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

From: William.wu
Date: Sun Jul 24 2016 - 12:05:59 EST


Dear Rob,


On 2016/7/17 6:57, Rob Herring wrote:
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.
^
space
I'll fix it next patch, thanks:-)

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 Herring)

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 100644
--- 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 3.
+ - 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.
Yesï I agree with you. âphy_type = "utmi_wide" really means 16-bit UTMI width.
Thanks very much for your rigorous check.

And according to Heiko's helpful suggestionïI double check the kernel code and
look over UTMI/UTMI+ specïI confirm that there is already generic code in
drivers/usb/phy/of.c about utmi interface, 'phy_type = "utmi"' means 8-bit interface,
and 'phy_type = "utmi_wide"' means 16-bit interface.

So I think I don't need to add a new dts property 'snps,phyif-utmi-width' hereï
but just use theâphy_typeâ property to confirm UTMI+ interface for dwc3.


Rob