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
