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, 55 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index cd3f511847ec..2590a5c90725 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -31,6 +31,7 @@
 #include "../../../platform/x86/intel_ips.h"
 #include <linux/module.h>
 #include <drm/i915_powerwell.h>
+#include <linux/pm_runtime.h>
 
 /**
  * RC6 is a special power stage which allows the GPU to enter an very
@@ -5961,6 +5962,60 @@ void intel_aux_display_runtime_put(struct drm_i915_private *dev_priv)
         hsw_enable_package_c8(dev_priv);
 }
 
+void intel_runtime_pm_get(struct drm_i915_private *dev_priv)
+{
+        struct drm_device *dev = dev_priv->dev;
+        struct device *device = &dev->pdev->dev;
+
+        if (!HAS_RUNTIME_PM(dev))
+                return;
+
+        pm_runtime_get_sync(device);
+        WARN(dev_priv->pm.suspended, "Device still suspended.\n");
+}
+
+void intel_runtime_pm_put(struct drm_i915_private *dev_priv)
+{
+        struct drm_device *dev = dev_priv->dev;
+        struct device *device = &dev->pdev->dev;
+
+        if (!HAS_RUNTIME_PM(dev))
+                return;
+
+        pm_runtime_mark_last_busy(device);
+        pm_runtime_put_autosuspend(device);
+}
+
+void intel_init_runtime_pm(struct drm_i915_private *dev_priv)
+{
+        struct drm_device *dev = dev_priv->dev;
+        struct device *device = &dev->pdev->dev;
+
+        dev_priv->pm.suspended = false;
+
+        if (!HAS_RUNTIME_PM(dev))
+                return;
+
+        pm_runtime_set_active(device);
+
+        pm_runtime_set_autosuspend_delay(device, 10000); /* 10s */
+        pm_runtime_mark_last_busy(device);
+        pm_runtime_use_autosuspend(device);
+}
+
+void intel_fini_runtime_pm(struct drm_i915_private *dev_priv)
+{
+        struct drm_device *dev = dev_priv->dev;
+        struct device *device = &dev->pdev->dev;
+
+        if (!HAS_RUNTIME_PM(dev))
+                return;
+
+        /* Make sure we're not suspended first. */
+        pm_runtime_get_sync(device);
+        pm_runtime_disable(device);
+}
+
 /* Set up chip specific power management-related functions */
 void intel_init_pm(struct drm_device *dev)
 {