GitLab

Rule 8.3: All declarations of an object or function shall
          use the same names and type qualifiers.

Change-Id: Iff384187c74a598a4e73f350a1893b60e9d16cec
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

Delay functions like udelay() are often used to ensure that the
necessary time passed to allow some asynchronous event to finish, such
as the stabilization delay for a power rail. For these use cases it is
not very problematic if the delay is slightly longer than requested,
but it is critical that the delay must never be shorter.

The current udelay() implementation contains two hazards that may cause
the delay to be slightly shorter than intended: Firstly, the amount of
ticks to wait is calculated with an integer division, which may cut off
the last fraction of ticks needed. Secondly, the delay may be short by a
fraction of a tick because we do not know whether the initial ("start")
sample of the timer was near the start or near the end of the current
tick. Thus, if the code intends to wait for one tick, it might read the
timer value close to the end of the current tick and then read it again
right after the start of the next tick, concluding that the duration of
a full tick has passed when it in fact was just a fraction of it.

This patch rounds up the division and always adds one extra tick to
counteract both problems and ensure that delays will always be larger
but never smaller than requested.

Change-Id: Ic5fe5f858b5cdf3c0dbf3e488d4d5702d9569433
Signed-off-by: Julius Werner <jwerner@chromium.org>

Use NULL instead of 0 where required.
Include headers to have the prototype of the functions.
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/



Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Add delay timer implementation based on the system generic counter.
This either uses the platform's implementation of
`plat_get_syscnt_freq()` or explicit clock multiplier/divider values
provided by the platform.

The current implementation of udelay has been modified to avoid
unnecessary calculations while waiting on the loop and to make it
easier to check for overflows.

Change-Id: I9062e1d506dc2f68367fd9289250b93444721732

The API is simple. The BSP or specific timer driver creates an
instance of timer_ops_t, fills in the timer specific data, then calls
timer_init(). The timer specific data includes a function pointer
to return the timer value and a clock multiplier/divider. The ratio
of the multiplier and the divider is the clock frequency in MHz.

After that, mdelay() or udelay() can be called to delay execution for
the specified time (milliseconds or microseconds, respectively).

Change-Id: Icf8a295e1d25874f789bf28b7412156329dc975c
Co-authored-by: Dan Handley <dan.handley@arm.com>