intel_th: Allow forcing host mode through drvdata

Some devices can only operate in host mode, so we need means of
communicating this to the core driver on per-device basis. This
adds a flag to drvdata to signal host-only capability to the core.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>

2 files changed, 7 insertions, 3 deletions

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 8f820c182240..da962aa2cef5 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -630,7 +630,8 @@ intel_th_subdevice_alloc(struct intel_th *th,
                 thdev->output.port = -1;
                 thdev->output.scratchpad = subdev->scrpd;
         } else if (subdev->type == INTEL_TH_SWITCH) {
-                thdev->host_mode = host_mode;
+                thdev->host_mode =
+                        INTEL_TH_CAP(th, host_mode_only) ? true : host_mode;
                 th->hub = thdev;
         }
 
@@ -729,7 +730,8 @@ static int intel_th_populate(struct intel_th *th)
                 struct intel_th_device *thdev;
 
                 /* only allow SOURCE and SWITCH devices in host mode */
-                if (host_mode && subdev->type == INTEL_TH_OUTPUT)
+                if ((INTEL_TH_CAP(th, host_mode_only) || host_mode) &&
+                    subdev->type == INTEL_TH_OUTPUT)
                         continue;
 
                 /*
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index cdeed3b017d0..780206dc9012 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -42,9 +42,11 @@ struct intel_th_output {
 /**
  * struct intel_th_drvdata - describes hardware capabilities and quirks
  * @tscu_enable:        device needs SW to enable time stamping unit
+ * @host_mode_only:     device can only operate in 'host debugger' mode
  */
 struct intel_th_drvdata {
-        unsigned int    tscu_enable        : 1;
+        unsigned int    tscu_enable        : 1,
+                        host_mode_only     : 1;
 };
 
 #define INTEL_TH_CAP(_th, _cap) ((_th)->drvdata ? (_th)->drvdata->_cap : 0)