WSL2-Linux-Kernel/drivers/soundwire/slave.c

115 строки
2.6 KiB
C

// 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