soundwire: intel: add CLK_STOP_TEARDOWN for pm_runtime suspend

Now that we have options, add support for TEARDOWN mode (same
functionality as existing code)

All other modes will be added in follow-up patches.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-8-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/intel.c

@@ -1548,6 +1548,7 @@ static int intel_suspend_runtime(struct device *dev)
 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_bus *bus = &cdns->bus;
+	u32 clock_stop_quirks;
 	int ret;
 
 	if (bus->prop.hw_disabled) {
@@ -1556,21 +1557,31 @@ static int intel_suspend_runtime(struct device *dev)
 		return 0;
 	}
 
-	ret = sdw_cdns_enable_interrupt(cdns, false);
-	if (ret < 0) {
-		dev_err(dev, "cannot disable interrupts on suspend\n");
-		return ret;
-	}
+	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 
-	ret = intel_link_power_down(sdw);
-	if (ret) {
-		dev_err(dev, "Link power down failed: %d", ret);
-		return ret;
-	}
+	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
 
-	intel_shim_wake(sdw, false);
+		ret = sdw_cdns_enable_interrupt(cdns, false);
+		if (ret < 0) {
+			dev_err(dev, "cannot disable interrupts on suspend\n");
+			return ret;
+		}
 
-	return 0;
+		ret = intel_link_power_down(sdw);
+		if (ret) {
+			dev_err(dev, "Link power down failed: %d", ret);
+			return ret;
+		}
+
+		intel_shim_wake(sdw, false);
+
+	} else {
+		dev_err(dev, "%s clock_stop_quirks %x unsupported\n",
+			__func__, clock_stop_quirks);
+		ret = -EINVAL;
+	}
+
+	return ret;
 }
 
 static int intel_resume(struct device *dev)
@@ -1645,6 +1656,7 @@ static int intel_resume_runtime(struct device *dev)
 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
 	struct sdw_intel *sdw = cdns_to_intel(cdns);
 	struct sdw_bus *bus = &cdns->bus;
+	u32 clock_stop_quirks;
 	int ret;
 
 	if (bus->prop.hw_disabled) {
@@ -1653,28 +1665,36 @@ static int intel_resume_runtime(struct device *dev)
 		return 0;
 	}
 
-	ret = intel_init(sdw);
-	if (ret) {
-		dev_err(dev, "%s failed: %d", __func__, ret);
-		return ret;
-	}
+	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
 
-	/*
-	 * make sure all Slaves are tagged as UNATTACHED and provide
-	 * reason for reinitialization
-	 */
-	sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
+	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
+		ret = intel_init(sdw);
+		if (ret) {
+			dev_err(dev, "%s failed: %d", __func__, ret);
+			return ret;
+		}
 
-	ret = sdw_cdns_enable_interrupt(cdns, true);
-	if (ret < 0) {
-		dev_err(dev, "cannot enable interrupts during resume\n");
-		return ret;
-	}
+		/*
+		 * make sure all Slaves are tagged as UNATTACHED and provide
+		 * reason for reinitialization
+		 */
+		sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
 
-	ret = sdw_cdns_exit_reset(cdns);
-	if (ret < 0) {
-		dev_err(dev, "unable to exit bus reset sequence during resume\n");
-		return ret;
+		ret = sdw_cdns_enable_interrupt(cdns, true);
+		if (ret < 0) {
+			dev_err(dev, "cannot enable interrupts during resume\n");
+			return ret;
+		}
+
+		ret = sdw_cdns_exit_reset(cdns);
+		if (ret < 0) {
+			dev_err(dev, "unable to exit bus reset sequence during resume\n");
+			return ret;
+		}
+	} else {
+		dev_err(dev, "%s clock_stop_quirks %x unsupported\n",
+			__func__, clock_stop_quirks);
+		ret = -EINVAL;
 	}
 
 	return ret;

drivers/soundwire/intel.h

@@ -17,6 +17,7 @@
  * @dev: device implementing hw_params and free callbacks
  * @shim_lock: mutex to handle access to shared SHIM registers
  * @shim_mask: global pointer to check SHIM register initialization
+ * @clock_stop_quirks: mask defining requested behavior on pm_suspend
  * @cdns: Cadence master descriptor
  * @list: used to walk-through all masters exposed by the same controller
  */
@@ -31,6 +32,7 @@ struct sdw_intel_link_res {
 	struct device *dev;
 	struct mutex *shim_lock; /* protect shared registers */
 	u32 *shim_mask;
+	u32 clock_stop_quirks;
 	struct sdw_cdns *cdns;
 	struct list_head list;
 };

drivers/soundwire/intel_init.c

@@ -249,6 +249,7 @@ static struct sdw_intel_ctx
 		link->ops = res->ops;
 		link->dev = res->dev;
 
+		link->clock_stop_quirks = res->clock_stop_quirks;
 		link->shim_lock = &ctx->shim_lock;
 		link->shim_mask = &ctx->shim_mask;