From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: [PATCH] Add 'dma-coherent' property as a standard property Date: Wed, 4 Mar 2020 18:36:31 -0600 Message-ID: <20200305003631.4121-1-robh@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: devicetree-spec-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: devicetree-spec-u79uwXL29TY76Z2rM5mHXA@public.gmane.org The 'dma-coherent' property was added for architectures which by default have non-coherent I/O (e.g. Arm) as a way to specify certain devices are coherent. It's been in use since 2012. Signed-off-by: Rob Herring --- source/devicetree-basics.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/source/devicetree-basics.rst b/source/devicetree-basics.rst index 8292a312ba5a..90d49a1835c7 100644 --- a/source/devicetree-basics.rst +++ b/source/devicetree-basics.rst @@ -804,6 +804,19 @@ Description: from the *#size-cells* of this node (the node in which the dma-ranges property appears). +dma-coherent +~~~~~~~~~~~~ + +Property name: ``dma-coherent`` + +Value type: ```` + +Description: + For architectures which are by default non-coherent for I/O, the + *dma-coherent* property is used to indicate a device is capable of + coherent DMA operations. Some architectures have coherent DMA by default + and this property is not applicable. + name (deprecated) ~~~~~~~~~~~~~~~~~ -- 2.20.1