The AST2500 SoC family changes the runtime behaviour of the hardware
strapping register (SCU70) to write-1-set/write-1-clear, with
write-1-clear implemented on the "read-only" SoC revision register
(SCU7C). For the the AST2400, the hardware strapping is
runtime-configured with read-modify-write semantics.
Signed-off-by: NAndrew Jeffery <andrew@aj.id.au>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Message-id: 20180709143524.17480-1-andrew@aj.id.au
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

All Aspeed SoC clocks are driven by an input source clock which can
have different frequencies : 24MHz or 25MHz, and also, on the Aspeed
AST2400 SoC, 48MHz. The H-PLL (CPU) clock is defined from a
calculation using parameters in the H-PLL Parameter register or from a
predefined set of frequencies if the setting is strapped by hardware
(Aspeed AST2400 SoC). The other clocks of the SoC are then defined
from the H-PLL using dividers.

We introduce first the APB clock because it should be used to drive
the Aspeed timer model.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Message-id: 20180622075700.5923-2-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The ASPEED hardware contains a lock register for the SCU that disables
any writes to the SCU when it is locked. The machine comes up with the
lock enabled, but on all known hardware u-boot will unlock it and leave
it unlocked when loading the kernel.

This means the kernel expects the SCU to be unlocked. When booting from
an emulated ROM the normal u-boot unlock path is executed. Things don't
go well when booting using the -kernel command line, as u-boot does not
run first.

Change behaviour so that when a kernel is passed to the machine, set the
reset value of the SCU to be unlocked.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Reviewed-by: NCédric Le Goater <clg@kaod.org>
Message-id: 20171114122018.12204-1-joel@jms.id.au
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

There is not much differences with the A0 revision apart from the DDR
calibration.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Message-id: 1480434248-27138-10-git-send-email-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Based on previous work done by Andrew Jeffery <andrew@aj.id.au>.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1473438177-26079-9-git-send-email-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

This gives some explanation behind the magic number 0x120CE416.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1473438177-26079-8-git-send-email-clg@kaod.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

AST2400_A0_SILICON_REV is defined twice. Fix this by including the
definition in the header file as well as the routine to check if a
silicon revision is supported. It will useful to reuse in other
controllers.

Let's add also AST2500_A0_SILICON_REV for future use.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-id: 1467994016-11678-5-git-send-email-clg@kaod.org
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The SCU is a collection of chip-level control registers that manage the
various functions supported by ASPEED SoCs. Typically the bits control
interactions with clocks, external hardware or reset behaviour, and we
can largly take a hands-off approach to reads and writes.

Firmware makes heavy use of the state to determine how to boot, but the
reset values vary from SoC to SoC (eg AST2400 vs AST2500). A qdev
property is exposed so that the integrating SoC model can configure the
silicon revision, which in-turn selects the appropriate reset values.
Further qdev properties are exposed so the board model can configure the
board-dependent hardware strapping.

Almost all provided AST2400 reset values are specified by the datasheet.
The notable exception is SOC_SCRATCH1, where we mark the DRAM as
successfully initialised to avoid unnecessary dark corners in the SoC's
u-boot support.
Signed-off-by: NAndrew Jeffery <andrew@aj.id.au>
Message-id: 1466744305-23163-2-git-send-email-andrew@aj.id.au
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
[PMM: drop unnecessary inttypes.h include]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>