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authorLinus Torvalds <torvalds@linux-foundation.org>2021-02-22 10:57:46 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-22 10:57:46 -0800
commit0e63a5c6ba9679a903f95b10827f74fe183017fa (patch)
tree4d1846ddca080645a642b276935d1893d2127204 /Documentation/driver-api/men-chameleon-bus.rst
parentae42c3173ba5cbe12fab0dad330e997c4ff9f68a (diff)
parent3c2e0a489da6a7c48ad67a246c7a287fcb4a4607 (diff)
Merge tag 'docs-5.12' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet: "It has been a relatively quiet cycle in docsland. - As promised, the minimum Sphinx version to build the docs is now 1.7, and we have dropped support for Python 2 entirely. That allowed the removal of a bunch of compatibility code. - A set of treewide warning fixups from Mauro that I applied after it became clear nobody else was going to deal with them. - The automarkup mechanism can now create cross-references from relative paths to RST files. - More translations, typo fixes, and warning fixes" * tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits) docs: kernel-hacking: be more civil docs: Remove the Microsoft rhetoric Documentation/admin-guide: kernel-parameters: Update nohlt section doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" docs: Document cross-referencing using relative path docs: Enable usage of relative paths to docs on automarkup docs: thermal: fix spelling mistakes Documentation: admin-guide: Update kvm/xen config option docs: Make syscalls' helpers naming consistent coding-style.rst: Avoid comma statements Documentation: /proc/loadavg: add 3 more field descriptions Documentation/submitting-patches: Add blurb about backtraces in commit messages Docs: drop Python 2 support Move our minimum Sphinx version to 1.7 Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams scripts/kernel-doc: add internal hyperlink to DOC: sections Update Documentation/admin-guide/sysctl/fs.rst docs: Update DTB format references docs: zh_CN: add iio index.rst translation docs/zh_CN: add iio ep93xx_adc.rst translation ...
Diffstat (limited to 'Documentation/driver-api/men-chameleon-bus.rst')
-rw-r--r--Documentation/driver-api/men-chameleon-bus.rst12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/driver-api/men-chameleon-bus.rst b/Documentation/driver-api/men-chameleon-bus.rst
index 1b1f048aa748..6f0b9ee47595 100644
--- a/Documentation/driver-api/men-chameleon-bus.rst
+++ b/Documentation/driver-api/men-chameleon-bus.rst
@@ -18,6 +18,7 @@ MEN Chameleon Bus
4.1 The driver structure
4.2 Probing and attaching
4.3 Initializing the driver
+ 4.4 Using DMA
Introduction
@@ -173,3 +174,14 @@ module at the MCB core::
The module_mcb_driver() macro can be used to reduce the above code::
module_mcb_driver(foo_driver);
+
+Using DMA
+---------
+
+To make use of the kernel's DMA-API's function, you will need to use the
+carrier device's 'struct device'. Fortunately 'struct mcb_device' embeds a
+pointer (->dma_dev) to the carrier's device for DMA purposes::
+
+ ret = dma_set_mask_and_coherent(&mdev->dma_dev, DMA_BIT_MASK(dma_bits));
+ if (rc)
+ /* Handle errors */