mbox series

[0/3] implement workaround for ERR051725

Message ID 20250614125645.207732-1-xu.yang_2@nxp.com
Headers show
Series implement workaround for ERR051725 | expand

Message

Xu Yang June 14, 2025, 12:56 p.m. UTC 
Currently, the USB2.0 phy on some imx7d compliant Soc has below issue.

ERR051725:
USB: With the USB controller configured as device mode, Clearing the RS
bit of USBCMD register fails to cause USB device to be detached

Description
1. USB controller working as high speed device mode with USB gadget
   function enabled
2. Cable plugged into USB host
3. Use case is software-controlled detach from USB device side

The expected result is device side terminations removed, increase in USB
signal amplitude, USB host detect device is detached. But the issue is
that the clear RS bit of USBCMD register cannot cause device detach event.

Workaround
  - Use the below steps to detach from the host:
      write USBCMD.RS = 0b
      write CTRL2[7:6] = 01b
      write CTRL2[8] = 1b
  - As CTRL2[8] is set at detach case, so attach the steps should add clear
    CTRL2[8]:
      write USBCMD.RS = 1b
      write CTRL2[8] = 0b

This will add workaround for it.

Xu Yang (3):
  usb: chipidea: udc: add CI_HDRC_CONTROLLER_PULLUP_EVENT event
  usb: chipidea: imx: add imx_usbmisc_pullup() hook
  usb: chipidea: imx: implement workaround for ERR051725

 drivers/usb/chipidea/ci_hdrc_imx.c |  5 ++++
 drivers/usb/chipidea/ci_hdrc_imx.h |  1 +
 drivers/usb/chipidea/udc.c         |  5 ++++
 drivers/usb/chipidea/usbmisc_imx.c | 39 ++++++++++++++++++++++++++++++
 include/linux/usb/chipidea.h       |  1 +
 5 files changed, 51 insertions(+)