Merge "dt-bindings: bus: mhi: add missing entries for configuration s…

…upport"

Documentation/devicetree/bindings/bus/mhi.txt

@@ -47,6 +47,20 @@ Main node properties:
   Definition: Set to true if MHI device supports sending subsystem failure
 	reason upon assert in case PCIe link is functional.
 
+- mhi,allow-m1
+  Usage: optional
+  Value type: <bool>
+  Definition: Set to true if MHI device does not support autonomous low
+	power modes entry.
+
+- mhi,skip-forced-suspend
+  Usage: optional
+  Value type: <bool>
+  Definition: Set to true if MHI device does not require support for a forced
+	suspend/resume cycle at bootup since it has no requirement to switch
+	to a separate set of mission mode PCIe phy settings to enable low power
+	modes.
+
 ============================
 mhi channel node properties:
 ============================

arch/arm64/boot/dts/qcom/sm8150-lemur.dtsi

@@ -42,6 +42,7 @@
 	qcom,smmu-cfg = <0x1d>;
 	qcom,addr-win = <0x0 0x20000000 0x0 0x2fffffff>;
 	mhi,sfr-support;
+	mhi,skip-forced-suspend;
 
 	/* controller noc frequency scaling configuration */
 	qcom,msm-bus,name = "mhi1";
@@ -286,6 +287,7 @@
 	qcom,smmu-cfg = <0x1d>;
 	qcom,addr-win = <0x0 0x20000000 0x0 0x2fffffff>;
 	mhi,sfr-support;
+	mhi,skip-forced-suspend;
 
 	/* controller noc frequency scaling configuration */
 	qcom,msm-bus,name = "mhi0";

drivers/bus/mhi/controllers/mhi_qcom.c

@@ -605,13 +605,15 @@ static void mhi_status_cb(struct mhi_controller *mhi_cntrl,
 		 * we need to force a suspend so device can switch to
 		 * mission mode pcie phy settings.
 		 */
-		pm_runtime_get(dev);
-		ret = mhi_force_suspend(mhi_cntrl);
-		if (!ret) {
-			MHI_CNTRL_LOG("Attempt resume after forced suspend\n");
-			mhi_runtime_resume(dev);
+		if (!mhi_dev->skip_forced_suspend) {
+			pm_runtime_get(dev);
+			ret = mhi_force_suspend(mhi_cntrl);
+			if (!ret) {
+				MHI_CNTRL_LOG("Resume after forced suspend\n");
+				mhi_runtime_resume(dev);
+			}
+			pm_runtime_put(dev);
 		}
-		pm_runtime_put(dev);
 		mhi_arch_mission_mode_enter(mhi_cntrl);
 		pm_runtime_allow(&mhi_dev->pci_dev->dev);
 		break;
@@ -752,8 +754,22 @@ static struct mhi_controller *mhi_register_controller(struct pci_dev *pci_dev)
 		goto error_register;
 
 	use_bb = of_property_read_bool(of_node, "mhi,use-bb");
+
+	/*
+	 * Certain devices would send M1 events to MHI as they may not have
+	 * autonomous M2 support. MHI host can skip registering for link
+	 * inactivity timeouts in that case.
+	 */
 	mhi_dev->allow_m1 = of_property_read_bool(of_node, "mhi,allow-m1");
 
+	/*
+	 * Certain devices do not require a forced suspend/resume cycle at
+	 * mission mode entry after boot as they do not need to switch to
+	 * separate phy settings in order to enable low power modes
+	 */
+	mhi_dev->skip_forced_suspend = of_property_read_bool(of_node,
+						"mhi,skip-forced-suspend");
+
 	/*
 	 * if s1 translation enabled or using bounce buffer pull iova addr
 	 * from dt

drivers/bus/mhi/controllers/mhi_qcom.h

@@ -74,6 +74,7 @@ struct mhi_dev {
 	bool allow_m1;
 	bool mdm_state;
 	bool disable_pci_lpm;
+	bool skip_forced_suspend;
 	dma_addr_t iova_start;
 	dma_addr_t iova_stop;
 	enum mhi_suspend_mode suspend_mode;