Hi Jean,
Hi Sherry,
On 03/09/2019 14:44, Sherry Sun wrote:
Hi Jean,
On 02/09/2019 13:29, Sherry Sun wrote:
Hi Vignesh,
Hi Sherry,
[...]
> AFAIK, U-Boot does not support runtime switching of USB port to > host from device and vice versa. This is the case for existing > driver like
DWC3/MUSB etc.
> Ideally we would need a role switch driver that unbinds and > rebinds host vs device driver as when required based on U-Boot > cmd or via an API (if required to be done during SPL stage etc). I wonder if we can add two subnodes under the wrapper node as below,
one bind to usb gadget driver and another bind to usb host driver.
So if we want to use usb device, just call the gadget driver, and if want to
use usb host, just call the host driver. The driver will probe correspond
node.
I'm not sure if it is feasible, what do you think about it?
usbss0: cdns_usb@4104000 { compatible = "ti,j721e-usb"; [....] usb0: usb@6010000 { /* xhci reg address*/ compatible = "cdns,usb3-1.0.1";dr_mode = "host"; [....] } usb1: usb@6020000 { /* dev reg address*/ compatible = "cdns,usb3-1.0.1"; dr_mode = "peripheral"; [....] } }
But this is not how DT would look in kernel. There will be single DT node representing both Host and Device node. DT repesentation should not be changed based on OS/bootloader, its HW description and must
remain same.
Unbinding host/gadget driver and rebinding with a different role should not be hard as the U-Boot core infrastructure exists.
Moreover if xhci reg and dev reg are separated into different nodes dont we still need access to OTG register block to switch b/w host and
device mode?
I think we may not need to access OTG register if we add two subnodes for
gadget and host.
But I see a for loop in dwc3_glue_bind() as follows, if there only one single
node representing both Host and Device node under usb wrapper node, why we need this for loop?
212 for (node = fdt_first_subnode(fdt, dev_of_offset(parent)); node >
0;
213 node = fdt_next_subnode(fdt, node)) {
I believe this is a legacy from the code it was inspired from.
Indeed the loop is not required.
Like Vignesh I think we must stick with the dt-bindings used by the kernel.
Thanks for your reply, I understand now.
BTW we are working on the USB3 support right now that is lacking in our
tree.
I choose to keep the PHY drivers as close as possible to their linux version. I'll probably start posting preliminary patches this week.
If you have the USB3 working in the kernel, can you point to a tree where I can have a look at the drivers and dt-bindings ?
Sure, you can see our downstream kernel code at my github, here is the
link address: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub .com%2Fsherrysun1%2Flinux- imx.git&data=02%7C01%7Csherry.sun%40nxp.com%7C368ba21c33c048 fd137208d735199870%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7 C637036256383501199&sdata=y4AB0RpG%2F7Skk34yccpkW9TQsDWpi 6OJhtlRWid1DM0%3D&reserved=0.
And look forward to seeing your patches in uboot maillist.
It will take some times before I can post on the mailing list because I did the work on top TI's u-boot. But you can find the patches under https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub .com%2Fjjhiblot%2Fu- boot%2Ftree%2Fusb3_cleanup_v2&data=02%7C01%7Csherry.sun%40n xp.com%7C368ba21c33c048fd137208d735199870%7C686ea1d3bc2b4c6fa92c d99c5c301635%7C0%7C0%7C637036256383511193&sdata=ozU9gYDTO %2FkoB4NwU1R2omGw9%2F%2Fyf6MPxBz1%2FtQ8Lgg%3D&reserved= 0. https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu b.com%2Fjjhiblot%2Fu- boot%2Ftree%2Fusb3_cleanup_v2&data=02%7C01%7Csherry.sun%40n xp.com%7C368ba21c33c048fd137208d735199870%7C686ea1d3bc2b4c6fa92c d99c5c301635%7C0%7C0%7C637036256383511193&sdata=ozU9gYDTO %2FkoB4NwU1R2omGw9%2F%2Fyf6MPxBz1%2FtQ8Lgg%3D&reserved= 0
The DTS bindings are the same as under Linux. The CDNS3 driver is a port of the iteration v11 of the linux driver that has just been merged in the linux usb tree (https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fbalbi%2Fusb.git%2Flog %2F%3Fh%3Dnext&data=02%7C01%7Csherry.sun%40nxp.com%7C368b a21c33c048fd137208d735199870%7C686ea1d3bc2b4c6fa92cd99c5c301635% 7C0%7C0%7C637036256383511193&sdata=OxjRaHtDmkJBJ41qwfOtf2Zj WACskvcAuUUPDRuYDcA%3D&reserved=0)
Care has been taken to keep the changes with linux minimal to ease the maintenance: the drivers are quite new and will probably evolve quite a bit in the next few months.
Thanks for your information, I will try to test your cdns3 patches on i.MX8 platform recently.
Best regards Sherry Sun
JJ
Best regards Sherry sun
JJ
Best regards Sherry sun
Regards Vignesh
Best regards Sherry sun
> Regards > Vignesh > >> Best regards >> Sherry sun >> >>> JJ >>> >>>>> Then when binding the wrapper node, it will hard-coded the >>>>> two >>> subnodes >>>>> to different driver(gadge/host driver) according to the >>>>> dr_mode property >>> in >>>>> nodes. >>>>> >>>> Do you think I understand it right? >>>> Best regards >>>> Sherry sun >>>> >>>>> Best regards >>>>> Sherry sun >>>>> >>>>>> JJ >>>>>> >>>>>> >>>>>> >>>>>>>>>>>> + { } >>>>>>>>>>>> +}; >>>>> _______________________________________________ >>>>> U-Boot mailing list >>>>> U-Boot@lists.denx.de >>>>> https://l >>>>>
ists.d&data=02%7C01%7Csherry.sun%40nxp.com%7C7d1d76a7124f4c3f
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> 70276
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> o1kA%3 >>>>> D&reserved=0 >>>>> enx.de%2Flistinfo%2Fu- >>>>>
boot&data=02%7C01%7Csherry.sun%40nxp.com%7C35f1d34da1ea4b7
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C637025710721487079&sdata=Nfk0qWtSViz60wJHAOr2m5tgIwTWjNwI
>>>>> GrNOxDH6HC0%3D&reserved=0 > -- > Regards > Vignesh