chipidea: usbmisc_imx: i.MX93 support

[Stefan Wahren]

Hi Xu,

Am 24.06.26 um 04:50 schrieb Xu Yang:
> On Tue, Jun 23, 2026 at 12:23:12PM +0200, Stefan Wahren wrote:
>> Hi,
>>
>> during debugging USB OTG on our custom i.MX93 board, we noticed remarkable
>> differences between the implementation of the chipidea/usbmisc_imx and the
>> official NXP i.MX93 Reference Manual [1].
>>
>> Is the USB OTG part including PHY of the i.MX93 officially supported in
>> Linux Mainline?
> Yes.
>
>> According to imx91_93_common.dtsi the USB IP of the i.MX93 should be
>> identical to i.MX8MM [2]
>>
>>      usbmisc1: usbmisc at 4c100200 {
>>
>>          compatible = "fsl,imx8mm-usbmisc", "fsl,imx7d-usbmisc",
>> "fsl,imx6q-usbmisc";
>>
>> But looking at the PHY register definition and reset values in the NXP
>> i.MX93 Reference Manual,
>>
>> the registers are comparable to the i.MX95 [3] ones.
>>
>> Could you please clarify which source is correct (Mainline DTS vs Reference
>> Manual)?
> The Reference Manual is correct.
>
>> Looking deeper at chipidea/usbmisc_imx shows the usage of the following
>> register bits
>>
>> #define MX7D_USB_OTG_PHY_CFG2_CHRG_CHRGSEL         BIT(0)
>>
>> #define MX7D_USB_OTG_PHY_CFG2_CHRG_VDATDETENB0              BIT(1)
>>
>> #define MX7D_USB_OTG_PHY_CFG2_CHRG_VDATSRCENB0              BIT(2)
>>
>> #define MX7D_USB_OTG_PHY_CFG2_CHRG_DCDENB           BIT(3)
>>
>> #define MX7D_USB_OTG_PHY_STATUS_LINE_STATE0              BIT(0)
>>
>> #define MX7D_USB_OTG_PHY_STATUS_LINE_STATE1              BIT(1)
>>
>> #define MX7D_USB_OTG_PHY_STATUS_CHRGDET                    BIT(29)
>>
>> According to NXP i.MX93 & i.MX95 Reference Manual, these are bits reserved.
>>
>> Is it correct that the chipidea/usbmisc_imx use these bits on i.MX93?
> i.MX93 & i.MX95 no longer claims to support Battery charger detection. So these
> bits are reserved. However, at the IP level, accessing these bits will not produce
> errors. We will remove .charger_detection hook for the i.MX9 series in the future.
I think the access to MX6_BM_NON_BURST_SETTING should be addressed, too.
> Do you want to use Battery charger detection on i.MX93?
No, we don't need this feature in our case. We suspect the cause for our 
issue comes from the hardware design of the board.

Thanks
>
> Thanks,
> Xu Yang
>
>> Best regards
>>
>> [1] - https://www.nxp.com/docs/en/reference-manual/IMX93RM.pdf
>> <https://www.nxp.com/docs/en/reference-manual/IMX93RM.pdf>
>>
>> [2] - https://www.nxp.com/docs/en/reference-manual/IMX8MMRM.pdf
>> <https://www.nxp.com/docs/en/reference-manual/IMX8MMRM.pdf>
>>
>> [3] - https://www.nxp.com/docs/en/reference-manual/IMX95RM.pdf
>> <https://www.nxp.com/docs/en/reference-manual/IMX95RM.pdf>
>>