mirror of
https://github.com/AsahiLinux/u-boot
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46 lines
1 KiB
C
46 lines
1 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Utility functions for ACPI
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*
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* Copyright 2023 Google LLC
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*/
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#include <common.h>
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#include <mapmem.h>
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#include <acpi/acpi_table.h>
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#include <asm/global_data.h>
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DECLARE_GLOBAL_DATA_PTR;
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struct acpi_table_header *acpi_find_table(const char *sig)
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{
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struct acpi_rsdp *rsdp;
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struct acpi_rsdt *rsdt;
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int len, i, count;
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rsdp = map_sysmem(gd_acpi_start(), 0);
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if (!rsdp)
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return NULL;
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rsdt = map_sysmem(rsdp->rsdt_address, 0);
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len = rsdt->header.length - sizeof(rsdt->header);
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count = len / sizeof(u32);
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for (i = 0; i < count; i++) {
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struct acpi_table_header *hdr;
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hdr = map_sysmem(rsdt->entry[i], 0);
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if (!memcmp(hdr->signature, sig, ACPI_NAME_LEN))
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return hdr;
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if (!memcmp(hdr->signature, "FACP", ACPI_NAME_LEN)) {
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struct acpi_fadt *fadt = (struct acpi_fadt *)hdr;
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if (!memcmp(sig, "DSDT", ACPI_NAME_LEN) && fadt->dsdt)
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return map_sysmem(fadt->dsdt, 0);
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if (!memcmp(sig, "FACS", ACPI_NAME_LEN) &&
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fadt->firmware_ctrl)
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return map_sysmem(fadt->firmware_ctrl, 0);
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}
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}
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return NULL;
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}
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