u-boot can be embedded within a FIT image with multiple DTBs. It then
selects at run-time which one is best suited for the platform.
Use the same principle here for the SPL: put the DTBs in a FIT image,
compress it (LZO, GZIP, or no compression) and append it at the end of the
SPL.
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
[trini: Move default y of SPL_MULTI_DTB_FIT_DYN_ALLOC to it being the
default choice if SYS_MALLOC_F, drop spl.h include from lib/fdtdec.c
it's unused.]
Signed-off-by Tom Rini <trini@konsulko.com>
The filename of the auto-generated file is the same as the file that
includes it. Even though the form is in the generated/ subdirectory, this
could be confused.
Rename the generated file to something that makes it clear it is
auto-generated.
Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
On some systems `python` is `python3` (for instance, Archlinux). The
`PYTHON` variable can be used to point to `python2` to have a successful
build.
The use of `PYTHON` is currently limited in the Makefile and needs to be
extended in other places:
First, pylibfdt is required to be a Python 2 binding (binman imports
pylibfdt and is only compatible Python 2), so its setup.py needs to be
called accordingly. An alternative would be to change the libfdt
setup.py shebang to python2, but the binding is actually portable. Also,
it would break on system where there is no such thing as `python2`.
Secondly, the libfdt import checks need to be done against Python 2 as
well since the Python 2 compiled modules (in this case _libdft.so) can
not be imported from Python 3.
Note on the libfdt imports: "@if ! PYTHONPATH=tools $(PYTHON) -c 'import
libfdt'; then..." is probably simpler than the currently sub-optimal
pipe.
Reviewed-by: Jonathan Gray <jsg@jsg.id.au>
About a quarter of the files in common/ relate to the environment. It
seems better to put these into their own subdirectory and remove the
prefix.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Now that we have split up SPL_LDSCRIPT into a SPL and TPL variant and
have started to use the TPL-variant for the RK3368, it's time to clean
up behind ourselves: move both variants into Kconfig and remove them
from the whitelist.
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
For the bringup of the RK3368, we need to support TPL and SPL running
from different addresses... which requires both stages to use a
distinct TEXT_BASE.
This commit adds support for having a separate LDSCRIPT for TPL (which
is expected to make use of the TPL_MAX_SIZE define) and for having a
the option of defining TPL_TEXT_BASE and having the TPL stage linked
against this address.
Note that the handling of the TEXT_BASE is designed to not interfere
with the previous assumption that SPL_TEXT_BASE should be used for TPL
as well, unless TPL_TEXT_BASE is defined. For this reason, the test
in Makefile.spl uses the following (seemingly redundant checks):
1. looks for $(SPL_TPL_)TEXT_BASE
2. looks for SPL_TEXT_BASE (even when building in TPL)
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
For the RK3368, we want to use OF_PLATDATA in TPL, but full OF_CONTROL
in SPL: this requires the introduction of a new family of
configuration options to decouple SPL_OF_CONTROL and SPL_OF_PLATDATA
from TPL.
Consequently, Makefile.spl needs to be adjusted to test for these
configuration items through the $(SPL_TPL_) macro instead of
hard-coding the SPL variant.
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
This is needed by binman and dtoc, so if those are being used, check that
the library is present and complain if not. Make sure that any error
appears on stderr so that buildman notices it.
This means that the fallback library (which uses fdtget) will not be used
anymore and swig will need to be installed to use binman / dtoc.
This affects any board which uses binman (currently sunxi and x86) or dtoc
(anything that uses CONFIG_SPL_OF_PLATDATA, currently some rockchip
boards).
Signed-off-by: Simon Glass <sjg@chromium.org>
This patch updates the mksunxiboot tool to optionally add
the default device tree name string to the SPL header. This
information can be used by the firmware upgrade tools to
protect users from harming themselves by trying to upgrade
to an incompatible bootloader.
