Introduce driver for STM32 IWDG peripheral (Independent Watchdog).
It is configured according to device tree content and should be enabled
from there.
The watchdog is not started by default. It can be started after an HW
reset if the dedicated OTP is fused.

The watchdog also needs to be frozen if a debugger is attached.
This is done by configuring the correct bits in DBGMCU.
This configuration is allowed by checking BSEC properties.

An increase of BL2 size is also required when adding this new code.

Change-Id: Ide7535d717885ce2f9c387cf17afd8b5607f3e7f
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>

Remove useless private structure in function prototypes.
Add a reference counter on clocks.
Prepare for future secured/shared/non-secured clocks.

Change-Id: I3dbed81721da5ceff5e10b2c4155b1e340c036ee
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Nicolas LE BAYON <nicolas.le.bayon@st.com>

PWR, RCC, DDRPHYC & DDRCTRL addresses can be retrieved from device tree.
Platform asserts the value read from the DT are the SoC addresses.

Change-Id: I43f0890b51918a30c87ac067d3780ab27a0f59de
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Nicolas LE BAYON <nicolas.le.bayon@st.com>

timeout_init_us(some_timeout_us); returns a reference to detect
timeout for the provided microsecond delay value from current time.

timeout_elapsed(reference) return true/false whether the reference
timeout is elapsed.

This change is inspired by the OP-TEE OS timeout resources [1].

 [1] https://github.com/OP-TEE/optee_os/blob/3.4.0/core/arch/arm/include/kernel/delay.h#L45

Change-Id: Id81ff48aa49693f555dc621064878417101d5587
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

Mainly remove suffix 1 from prefix stm32mp1 in several macros and functions
that can be used in drivers shared by different platforms.

Change-Id: I2295c44f5b1edac7e80a93c0e8dfd671b36e88e7
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>

Some parts of code could be shared with platform derivatives,
or new platforms.
A new folder plat/st/common is created to put common parts.

stm32mp_common.h is a common API aggregate.

Remove some casts where applicable.
Fix some types where applicable.
Remove also some platform includes that are already in stm32mp1_def.h.

Change-Id: I46d763c8d9e15732d1ee7383207fd58206d7f583
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>