[PATCH v3 2/2] ARM: dts: utilite-pro: add mmc card slot support

Hi Shawn,

On 06/15/2016 12:33 PM, Igor Grinberg wrote:

Hi Christopher,

On 06/15/2016 12:16 PM, Christopher Spinrath wrote:

quoted

Hi Igor,

On 06/15/2016 08:40 AM, Igor Grinberg wrote:

quoted

Hi Christopher,

On 06/13/2016 02:24 AM, christopher.spinrath at rwth-aachen.de wrote:

quoted

From: Christopher Spinrath <redacted>

The Utilite Pro has a mmc card slot connected to the usdhc3
controller. There is no card detection until hardware revision 1.3.

Add support for it and signal the controller with the broken-cd
property that polling has to be used to detect a card.

Signed-off-by: Christopher Spinrath <redacted>
Reviewed-by: Fabio Estevam <redacted>
---

Notes:
    Changes since v2:
     - add Fabio's Reviewed-By
    
    Changes since v1:
     - enhance commit message to explain to the broken-cd property

 arch/arm/boot/dts/imx6q-utilite-pro.dts | 44 +++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/arch/arm/boot/dts/imx6q-utilite-pro.dts b/arch/arm/boot/dts/imx6q-utilite-pro.dts
index 7219745..6199063 100644
--- a/arch/arm/boot/dts/imx6q-utilite-pro.dts
+++ b/arch/arm/boot/dts/imx6q-utilite-pro.dts

[...]

quoted

@@ -151,3 +184,14 @@
 	uart-has-rtscts;
 	status = "okay";
 };
+
+&usdhc3 {
+	pinctrl-names = "default", "state_100mhz", "state_200mhz";
+	pinctrl-0 = <&pinctrl_usdhc3>;
+	pinctrl-1 = <&pinctrl_usdhc3_100mhz>;
+	pinctrl-2 = <&pinctrl_usdhc3_200mhz>;
+	no-1-8-v;
+	broken-cd;

A wast majority of boards produced are of revision >=1.3.
Can we please have the default as revision 1.3 with cd?
And let the patch you have submitted to U-Boot do the job
for older revisions?

Well, my board has revision 1.0. So I cannot test that and feel uneasy
to put my Signed-off-by under such a patch. IMHO the best solution would
be that someone with a revision >= 1.3 board sends a follow-up patch
adding the cd-gpios.

If I resend the patch with cd-gpios could you test it and provide a
Tested-By?

Yes. Absolutely.

Can we have your opinion on that matter?

quoted

The other question is: should the dts provide a working/sane
configuration for all boards (which the broken-cd approach is)
independently of the bootloader?

Well, no, I wouldn't go that way, as "why wouldn't we just use the
broken-cd approach on all boards and not bother with gpio-cds"...
We do want the gpio-cd to work as expected where it can.

quoted

Is it ok to put both, the  cd-gpios and
the broken-cd property into the dts and let the bootloader remove the
broken-cd property for revision >= 1.3 (due to the documentation it is
not but the driver favourites the broken cd property - hence, it would
work)?

That sounds sane from my POV (unless I'm missing something), but
will have to have comments explaining what is going on.

There are two main reasons why I would not want to have the broken-cd
as a default:
1) It is not broken... It just does not exist prior to revision 1.3.
2) There are more boards of revision >=1.3 then older ones outside and
   we would want them to work as expected even with older U-Boot versions.