[PATCH] phy: fsl-imx8mq-usb: add debugfs to access control register

Xu Yang xu.yang_2 at nxp.com
Sun Dec 21 17:59:43 PST 2025


On Fri, Dec 19, 2025 at 11:34:56AM +0200, Daniel Baluta wrote:
> On Fri, Dec 19, 2025 at 9:56 AM Xu Yang <xu.yang_2 at nxp.com> wrote:
> >
> > The CR port is a simple 16-bit data/address parallel port that is
> > provided for on-chip access to the control registers inside the
> > USB 3.0 femtoPHY. While access to these registers is not required
> > for normal PHY operation, this interface enables you to access
> > some of the PHY’s diagnostic features during normal operation or
> > to override some basic PHY control signals.
> >
> > 3 debugfs files are created to read and write control registers,
> > all use hexadecimal format:
> > ctrl_reg_base: the register offset to write, or the start offset
> >                to read.
> > ctrl_reg_count: how many continuous registers to be read.
> > ctrl_reg_value: read to show the continuous registers value from
> >                 the offset in ctrl_reg_base, to ctrl_reg_base
> >                 + ctrl_reg_count - 1, one line for one register.
> >                 when write, override the register at ctrl_reg_base,
> >                 one time can only change one 16bits register.
> >
> > Signed-off-by: Li Jun <jun.li at nxp.com>
> > Signed-off-by: Xu Yang <xu.yang_2 at nxp.com>
> > ---
> >  drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 221 ++++++++++++++++++++-
> >  1 file changed, 220 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> > index ad8a55012e42..cb2392008ad2 100644
> > --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> > +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> > @@ -1,8 +1,9 @@
> >  // SPDX-License-Identifier: GPL-2.0+
> > -/* Copyright (c) 2017 NXP. */
> > +/* Copyright (c) 2017-2025 NXP. */
> 
> While you are at it can you remove the (c). New policy
> from NXP is to use directly:
> 
> Copyright 2017-2025 NXP.


Sure. Will do.

Thanks,
Xu Yang



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