drm/i915: add initial Runtime PM functions

This patch adds the initial infrastructure to allow a Runtime PM
implementation that sets the device to its D3 state. The patch just
adds the necessary callbacks and the initial infrastructure.

We still don't have any platform that actually uses this
infrastructure, we still don't call get/put in all the places we need
to, and we don't have any function to save/restore the state of the
registers. This is not a problem since no platform uses the code added
by this patch. We have a few people simultaneously working on runtime
PM, so this initial code could help everybody make their plans.

V2: - Move some functions to intel_pm.c
    - Remove useless pm_runtime_allow() call at init
    - Remove useless pm_runtime_mark_last_busy() call at get
    - Use pm_runtime_get_sync() instead of 2 calls
    - Add a WARN to check if we're really awake

V3: - Rebase.

V4: - Don't need to call pci_{save,restore}_state and
      pci_set_power_sate, since they're already called by the PCI
      layer
    - Remove wrong pm_runtime_enable() call at init_runtime_pm

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 13076db65eb..7d213617029 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -502,6 +502,8 @@ static int i915_drm_freeze(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_crtc *crtc;
 
+	intel_runtime_pm_get(dev_priv);
+
 	/* ignore lid events during suspend */
 	mutex_lock(&dev_priv->modeset_restore_lock);
 	dev_priv->modeset_restore = MODESET_SUSPENDED;
@@ -686,6 +688,8 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
 	mutex_lock(&dev_priv->modeset_restore_lock);
 	dev_priv->modeset_restore = MODESET_DONE;
 	mutex_unlock(&dev_priv->modeset_restore_lock);
+
+	intel_runtime_pm_put(dev_priv);
 	return error;
 }
 
@@ -900,6 +904,36 @@ static int i915_pm_poweroff(struct device *dev)
 	return i915_drm_freeze(drm_dev);
 }
 
+static int i915_runtime_suspend(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	WARN_ON(!HAS_RUNTIME_PM(dev));
+
+	DRM_DEBUG_KMS("Suspending device\n");
+
+	dev_priv->pm.suspended = true;
+
+	return 0;
+}
+
+static int i915_runtime_resume(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	WARN_ON(!HAS_RUNTIME_PM(dev));
+
+	DRM_DEBUG_KMS("Resuming device\n");
+
+	dev_priv->pm.suspended = false;
+
+	return 0;
+}
+
 static const struct dev_pm_ops i915_pm_ops = {
 	.suspend = i915_pm_suspend,
 	.resume = i915_pm_resume,
@@ -907,6 +941,8 @@ static const struct dev_pm_ops i915_pm_ops = {
 	.thaw = i915_pm_thaw,
 	.poweroff = i915_pm_poweroff,
 	.restore = i915_pm_resume,
+	.runtime_suspend = i915_runtime_suspend,
+	.runtime_resume = i915_runtime_resume,
 };
 
 static const struct vm_operations_struct i915_gem_vm_ops = {