regulator node names and unit-addresses? (Re: [PATCH v2 1/5] ARM: shmobile: kzm9d: Remove spurious regulator base addresses)

Hi Simon,

(pulling in regulator people and DT list)

On Wed, Sep 24, 2014 at 3:13 AM, Simon Horman [off-list ref] wrote:

On Wed, Sep 17, 2014 at 09:33:49AM +0200, Geert Uytterhoeven wrote:

quoted

On Wed, Sep 17, 2014 at 2:48 AM, Simon Horman
[off-list ref] wrote:

quoted

As there is no reg property the regulator nodes should
not include @...

You missed an important part of my comment:

"However, in the absence of a unit-address, the node name must be unique."

quoted

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Simon Horman <redacted>

---
v2
* First post
---
 arch/arm/boot/dts/emev2-kzm9d.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/emev2-kzm9d.dts b/arch/arm/boot/dts/emev2-kzm9d.dts
index 50ccd15..f27fcf0 100644
--- a/arch/arm/boot/dts/emev2-kzm9d.dts
+++ b/arch/arm/boot/dts/emev2-kzm9d.dts

@@ -27,7 +27,7 @@
                bootargs = "console=ttyS1,115200n81 ignore_loglevel root=/dev/nfs ip=dhcp";
        };

-       reg_1p8v: regulator at 0 {
+       reg_1p8v: regulator {
                compatible = "regulator-fixed";
                regulator-name = "fixed-1.8V";
                regulator-min-microvolt = <1800000>;

@@ -36,7 +36,7 @@
                regulator-boot-on;
        };

-       reg_3p3v: regulator at 1 {
+       reg_3p3v: regulator {
                compatible = "regulator-fixed";
                regulator-name = "fixed-3.3V";
                regulator-min-microvolt = <3300000>;

Now there are two "regulator" nodes.

Dtc will not complain, but will assume the second contains overrides for
first. "vddvario-supply" and "vdd33a-supply" of node "lan9220 at 20000000"
will both the point to the same node, and the network may not work.

You can see this yourself running

    dtc -I dtb -O dts arch/arm/boot/dts/emev2-kzm9d.dtb

What should we call the nodes?

"regulator0" and "regulator1"?
"regulator1v8" and "regulator3v3"?

Documentation/devicetree/bindings/regulator/regulator.txt doesn't mention
node names or (presence/lack of) unit-adresses, but the examples do have
unit-addresses.

Is this another case where we don't follow the "no reg, no unit-address"
ePAPR rule?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds