[ Upstream commit cbf164cd44e06c78938b4a4a4479d3541779c319 ]
The original _bin2bcd() function used / 10 and % 10 operations for
conversion. Although GCC optimizes these operations and does not generate
division or modulus instructions, the new implementation reduces the
number of mov instructions in the generated code for both x86-64 and ARM
architectures.
This optimization calculates the tens digit using (val * 103) >> 10, which
is accurate for values of 'val' in the range [0, 178]. Given that the
valid input range is [0, 99], this method ensures correctness while
simplifying the generated code.
Link: https://lkml.kernel.org/r/20240812170229.229380-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun Huang (Jim) <jserv@ccns.ncku.edu.tw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[visitorckw@gmail.com: Adapt to bin2bcd() in include/bcd.h]
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
We don't need to use u8, and if we avoid it, it isn't so much of a problem
that rtc.h includes this header. With this change we can include rtc.h from
sandbox files.
Signed-off-by: Simon Glass <sjg@chromium.org>
In the process, also remove backward-compatiblity macros BIN_TO_BCD and
BCD_TO_BIN and update the sole board using them to use the new bin2bcd
and bcd2bin instead
Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
This patch adds support for the Xicor/Intersil X1205 RTC used on the
AMCC Makalu eval board. This driver is basically cloned from the Linux
driver version (2.6.23).
This patch also introduces the Linux bcd.h header for the BCD2BIN/
BIN2BCD conversions. In the future some of the other U-Boot RTC driver
should be converted to also use this header instead of implementing
their own local copy of these functions/macros.
Signed-off-by: Stefan Roese <sr@denx.de>
