Hi Marek,
On 2023/01/23 12:37, Marek Vasut wrote:
On 1/23/23 04:08, Kunihiko Hayashi wrote:
Hello Hayashi-san,
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig index f010291d02..dadaa083e7 100644 --- a/drivers/usb/dwc3/Kconfig +++ b/drivers/usb/dwc3/Kconfig @@ -25,14 +25,14 @@ config USB_DWC3_OMAP config USB_DWC3_GENERIC bool "Generic implementation of a DWC3 wrapper (aka dwc3 glue)"
- depends on DM_USB && USB_DWC3 && MISC
- depends on DM_USB && USB_DWC3 && (MISC || SIMPLE_BUS)
I'm afraid I don't understand why this change is needed for all variants of DWC3.
Although dwc3-generic is declared as UCLASS_NOP, the similar glue driver dwc3-meson-glx is declared as UCLASS_SIMPLE_BUS.
I think here it makes sense, because "amlogic,meson-axg-usb-ctrl" behaves like a bus with subnodes:
arch/arm/dts/meson-axg.dtsi: 227 usb: usb@ffe09080 { 228 compatible = "amlogic,meson-axg-usb-ctrl"; 229 reg = <0x0 0xffe09080 0x0 0x20>; ... 244 dwc2: usb@ff400000 { 245 compatible = "amlogic,meson-g12a-usb", "snps,dwc2"; 246 reg = <0x0 0xff400000 0x0 0x40000>; ... 255 }; 256 257 dwc3: usb@ff500000 { 258 compatible = "snps,dwc3"; 259 reg = <0x0 0xff500000 0x0 0x100000>; ... 264 }; 265 };
arch/arm/dts/meson-gxl.dtsi 17 usb: usb@d0078080 { 18 compatible = "amlogic,meson-gxl-usb-ctrl"; 19 reg = <0x0 0xd0078080 0x0 0x20>; ... 34 dwc2: usb@c9100000 { 35 compatible = "amlogic,meson-g12a-usb", "snps,dwc2"; 36 reg = <0x0 0xc9100000 0x0 0x40000>; ... 45 }; 46 47 dwc3: usb@c9000000 { 48 compatible = "snps,dwc3"; 49 reg = <0x0 0xc9000000 0x0 0x100000>; ... 54 }; 55 };
On the other hand, the PXS2 controller for example is not a bus:
arch/arm/dts/uniphier-pxs2.dtsi: 596 _usb0: usb@65a00000 { 597 compatible = "socionext,uniphier-dwc3", "snps,dwc3"; 598 status = "disabled"; 599 reg = <0x65a00000 0xcd00>; ... 610 };
I understand. However, this node isn't used in u-boot. (see below for details)
Is this needed for socionext dwc3 variant to handle the simple-mfd in e.g. arch/arm/dts/uniphier-pxs3.dtsi :
614 usb-glue@65b00000 { 615 compatible = "socionext,uniphier-pxs3-dwc3-glue", 616 "simple-mfd";
?
In case of U-Boot, the glue driver is probed by:
/* FIXME: U-Boot own node */ usb@65b00000 { compatible = "socionext,uniphier-pxs3-dwc3";And dwc3-uniphier is also declared as UCLASS_SIMPLE_BUS. Even if using "simple-mfd", this is included in drivers/core/simple-bus.c which is declared as UCLASS_SIMPLE_BUS.
If I understand this correctly, node compatible with "socionext,uniphier-pxs3-dwc3-glue" is not used at all , right ?
Yes. Original uniphier devicetree has the following usb nodes.
usb@65a00000 { compatible = "snps,dwc3"; }; usb-glue@65b00000 { compatible = "socionext,uniphier-pxs3-dwc3-glue", "simple-mfd"; };
However, U-Boot dwc3-generic needs to put dwc3 node under the glue node. Due to this restriction, there is another usb node dedicated to u-boot.
/* FIXME: U-Boot own node */ usb@65b00000 { /* glue */ compatible = "socionext,uniphier-pxs3-dwc3";
dwc3@65a00000 { compatible = "snps,dwc3"; }; };
So instead of "socionext,uniphier-pxs3-dwc3-glue", the glue driver uses "socionext,uniphier-pxs3-dwc3" in U-Boot.
The generic driver binds to node compatible with "socionext,uniphier-dwc3" , right ?
No, the generic driver binds "socionext,uniphier-pxs3-dwc3".
That means, there is nothing which would be a bus, and so the dwc3-uniphier.c can be switched from UCLASS_SIMPLE_BUS to UCLASS_NOP , is that correct ?
There is still the issue of different usb node between Original and u-boot, however, the glue driver can be switched to UCLASS_NOP.
Thank you,
--- Best Regards Kunihiko Hayashi