src/acpi/acpi_hpet.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <acpi/acpi.h>
   4 #include <arch/hpet.h>
   5 #include <console/console.h>
   6 #include <device/device.h>
   7 #include <device/mmio.h>
   8 #include <version.h>
   9
  10
  11 /* http://www.intel.com/hardwaredesign/hpetspec_1.pdf */
  12 static void acpi_create_hpet(acpi_hpet_t *hpet)
  13 {
  14         acpi_header_t *header = &(hpet->header);
  15         acpi_addr_t *addr = &(hpet->addr);
  16
  17         memset((void *)hpet, 0, sizeof(acpi_hpet_t));
  18
  19         if (!header)
  20                 return;
  21
  22         /* Fill out header fields. */
  23         memcpy(header->signature, "HPET", 4);
  24         memcpy(header->oem_id, OEM_ID, 6);
  25         memcpy(header->oem_table_id, ACPI_TABLE_CREATOR, 8);
  26         memcpy(header->asl_compiler_id, ASLC, 4);
  27
  28         header->asl_compiler_revision = asl_revision;
  29         header->length = sizeof(acpi_hpet_t);
  30         header->revision = get_acpi_table_revision(HPET);
  31
  32         /* Fill out HPET address. */
  33         addr->space_id = ACPI_ADDRESS_SPACE_MEMORY;
  34         addr->bit_width = 64;
  35         addr->bit_offset = 0;
  36         addr->addrl = HPET_BASE_ADDRESS & 0xffffffff;
  37         addr->addrh = ((unsigned long long)HPET_BASE_ADDRESS) >> 32;
  38
  39         hpet->id = read32p(HPET_BASE_ADDRESS);
  40         hpet->number = 0;
  41         hpet->min_tick = CONFIG_HPET_MIN_TICKS;
  42
  43         header->checksum = acpi_checksum((void *)hpet, sizeof(acpi_hpet_t));
  44 }
  45
  46 unsigned long acpi_write_hpet(const struct device *device, unsigned long current,
  47                               acpi_rsdp_t *rsdp)
  48 {
  49         acpi_hpet_t *hpet;
  50
  51         /*
  52          * We explicitly add these tables later on:
  53          */
  54         printk(BIOS_DEBUG, "ACPI:    * HPET\n");
  55
  56         hpet = (acpi_hpet_t *)current;
  57         current += sizeof(acpi_hpet_t);
  58         current = ALIGN_UP(current, 16);
  59         acpi_create_hpet(hpet);
  60         acpi_add_table(rsdp, hpet);
  61
  62         return current;
  63 }