1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
new file mode 100644
index 0000000000..060c2982e2
--- /dev/null
+++ b/drivers/soundwire/slave.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2015-17 Intel Corporation.
+
+#include <linux/acpi.h>
+#include <linux/of.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+#include "bus.h"
+#include "sysfs_local.h"
+
+static void sdw_slave_release(struct device *dev)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
+
+	mutex_destroy(&slave->sdw_dev_lock);
+	kfree(slave);
+}
+
+struct device_type sdw_slave_type = {
+	.name =		"sdw_slave",
+	.release =	sdw_slave_release,
+	.uevent =	sdw_slave_uevent,
+};
+
+int sdw_slave_add(struct sdw_bus *bus,
+		  struct sdw_slave_id *id, struct fwnode_handle *fwnode)
+{
+	struct sdw_slave *slave;
+	int ret;
+	int i;
+
+	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
+	if (!slave)
+		return -ENOMEM;
+
+	/* Initialize data structure */
+	memcpy(&slave->id, id, sizeof(*id));
+	slave->dev.parent = bus->dev;
+	slave->dev.fwnode = fwnode;
+
+	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
+		/* name shall be sdw:ctrl:link:mfg:part:class */
+		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x",
+			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
+			     id->class_id);
+	} else {
+		/* name shall be sdw:ctrl:link:mfg:part:class:unique */
+		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x:%01x",
+			     bus->controller_id, bus->link_id, id->mfg_id, id->part_id,
+			     id->class_id, id->unique_id);
+	}
+
+	slave->dev.bus = &sdw_bus_type;
+	slave->dev.of_node = of_node_get(to_of_node(fwnode));
+	slave->dev.type = &sdw_slave_type;
+	slave->dev.groups = sdw_slave_status_attr_groups;
+	slave->bus = bus;
+	slave->status = SDW_SLAVE_UNATTACHED;
+	init_completion(&slave->enumeration_complete);
+	init_completion(&slave->initialization_complete);
+	slave->dev_num = 0;
+	slave->probed = false;
+	slave->first_interrupt_done = false;
+	mutex_init(&slave->sdw_dev_lock);
+
+	for (i = 0; i < SDW_MAX_PORTS; i++)
+		init_completion(&slave->port_ready[i]);
+
+	mutex_lock(&bus->bus_lock);
+	list_add_tail(&slave->node, &bus->slaves);
+	mutex_unlock(&bus->bus_lock);
+
+	ret = device_register(&slave->dev);
+	if (ret) {
+		dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
+
+		/*
+		 * On err, don't free but drop ref as this will be freed
+		 * when release method is invoked.
+		 */
+		mutex_lock(&bus->bus_lock);
+		list_del(&slave->node);
+		mutex_unlock(&bus->bus_lock);
+		put_device(&slave->dev);
+
+		return ret;
+	}
+	sdw_slave_debugfs_init(slave);
+
+	return ret;
+}
+EXPORT_SYMBOL(sdw_slave_add);
+
+#if IS_ENABLED(CONFIG_ACPI)
+
+static bool find_slave(struct sdw_bus *bus,
+		       struct acpi_device *adev,
+		       struct sdw_slave_id *id)
+{
+	u64 addr;
+	unsigned int link_id;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(adev->handle,
+				       METHOD_NAME__ADR, NULL, &addr);
+
+	if (ACPI_FAILURE(status)) {
+		dev_err(bus->dev, "_ADR resolution failed: %x\n",
+			status);
+		return false;
+	}
+
+	if (bus->ops->override_adr)
+		addr = bus->ops->override_adr(bus, addr);
+
+	if (!addr)
+		return false;
+
+	/* Extract link id from ADR, Bit 51 to 48 (included) */
+	link_id = SDW_DISCO_LINK_ID(addr);
+
+	/* Check for link_id match */
+	if (link_id != bus->link_id)
+		return false;
+
+	sdw_extract_slave_id(bus, addr, id);
+
+	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
+ *
+ * Scans Master ACPI node for SDW child Slave devices and registers it.
+ */
+int sdw_acpi_find_slaves(struct sdw_bus *bus)
+{
+	struct acpi_device *parent;
+
+	parent = ACPI_COMPANION(bus->dev);
+	if (!parent) {
+		dev_err(bus->dev, "Can't find parent for acpi bind\n");
+		return -ENODEV;
+	}
+
+	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
+}
+
+#endif
+
+/*
+ * sdw_of_find_slaves() - Find Slave devices in master device tree node
+ * @bus: SDW bus instance
+ *
+ * Scans Master DT node for SDW child Slave devices and registers it.
+ */
+int sdw_of_find_slaves(struct sdw_bus *bus)
+{
+	struct device *dev = bus->dev;
+	struct device_node *node;
+
+	for_each_child_of_node(bus->dev->of_node, node) {
+		int link_id, ret, len;
+		unsigned int sdw_version;
+		const char *compat = NULL;
+		struct sdw_slave_id id;
+		const __be32 *addr;
+
+		compat = of_get_property(node, "compatible", NULL);
+		if (!compat)
+			continue;
+
+		ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
+			     &id.mfg_id, &id.part_id, &id.class_id);
+
+		if (ret != 4) {
+			dev_err(dev, "Invalid compatible string found %s\n",
+				compat);
+			continue;
+		}
+
+		addr = of_get_property(node, "reg", &len);
+		if (!addr || (len < 2 * sizeof(u32))) {
+			dev_err(dev, "Invalid Link and Instance ID\n");
+			continue;
+		}
+
+		link_id = be32_to_cpup(addr++);
+		id.unique_id = be32_to_cpup(addr);
+		id.sdw_version = sdw_version;
+
+		/* Check for link_id match */
+		if (link_id != bus->link_id)
+			continue;
+
+		sdw_slave_add(bus, &id, of_fwnode_handle(node));
+	}
+
+	return 0;
+}