On Thu, Feb 23, 2012 at 2:11 PM, Jason [off-list ref] wrote:

On Thu, Feb 23, 2012 at 01:18:55PM -0700, Grant Likely wrote:

quoted

On Thu, Feb 23, 2012 at 12:52 PM, Jason Cooper [off-list ref] wrote:

quoted

Initially, copied guruplug-setup.c and did s/guruplug/dreamplug/g.
Then, switched to SPI based NOR flash.

After talking to Arnd Bergman, chose an incremental approach to adding
devicetree support.  First, we use the dtb to tell us we are on the
dreamplug, then we gradually port over drivers.

Driver porting will start with the uart (see next patch), and progress
from there.  Possibly, spi/flash/partitions will be next.

When done, board-dt.c will no longer be dreamplug specific, and dt's can
be made for the other kirkwood boards.

Signed-off-by: Jason Cooper <redacted>
---
Changes from v1

  - attempting dts, looking for pointers.

Changes from v2

  - resubmit as MACH_TYPE_DREAMPLUG (3550) is in arm/for-next, rebased
    against same.
  - removed lame fdt attempt, others are working on kirkwood fdt.  Will
    convert once kirkwood fdt is mainline.
  - s/boot_params/atag_offset/
  - added kirkwood_reset
  - 1 checkpatch.pl warning (help in Kconfig), looks the same as all
    other kirkwood boards...

Changes from v3

  - rebased against v3.3-rc3 (recommended by Arnd)
  - use devicetree to determine which board we are on
  - added patch to configure uart0 from devicetree

Changes from v4

  - fixed Kconfig logic so user can always see 'Dreamplug' in menuconfig.
  - changed 'marvell,dreamplug' to 'globalscale,dreamplug' as suggested by
    Grant Likely.
  - fixed of_machine_is_compatible() logic for calling dreamplug specific
    init functions.

 arch/arm/boot/dts/kirkwood-dreamplug.dts |   18 +++
 arch/arm/boot/dts/kirkwood.dtsi          |    6 +
 arch/arm/mach-kirkwood/Kconfig           |   14 +++
 arch/arm/mach-kirkwood/Makefile          |    1 +
 arch/arm/mach-kirkwood/Makefile.boot     |    2 +
 arch/arm/mach-kirkwood/board-dt.c        |  182 ++++++++++++++++++++++++++++++
 6 files changed, 223 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/boot/dts/kirkwood-dreamplug.dts
 create mode 100644 arch/arm/boot/dts/kirkwood.dtsi
 create mode 100644 arch/arm/mach-kirkwood/board-dt.c

diff --git a/arch/arm/boot/dts/kirkwood-dreamplug.dts b/arch/arm/boot/dts/kirkwood-dreamplug.dts
new file mode 100644
index 0000000..765813f
--- /dev/null
+++ b/arch/arm/boot/dts/kirkwood-dreamplug.dts

@@ -0,0 +1,18 @@
+/dts-v1/;
+
+/include/ "kirkwood.dtsi"
+
+/ {
+       model = "Globalscale Technologies Dreamplug";
+       compatible = "globalscale,dreamplug", "globalscale,kirkwood";

Hahaha... okay, more clarification is needed here.

The compatible property is a list, and the first entry must always be
the exact device model.  That is why the vendor of the hardware is in
the prefix.  However, the following entries are a list of devices that
it is 'compatible' with.  In the case of the top-level compatible
property, we've been using the convention of including a string for
the SoC, and in that case the manufacturer is indeed Marvell.

Also, *be specific*.  Kirkwood is a family of processors, not a single
SoC.  The compatible string should reflect that.  So, in your case,
compatible should look something like:

compatible = "globalscale,dreamplug", "marvell,kirkwood-88f6281";

ahhh... ok.  So, my board-dt.c should have:

static const char *kirkwood_dt_board_compat[] = {
       "marvell,kirkwood",
       NULL
};

And then the test to run the dreamplug specific init should be:

       if (of_machine_is_compatible("globalscale,dreamplug"))
               dreamplug_init();

And then, kirkwood.dtsi:

compatible = "marvell,kirkwood";

and kirkwood-dreamplug.dts:

compatible = "globalscale,dreamplug", "marvell,kirkwood-88f6281-a1";


My only question is, should the kirkwood.dtsi have just
"marvell,kirkwood", or "marvell,kirkwood","marvell,kirkwood-88f6281-a1"?

Fix the order.  The list is ordered from most specific to least.
Also, if the silicon revision can be read out of the SoC at runtime,
then including the -a1 revision is probably overkill.

So, something like the following is fine:

compatible = "globalscale,dreamplug", "marvell,kirkwood-88f6281",
"marvell,kirkwood";

BTW, does the dreamplug have a part number?

I'm guessing kirkwood.dtsi is a generic devicetree, and should just be
"marvell,kirkwood".  If that's true, then *kirkwood_dt_board_compat
should just be "marvell,kirkwood" since board-dt.c should be able to
handle any kirkwood SoC.

Sorry for being so dense.

thx,

Jason.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.