[1/5,v3] usb: host: add DT bindings for faraday fotg2

Commit Message

Hans Ulli Kroll April 24, 2017, 4:53 p.m. UTC

Hi Linus

On Fri, 21 Apr 2017, Linus Walleij wrote:

> From: Hans Ulli Kroll <[e-mail]>
> 
> This adds device tree bindings for the Faraday FOTG2
> dual-mode host controller.
> 
> Cc: [e-mail]
> Signed-off-by: Hans Ulli Kroll <[e-mail]>
> Signed-off-by: Linus Walleij <[e-mail]>
> ---
> ChangeLog v1->v3:
> - Change compatible to "faraday,fotg210" as the name of the
>   hardware block.
> - Add an elaborate SoC-specific compatible string for the
>   Cortina Systems Gemini so that SoC-specific features can
>   be enabled.
> - Add cortina,gemini-mini-b to indicate a Gemini PHY with
>   a Mini-B adapter connected.
> - Indicated that the Gemini version can handle "wakeup-source".
> - Add optional IP block clock.
> ---
>  .../devicetree/bindings/usb/faraday,fotg210.txt    | 35 ++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/faraday,fotg210.txt
> 

Got NAK'ed from Rob on some ealier round due missing "device mode" on this 
IP. I've blatantly overrided this to a host only driver.

These are the needed changes in DT to support both modes
Note the -dr at the end of fotg210, to reflect this in an dual role device

Comments

Linus Walleij April 25, 2017, 8:12 a.m. UTC | #1

On Mon, Apr 24, 2017 at 6:53 PM, Hans Ulli Kroll
<[e-mail]> wrote:

> Got NAK'ed from Rob on some ealier round due missing "device mode" on this
> IP. I've blatantly overrided this to a host only driver.
>
> These are the needed changes in DT to support both modes
> Note the -dr at the end of fotg210, to reflect this in an dual role device

OK I understood the discussion such that the compatible should
simply be ""faraday,fotg210" as that is the name of the hardware
IP block. This is the name of the hardware name in the Faraday
page:
http://www.faraday-tech.com/html/Product/IPProduct/InterfaceIP/USB2_0.htm

Any other string implies how it is used, so that was what I understood
as the reason to reject it with the "-hcd" (host controller device) suffix.

> +- dr_mode : indicates the working mode for "fotg210-dr" compatible
> +   controllers.  Can be "host", "peripheral". Default to
> +   "host" if not defined for backward compatibility.

This seems right, so it is part of the generic bindings, correct?

>  usb@68000000 {
> -       compatible = "cortina,gemini-usb", "faraday,fotg210";
> +       compatible = "cortina,gemini-usb", "faraday,fotg210-dr";

But this would be wrong, because the compatible should only
indicate what kind of hardware it is, not how it is going to be used
(whether as host only, slave only or dual-role (OTG).

I hope I didn't get anything wrong here :/

Yours,
Linus Walleij

Hans Ulli Kroll April 25, 2017, 7:07 p.m. UTC | #2

Hi Linus

On Tue, 25 Apr 2017, Linus Walleij wrote:

> On Mon, Apr 24, 2017 at 6:53 PM, Hans Ulli Kroll
> <[e-mail]> wrote:
> 
> > Got NAK'ed from Rob on some ealier round due missing "device mode" on this
> > IP. I've blatantly overrided this to a host only driver.
> >
> > These are the needed changes in DT to support both modes
> > Note the -dr at the end of fotg210, to reflect this in an dual role device
> 
> OK I understood the discussion such that the compatible should
> simply be ""faraday,fotg210" as that is the name of the hardware
> IP block. This is the name of the hardware name in the Faraday
> page:
> http://www.faraday-tech.com/html/Product/IPProduct/InterfaceIP/USB2_0.htm
> 
> Any other string implies how it is used, so that was what I understood
> as the reason to reject it with the "-hcd" (host controller device) suffix.
> 
> > +- dr_mode : indicates the working mode for "fotg210-dr" compatible
> > +   controllers.  Can be "host", "peripheral". Default to
> > +   "host" if not defined for backward compatibility.
> 
> This seems right, so it is part of the generic bindings, correct?
> 
> >  usb@68000000 {
> > -       compatible = "cortina,gemini-usb", "faraday,fotg210";
> > +       compatible = "cortina,gemini-usb", "faraday,fotg210-dr";
> 
> But this would be wrong, because the compatible should only
> indicate what kind of hardware it is, not how it is going to be used
> (whether as host only, slave only or dual-role (OTG).
> 

for compatible I think yes.
But in Rob's opinion we missed the device part of the controller.

Greetings
Hans Ulli Kroll

Patch

diff --git a/Documentation/devicetree/bindings/usb/faraday,fotg210.txt 
b/Documentation/devicetree/bindings/usb/faraday,fotg210.txt
index cf06808303e2..862cda19e9d3 100644
--- a/Documentation/devicetree/bindings/usb/faraday,fotg210.txt
+++ b/Documentation/devicetree/bindings/usb/faraday,fotg210.txt
@@ -13,6 +13,9 @@  Required properties:
 Optional properties:
 - clocks: should contain the IP block clock
 - clock-names: should be "PCLK" for the IP block clock
+- dr_mode : indicates the working mode for "fotg210-dr" compatible
+   controllers.  Can be "host", "peripheral". Default to
+   "host" if not defined for backward compatibility.
 
 Required properties for "cortina,gemini-usb" compatible:
 - syscon: a phandle to the system controller to access PHY registers
@@ -25,7 +28,7 @@  Optional properties for "cortina,gemini-usb" compatible:
 Example for Gemini:
 
 usb@68000000 {
-       compatible = "cortina,gemini-usb", "faraday,fotg210";
+       compatible = "cortina,gemini-usb", "faraday,fotg210-dr";
        reg = <0x68000000 0x1000>;
        interrupts = <10 IRQ_TYPE_LEVEL_HIGH>;
        clocks = <&cc 12>;