The latest ARM CoreSight specification updates the component identification requirements for all components attached to an AMBA bus. (ARM IHI 0029E)
This specification defines bits 15:12 in the ComponentID (CID) value as the device class. Identification requirements now depend on this class. Class 0xF: Traditional components identified by Peripheral ID (PID) only. Class 0x9: CoreSight components may be identified by a Universal Component Identifier (UCI) consisting of the PID plus CoreSight DevType and DevArch values.
Current and future ARM CoreSight IP will now use the same PID for components on the same function - e.g. the ETM, CTI, PMU and Debug elements associated with a core. The first core to use this UCI method is the A35, which currently has binding entries in the ETMv4 driver.
This patchset prepares for the addition of the upcoming CTI driver, which will need to correctly bind with A35 and future hardware, while overcoming the limitation of binding by PID alone, which cannot now work.
The patchset updates the current AMBA Identification mechanism, which was already differentiating between 0xF and 0x9 CIDs, to add additional UCI compliant tests for the for the 0x9 device class.
Additional UCI structures are provided and added to the ETMv4 driver as appropriate.
Changes since v2: Simplification of amba_cs_uci_id_match(). Fix CID class bitfield comments. Dropped RFC tag on patchset.
Mike Leach (2): drivers: amba: Updates to component identification for driver matching. coresight: etmv4: Update ID register table to add UCI support
drivers/amba/bus.c | 45 +++++++++++++++---- drivers/hwtracing/coresight/coresight-etm4x.c | 18 +++++++- include/linux/amba/bus.h | 32 +++++++++++++ 3 files changed, 86 insertions(+), 9 deletions(-)