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// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
//
// This file is provided under a dual BSD/GPLv2 license. When using or
// redistributing this file, you may do so under either license.
//
// Copyright(c) 2023 Advanced Micro Devices, Inc. All rights reserved.
//
// Authors: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
/*
* SDW AMD ACPI scan helper function
*/
#include <linux/acpi.h>
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/fwnode.h>
#include <linux/module.h>
#include <linux/soundwire/sdw_amd.h>
#include <linux/string.h>
int amd_sdw_scan_controller(struct sdw_amd_acpi_info *info)
{
struct acpi_device *adev = acpi_fetch_acpi_dev(info->handle);
u32 sdw_bitmap = 0;
u8 count = 0;
int ret;
if (!adev)
return -EINVAL;
/* Found controller, find links supported */
ret = fwnode_property_read_u32_array(acpi_fwnode_handle(adev),
"mipi-sdw-manager-list", &sdw_bitmap, 1);
if (ret) {
dev_err(&adev->dev,
"Failed to read mipi-sdw-manager-list: %d\n", ret);
return -EINVAL;
}
count = hweight32(sdw_bitmap);
/* Check count is within bounds */
if (count > info->count) {
dev_err(&adev->dev, "Manager count %d exceeds max %d\n",
count, info->count);
return -EINVAL;
}
if (!count) {
dev_dbg(&adev->dev, "No SoundWire Managers detected\n");
return -EINVAL;
}
dev_dbg(&adev->dev, "ACPI reports %d SoundWire Manager devices\n", count);
info->link_mask = sdw_bitmap;
return 0;
}
EXPORT_SYMBOL_NS(amd_sdw_scan_controller, SND_AMD_SOUNDWIRE_ACPI);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("AMD SoundWire ACPI helpers");
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