Re: [PATCH v5 1/4] dt-bindings: power: reset: add document for reboot-mode driver

[Andy Yan]

Hi Rob:


On 2016å03æ17æ 23:52, Rob Herring wrote:
> On Tue, Mar 08, 2016 at 08:23:05PM +0800, Andy Yan wrote:
> > add device tree bindings document for reboot-mode driver
> >
> > Signed-off-by: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
> >
> > ---
> >
> > Changes in v5:
> > - delete a unnecessary blank line in syscon-reboot-mode.txt
> > - rename macro BOOT_LOADER to BOOT_BL_DOWNLOAD, which gives a more clear mean
> >
> > Changes in v4:
> > - remove mode-maskrom
> > - rename mode-fastboot to mode-bootloader to keep compatible with the exiting Android device
> >
> > Changes in v3:
> > - descirbe all reboot mode as properity instead of subnode
> >
> > Changes in v2: None
> > Changes in v1: None
> >
> >   .../bindings/power/reset/reboot-mode.txt           | 24 +++++++++++++++
> >   .../bindings/power/reset/syscon-reboot-mode.txt    | 34 ++++++++++++++++++++++
> >   2 files changed, 58 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/power/reset/reboot-mode.txt
> >   create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> >
> > diff --git a/Documentation/devicetree/bindings/power/reset/reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/reboot-mode.txt
> > new file mode 100644
> > index 0000000..3457949
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/power/reset/reboot-mode.txt
> > @@ -0,0 +1,24 @@
> > +Generic reboot mode core map driver
> > +
> > +This driver get reboot mode arguments and call the write
> > +interface to stores the magic value in special register
> > +or ram . Then the bootloader can read it and take different
> > +action according the argument stored.
> > +
> > +All mode properties are vendor specific, it is a indication to tell
> > +the bootloder what to do when the system reboot, and should be named
> > +as mode-xxx = <magic> (xxx is mode name).
> > +
> > +- mode-normal: Normal reboot mode, system reboot with command "reboot".
> > +- mode-recovery: Android Recovery mode, it is a mode to format the device or update a new image.
> > +- mode-bootloader: Android fastboot mode, it's a mode to re-flash partitions on the Android based device.
> > +- mode-loader: A bootloader mode, it's a mode used to download image on Rockchip platform,
> > +	       usually used in development.
> > +
> > +Example:
> > +	reboot-mode {
> > +		mode-normal = <BOOT_NORMAL>;
> > +		mode-recovery = <BOOT_RECOVERY>;
> > +		mode-bootloader = <BOOT_FASTBOOT>;
> > +		mode-loader = <BOOT_BL_DOWNLOAD>;
> > +	}
> > diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> > new file mode 100644
> > index 0000000..d03cb52
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> > @@ -0,0 +1,34 @@
> > +SYSCON reboot mode driver
> > +
> > +This driver get reboot mode magic value form reboot-mode driver
> > +and stores it in a SYSCON mapped register. Then the bootloader
> > +can read it and take different action according to the magic
> > +value stored.
> > +
> > +This DT node should be represented as a sub-node of a "syscon", "simple-mfd"
> > +node.
> > +
> > +Required properties:
> > +- compatible: should be "syscon-reboot-mode"
> > +- offset: offset in the register map for the storage register (in bytes)
> > +
> > +Optional properity:
> > +- mask: the mask bits of the mode magic value, default set to 0xffffffff if missing.
> I can't see how this is used. I would drop it for now.
>
> With that change:
>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>

The mask is suggested by Moritz Fischer in V2[0]. And I found Tegra did 
indeed only use some bits of one register to store the reboot mode[1].

@Heiko: It seems that this patch series can land now, but the dts parts 
belong to  two different branch(arm32 and arm64) . And these
two parts both depends on one head file rockchip_boot-mode.h, So I hope 
some suggestions from you how to deal with it.

   [0] https://lkml.org/lkml/2016/1/27/225
   [1] drivers/soc/tegra/pmc.c  (tegra_pmc_restart_notify)
> > +
> > +The rest of the properties should follow the generic reboot-mode discription
> > +found in reboot-mode.txt
> > +
> > +Example:
> > +	pmu: pmu@20004000 {
> > +		compatible = "rockchip,rk3066-pmu", "syscon", "simple-mfd";
> > +		reg = <0x20004000 0x100>;
> > +
> > +		reboot-mode {
> > +			compatible = "syscon-reboot-mode";
> > +			offset = <0x40>;
> > +			mode-normal = <BOOT_NORMAL>;
> > +			mode-recovery = <BOOT_RECOVERY>;
> > +			mode-bootloader = <BOOT_FASTBOOT>;
> > +			mode-loader = <BOOT_BL_DOWNLOAD>;
> > +		};
> > +	};
> > --
> > 1.9.1