drivers/soundwire/slave.c

Source file repositories/reference/linux-study-clean/drivers/soundwire/slave.c

File Facts

System
Linux kernel
Corpus path
drivers/soundwire/slave.c
Extension
.c
Size
7108 bytes
Lines
287
Domain
Driver Families
Bucket
drivers/soundwire
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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
 *

Annotation

Implementation Notes