allwinner: Reserve and map space for the SCP firmware ...

The SCP firmware is allocated the last 16KiB of SRAM A2. This includes
the SCPI shared memory area, which must be mapped as MT_DEVICE to
prevent problems with cache coherency between the AP CPUs and the SCP.
For simplicity, map the whole SCP region as MT_DEVICE.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Ie39eb5ff281b8898a3c1d9748dc08755f528e2f8

allwinner: Adjust SRAM A2 base to include the ARISC vectors ...

The ARISC vector area consists of 0x4000 bytes before the beginning of
usable SRAM. Still, it is technically a part of SRAM A2, so include it
in the memory definition. This avoids the confusing practice of
subtracting from the beginning of the SRAM region when referencing the
ARISC vectors.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Iae89e01aeab93560159562692e03e88306e2a1bf

allwinner: Clean up MMU setup ...

Remove the general BL31 mmap region: it duplicates the existing static
mapping for the entire SRAM region. Use the helper definitions when
applicable to simplify the code and add the MT_EXECUTE_NEVER flag.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I7a6b79e50e4b5c698774229530dd3d2a89e94a6d

allwinner: Reenable USE_COHERENT_MEM ...

Now that there is plenty of space (32 KiB) available for NOBITS
sections, we can afford using an entire page for coherent memory. In
fact, because it simplifies the code, this is a beneficial change for
loaded image (.text) size, where we are still close to the size limit.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I0b899dabcb162015c63b0e4aed0869569c889ed9

allwinner: Enable clock before resetting I2C/RSB ...

The clock must be running for the module to be reset.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Ic8fafc946f3a1a697174b91288e357ffa033ab9a

allwinner: Fix incorrect ARISC code patch offset check ...

The current range check for the offset is wrong: it is counting bytes,
while indexing an array of uint32_t. Since the offset is always zero,
the parameter is unnecessary. Instead of adding more code to fix the
check, remove the parameter to avoid the problem entirely.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Iadfc7d027155adc754e017b3462233ce9a1d64f6

allwinner: Constify data structures ...

This maximizes the amount of data protected by the MMU.

Signed-off-by: Samuel Holland <samuel@sholland.org>

Sanitise includes across codebase ...

Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928d5b7 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3a282 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca33988b9 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

allwinner: Prepare for executing code on the management processor ...

The more recent Allwinner SoCs contain an OpenRISC management
controller (called arisc or CPUS), which shares the bus with the ARM cores,
but runs on a separate power domain. This is meant to handle power
management with the ARM cores off.
There are efforts to run sophisticated firmware on that core
(communicating via SCPI with the ARM world), but for now can use it for
the rather simple task of helping to turn the ARM cores off. As this
cannot be done by ARM code itself (because execution stops at the
first of the three required steps), we can offload some instructions to
this management processor.
This introduces a helper function to hand over a bunch of instructions
and triggers execution. We introduce a bakery lock to avoid two cores
trying to use that (single) arisc core. The arisc code is expected to
put itself into reset after is has finished execution.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: H6: Factor out I2C platform setup ...

In the H6 platform code there is a routine to do the platform
initialisation of the R_I2C controller. We will need a very similar
setup routine to initialise the RSB controller on the A64.

Move this code to sunxi_common.c and generalise it to support all SoCs
and also to cover the related RSB bus.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Introduce GPIO helper function ...

Many boards without a dedicated PMIC contain simple regulators, which
can be controlled via GPIO pins.

To later allow turning them off easily, introduce a simple function to
configure a given pin as a GPIO out pin and set it to the desired level.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Export sunxi_private.h ...

So far we have a sunxi_private.h header file in the common code directory.
This holds the prototypes of various functions we share in *common*
code. However we will need some of those in the platform specific code
parts as well, and want to introduce new functions shared across the
whole platform port.

So move the sunxi_private.h file into the common/include directory, so
that it becomes visible to all parts of the platform code.
Fix up the existing #includes and add missing ones, also add the
sunxi_read_soc_id() prototype here.

This will be used in follow up patches.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Disable USE_COHERENT_MEM ...

According to the documentation, platforms may choose to trade memory
footprint for performance (and elegancy) by not providing a separately
mapped coherent page.

Since a debug build is getting close to the SRAM size limit already, this
allows us to save about 3.5KB of BSS and have some room for future
enhancements.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Adjust memory mapping to fit into 256MB ...

At the moment we map as much of the DRAM into EL3 as possible, however
we actually don't use it. The only exception is the secure DRAM for
BL32 (if that is configured).

To decrease the memory footprint of ATF, we save on some page tables by
reducing the memory mapping to the actually required regions: SRAM, device
MMIO, secure DRAM and U-Boot (to be used later).
This introduces a non-identity mapping for the DRAM regions.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Detect and output current SoC ...

So far we already support booting on two different SoCs, and we will
shortly add a third, so add some code to determine the current SoC type.
This can be later used to runtime detect certain properties.

Also print the SoC name to the console, to give valuable debug information.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Don't map boot ROM ...

There is nothing we need from the BootROM area, so we also don't need
to map it in EL3.

Remove the mapping and reduce the number of MMAP regions by one.

Reported-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: common: add missing header ...

Some code in sunxi_common.c requires symbols defined in sunxi_private.h,
so add the header to that file.
It was included via another header before, but let's make this explicit.

Reported-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

allwinner: Introduce basic platform support ...

This platform supports Allwinner's SoCs with ARMv8 cores. So far they
all sport a single cluster of Cortex-A53 cores.

"sunxi" is the original code name used for this platform, and since it
appears in the Linux kernel and in U-Boot as well, we use it here as a
short file name prefix and for identifiers.

This port includes BL31 support only. U-Boot's SPL takes the role of the
primary loader, also doing the DRAM initialization. It then loads the
rest of the firmware, namely ATF and U-Boot (BL33), then hands execution
over to ATF.

This commit includes the basic platform code shared across all SoCs.
There is no platform.mk yet.

[Andre: moved files into proper directories, supported RESET_TO_BL31,
	various clean ups and simplifications ]

Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>