Merge branch '2021-12-23-make-OF_BOARD-a-boolean' into next

Merge v8 of Simon's series to make CONFIG_OF_BOARD a boolean option.
Quoting him:

With Ilias' efforts we have dropped OF_PRIOR_STAGE and OF_HOSTFILE so
there are only three ways to obtain a devicetree:

   - OF_SEPARATE - the normal way, where the devicetree is built and
      appended to U-Boot
   - OF_EMBED - for development purposes, the devicetree is embedded in
      the ELF file (also used for EFI)
   - OF_BOARD - the board figures it out on its own

The last one is currently set up so that no devicetree is needed at all
in the U-Boot tree. Most boards do provide one, but some don't. Some
don't even provide instructions on how to boot on the board.

The problems with this approach were covered in another patch[1], since
removed from this series.

In practice, OF_BOARD is not really distinct from OF_SEPARATE. Any board
can obtain its devicetree at runtime, even it is has a devicetree built
in U-Boot. This is because U-Boot may be a second-stage bootloader and its
caller may have a better idea about the hardware available in the machine.
This is the case with a few QEMU boards, for example.

So it makes no sense to have OF_BOARD as a 'choice'. It should be an
option, available with either OF_SEPARATE or OF_EMBED. This would allow
rpi3, for example, to run with the devicetree provided by the prior
bootloader.

This series makes this change, adding various missing devicetree files
(and placeholders) to make the build work.

To make the 'prior stage' side of things more deterministic, a new
OF_HAS_PRIOR_STAGE is added, which cannot be disabled by updated a board's
defconfig. This should help to prevent mistakes.

It also adds a run-time message showing where the devicetree came from,
as well as warnings if the board's expected flow is not being used. This
comes originally from the 'standard passage' series, which depends on
this series.

It also provides a few qemu clean-ups discovered along the way. The
qemu-riscv64_spl problem is fixed.

Please see [2] for discussion on the v6 series.

I put Heinrich's Tested-by tag[3] for the series onto the three devicetree
patches (ARM and RISC-V) that I think it most affects. It isn't possible
to apply a tag to a whole series at present and in any case there are
changes in v7.

This series is available at u-boot-dm/ofb-working

[1] https://patchwork.ozlabs.org/project/uboot/patch/[email protected]/
[2] https://lore.kernel.org/u-boot/20211205133207.GW1220664@bill-the-cat/T/#mcd8c0258827fbc1bb3000b7ff9ba0929df1ddcb2
[3] https://lore.kernel.org/u-boot/[email protected]/raw

3 files changed, 25 insertions, 1 deletions

diff --git a/include/dm/device.h b/include/dm/device.h
index 544734ecb31..cf785f7ae21 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -593,7 +593,7 @@ int device_get_child(const struct udevice *parent, int index,
 		     struct udevice **devp);
 
 /**
- * device_get_child_count() - Get the available child count of a device
+ * device_get_child_count() - Get the child count of a device
  *
  * Returns the number of children to a device.
  *
@@ -602,6 +602,15 @@ int device_get_child(const struct udevice *parent, int index,
 int device_get_child_count(const struct udevice *parent);
 
 /**
+ * device_get_decendent_count() - Get the total number of decendents of a device
+ *
+ * Returns the total number of decendents, including all children
+ *
+ * @parent:	Parent device to check
+ */
+int device_get_decendent_count(const struct udevice *parent);
+
+/**
  * device_find_child_by_seq() - Find a child device based on a sequence
  *
  * This searches for a device with the given seq.
diff --git a/include/dm/root.h b/include/dm/root.h
index 42510b106ab..780f269db65 100644
--- a/include/dm/root.h
+++ b/include/dm/root.h
@@ -131,4 +131,12 @@ int dm_remove_devices_flags(uint flags);
 static inline int dm_remove_devices_flags(uint flags) { return 0; }
 #endif
 
+/**
+ * dm_get_stats() - Get some stats for driver mode
+ *
+ * @device_countp: Returns total number of devices that are bound
+ * @uclass_countp: Returns total number of uclasses in use
+ */
+void dm_get_stats(int *device_countp, int *uclass_countp);
+
 #endif
diff --git a/include/dm/uclass-internal.h b/include/dm/uclass-internal.h
index 49808c5c856..fb0edcc2969 100644
--- a/include/dm/uclass-internal.h
+++ b/include/dm/uclass-internal.h
@@ -307,6 +307,13 @@ static inline int uclass_pre_remove_device(struct udevice *dev) { return 0; }
 #endif
 
 /**
+ * uclass_get_count() - Get the number of uclasses
+ *
+ * Returns the number of uclasses instantiated in driver model
+ */
+int uclass_get_count(void);
+
+/**
  * uclass_find() - Find uclass by its id
  *
  * @id:		Id to serach for