]> git.baikalelectronics.ru Git - kernel.git/commit
coresight: etm: retrieve and handle atclk
authorLinus Walleij <linus.walleij@linaro.org>
Tue, 19 May 2015 16:55:14 +0000 (10:55 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 May 2015 18:12:08 +0000 (11:12 -0700)
commitf11197b25a3786ab412d166e183e07dda92dfbfd
tree0b02b9f0e59571e903e81d9984f42539220c61cb
parent339f950115de690ae42f5a919fb4090cef7d0e56
coresight: etm: retrieve and handle atclk

As can be seen from the datasheet of the CoreSight
Components, DDI0401C A.1.1 the ETM has a clock signal
apart from the AHB interconnect ("amba_pclk", that we're
already handling) called ATCLK, ARM Trace Clock, that SoC
implementers may provide from an entirely different clock
source. So to model this correctly create an optional
path for handling ATCLK alongside the PCLK so we don't
break old platforms that only define PCLK ("amba_pclk") but
still makes it possible for SoCs that have both clock signals
(such as the DB8500) to fetch and prepare/enable/disable/
unprepare both clocks.

The ATCLK is enabled and disabled using the runtime PM
callbacks.

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-etm.h
drivers/hwtracing/coresight/coresight-etm3x.c