The primary use case here is a non-removable bootable media
(such as NAND, eMMC or SPI flash), which already may have
a properly working, but a little bit outdated bootloader
installed. For example, the user may download or build a
new U-Boot image for "Cubieboard", and then attemept to
install it on a "Cubieboard2" hardware by mistake as a
replacement for the already existing bootloader. If this
happens, the flash programming tool can identify this
problem and warn the user.
The size of the SPL header is also increased from 64 bytes
to 96 bytes to provide enough space for the device tree name
string.
[Andre: split patch to remove OF_LIST hash feature]
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
When OF control is enabled for the SPL stage, nodes are removed from
the DTB to reduce its size. While /chosen is kept, /config is removed.
There's no reason why /chosen should be kept over /config (and as we
would like to put properties into /config that control the SPL stage),
we add '/config' to the list of nodes to be retained for the SPL stage.
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
Since Binutils 1a9ccd70f9a7[1] u-boot will not link targets that set
CONFIG_SYS_TEXT_BASE=0 with the following error:
LD u-boot
arm-linux-gnueabi-ld.bfd: u-boot: Not enough room for program headers, try
linking with -N
arm-linux-gnueabi-ld.bfd: final link failed: Bad value
The issue can be reproduced with the bad binutils and the rock2_defconfig
target.
This issue was also encountered by the powerpc kernel[2], with the fix
being to pass --no-dynamic-linker for linkers newer than 2.26 when this
flag was introduced. The option tells ld that the PIE or shared lib does
not need loaded program headers.
Ubuntu Zesty's Binutils 2.27.51.20161202 hits this error.
[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=1a9ccd70f9a7
[2] https://git.kernel.org/cgit/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=ff45000fcb56b5b0f1a14a865d3541746d838a0a
Signed-off-by: Joel Stanley <joel@jms.id.au>
[AF: Apply to LDFLAGS_$(SPL_BIN) as well, suggested by Tom Rini]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Introduce a new sunxi-spl-with-ecc.bin image with already the right header,
ECC, randomizer and padding for the BROM to be able to read it.
It needs to be flashed using a raw access to the NAND so that the
controller doesn't change a thing to it, since we already have all the
right parameters.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
At present we have SPL_ which can be used in Makefiles to select between
normal and SPL CONFIGs like this:
obj-$(CONFIG_$(SPL_)DM) += core/
When TPL is being built, SPL_ has the value 'SPL' which is generally a
good idea since they tend to follow each other. But in extreme situations
we may want to distinugish between SPL and TPL. For example we may not
want to enable CONFIG_DM with TPL.
Add a new SPL_TPL_ variable which is set to either empty (for U-Boot
proper), 'SPL' or 'TPL'. This may prove useful with TPL-specific options.
Signed-off-by: Simon Glass <sjg@chromium.org>
Right now the u-boot,dm-pre-reloc flag will make each marked node
always appear in both spl and tpl. But systems needing an additional
tpl might have special constraints for each, like the spl needing to
be very tiny.
So introduce two additional flags to mark nodes for only spl or tpl
environments and introduce a function dm_fdt_pre_reloc to automate
the necessary checks in code instances checking for pre-relocation
flags.
The behaviour of the original flag stays untouched and still marks
a node for both spl and tpl.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
When SPL is used we need to build the 16-bit start-up code. Add Makefile
rules to handle this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
When BSS does not immediate follow the SPL image we don't need padding
before the device tree. Remove it in this case.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This Makefile variable can be used in the architecture's main Makefile but
at present it is not set up until later. Set it just before this Makefile is
included.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
To being able to sign created binaries, we need to know the HAB Blocks
for that image. Especially for the imximage type the HAB Blocks are
only available during creation of the image. We want to preserve the
information until we get to sign the files.
In the verbose case we still get them printed out instead of writing
to log files.
Cc: sbabic@denx.de
v2-Changes:
- No usage of MKIMAGEOUTPUT_$(@F) macro.
- Predefine default value /dev/null in every involved Makefile.
Signed-off-by: Sven Ebenfeld <sven.ebenfeld@gmail.com>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Tested-by: George McCollister <george.mccollister@gmail.com>
Introduce USB Gadget config option. This allows to combine Makefile
entries for SPL_USBETH_SUPPORT and SPL_DFU_SUPPORT.
