Merge branch 'acpi-bus'

Merge ACPI device object management changes for v5.20-rc1.

 - Use the facilities provided by the driver core and some additional
   helpers to handle the children of a given ACPI device object in
   multiple places instead of using the children and node list heads in
   struct acpi_device which is error prone (Rafael Wysocki).

 - Fix ACPI-related device reference counting issue in the hisi_lpc bus
   driver (Yang Yingliang).

 - Drop the children and node list heads that are not needed any more
   from struct acpi_device (Rafael Wysocki).

 - Drop driver member from struct acpi_device (Uwe Kleine-König).

 - Drop redundant check from acpi_device_remove() (Uwe Kleine-König).

* acpi-bus:
  ACPI: bus: Drop unused list heads from struct acpi_device
  hisi_lpc: Use acpi_dev_for_each_child()
  bus: hisi_lpc: fix missing platform_device_put() in hisi_lpc_acpi_probe()
  ACPI: bus: Drop driver member of struct acpi_device
  ACPI: bus: Drop redundant check in acpi_device_remove()
  mfd: core: Use acpi_dev_for_each_child()
  ACPI / MMC: PM: Unify fixing up device power
  soundwire: Use acpi_dev_for_each_child()
  platform/x86/thinkpad_acpi: Use acpi_dev_for_each_child()
  ACPI: scan: Walk ACPI device's children using driver core
  ACPI: bus: Introduce acpi_dev_for_each_child_reverse()
  ACPI: video: Use acpi_dev_for_each_child()
  ACPI: bus: Export acpi_dev_for_each_child() to modules
  ACPI: property: Use acpi_dev_for_each_child() for child lookup
  ACPI: container: Use acpi_dev_for_each_child()
  USB: ACPI: Replace usb_acpi_find_port() with acpi_find_child_by_adr()
  thunderbolt: ACPI: Replace tb_acpi_find_port() with acpi_find_child_by_adr()
  ACPI: glue: Introduce acpi_find_child_by_adr()
  ACPI: glue: Introduce acpi_dev_has_children()
  ACPI: glue: Use acpi_dev_for_each_child()

1 files changed, 67 insertions, 50 deletions

diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index 669d7573320b..00f7b490a95d 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -127,6 +127,71 @@ static bool find_slave(struct sdw_bus *bus,
 	return true;
 }
 
+struct sdw_acpi_child_walk_data {
+	struct sdw_bus *bus;
+	struct acpi_device *adev;
+	struct sdw_slave_id id;
+	bool ignore_unique_id;
+};
+
+static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
+{
+	struct sdw_acpi_child_walk_data *cwd = data;
+	struct sdw_bus *bus = cwd->bus;
+	struct sdw_slave_id id;
+
+	if (adev == cwd->adev)
+		return 0;
+
+	if (!find_slave(bus, adev, &id))
+		return 0;
+
+	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
+	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
+		return 0;
+
+	if (cwd->id.unique_id != id.unique_id) {
+		dev_dbg(bus->dev,
+			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
+			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
+			cwd->id.part_id);
+		cwd->ignore_unique_id = false;
+		return 0;
+	}
+
+	dev_err(bus->dev,
+		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
+		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
+	return -ENODEV;
+}
+
+static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
+{
+	struct sdw_bus *bus = data;
+	struct sdw_acpi_child_walk_data cwd = {
+		.bus = bus,
+		.adev = adev,
+		.ignore_unique_id = true,
+	};
+	int ret;
+
+	if (!find_slave(bus, adev, &cwd.id))
+		return 0;
+
+	/* Brute-force O(N^2) search for duplicates. */
+	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
+				      sdw_acpi_check_duplicate, &cwd);
+	if (ret)
+		return ret;
+
+	if (cwd.ignore_unique_id)
+		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
+
+	/* Ignore errors and continue. */
+	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
+	return 0;
+}
+
 /*
  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
  * @bus: SDW bus instance
@@ -135,8 +200,7 @@ static bool find_slave(struct sdw_bus *bus,
  */
 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 {
-	struct acpi_device *adev, *parent;
-	struct acpi_device *adev2, *parent2;
+	struct acpi_device *parent;
 
 	parent = ACPI_COMPANION(bus->dev);
 	if (!parent) {
@@ -144,54 +208,7 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus)
 		return -ENODEV;
 	}
 
-	list_for_each_entry(adev, &parent->children, node) {
-		struct sdw_slave_id id;
-		struct sdw_slave_id id2;
-		bool ignore_unique_id = true;
-
-		if (!find_slave(bus, adev, &id))
-			continue;
-
-		/* brute-force O(N^2) search for duplicates */
-		parent2 = parent;
-		list_for_each_entry(adev2, &parent2->children, node) {
-
-			if (adev == adev2)
-				continue;
-
-			if (!find_slave(bus, adev2, &id2))
-				continue;
-
-			if (id.sdw_version != id2.sdw_version ||
-			    id.mfg_id != id2.mfg_id ||
-			    id.part_id != id2.part_id ||
-			    id.class_id != id2.class_id)
-				continue;
-
-			if (id.unique_id != id2.unique_id) {
-				dev_dbg(bus->dev,
-					"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
-					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
-				ignore_unique_id = false;
-			} else {
-				dev_err(bus->dev,
-					"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
-					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
-				return -ENODEV;
-			}
-		}
-
-		if (ignore_unique_id)
-			id.unique_id = SDW_IGNORED_UNIQUE_ID;
-
-		/*
-		 * don't error check for sdw_slave_add as we want to continue
-		 * adding Slaves
-		 */
-		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
-	}
-
-	return 0;
+	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
 }
 
 #endif