mei: me: use runtime PG pm domain for non wakeable devices

For non wakeable devices we can't use pci runtime framework
as we are not able to wakeup from D3 states.
Instead we create new pg runtime domain that only drives ME power
gating protocol to reduce the power consumption.

Signed-off-by: Tomas Winkler <[e-mail]>
Signed-off-by: Alexander Usyskin <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/mei/mei_dev.h

···
 	 * Power Gating support
 	 */
 	enum mei_pg_event pg_event;
+#ifdef CONFIG_PM_RUNTIME
+	struct dev_pm_domain pg_domain;
+#endif /* CONFIG_PM_RUNTIME */
 
 	unsigned char rd_msg_buf[MEI_RD_MSG_BUF_SIZE];	/* control messages */
 	u32 rd_msg_hdr;

drivers/misc/mei/pci-me.c

···
 
 MODULE_DEVICE_TABLE(pci, mei_me_pci_tbl);
 
+#ifdef CONFIG_PM_RUNTIME
+static inline void mei_me_set_pm_domain(struct mei_device *dev);
+static inline void mei_me_unset_pm_domain(struct mei_device *dev);
+#else
+static inline void mei_me_set_pm_domain(struct mei_device *dev) {}
+static inline void mei_me_unset_pm_domain(struct mei_device *dev) {}
+#endif /* CONFIG_PM_RUNTIME */
+
 /**
  * mei_quirk_probe - probe for devices that doesn't valid ME interface
  *
···
 
 	schedule_delayed_work(&dev->timer_work, HZ);
 
+	/*
+	* For not wake-able HW runtime pm framework
+	* can't be used on pci device level.
+	* Use domain runtime pm callbacks instead.
+	*/
+	if (!pci_dev_run_wake(pdev))
+		mei_me_set_pm_domain(dev);
+
 	if (mei_pg_is_enabled(dev))
 		pm_runtime_put_noidle(&pdev->dev);
 
···
 
 	dev_dbg(&pdev->dev, "stop\n");
 	mei_stop(dev);
+
+	if (!pci_dev_run_wake(pdev))
+		mei_me_unset_pm_domain(dev);
 
 	/* disable interrupts */
 	mei_disable_interrupts(dev);
···
 	dev_dbg(&pdev->dev, "rpm: me: runtime resume ret = %d\n", ret);
 
 	return ret;
+}
+
+/**
+ * mei_me_set_pm_domain - fill and set pm domian stucture for device
+ *
+ * @dev: mei_device
+ */
+static inline void mei_me_set_pm_domain(struct mei_device *dev)
+{
+	struct pci_dev *pdev  = dev->pdev;
+
+	if (pdev->dev.bus && pdev->dev.bus->pm) {
+		dev->pg_domain.ops = *pdev->dev.bus->pm;
+
+		dev->pg_domain.ops.runtime_suspend = mei_me_pm_runtime_suspend;
+		dev->pg_domain.ops.runtime_resume = mei_me_pm_runtime_resume;
+		dev->pg_domain.ops.runtime_idle = mei_me_pm_runtime_idle;
+
+		pdev->dev.pm_domain = &dev->pg_domain;
+	}
+}
+
+/**
+ * mei_me_unset_pm_domain - clean pm domian stucture for device
+ *
+ * @dev: mei_device
+ */
+static inline void mei_me_unset_pm_domain(struct mei_device *dev)
+{
+	/* stop using pm callbacks if any */
+	dev->pdev->dev.pm_domain = NULL;
 }
 #endif /* CONFIG_PM_RUNTIME */