| Bin Meng | ac63025 | 2018-07-18 21:42:15 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com> |
| 4 | */ |
| 5 | |
| 6 | #include <common.h> |
| 7 | #include <asm/acpi_table.h> |
| 8 | #include <asm/io.h> |
| 9 | #include <asm/tables.h> |
| 10 | |
| 11 | static struct acpi_rsdp *acpi_valid_rsdp(struct acpi_rsdp *rsdp) |
| 12 | { |
| 13 | if (strncmp((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0) |
| 14 | return NULL; |
| 15 | |
| 16 | debug("Looking on %p for valid checksum\n", rsdp); |
| 17 | |
| 18 | if (table_compute_checksum((void *)rsdp, 20) != 0) |
| 19 | return NULL; |
| 20 | debug("acpi rsdp checksum 1 passed\n"); |
| 21 | |
| 22 | if ((rsdp->revision > 1) && |
| 23 | (table_compute_checksum((void *)rsdp, rsdp->length) != 0)) |
| 24 | return NULL; |
| 25 | debug("acpi rsdp checksum 2 passed\n"); |
| 26 | |
| 27 | return rsdp; |
| 28 | } |
| 29 | |
| 30 | struct acpi_fadt *acpi_find_fadt(void) |
| 31 | { |
| 32 | char *p, *end; |
| 33 | struct acpi_rsdp *rsdp = NULL; |
| 34 | struct acpi_rsdt *rsdt; |
| 35 | struct acpi_fadt *fadt = NULL; |
| 36 | int i; |
| 37 | |
| 38 | /* Find RSDP */ |
| 39 | for (p = (char *)ROM_TABLE_ADDR; p < (char *)ROM_TABLE_END; p += 16) { |
| 40 | rsdp = acpi_valid_rsdp((struct acpi_rsdp *)p); |
| 41 | if (rsdp) |
| 42 | break; |
| 43 | } |
| 44 | |
| 45 | if (!rsdp) |
| 46 | return NULL; |
| 47 | |
| 48 | debug("RSDP found at %p\n", rsdp); |
| 49 | rsdt = (struct acpi_rsdt *)(uintptr_t)rsdp->rsdt_address; |
| 50 | |
| 51 | end = (char *)rsdt + rsdt->header.length; |
| 52 | debug("RSDT found at %p ends at %p\n", rsdt, end); |
| 53 | |
| 54 | for (i = 0; ((char *)&rsdt->entry[i]) < end; i++) { |
| 55 | fadt = (struct acpi_fadt *)(uintptr_t)rsdt->entry[i]; |
| 56 | if (strncmp((char *)fadt, "FACP", 4) == 0) |
| 57 | break; |
| 58 | fadt = NULL; |
| 59 | } |
| 60 | |
| 61 | if (!fadt) |
| 62 | return NULL; |
| 63 | |
| 64 | debug("FADT found at %p\n", fadt); |
| 65 | return fadt; |
| 66 | } |
| 67 | |
| 68 | void *acpi_find_wakeup_vector(struct acpi_fadt *fadt) |
| 69 | { |
| 70 | struct acpi_facs *facs; |
| 71 | void *wake_vec; |
| 72 | |
| 73 | debug("Trying to find the wakeup vector...\n"); |
| 74 | |
| 75 | facs = (struct acpi_facs *)(uintptr_t)fadt->firmware_ctrl; |
| 76 | |
| 77 | if (!facs) { |
| 78 | debug("No FACS found, wake up from S3 not possible.\n"); |
| 79 | return NULL; |
| 80 | } |
| 81 | |
| 82 | debug("FACS found at %p\n", facs); |
| 83 | wake_vec = (void *)(uintptr_t)facs->firmware_waking_vector; |
| 84 | debug("OS waking vector is %p\n", wake_vec); |
| 85 | |
| 86 | return wake_vec; |
| 87 | } |
| 88 | |
| 89 | void enter_acpi_mode(int pm1_cnt) |
| 90 | { |
| 91 | u16 val = inw(pm1_cnt); |
| 92 | |
| 93 | /* |
| 94 | * PM1_CNT register bit0 selects the power management event to be |
| 95 | * either an SCI or SMI interrupt. When this bit is set, then power |
| 96 | * management events will generate an SCI interrupt. When this bit |
| 97 | * is reset power management events will generate an SMI interrupt. |
| 98 | * |
| 99 | * Per ACPI spec, it is the responsibility of the hardware to set |
| 100 | * or reset this bit. OSPM always preserves this bit position. |
| 101 | * |
| 102 | * U-Boot does not support SMI. And we don't have plan to support |
| 103 | * anything running in SMM within U-Boot. To create a legacy-free |
| 104 | * system, and expose ourselves to OSPM as working under ACPI mode |
| 105 | * already, turn this bit on. |
| 106 | */ |
| 107 | outw(val | PM1_CNT_SCI_EN, pm1_cnt); |
| 108 | } |