clk: mvebu: Fix clk frequency value if SSCG is enabled

Browse source

When the SSCG (Spread Spectrum Clock Generator) is enabled, it shifts
the frequency of the clock. The percentage is no more than 1% but when
the clock is used for a timer it leads to a clock drift.

This patch allows to correct the affected clock when the SSCG is
enabled. The check is done in an new optional function related to each
SoC: is_sscg_enabled(). The fix is done with the other new optional
function related to each SoC: fix_sscg_deviation. If one these
functions are not present then no correction is done on the clock
frequency.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Leigh Brown <leigh@solinno.co.uk>
Link: https://lkml.kernel.org/r/1409645719-20003-2-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

...

This commit is contained in:

Gregory CLEMENT 2014-09-02 10:15:16 +02:00 • committed by Jason Cooper

parent 7d1311b93e

commit 15917b1602

2 changed files with 89 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

82

drivers/clk/mvebu/common.c

View file

7

drivers/clk/mvebu/common.h

View file