Re: [PATCH 1/2] dt-bindings: reset: imx8mq: Add _N suffix to IMX8MQ_RESET_MIPI_CSI*_RESET

Robby Cai
2026-04-14T10:44:21Z

On Wed, Apr 01, 2026 at 09:41:48AM +0200, Krzysztof Kozlowski wrote:
> On Tue, Mar 31, 2026 at 06:13:30PM +0800, Robby Cai wrote:
> > The assert logic of the MIPI CSI reset signals is active-low on i.MX8MQ,
> > but the existing names do not indicate this explicitly. To improve
> > consistency and clarity, append the _N suffix to all
> > IMX8MQ_RESET_MIPI_CSI*_RESET definitions. The deprecated
> > IMX8MQ_RESET_MIPI_CSI*_RESET versions remain temporarily for DT ABI
> > compatibility and will be removed at an appropriate time in the future.
> >
> > Signed-off-by: Robby Cai <robby.cai@nxp.com>
> > ---
> > include/dt-bindings/reset/imx8mq-reset.h | 18 ++++++++++++------
> > 1 file changed, 12 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/dt-bindings/reset/imx8mq-reset.h b/include/dt-bindings/reset/imx8mq-reset.h
> > index 705870693ec2..83a155dbbd4a 100644
> > --- a/include/dt-bindings/reset/imx8mq-reset.h
> > +++ b/include/dt-bindings/reset/imx8mq-reset.h
> > @@ -46,12 +46,18 @@
> > #define IMX8MQ_RESET_PCIEPHY2_PERST 35 /* i.MX8MM/i.MX8MN does NOT support */
> > #define IMX8MQ_RESET_PCIE2_CTRL_APPS_EN 36 /* i.MX8MM/i.MX8MN does NOT support */
> > #define IMX8MQ_RESET_PCIE2_CTRL_APPS_TURNOFF 37 /* i.MX8MM/i.MX8MN does NOT support */
> > -#define IMX8MQ_RESET_MIPI_CSI1_CORE_RESET 38 /* i.MX8MM/i.MX8MN does NOT support */
> > -#define IMX8MQ_RESET_MIPI_CSI1_PHY_REF_RESET 39 /* i.MX8MM/i.MX8MN does NOT support */
> > -#define IMX8MQ_RESET_MIPI_CSI1_ESC_RESET 40 /* i.MX8MM/i.MX8MN does NOT support */
> > -#define IMX8MQ_RESET_MIPI_CSI2_CORE_RESET 41 /* i.MX8MM/i.MX8MN does NOT support */
> > -#define IMX8MQ_RESET_MIPI_CSI2_PHY_REF_RESET 42 /* i.MX8MM/i.MX8MN does NOT support */
> > -#define IMX8MQ_RESET_MIPI_CSI2_ESC_RESET 43 /* i.MX8MM/i.MX8MN does NOT support */
> > +#define IMX8MQ_RESET_MIPI_CSI1_CORE_RESET 38 /* Deprecated. Use *_RESET_N instead */
> > +#define IMX8MQ_RESET_MIPI_CSI1_CORE_RESET_N 38 /* i.MX8MM/i.MX8MN does NOT support */
>
> That's quite a churn for no need. The entire point of these values being
> the binding is that it describes the ABI for SW and DTS, not your
> hardware registers.
>
> Whether signal is active low or high is kind of irrelevant. Linux uses
> it exactly the same way.
>

The original naming was taken from the reference manual at the time.
The upcoming RM revision will clarify that these resets are active-low and
use the _N suffix, consistent with MIPI DSI.

However, I agree that the DT binding and naming need not be changed.
I'll keep the existing binding and naming, and address this in v2 by fixing the
reset logic in the driver only.

Regards,
Robby