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>

Since we want clk_ops to be used in U-Boot as a whole, rename the Zynq
version until it can be converted to driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>

It is common for system reset to be available at multiple levels in modern
hardware. For example, an SoC may provide a reset option, and a board may
provide its own reset for reasons of security or thoroughness. It is useful
to be able to model this hardware without hard-coding the behaviour in the
SoC or board. Also there is a distinction sometimes between resetting just
the CPU (leaving GPIO state alone) and resetting all the PMICs, just cutting
power.

To achieve this, add a simple system reset uclass. It allows multiple devices
to provide reset functionality and provides a way to walk through them,
requesting a particular reset type until is it provided.

Signed-off-by: Simon Glass <sjg@chromium.org>

Some functions called by mkimage would like to know the output file size.
Initially this is the same as the input file size, but it may be affected by
adding headers, etc.

Add this information to the image parameters.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

As a debug option, add positive confirmation that SPL has completed
execution. This can help with diagnosing the location of unexpected hangs.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add an spl_init() function that does basic init such that board_init_f() can
use simple malloc(), device tree and driver model. Each one is set up only
if enabled for SPL.

Note: We really should refactor SPL such that there is a single
board_init_f() and rename the existing weak board_init_f() functions
provided by boards, calling them from the single board_init_f().

Signed-off-by: Simon Glass <sjg@chromium.org>

It can be quite confusing with a new platform to figure out why the device
tree cannot be located. Add some debug information for this case.

Signed-off-by: Simon Glass <sjg@chromium.org>

Split out the code in fdtdec which finds a number at the end of a string. It
can be useful in other situations.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add an implementation of RC4. This will be used by Rockchip booting but may
be useful in other situations.

Signed-off-by: Simon Glass <sjg@chromium.org>

Since Rockchip requires 32-bit serial access, add this to the driver.
Refactor a little to make this easier.

Signed-off-by: Simon Glass <sjg@chromium.org>

Several functions in this file should be marked as static. Update them.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add support for a driver which sets up DRAM and can return information about
the amount of RAM available. This is a first step towards moving RAM init
to driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>

This bloats the code size quite a bit and is less useful in SPL where there
is no command line.

Avoid including this code in SPL.

Signed-off-by: Simon Glass <sjg@chromium.org>

This functionality may be useful for setting up regulators early during
boot.

Signed-off-by: Simon Glass <sjg@chromium.org>

It is a common requirement to update some PMIC registers. Provide some
simple convenience functions to do this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

To reduce unnecessary code size in an uncommon code path, use debug()
where possible(). The driver returns an error which indicates failure.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

The device tree provides information about which regulators should be
on at boot, or always on. Use this to set them up automatically.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

The regulator_autoset() function mixes printf() output and PMIC adjustment
code. It provides a boolean to control the output. It is better to avoid
missing logic and output, and this permits a smaller SPL code size. So
split the output into a separate function.

Also rename the function to have a by_name() suffix, since we would like
to be able to pass a device when we know it, and thus avoid the name
search.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

Decide when the regulator is set up whether we want to auto-set the voltage
or current. This avoids the complex logic spilling into the processing code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

This is not user input (i.e. from the command line). It should be possible
to get the case correct and avoid the case-insensitive match. This will
help avoid sloppy device tree setups.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

It took a little while to figure this out, so this patch adds documentation
to help the next person who needs to do this.

Signed-off-by: Simon Glass <sjg@chromium.org>

Enable MMC using driver model in SPL for consistency with U-Boot proper.

Signed-off-by: Simon Glass <sjg@chromium.org>

Allow read errors to be diagnosed more easily.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add basic support for MMC, providing a uclass which can set up an MMC
device. This allows MMC drivers to move to using driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add a few messages to indicate progress and failure.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add a simple driver which allows use of LEDs attached to GPIOs. The linux
device tree binding is used.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add a simple uclass for LEDs, so that these can be controlled by the device
tree and activated when needed. LEDs are referred to by their label.

This implementation requires a driver for each type of LED (e.g GPIO, I2C).

Signed-off-by: Simon Glass <sjg@chromium.org>

Many SoCs have a number of system controllers which are dealt with as a
group by a single driver. It is a pain to have to add lots of compatible
strings and/or separate drivers for each. Instead we can identify the
controllers by a number and request the address of the one we want.

Add a simple implementation of this which can be used by SoC driver code.

Signed-off-by: Simon Glass <sjg@chromium.org>

Add a simple implementaton of register maps, supporting only direct I/O
for now. This can be enhanced later to support buses which have registers,
such as I2C, SPI and PCI.

It allows drivers which can operate with multiple buses to avoid dealing
with the particulars of register access on that bus.

Signed-off-by: Simon Glass <sjg@chromium.org>

This function can be used for testing to manually request a GPIO for use,
without resorting to the legacy GPIO API.

Signed-off-by: Simon Glass <sjg@chromium.org>

Provide a driver-model function to look up a GPIO name. Make the standard
function use it.

Signed-off-by: Simon Glass <sjg@chromium.org>

Now that we support driver model in SPL, allow GPIO drivers to be used there
also.

Signed-off-by: Simon Glass <sjg@chromium.org>

This parameter is named 'seq' but should be named 'of_offset'.

Signed-off-by: Simon Glass <sjg@chromium.org>

In some rare cases it is useful to be able to locate a device given a device
tree node offset. An example is when you have an alias that points to a node
and you want to find the associated device. The device may be SPI, MMC or
something else, but you don't need to know the uclass to find it.

Add a function to do a global search for a device, given its device tree
offset.

Signed-off-by: Simon Glass <sjg@chromium.org>

To avoid bloating SPL code, use debug() where possible in the driver model
core code. The error code is already returned, and can be investigated as
needed.

Signed-off-by: Simon Glass <sjg@chromium.org>

In SPL it is sometimes useful to be able to obtain a dump of the current
driver model state. Since commands are not available, provide a way to
directly call the functions to output this information.

Adjust the existing commands to use these functions.

Signed-off-by: Simon Glass <sjg@chromium.org>

At present printf() skips output if it can see there is no console. This
is really just an optimisation, and is not necessary. Also it is currently
incorrect in some cases. Rather than update the logic, just remove it so
that we don't need to keep it in sync.

Signed-off-by: Simon Glass <sjg@chromium.org>

When there is no console ready, allow the debug UART to be used for output.
This makes debugging of early code considerably easier.

Signed-off-by: Simon Glass <sjg@chromium.org>

This does not actually help any current arch. For x86 it makes it harder
to call (requires stack) and for ARM it has no effect. Drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>

U-Boot uses structures for hardware access so it is important that these
structures are correct. Add a way of asserting that a structure member is
at a particular offset. This can be created using the datasheet for the
hardware.

This implementation uses Static_assert() since BUILD_BUG_ON() only works
within functions.

Signed-off-by: Simon Glass <sjg@chromium.org>