If output subdevice driver is not loaded, activating it will try to
call its ->activate method and crash. Fix this by explicitly checking
for the driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Some subdevices (MSU, PTI) need to register their own driver-specific
attribute groups. Provide a way for those to pass their attribute
groups to the core driver in their driver structure so that the
core can take care of creating and removing them.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Intel TH implements a scratchpad register to indicate to the firmware
and external debuggers what trace configuration is enabled so that
everybody plays nicely together. The register is a bit field and the
bit assignment convention is described in the developer's manual.
This patch enables the driver to automatically set scratchpad register
bits according to the output configuration that's enabled.
Based on work by Yann Fouassier.
Signed-off-by: Yann Fouassier <yann.fouassier@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel(R) Trace Hub (TH) is a set of hardware blocks (subdevices) that
produce, switch and output trace data from multiple hardware and
software sources over several types of trace output ports encoded
in System Trace Protocol (MIPI STPv2) and is intended to perform
full system debugging.
For these subdevices, we create a bus, where they can be discovered
and configured by userspace software.
This patch creates this bus infrastructure, three types of devices
(source, output, switch), resource allocation, some callback mechanisms
to facilitate communication between the subdevices' drivers and some
common sysfs attributes.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>