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a0609a8d BM |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * Copyright (C) 2018, Bin Meng <[email protected]> | |
4 | */ | |
5 | ||
6 | #include <common.h> | |
f7ae49fc | 7 | #include <log.h> |
776cc201 | 8 | #include <acpi/acpi_table.h> |
a0609a8d BM |
9 | #include <asm/io.h> |
10 | #include <asm/tables.h> | |
11 | ||
12 | static struct acpi_rsdp *acpi_valid_rsdp(struct acpi_rsdp *rsdp) | |
13 | { | |
14 | if (strncmp((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0) | |
15 | return NULL; | |
16 | ||
17 | debug("Looking on %p for valid checksum\n", rsdp); | |
18 | ||
19 | if (table_compute_checksum((void *)rsdp, 20) != 0) | |
20 | return NULL; | |
21 | debug("acpi rsdp checksum 1 passed\n"); | |
22 | ||
23 | if ((rsdp->revision > 1) && | |
24 | (table_compute_checksum((void *)rsdp, rsdp->length) != 0)) | |
25 | return NULL; | |
26 | debug("acpi rsdp checksum 2 passed\n"); | |
27 | ||
28 | return rsdp; | |
29 | } | |
30 | ||
31 | struct acpi_fadt *acpi_find_fadt(void) | |
32 | { | |
33 | char *p, *end; | |
34 | struct acpi_rsdp *rsdp = NULL; | |
35 | struct acpi_rsdt *rsdt; | |
36 | struct acpi_fadt *fadt = NULL; | |
37 | int i; | |
38 | ||
39 | /* Find RSDP */ | |
40 | for (p = (char *)ROM_TABLE_ADDR; p < (char *)ROM_TABLE_END; p += 16) { | |
41 | rsdp = acpi_valid_rsdp((struct acpi_rsdp *)p); | |
42 | if (rsdp) | |
43 | break; | |
44 | } | |
45 | ||
46 | if (!rsdp) | |
47 | return NULL; | |
48 | ||
49 | debug("RSDP found at %p\n", rsdp); | |
50 | rsdt = (struct acpi_rsdt *)(uintptr_t)rsdp->rsdt_address; | |
51 | ||
52 | end = (char *)rsdt + rsdt->header.length; | |
53 | debug("RSDT found at %p ends at %p\n", rsdt, end); | |
54 | ||
55 | for (i = 0; ((char *)&rsdt->entry[i]) < end; i++) { | |
56 | fadt = (struct acpi_fadt *)(uintptr_t)rsdt->entry[i]; | |
57 | if (strncmp((char *)fadt, "FACP", 4) == 0) | |
58 | break; | |
59 | fadt = NULL; | |
60 | } | |
61 | ||
62 | if (!fadt) | |
63 | return NULL; | |
64 | ||
65 | debug("FADT found at %p\n", fadt); | |
66 | return fadt; | |
67 | } | |
68 | ||
69 | void *acpi_find_wakeup_vector(struct acpi_fadt *fadt) | |
70 | { | |
71 | struct acpi_facs *facs; | |
72 | void *wake_vec; | |
73 | ||
74 | debug("Trying to find the wakeup vector...\n"); | |
75 | ||
76 | facs = (struct acpi_facs *)(uintptr_t)fadt->firmware_ctrl; | |
77 | ||
78 | if (!facs) { | |
79 | debug("No FACS found, wake up from S3 not possible.\n"); | |
80 | return NULL; | |
81 | } | |
82 | ||
83 | debug("FACS found at %p\n", facs); | |
84 | wake_vec = (void *)(uintptr_t)facs->firmware_waking_vector; | |
85 | debug("OS waking vector is %p\n", wake_vec); | |
86 | ||
87 | return wake_vec; | |
88 | } | |
89 | ||
90 | void enter_acpi_mode(int pm1_cnt) | |
91 | { | |
92 | u16 val = inw(pm1_cnt); | |
93 | ||
94 | /* | |
95 | * PM1_CNT register bit0 selects the power management event to be | |
96 | * either an SCI or SMI interrupt. When this bit is set, then power | |
97 | * management events will generate an SCI interrupt. When this bit | |
98 | * is reset power management events will generate an SMI interrupt. | |
99 | * | |
100 | * Per ACPI spec, it is the responsibility of the hardware to set | |
101 | * or reset this bit. OSPM always preserves this bit position. | |
102 | * | |
103 | * U-Boot does not support SMI. And we don't have plan to support | |
104 | * anything running in SMM within U-Boot. To create a legacy-free | |
105 | * system, and expose ourselves to OSPM as working under ACPI mode | |
106 | * already, turn this bit on. | |
107 | */ | |
108 | outw(val | PM1_CNT_SCI_EN, pm1_cnt); | |
109 | } |