intel_th: Allow subdevice drivers to bring in own attribute groups

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>

2 files changed, 15 insertions, 0 deletions

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 4272f2ce5f6e..db0691929a60 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -71,6 +71,15 @@ static int intel_th_probe(struct device *dev)
         if (ret)
                 return ret;
 
+        if (thdrv->attr_group) {
+                ret = sysfs_create_group(&thdev->dev.kobj, thdrv->attr_group);
+                if (ret) {
+                        thdrv->remove(thdev);
+
+                        return ret;
+                }
+        }
+
         if (thdev->type == INTEL_TH_OUTPUT &&
             !intel_th_output_assigned(thdev))
                 ret = hubdrv->assign(hub, thdev);
@@ -91,6 +100,9 @@ static int intel_th_remove(struct device *dev)
                         return err;
         }
 
+        if (thdrv->attr_group)
+                sysfs_remove_group(&thdev->dev.kobj, thdrv->attr_group);
+
         thdrv->remove(thdev);
 
         if (intel_th_output_assigned(thdev)) {
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index eedd09332db6..15ebd48a29f2 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -115,6 +115,7 @@ intel_th_output_assigned(struct intel_th_device *thdev)
  * @enable:     enable tracing for a given output device
  * @disable:    disable tracing for a given output device
  * @fops:       file operations for device nodes
+ * @attr_group: attributes provided by the driver
  *
  * Callbacks @probe and @remove are required for all device types.
  * Switch device driver needs to fill in @assign, @enable and @disable
@@ -139,6 +140,8 @@ struct intel_th_driver {
         void                    (*deactivate)(struct intel_th_device *thdev);
         /* file_operations for those who want a device node */
         const struct file_operations *fops;
+        /* optional attributes */
+        struct attribute_group  *attr_group;
 
         /* source ops */
         int                     (*set_output)(struct intel_th_device *thdev,