Re: [PATCH v7 3/5] usb: dwc3: make usb2 phy utmi interface configurable in DT

From: William.wu
Date: Sun Jul 24 2016 - 12:25:15 EST

Dear Heiko,

On 2016/7/17 18:28, Heiko StÃbner wrote:
Am Samstag, 16. Juli 2016, 17:57:15 schrieb Rob Herring:
On Thu, Jul 14, 2016 at 04:59:20PM +0800, William Wu wrote:
Add snps,phyif-utmi-width devicetree property to configure
the UTMI+ PHY with an 8- or 16-bit interface. UTMI+ PHY
interface is a hardware property, and it's platform dependent.
Normally,the PHYIF can be configured during coreconsultant.

But for some specific USB cores(e.g. rk3399 SoC DWC3), the
default PHYIF configuration value is fault, so we need to
reconfigure it by software.

And refer to the DWC3 databook, the GUSB2PHYCFG.USBTRDTIM
must be set to the corresponding value according to the
UTMI+ PHY interface.

Signed-off-by: William Wu <william.wu@xxxxxxxxxxxxxx>
Changes in v7:
- remove quirk and use only one property to configure utmi (Heiko, Rob

Changes in v6:
- use '-' instead of '_' in dts (Rob Herring)

Changes in v5:
- None

Changes in v4:
- rebase on top of balbi testing/next, remove pdata (balbi)

Changes in v3:
- None

Changes in v2:
- add a quirk for phyif_utmi (balbi)

Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
drivers/usb/dwc3/core.c | 25
+++++++++++++++++++++++++ drivers/usb/dwc3/core.h
| 10 ++++++++++
3 files changed, 38 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
b/Documentation/devicetree/bindings/usb/dwc3.txt index 020b0e9..00cc541
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt

@@ -47,6 +47,9 @@ Optional properties:
- snps,hird-threshold: HIRD threshold
- snps,hsphy_interface: High-Speed PHY interface selection between
"utmi" for>
UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has value

+ - snps,phyif-utmi-width: the value to configure the core to support a
UTMI+ PHY + with an 8- or 16-bit interface. Value 8 select 8-bit
+ interface, value 16 select 16-bit interface.
Is 'phy_type = "utmi_wide"' not the same as 16-bit width?

Again, I think this should be common.
after knowing that I need to look for that "utmi_wide", I think I'd agree.

I found mention of that in usb/ci-hdrc-usb2.txt and usb/fsl-usb.txt and from
the coresponding code, I can see that they really mean the 16bit interface,
the Rockchip TRM as well as the spec [0] seems to call it UTMI+ but really
looks the same as utmi_wide.

Interestingly, there is already generic code in drivers/usb/phy/of.c so that
property should probably move to devicetree/bindings/usb/generic.txt
as well.



Thank you very much for your kindly help and helpful suggestion.:-D
I quite agree with you about use âphy_typeâ to config UTMI+ interface for DWC3 controller, and add the âphy_typeâ property to devicetree/bindings/usb/generic.txt.

So I shouldn't add a new dts property âsnps,phyif-utmi-widthâ hereï and just use âphy_typeâis enough.

BTW, I think rk3399 UTMI+ isn't the same as âutmi_wideâ. Because UTMI+ support both 8-bit data interface and 16-bit data interface, but refer to code in drivers/usb/phy/of.c and related driverïâphy_type = "utmi_wide"âmeans 16-bits, 'phy_type = utmi' means 8-bits.

Dear Felipeï how about your opinion about add âphy_typeâ to config UTMI+ interface?

Best Regards
William wu