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