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Ravi Babu <ravibabu@ti.com>
The DFU Kconfig menu entries should be part of the SPL
Kconfig file. Also avoid using the top level Makefile by
moving the config dependent build artifacts to the driver/
and driver/usb/gadget/ Makfiles.
With that, DFU can be built again in SPL if
CONFIG_SPL_DFU_SUPPORT is enabled.
Fixes: 6ad6102246 ("usb:gadget: Disallow DFU in SPL for now")
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
The Zynq/ZynqMP boot.bin file contains a region for register initialization
data. Filling in proper values in this table can reduce boot time
(e.g. about 50ms faster on QSPI boot) and also reduce the size of
the SPL binary.
The table is a simple text file with register+data on each line. Other
lines are simply skipped. The file can be passed to mkimage using the
"-R" parameter.
It is recommended to add reg init file to board folder.
For example:
CONFIG_BOOT_INIT_FILE="board/xilinx/zynqmp/xilinx_zynqmp_zcu102/reg.int
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
CONFIG_SUNXI -> CONFIG_ARCH_SUNXI
and removed CONFIG_SUNIX from config_whitelist.txt
Cc: Simon Glass <sjg@chromium.org>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jagan Teki <jteki@openedev.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Our build system still parses ad-hoc CONFIG options in header files
and generates include/autoconf.mk so that Makefiles can reference
them. This gimmick was introduced in the pre-Kconfig days and will
be kept until Kconfig migration is completed.
The include/autoconf.mk is generated like follows:
[1] Preprocess include/common.h with -DDO_DEPS_ONLY and
retrieve macros into include/autoconf.mk.tmp
[2] Reformat include/autoconf.mk.dep into include/autoconf.mk
with tools/scripts/define2mk.sed script
[3] Remove include/autoconf.mk.tmp
Here, include/autoconf.mk.tmp is similar to u-boot.cfg, which is
also generated by preprocessing include/config.h with -DDO_DEPS_ONLY.
In other words, there is much overlap among include/autoconf.mk and
u-boot.cfg build rules.
So, the idea is to split the build rule of include/autoconf.mk
into two stages. The first preprocesses headers into u-boot.cfg.
The second parses the u-boot.cfg into include/autoconf.mk. The
build rules of u-boot.cfg in Makefile and spl/Makefile will be gone.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Traditionally the DFU support is available only
as part 2nd stage boot loader(u-boot) and DFU
is not supported in SPL.
The SPL-DFU feature is useful for boards which
does not have MMC/SD, ethernet boot mechanism
to boot the board and only has USB inteface.
This patch add DFU support in SPL with RAM
memory device support to load and execute u-boot.
And then leverage full functionality DFU in
u-boot to flash boot inital binary images to
factory or bare-metal boards to memory devices
like SPI, eMMC, MMC/SD card using USB interface.
This SPL-DFU support can be enabled through
Menuconfig->Boot Images->Enable SPL-DFU support
Signed-off-by: Ravi Babu <ravibabu@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Prior to the previous patch, a freshly created .u-boot.cfg.cmd may not
correctly represent all dependencies for u-boot.cfg. The previous change
only solved this issue for fresh builds; when performing an incremental
build, the deficient .u-boot.cfg.cmd is already present, so u-boot.cfg
is not rebuilt, and hence .u-boot.cfg.cmd is not rebuilt with the correct
content.
Solve this by explicitly detecting when the dependency file .u-boot.cfg.d
has not been integrated into .u-boot.cfg.cmd, and force u-boot.cfg to be
rebuilt in this case by deleting it first. This is possible since
if_changed_dep will always delete .u-boot.cfg.d when it executes
successfully, so its presence means either that the previous build was
made by a source tree that contained a Makefile that didn't include the
previous patch, or that the build failed part way through executing
if_changed_dep for u-boot.cfg. Forcing a rebuild of u-boot.cfg is required
in the former case, and will cause no additional work in the latter case,
since the file would be rebuilt anyway for the same reason it was being
rebuilt by the previous build.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
cmd_cpp_cfg generates a dependency output, but because it's invoked using
if_changed rather than if_changed_dep, that dependency file is ignored.
