soundwire: Add Master registration
A Master adds a SoundWire bus instance which scans the firmware
provided for device description.
In this patch we scan ACPI namespaces and create SoundWire
Slave devices based on ACPI description
Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
new file mode 100644
index 0000000..ac103bd
--- /dev/null
+++ b/drivers/soundwire/slave.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2015-17 Intel Corporation.
+
+#include <linux/acpi.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+#include "bus.h"
+
+static void sdw_slave_release(struct device *dev)
+{
+ struct sdw_slave *slave = dev_to_sdw_dev(dev);
+
+ kfree(slave);
+}
+
+static int sdw_slave_add(struct sdw_bus *bus,
+ struct sdw_slave_id *id, struct fwnode_handle *fwnode)
+{
+ struct sdw_slave *slave;
+ int ret;
+
+ 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;
+
+ /* name shall be sdw:link:mfg:part:class:unique */
+ dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
+ bus->link_id, id->mfg_id, id->part_id,
+ id->class_id, id->unique_id);
+
+ slave->dev.release = sdw_slave_release;
+ slave->dev.bus = &sdw_bus_type;
+ slave->bus = bus;
+ slave->status = SDW_SLAVE_UNATTACHED;
+ slave->dev_num = 0;
+
+ 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;
+}
+
+#if IS_ENABLED(CONFIG_ACPI)
+/*
+ * 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 *adev, *parent;
+
+ parent = ACPI_COMPANION(bus->dev);
+ if (!parent) {
+ dev_err(bus->dev, "Can't find parent for acpi bind\n");
+ return -ENODEV;
+ }
+
+ list_for_each_entry(adev, &parent->children, node) {
+ unsigned long long addr;
+ struct sdw_slave_id id;
+ 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 status;
+ }
+
+ /* Extract link id from ADR, Bit 51 to 48 (included) */
+ link_id = (addr >> 48) & GENMASK(3, 0);
+
+ /* Check for link_id match */
+ if (link_id != bus->link_id)
+ continue;
+
+ sdw_extract_slave_id(bus, addr, &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;
+}
+
+#endif