1 files changed, 108 insertions, 0 deletions
diff --git a/arch/x86/lib/acpi.c b/arch/x86/lib/acpi.c
new file mode 100644
index 0000000000..cba9c24dd4
--- /dev/null
+++ b/arch/x86/lib/acpi.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <asm/acpi_table.h>
+#include <asm/io.h>
+#include <asm/tables.h>
+
+static struct acpi_rsdp *acpi_valid_rsdp(struct acpi_rsdp *rsdp)
+{
+	if (strncmp((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0)
+		return NULL;
+
+	debug("Looking on %p for valid checksum\n", rsdp);
+
+	if (table_compute_checksum((void *)rsdp, 20) != 0)
+		return NULL;
+	debug("acpi rsdp checksum 1 passed\n");
+
+	if ((rsdp->revision > 1) &&
+	    (table_compute_checksum((void *)rsdp, rsdp->length) != 0))
+		return NULL;
+	debug("acpi rsdp checksum 2 passed\n");
+
+	return rsdp;
+}
+
+struct acpi_fadt *acpi_find_fadt(void)
+{
+	char *p, *end;
+	struct acpi_rsdp *rsdp = NULL;
+	struct acpi_rsdt *rsdt;
+	struct acpi_fadt *fadt = NULL;
+	int i;
+
+	/* Find RSDP */
+	for (p = (char *)ROM_TABLE_ADDR; p < (char *)ROM_TABLE_END; p += 16) {
+		rsdp = acpi_valid_rsdp((struct acpi_rsdp *)p);
+		if (rsdp)
+			break;
+	}
+
+	if (!rsdp)
+		return NULL;
+
+	debug("RSDP found at %p\n", rsdp);
+	rsdt = (struct acpi_rsdt *)(uintptr_t)rsdp->rsdt_address;
+
+	end = (char *)rsdt + rsdt->header.length;
+	debug("RSDT found at %p ends at %p\n", rsdt, end);
+
+	for (i = 0; ((char *)&rsdt->entry[i]) < end; i++) {
+		fadt = (struct acpi_fadt *)(uintptr_t)rsdt->entry[i];
+		if (strncmp((char *)fadt, "FACP", 4) == 0)
+			break;
+		fadt = NULL;
+	}
+
+	if (!fadt)
+		return NULL;
+
+	debug("FADT found at %p\n", fadt);
+	return fadt;
+}
+
+void *acpi_find_wakeup_vector(struct acpi_fadt *fadt)
+{
+	struct acpi_facs *facs;
+	void *wake_vec;
+
+	debug("Trying to find the wakeup vector...\n");
+
+	facs = (struct acpi_facs *)(uintptr_t)fadt->firmware_ctrl;
+
+	if (!facs) {
+		debug("No FACS found, wake up from S3 not possible.\n");
+		return NULL;
+	}
+
+	debug("FACS found at %p\n", facs);
+	wake_vec = (void *)(uintptr_t)facs->firmware_waking_vector;
+	debug("OS waking vector is %p\n", wake_vec);
+
+	return wake_vec;
+}
+
+void enter_acpi_mode(int pm1_cnt)
+{
+	u16 val = inw(pm1_cnt);
+
+	/*
+	 * PM1_CNT register bit0 selects the power management event to be
+	 * either an SCI or SMI interrupt. When this bit is set, then power
+	 * management events will generate an SCI interrupt. When this bit
+	 * is reset power management events will generate an SMI interrupt.
+	 *
+	 * Per ACPI spec, it is the responsibility of the hardware to set
+	 * or reset this bit. OSPM always preserves this bit position.
+	 *
+	 * U-Boot does not support SMI. And we don't have plan to support
+	 * anything running in SMM within U-Boot. To create a legacy-free
+	 * system, and expose ourselves to OSPM as working under ACPI mode
+	 * already, turn this bit on.
+	 */
+	outw(val | PM1_CNT_SCI_EN, pm1_cnt);
+}