coresight: etb: let runtime PM handle core clock
authorLinus Walleij <linus.walleij@linaro.org>
Tue, 19 May 2015 16:55:11 +0000 (10:55 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 May 2015 18:12:08 +0000 (11:12 -0700)
commit1b19f59dca70d802cee8a7d324c2340fdf0bd258
tree4301b066f343853bfde25ee802341df72c50d01c
parentb5913d64366925c78cbe25e28a0599c89ef23bcd
coresight: etb: let runtime PM handle core clock

This uses runtime PM to manage the PCLK ("amba_pclk") instead
of screwing around with the framework by going in and taking
a copy from the amba device. The amba bus core will unprepare
and disable the clock when the device is unused when
CONFIG_PM is selected, else the clock will be always on.

Prior to this patch, as the AMBA primecell bus code enables
the PCLK, it would be left on after probe as
the clk_prepare_enable() and clk_disable_unprepare() was
called and thus just increase and decreas the refcount by
one, without it reaching zero and actually disabling the
clock. Now the runtime PM callbacks will make sure the PCLK
is properly disabled after probe.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/coresight/coresight-etb10.c