path: root/drivers/hwtracing/coresight/coresight-priv.h
diff options
authorSuzuki K Poulose <suzuki.poulose@arm.com>2018-09-20 13:18:11 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-25 20:09:19 +0200
commit2478a6ae4a6a4c8e3f7e9f6f849dffe92e5238e1 (patch)
treec1250692bc7cf6a36e6ecd3da9c5b141d9050e0f /drivers/hwtracing/coresight/coresight-priv.h
parent30af4fb619e5126cb3152072e687b377fc9398d6 (diff)
coresight: Add support for CLAIM tag protocol
Coresight architecture defines CLAIM tags for a device to negotiate control of the components (external agent vs self-hosted). Each device has a pair of registers (CLAIMSET & CLAIMCLR) for managing the CLAIM tags. However, the protocol for the CLAIM tags is IMPLEMENTATION DEFINED. PSCI has recommendations for the use of the CLAIM tags to negotiate controls for external agent vs self-hosted use. This patch implements the recommended protocol by PSCI. The claim/disclaim operations are performed from the device specific drivers. The disadvantage is that the calls are sprinkled in each driver, but this makes the operation much simpler. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-priv.h')
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index c11da5564a67..579f34943bf1 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -25,6 +25,13 @@
#define CORESIGHT_DEVID 0xfc8
+ * Coresight device CLAIM protocol.
+ * See PSCI - ARM DEN 0022D, Section: 6.8.1 Debug and Trace save and restore.
+ */
#define TIMEOUT_US 100
#define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb)