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1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)2//3// This file is provided under a dual BSD/GPLv2 license. When using or4// redistributing this file, you may do so under either license.5//6// Copyright(c) 2023 Advanced Micro Devices, Inc. All rights reserved.7//8// Authors: Vijendar Mukunda <Vijendar.Mukunda@amd.com>9 10/*11 * SDW AMD ACPI scan helper function12 */13 14#include <linux/acpi.h>15#include <linux/bits.h>16#include <linux/bitfield.h>17#include <linux/device.h>18#include <linux/errno.h>19#include <linux/export.h>20#include <linux/fwnode.h>21#include <linux/module.h>22#include <linux/soundwire/sdw_amd.h>23#include <linux/string.h>24 25int amd_sdw_scan_controller(struct sdw_amd_acpi_info *info)26{27 struct acpi_device *adev = acpi_fetch_acpi_dev(info->handle);28 u32 sdw_bitmap = 0;29 u8 count = 0;30 int ret;31 32 if (!adev)33 return -EINVAL;34 35 /* Found controller, find links supported */36 ret = fwnode_property_read_u32_array(acpi_fwnode_handle(adev),37 "mipi-sdw-manager-list", &sdw_bitmap, 1);38 if (ret) {39 dev_err(&adev->dev,40 "Failed to read mipi-sdw-manager-list: %d\n", ret);41 return -EINVAL;42 }43 count = hweight32(sdw_bitmap);44 /* Check count is within bounds */45 if (count > info->count) {46 dev_err(&adev->dev, "Manager count %d exceeds max %d\n",47 count, info->count);48 return -EINVAL;49 }50 51 if (!count) {52 dev_dbg(&adev->dev, "No SoundWire Managers detected\n");53 return -EINVAL;54 }55 dev_dbg(&adev->dev, "ACPI reports %d SoundWire Manager devices\n", count);56 info->link_mask = sdw_bitmap;57 return 0;58}59EXPORT_SYMBOL_NS(amd_sdw_scan_controller, SND_AMD_SOUNDWIRE_ACPI);60 61MODULE_LICENSE("Dual BSD/GPL");62MODULE_DESCRIPTION("AMD SoundWire ACPI helpers");63