acpi: Move the table-finding functions into the libary

This is useful for other features. Move the function into library code
so it can be used outside just the 'acpi' command.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

4 files changed, 56 insertions, 39 deletions

diff --git a/cmd/acpi.c b/cmd/acpi.c
index 991b5235e2..e70913e40b 100644
--- a/cmd/acpi.c
+++ b/cmd/acpi.c
@@ -36,49 +36,11 @@ static void dump_hdr(struct acpi_table_header *hdr)
 	}
 }
 
-/**
- * find_table() - Look up an ACPI table
- *
- * @sig: Signature of table (4 characters, upper case)
- * Return: pointer to table header, or NULL if not found
- */
-struct acpi_table_header *find_table(const char *sig)
-{
-	struct acpi_rsdp *rsdp;
-	struct acpi_rsdt *rsdt;
-	int len, i, count;
-
-	rsdp = map_sysmem(gd_acpi_start(), 0);
-	if (!rsdp)
-		return NULL;
-	rsdt = map_sysmem(rsdp->rsdt_address, 0);
-	len = rsdt->header.length - sizeof(rsdt->header);
-	count = len / sizeof(u32);
-	for (i = 0; i < count; i++) {
-		struct acpi_table_header *hdr;
-
-		hdr = map_sysmem(rsdt->entry[i], 0);
-		if (!memcmp(hdr->signature, sig, ACPI_NAME_LEN))
-			return hdr;
-		if (!memcmp(hdr->signature, "FACP", ACPI_NAME_LEN)) {
-			struct acpi_fadt *fadt = (struct acpi_fadt *)hdr;
-
-			if (!memcmp(sig, "DSDT", ACPI_NAME_LEN) && fadt->dsdt)
-				return map_sysmem(fadt->dsdt, 0);
-			if (!memcmp(sig, "FACS", ACPI_NAME_LEN) &&
-			    fadt->firmware_ctrl)
-				return map_sysmem(fadt->firmware_ctrl, 0);
-		}
-	}
-
-	return NULL;
-}
-
 static int dump_table_name(const char *sig)
 {
 	struct acpi_table_header *hdr;
 
-	hdr = find_table(sig);
+	hdr = acpi_find_table(sig);
 	if (!hdr)
 		return -ENOENT;
 	printf("%.*s @ %08lx\n", ACPI_NAME_LEN, hdr->signature,
diff --git a/include/acpi/acpi_table.h b/include/acpi/acpi_table.h
index 4030d25c66..7ed0443c82 100644
--- a/include/acpi/acpi_table.h
+++ b/include/acpi/acpi_table.h
@@ -923,6 +923,14 @@ int acpi_fill_csrt(struct acpi_ctx *ctx);
  */
 ulong write_acpi_tables(ulong start);
 
+/**
+ * acpi_find_table() - Look up an ACPI table
+ *
+ * @sig: Signature of table (4 characters, upper case)
+ * Return: pointer to table header, or NULL if not found
+ */
+struct acpi_table_header *acpi_find_table(const char *sig);
+
 #endif /* !__ACPI__*/
 
 #include <asm/acpi_table.h>
diff --git a/lib/acpi/Makefile b/lib/acpi/Makefile
index 12337abaec..c1c9675b5d 100644
--- a/lib/acpi/Makefile
+++ b/lib/acpi/Makefile
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0+
 #
 
+obj-y += acpi.o
+
 ifdef CONFIG_$(SPL_TPL_)GENERATE_ACPI_TABLE
 
 obj-$(CONFIG_$(SPL_)ACPIGEN) += acpigen.o
diff --git a/lib/acpi/acpi.c b/lib/acpi/acpi.c
new file mode 100644
index 0000000000..14b15754f4
--- /dev/null
+++ b/lib/acpi/acpi.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Utility functions for ACPI
+ *
+ * Copyright 2023 Google LLC
+ */
+
+#include <common.h>
+#include <mapmem.h>
+#include <acpi/acpi_table.h>
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct acpi_table_header *acpi_find_table(const char *sig)
+{
+	struct acpi_rsdp *rsdp;
+	struct acpi_rsdt *rsdt;
+	int len, i, count;
+
+	rsdp = map_sysmem(gd_acpi_start(), 0);
+	if (!rsdp)
+		return NULL;
+	rsdt = map_sysmem(rsdp->rsdt_address, 0);
+	len = rsdt->header.length - sizeof(rsdt->header);
+	count = len / sizeof(u32);
+	for (i = 0; i < count; i++) {
+		struct acpi_table_header *hdr;
+
+		hdr = map_sysmem(rsdt->entry[i], 0);
+		if (!memcmp(hdr->signature, sig, ACPI_NAME_LEN))
+			return hdr;
+		if (!memcmp(hdr->signature, "FACP", ACPI_NAME_LEN)) {
+			struct acpi_fadt *fadt = (struct acpi_fadt *)hdr;
+
+			if (!memcmp(sig, "DSDT", ACPI_NAME_LEN) && fadt->dsdt)
+				return map_sysmem(fadt->dsdt, 0);
+			if (!memcmp(sig, "FACS", ACPI_NAME_LEN) &&
+			    fadt->firmware_ctrl)
+				return map_sysmem(fadt->firmware_ctrl, 0);
+		}
+	}
+
+	return NULL;
+}