rockchip: rk3576: Properly handle USB controller takeover from BootROM #20
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
alchark
requested changes
Jan 20, 2026
Collaborator
There was a problem hiding this comment.
Definitely a separate change. It's also technically a "HACK", because one doesn't directly edit device trees which reside under dts/upstream.
Contributor
Author
There was a problem hiding this comment.
I can move it into rk3576-u-boot.dtsi. Should work from there as well.
Collaborator
There was a problem hiding this comment.
Yes please. Better still would be to make it work in OTG mode and ensure that a RAM bundle sets the controller to peripheral mode via the boot command, because one may also want to be able to insert a USB drive into the port and boot from it
| /* Disable USB3OTG0 U3 port, later enabled by USBDP PHY driver */ | ||
| writel(0xffff0188, USB_GRF_BASE + USB3OTG0_CON1); | ||
| if (read_brom_bootsource_id() == BROM_BOOTSOURCE_USB) { | ||
| writel(0x00200020, TOP_CRU_BASE + TOP_CRU_SOFTRST_CON47); |
Collaborator
There was a problem hiding this comment.
Can you add #define's for all the bit values please? Otherwise it's hard to understand what is going on.
ya-mouse
force-pushed
the
splram-8c58ad9a
branch
2 times, most recently
from
672a71a to
ae9f9aa
Compare
When booting via USB download mode (Maskrom), the BootROM leaves the
USB3OTG0 controller in an active state. U-Boot must properly reset
the controller before reinitializing it for fastboot or other USB
gadget functions.
Changes:
1. Detect USB boot source using read_brom_bootsource_id()
2. When booted from USB:
- Assert USB3OTG0 reset via TOP_CRU_SOFTRST_CON47
- Wait 1ms for reset to complete
- Deassert reset
- Wait 1ms for controller to stabilize
- Configure USB_GRF for proper operation
3. When booted from other sources:
- Keep existing behavior of disabling U3 port initially
(USBDP PHY driver enables it later when needed)
Also update rk3576-evb1-v10.dts to set dr_mode = "peripheral" for
usb_drd0_dwc3 to support fastboot gadget mode by default.
Without this fix, USB fastboot fails when U-Boot is loaded via
Maskrom USB download because the controller state is inconsistent.
Change-Id: e22b349e-fdde-40e8-a991-b3a49e37e645
Signed-off-by: Anton Burticica <mouse@ya.ru>
ya-mouse
force-pushed
the
splram-8c58ad9a
branch
from
ae9f9aa to
ed5ba9f
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When booting via USB download mode (Maskrom), the BootROM leaves the USB3OTG0 controller in an active state. U-Boot must properly reset the controller before reinitializing it for fastboot or other USB gadget functions.
Changes:
Also update rk3576-evb1-v10.dts to set dr_mode = "peripheral" for usb_drd0_dwc3 to support fastboot gadget mode by default.
Without this fix, USB fastboot fails when U-Boot is loaded via Maskrom USB download because the controller state is inconsistent.
Change-Id: e22b349e-fdde-40e8-a991-b3a49e37e645