Re: [PATCH v2 2/4] can: fixed-transceiver: Add documentation for CAN fixed transceiver bindings
From: Andrew Lunn <andrew@lunn.ch>
Date: 2017-07-26 16:41:34
Also in:
linux-can, linux-devicetree, lkml
On Mon, Jul 24, 2017 at 06:05:19PM -0500, Franklin S Cooper Jr wrote:
quoted hunk ↗ jump to hunk
Add documentation to describe usage of the new fixed transceiver binding. This new binding is applicable for any CAN device therefore it exists as its own document. Signed-off-by: Franklin S Cooper Jr <redacted> --- Version 2: Tweak commit message working Tweak wording for properties Drop unit addressing Give example if CAN-FD isn't supported .../bindings/net/can/fixed-transceiver.txt | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/net/can/fixed-transceiver.txtdiff --git a/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt new file mode 100644 index 0000000..dc7e3eb --- /dev/null +++ b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt@@ -0,0 +1,42 @@ +Fixed transceiver Device Tree binding +------------------------------ + +CAN transceiver typically limits the max speed in standard CAN and CAN FD +modes. Typically these limitations are static and the transceivers themselves +provide no way to detect this limitation at runtime. For this situation, +the "fixed-transceiver" node can be used. + +Properties: + +Optional: + max-arbitration-speed: a positive non 0 value that determines the max + speed that CAN can run in non CAN-FD mode or during the + arbitration phase in CAN-FD mode.
Hi Franklin Since this and the next property are optional, it is good to document what happens when they are not in the DT blob. Also document what 0 means.
+ + max-data-speed: a positive non 0 value that determines the max data rate + that can be used in CAN-FD mode. A value of -1 implies + CAN-FD is not supported by the transceiver.
-1 is ugly. I think it would be better to have a missing
max-data-speed property indicate that CAN-FD is not supported. And
maybe put 'fd' into the property name.
Andrew