Commit bc83a877 authored by Ran Wang's avatar Ran Wang Committed by Greg Kroah-Hartman

dt-bindings: usb: dwc3: Add snps,host-vbus-glitches-quirk avoid vbus glitch

When DWC3 is set to host mode by programming register DWC3_GCTL, VBUS
(or its control signal) will turn on immediately on related Root Hub
ports. Then the VBUS will be de-asserted for a little while during xhci
reset (conducted by xhci driver) for a little while and back to normal.

This VBUS glitch might cause some USB devices emuration fail if kernel
boot with them connected. One SW workaround which can fix this is to
program all PORTSC[PP] to 0 to turn off VBUS immediately after setting
host mode in DWC3 driver(per signal measurement result, it will be too
late to do it in xhci-plat.c or xhci.c).
Signed-off-by: default avatarRan Wang <ran.wang_1@nxp.com>
Reviewed-by: default avatarPeter Chen <peter.chen@nxp.com>
Signed-off-by: default avatarFrank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240124152525.3910311-3-Frank.Li@nxp.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c35ba0ac
......@@ -273,6 +273,13 @@ properties:
with an external supply.
type: boolean
snps,host-vbus-glitches-quirk:
description:
When set, power off all Root Hub ports immediately after
setting host mode to avoid vbus (negative) glitch happen in later
xhci reset. And the vbus will back to 5V automatically when reset done.
type: boolean
snps,is-utmi-l1-suspend:
description:
True when DWC3 asserts output signal utmi_l1_suspend_n, false when
......
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