platform/x86/intel/tpmi: Add API to get debugfs root

Add new API to get the debugfs root directory for TPMI. This allows any
TPMI devices to add their own debugfs items under the same directory
structure.

Reviewed-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Ilpo Järvinen <[e-mail]>
Signed-off-by: Tero Kristo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ilpo Järvinen <[e-mail]>

drivers/platform/x86/intel/tpmi.c

···
 }
 EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI);
 
+struct dentry *tpmi_get_debugfs_dir(struct auxiliary_device *auxdev)
+{
+	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(auxdev->dev.parent);
+	struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(&intel_vsec_dev->auxdev);
+
+	return tpmi_info->dbgfs_dir;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_debugfs_dir, INTEL_TPMI);
+
 static int tpmi_pfs_dbg_show(struct seq_file *s, void *unused)
 {
 	struct intel_tpmi_info *tpmi_info = s->private;

include/linux/intel_tpmi.h

···
 int tpmi_get_resource_count(struct auxiliary_device *auxdev);
 int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id, bool *read_blocked,
 			    bool *write_blocked);
+struct dentry *tpmi_get_debugfs_dir(struct auxiliary_device *auxdev);
 #endif