On 08/03/2017 07:22 AM, Sergei Shtylyov wrote:

On 08/03/2017 12:48 PM, Franklin S Cooper Jr wrote:

quoted

quoted

quoted

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>
---
   .../bindings/net/can/fixed-transceiver.txt         | 24
++++++++++++++++++++++
   1 file changed, 24 insertions(+)
   create mode 100644
Documentation/devicetree/bindings/net/can/fixed-transceiver.txt

diff --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..2f58838b

--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt

@@ -0,0 +1,24 @@
+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.
+
+Required Properties:
+ max-bitrate:    a positive non 0 value that determines the max
+        speed that CAN/CAN-FD can run. Any other value
+        will be ignored.
+
+Examples:
+
+Based on Texas Instrument's TCAN1042HGV CAN Transceiver
+
+m_can0 {
+    ....
+    fixed-transceiver@0 {

    The <unit-address> (after @) must only be specified if there's "reg"

Sorry. Fixed this in my v2 and some how it came back. Will fix.

quoted

prop in the device node. Also, please name the node "can-transceiver@"
to be more in line with the DT spec. which requires generic node names.

Its possible for future can transceivers drivers to be created. So I

   So what? Ah, you are using the node name to match in the CAN drivers...

quoted

thought including fixed was important to indicate that this is a "dumb"
transceiver similar to "fixed-link".

   I'm not sure the "fixed-link" MAC subnode assumed any transceiver at
all...

Your right. I wasn't trying to imply that it does. What I meant was that
having a node named "can-transceiver" may be a bit confusing in the
future if can transceiver drivers are created. Prefix of "fixed" atleast
to me makes it clear that this is something unique or a generic
transceiver with limitations. Similar to "fixed-link" which is for MACs
not connected to MDIO managed phy. Calling this subnode
"can-transceiver" to me would be like renaming "fixed-link" to "phy".

quoted

So would "fixed-can-transceiver" be
ok or do you want to go with can-transceiver?

   I'm somewhat perplexed at this point...

If my reasoning still didn't change your views then I'll make the switch.

MBR, Sergei