This macro currently supports only one parameter. Based on Linux iopoll,
let's extend read_poll_timeout common API to allow multiple variable
parameters.

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>

Add readl poll API with sleep and timeout support.

This change is referenced from Linux from below commit:
commit <5f5323a14cad19323060a8cbf9d96f2280a462dd> ("iopoll:
introduce read_poll_timeout macro")

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

Some drivers and other bsp code not only poll the
register with timeout but also required to delay
on each transaction.

This patch add that requirement by adding sleep_us
variable so-that read_poll_timeout now support
delay as well.

This change is referenced from Linux from below commit:
commit <5f5323a14cad19323060a8cbf9d96f2280a462dd> ("iopoll:
introduce read_poll_timeout macro")

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

Add read_poll_timeout common API similar to Linux iopoll.

readx_poll_timeout will trigger read_poll_timeout with
proper op. This will help to extend the functionalities
like sleep_us to poll timeout in future.

This change is referenced from Linux from below commit:
commit <5f5323a14cad19323060a8cbf9d96f2280a462dd> ("iopoll:
introduce read_poll_timeout macro")

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

This was imported from Linux 4.9 and adjusted for U-Boot.

 - Replace the license block with SPDX
 - Drop all *_atomic variants, which make no sense for U-Boot
 - Remove the sleep_us argument, which makes no sense for U-Boot

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>