]> git.baikalelectronics.ru Git - kernel.git/commit
coresight: etb: retrieve and handle atclk
authorLinus Walleij <linus.walleij@linaro.org>
Tue, 19 May 2015 16:55:16 +0000 (10:55 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 May 2015 18:12:08 +0000 (11:12 -0700)
commitfacf9b8d2e9dc384a0f75230a63d464003ae6151
tree7b1baa05fb305f8f260c5c570270ae9cdd7b0f5b
parentb862409c361b31adbce712aebab305bc01715a20
coresight: etb: retrieve and handle atclk

As can be seen from the datasheet of the CoreSight
Components, DDI0314 table A-8 the ETB 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-etb10.c