This results in Kbuild not knowing about which files u-boot.cfg depends
on, so it may not be rebuilt when required.
A practical result of this is that u-boot.cfg may continue to reference
CONFIG_ options that no longer exist in the source tree, and this can
cause the adhoc config options check to fail.
This change modifies Makefile to use if_changed_dep, which in turn causes
all dependencies to be known to the next make invocation.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
At present TPL uses the same options as SPL support. In a few cases the board
config enables or disables the SPL options depending on whether
CONFIG_TPL_BUILD is defined.
With the move to Kconfig, options are determined for the whole build and
(without a hack like an #undef in a header file) cannot be controlled in this
way.
Create new TPL options for these and update users. This will allow Kconfig
conversion to proceed for these boards.
Signed-off-by: Simon Glass <sjg@chromium.org>
When of-platdata is used in SPL we don't use the device tree. So there is no
point in attaching it. Adjust the Makefile to skip attaching the device tree
when of-platdata is enabled.
Signed-off-by: Simon Glass <sjg@chromium.org>
Update the Makefile to call dtoc to create the C header and source files,
then build these into the image.
Signed-off-by: Simon Glass <sjg@chromium.org>
Overriding the final link rule is possible with U-Boot proper. It us used to
create a sandbox image links with host libraries. To build a sandbox SPL
image we need the same feature for SPL.
To support this, update the SPL link rule so sandbox can override it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add support for the zynqmpimage to mkimage.
Only basic functionality is supported without encryption and register
initialization with one partition which is filled by U-Boot SPL.
For more detail information look at Xilinx ZynqMP TRM.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
dtb is already included in binary that's why there is no need to replace
u-boot-spl.bin with u-boot-spl-dtb.bin. This is only needed for
OF_SEPARATE is enabled. Only copy -nodtb.bin version which is straight
output from objcopy -O binary.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
The build command of u-boot-spl.dtb is not constant, but dependent
on CONFIG_OF_SPL_REMOVE_PROPS. Use $(call if_changed,...) so that
the change of CONFIG_OF_SPL_REMOVE_PROPS is detected.
Also, add tools/fdtgrep to the dependency to make sure u-boot-spl.dtb
is generated by the up-to-date fdtgrep in case the tool is modified.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
FORCE is needed for $(call if_changed,...) to be evaluated every time.
Otherwise, the command is not executed when the command line has
changed but any prerequisite has not been updated.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
These rules are only used for SOCFPGA, SUNXI, but no need to hide
them from other SoCs.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
At present u-boot-spl.bin holds the plain SPL binary without the device
tree. This is somewhat annoying since you need either u-boot-spl.bin or
u-boot-spl-dtb.bin depending on whether device tree is used.
Adjust the build such that u-boot-spl.bin includes a device tree
(if enabled), and the plain binary is in u-boot-spl-nodtb.bin. For now
u-boot-spl-dtb.bin remains the same.
Tested-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
There are a lot of unrelated files in common, including all of the commands.
Moving them into their own directory makes them easier to find and is more
logical.
Some commands include non-command code, such as cmd_scsi.c. This should be
sorted out at some point so that the function can be enabled with or without
the associated command.
Unfortunately, with m68k I get this error:
m68k: + M5329AFEE
+arch/m68k/cpu/mcf532x/start.o: In function `_start':
+arch/m68k/cpu/mcf532x/start.S:159:(.text+0x452): relocation truncated to fit: R_68K_PC16 against symbol `board_init_f' defined in .text.board_init_f section in common/built-in.o
I hope someone can shed some light on what this means. I hope it isn't
depending on the position of code in the image.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>
Add a build target to generate 'boot.bin' which includes SPL. This is
used by the platforms BootROM to load SPL directly.
This change also conditionally changes what the 'boot.bin' target
generates depending on the SoC. Leaving the behaviour unchanged for the
AT91 targets.
Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Andreas Bießmann <andreas.devel@googlemail.com>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
CONFIG_OF_EMBED=y is the option which is here only for testing purpose
and shouldn't be enabled by default as is describe at:
"dts: Add a comment about CONFIG_OF_EMBED being for local use"
(sha1: 3d3f60cb7a)
But still enabling this option locally shouldn't end up with compilation
error when you build SPL. This patch fix it.
Compilation error:
lib/built-in.o: In function `fdtdec_setup':
/mnt/disk/u-boot/lib/fdtdec.c:1246: undefined reference to
`__dtb_dt_begin'
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reported-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
At present this file is generated even when device tree is not enabled in
SPL. Avoid this, since this file serves no purpose in that case.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
This function will be used by both SPL and U-Boot proper. So move it into
a common place. Also change the #ifdef so that the early malloc() area is
not set up in SPL if CONFIG_SYS_SPL_MALLOC_START is defined. In that case
it would never actually be used, and just chews up stack space.
Signed-off-by: Simon Glass <sjg@chromium.org>
Just preparing for upcoming cleaning.
The board-specific linker script board/vpac270/u-boot-spl.lds
has been touched to avoid build error. It does not change the
size of spl/u-boot-spl.bin for this board, so it should be OK.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add build target for generating boot partition images recognised by
the SoCFPGA BootROM. The SoCFPGA BootROM expects four copies of the
u-boot-spl-dtb.sfp at the beginning of boot partition. Those are
u-boot-spl-dtb.bin augmented by a header with which the BootROM can
work. The u-boot-dtb.img uImage is appended to this to produce a
full boot partition image, the u-boot-with-spl-dtb.sfp . This is
the name of the final target.
Signed-off-by: Marek Vasut <marex@denx.de>
This patch enables the SDRAM controller that is used on Altera's SoCFPGA
family. This patch configures the SDRAM controller based on a configuration
file that is generated from the Quartus tool, sdram_config.h.
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
This patch adds the DDR3 setup and training code taken from the Marvell
U-Boot repository. This code used to be included as a binary (bin_hdr)
into the Armada A38x boot image. Not linked with the main U-Boot. With this
code addition and the serdes/PHY setup code, the Armada A38x support
in mainline U-Boot is finally self-contained. So the complete image
for booting can be built from mainline U-Boot. Without any additional
external inclusion.
Note:
This code has undergone many hours (days!) of coding-style cleanup and
refactoring. It still is not checkpatch clean though, I'm afraid. As the
factoring of the code has so many levels of indentation that many lines
are longer than 80 chars.
Signed-off-by: Stefan Roese <sr@denx.de>
With the upcoming addition of the Armada 38x DDR support, which is not
compatible to the Armada XP DDR init code, we need to introduce a new
directory infrastructure. To support multiple Marvell DDR controller.
This will be the new structure:
drivers/ddr/marvell/axp
Supporting Armada XP (AXP) devices (and perhaps Armada 370)
drivers/ddr/marvell/a38x
Supporting Armada 38x devices (and perhaps Armada 39x)
Signed-off-by: Stefan Roese <sr@denx.de>
Clocks are an important feature of platforms and have become increasing
complex with time. Most modern SoCs have multiple PLLs and dozens of clock
dividers which distribute clocks to on-chip peripherals.
Some SoC implementations have a clock API which is private to that SoC family,
e.g. Tegra and Exynos. This is useful but it would be better to have a
common API that can be understood and used throughout U-Boot.
Add a simple clock API as a starting point. It supports querying and setting
the rate of a clock. Each clock is a device. To reduce memory and processing
overhead the concept of peripheral clocks is provided. These do not need to
be explicit devices - it is possible to write a driver that can adjust the
I2C clock (for example) without an explicit I2C clock device. This can
dramatically reduce the number of devices (and associated overhead) in a
complex SoC.
Clocks are referenced by a number, and it is expected that SoCs will define
that numbering themselves via an enum.
Signed-off-by: Simon Glass <sjg@chromium.org>
