[PATCH v6 2/6] drm/i915/pxp: add device link between i915 and mei_pxp

[Alan Previn]

From: Alexander Usyskin <alexander.usys...@intel.com>

Add device link with i915 as consumer and mei_pxp as supplier
to ensure proper ordering of power flows.

V2: condition on absence of heci_pxp to filter out DG

Signed-off-by: Alexander Usyskin <alexander.usys...@intel.com>
---
 drivers/gpu/drm/i915/pxp/intel_pxp_tee.c   | 11 +++++++++++
 drivers/gpu/drm/i915/pxp/intel_pxp_types.h |  6 ++++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c 
b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
index 73aa8015f828..cd5b86216506 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
@@ -127,6 +127,12 @@ static int i915_pxp_tee_component_bind(struct device 
*i915_kdev,
        intel_wakeref_t wakeref;
        int ret = 0;
 
+       if (!HAS_HECI_PXP(i915)) {
+               pxp->component_dev_link = device_link_add(i915_kdev, tee_kdev, 
DL_FLAG_STATELESS);
+               if (drm_WARN_ON(&i915->drm, !pxp->component_dev_link))
+                       return -ENODEV;
+       }
+
        mutex_lock(&pxp->tee_mutex);
        pxp->pxp_component = data;
        pxp->pxp_component->tee_dev = tee_kdev;
@@ -169,6 +175,11 @@ static void i915_pxp_tee_component_unbind(struct device 
*i915_kdev,
        mutex_lock(&pxp->tee_mutex);
        pxp->pxp_component = NULL;
        mutex_unlock(&pxp->tee_mutex);
+
+       if (pxp->component_dev_link) {
+               device_link_remove(i915_kdev, tee_kdev);
+               pxp->component_dev_link = NULL;
+       }
 }
 
 static const struct component_ops i915_pxp_tee_component_ops = {
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h 
b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
index 7dc5f08d1583..efd2f3915abe 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
@@ -32,6 +32,12 @@ struct intel_pxp {
         * which are protected by &tee_mutex.
         */
        struct i915_pxp_component *pxp_component;
+
+       /**
+        * @component_dev_link: device link of the pxp-component enforcing i915 
as the
+        * consumer. This is needed for legacy platform (TGL/ADL) full-feature 
usage.
+        */
+       struct device_link *component_dev_link;
        /**
         * @pxp_component_added: track if the pxp component has been added.
         * Set and cleared in tee init and fini functions respectively.
-- 
2.39.0