Re: [PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Franklin S Cooper Jr]

Hi Sergei,

On 08/03/2017 10:38 AM, Franklin S Cooper Jr wrote:
> 
> 
> On 08/03/2017 07:22 AM, Sergei Shtylyov wrote:
>> On 08/03/2017 12:48 PM, Franklin S Cooper Jr wrote:
>>
> 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 
> ---
>.../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 000..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  (after @) must only be specified if there's "reg"
>>>
>>> Sorry. Fixed this in my v2 and some how it came back. Will fix.
>>>
 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...
>>
>>> 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".
> 
>>
>>> 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.

I went ahead and made your suggested switch in my v4. Thanks for taking
the time to review this series.
>>
>> MBR, Sergei

Re: [PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Franklin S Cooper Jr]

On 08/03/2017 07:22 AM, Sergei Shtylyov wrote:
> On 08/03/2017 12:48 PM, Franklin S Cooper Jr wrote:
> 
 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 
 ---
.../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 000..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  (after @) must only be specified if there's "reg"
>>
>> Sorry. Fixed this in my v2 and some how it came back. Will fix.
>>
>>> 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...
> 
>> 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".

> 
>> 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

Re: [PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Sergei Shtylyov]

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


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 
---
   .../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 000..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  (after @) must only be specified if there's "reg"


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


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...


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...


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


   I'm somewhat perplexed at this point...

MBR, Sergei

Re: [PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Franklin S Cooper Jr]

On 08/03/2017 04:18 AM, Sergei Shtylyov wrote:
> Hello!
> 
> On 8/3/2017 3:51 AM, Franklin S Cooper Jr wrote:
> 
>> 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 
>> ---
>>   .../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 000..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  (after @) must only be specified if there's "reg"

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

> 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
thought including fixed was important to indicate that this is a "dumb"
transceiver similar to "fixed-link". So would "fixed-can-transceiver" be
ok or do you want to go with can-transceiver?
> 
> [...]

> 
> MBR, Sergei

Re: [PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Sergei Shtylyov]

Hello!

On 8/3/2017 3:51 AM, Franklin S Cooper Jr wrote:


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 
---
  .../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 000..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  (after @) must only be specified if there's "reg" 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.


[...]

MBR, Sergei

[PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Franklin S Cooper Jr]

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 
---
 .../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 000..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 {
+   max-bitrate = <500>;
+   };
+   ...
+};
-- 
2.9.4.dirty