RE: [PATCH] Document: dt: binding: imx: Fix PAD_CTL_DSE_X*

[Aisheng Dong <aisheng.dong@xxxxxxx>]

+ Haibo

> From: Stefan Agner [mailto:stefan@xxxxxxxx]
> Sent: Tuesday, February 26, 2019 9:22 PM
> 
> On 26.02.2019 13:21, Aisheng Dong wrote:
> >> From: Christina Quast [mailto:cquast@xxxxxxxxxxxxxxxxxxx]
> >> Sent: Saturday, February 23, 2019 1:01 AM
> >>
> >> In the iMX7d datasheet, the PAD_CTL_DSE_X* values are different from
> >> the documentation.
> >>
> >
> > It's a doc problem.
> > Latest RM seems got updated.
> >
> > As here it's a reference definition in binding doc and device tree
> > actually does not use it (IMX Pinctrl use raw data to set pad
> > configuration). So it won't cause any compatibility issue to me.
> >
> > Please update the patch title to:
> > dt-bindings: pinctrl: imx7d: xxxxx
> >
> > Otherwise:
> > Ack-by: Dong Aisheng <aisheng.dong@xxxxxxx>
> 
> Btw, I saw that imx7d-sdb.dts (and probably other i.MX 7 boards too) use three
> different settings for usdhc pinctrl: 0x59, 0x5a and 0x5b (for default, 100MHz
> and 200MHz respectively). One would expect that higher frequency use higher
> driver strength (and this is the case for i.MX 6).
> But with this new/corrected pad values this means we use x4, x2 and x6 for
> default, 100MHz and 200MHz respectively. This hardly seems right..?
> Probably needs fixing too?
> 

Yes, that's true.
Especially 100Mhz setting should be updated.

Haibo,
Can you please help double check if X2 for 50Mhz and X4 for 100Mhz can work stably
on MX7D SDB?
If yes, we'd like to update the pad setting according to new RM version.

Regards
Dong Aisheng

> --
> Stefan
> 
> 
> >
> > Regards
> > Dong Aisheng
> >
> >> Signed-off-by: Christina Quast <cquast@xxxxxxxxxxxxxxxxxxx>
> >> ---
> >>  .../devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt       | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git
> >> a/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> >> b/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> >> index 6666277c3acb..8ac1d0851a0f 100644
> >> --- a/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> >> +++ b/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> >> @@ -48,9 +48,9 @@ PAD_CTL_HYS                     (1 << 3)
> >>  PAD_CTL_SRE_SLOW                (1 << 2)
> >>  PAD_CTL_SRE_FAST                (0 << 2)
> >>  PAD_CTL_DSE_X1                  (0 << 0)
> >> -PAD_CTL_DSE_X2                  (1 << 0)
> >> -PAD_CTL_DSE_X3                  (2 << 0)
> >> -PAD_CTL_DSE_X4                  (3 << 0)
> >> +PAD_CTL_DSE_X4                  (1 << 0)
> >> +PAD_CTL_DSE_X2                  (2 << 0)
> >> +PAD_CTL_DSE_X6                  (3 << 0)
> >>
> >
> >
> >>  Examples:
> >>  While iomuxc-lpsr is intended to be used by dedicated peripherals to
> >> take
> >> --
> >> 2.20.1
> >>
> >>
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