kernel/linux.git/drivers/iio/buffer/industrialio-buffer-dmaengine.c, branch v6.18.21

iio: buffer-dmaengine: enable .get_dma_dev()

2025-10-13T07:38:08+00:00

Wire up the .get_dma_dev() callback to use the DMA buffer infrastructure's implementation. This ensures that DMABUF operations use the correct DMA device for mapping, which is essential for proper operation on systems where memory is mapped above the 32-bit range. Without this callback, the core would fall back to using the IIO device's parent, which may not have the appropriate DMA mask configuration for high memory access. Fixes: 7a86d469983a ("iio: buffer-dmaengine: Support new DMABUF based userspace API") Reviewed-by: David Lechner Signed-off-by: Nuno Sá Cc: Signed-off-by: Jonathan Cameron

iio: buffer-dmaengine: add devm_iio_dmaengine_buffer_setup_with_handle()

2025-02-10T18:47:49+00:00

Add a new devm_iio_dmaengine_buffer_setup_with_handle() function to handle cases where the DMA channel is managed by the caller rather than being requested and released by the iio_dmaengine module. Reviewed-by: Nuno Sa Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-9-e48a489be48c@baylibre.com Signed-off-by: Jonathan Cameron

iio: buffer-dmaengine: split requesting DMA channel from allocating buffer

2025-02-10T18:47:29+00:00

Refactor the IIO dmaengine buffer code to split requesting the DMA channel from allocating the buffer. We want to be able to add a new function where the IIO device driver manages the DMA channel, so these two actions need to be separate. To do this, calling dma_request_chan() is moved from iio_dmaengine_buffer_alloc() to iio_dmaengine_buffer_setup_ext(). A new __iio_dmaengine_buffer_setup_ext() helper function is added to simplify error unwinding and will also be used by a new function in a later patch. iio_dmaengine_buffer_free() now only frees the buffer and does not release the DMA channel. A new iio_dmaengine_buffer_teardown() function is added to unwind everything done in iio_dmaengine_buffer_setup_ext(). This keeps things more symmetrical with obvious pairs alloc/free and setup/teardown. Calling dma_get_slave_caps() in iio_dmaengine_buffer_alloc() is moved so that we can avoid any gotos for error unwinding. Reviewed-by: Nuno Sa Signed-off-by: David Lechner Link: https://patch.msgid.link/20250207-dlech-mainline-spi-engine-offload-2-v8-8-e48a489be48c@baylibre.com Signed-off-by: Jonathan Cameron

iio: buffer-dmaengine: document iio_dmaengine_buffer_setup_ext

2024-12-07T17:47:58+00:00

The iio_dmaengine_buffer_setup_ext() function is public and should be documented. Also, while touching this, fix the description of @dev in related functions. @dev does not strictly have to be the parent of the IIO device. It is only passed to dma_request_chan() so strictly speaking, it can be any device that is a valid DMA channel consumer. Signed-off-by: David Lechner Link: https://patch.msgid.link/20241115-dlech-mainline-spi-engine-offload-2-v5-9-bea815bd5ea5@baylibre.com Signed-off-by: Jonathan Cameron

module: Convert symbol namespace to string literal

2024-12-02T19:34:44+00:00

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

Merge 6.11-rc7 into char-misc-next

2024-09-09T06:36:23+00:00

We need the char-misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman

iio: buffer-dma: Move exports into IIO_DMA_BUFFER namespace

2024-08-03T09:13:43+00:00

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-dmaengine: fix releasing dma channel on error

2024-07-29T19:31:23+00:00

If dma_get_slave_caps() fails, we need to release the dma channel before returning an error to avoid leaking the channel. Fixes: 2d6ca60f3284 ("iio: Add a DMAengine framework based buffer") Signed-off-by: David Lechner Link: https://patch.msgid.link/20240723-iio-fix-dmaengine-free-on-error-v1-1-2c7cbc9b92ff@baylibre.com Cc: Signed-off-by: Jonathan Cameron

iio: buffer-dmaengine: Support new DMABUF based userspace API

2024-06-30T10:29:28+00:00

Use the functions provided by the buffer-dma core to implement the DMABUF userspace API in the buffer-dmaengine IIO buffer implementation. Since we want to be able to transfer an arbitrary number of bytes and not necesarily the full DMABUF, the associated scatterlist is converted to an array of DMA addresses + lengths, which is then passed to dmaengine_prep_slave_dma_array(). Signed-off-by: Paul Cercueil Co-developed-by: Nuno Sa Signed-off-by: Nuno Sa Link: https://patch.msgid.link/20240620122726.41232-6-paul@crapouillou.net Signed-off-by: Jonathan Cameron

iio: buffer-dmaengine: Enable write support

2024-04-20T14:41:32+00:00

Use the iio_dma_buffer_write() and iio_dma_buffer_space_available() functions provided by the buffer-dma core, to enable write support in the buffer-dmaengine code. 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-v4-5-5ca45b4de294@analog.com Signed-off-by: Jonathan Cameron