the IIO_BLOCK_STATE_DEQUEUED is now useless, and can be removed. Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20231219175009.65482-2-paul@crapouillou.net Signed-off-by: Jonathan Cameron

iio: dma-buffer: Cleanup buffer.h/buffer_impl.h includes

2020-04-19T15:56:31Z

The IIO DMA buffer is a DMA buffer implementation. As such it should include buffer_impl.h rather than buffer.h. The include to buffer.h in buffer-dma.h should be buffer_impl.h so it has access to the struct iio_buffer definition. The code currently only works because all places that use buffer-dma.h include buffer_impl.h before it. The include to buffer.h in industrialio-buffer-dma.c can be removed since those file does not reference any of buffer consumer functions. Signed-off-by: Lars-Peter Clausen Tested-by: Alexandru Ardelean Signed-off-by: Jonathan Cameron