acpi: Support writing a UUID
ACPI supports writing a UUID in a special format. Add a function to handle
this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index 0a6c1e3..3e8374e 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -11,6 +11,7 @@
#include <common.h>
#include <dm.h>
#include <log.h>
+#include <uuid.h>
#include <acpi/acpigen.h>
#include <dm/acpi.h>
@@ -249,3 +250,40 @@
acpigen_emit_byte(ctx, NAME_OP);
acpigen_emit_namestring(ctx, namepath);
}
+
+/*
+ * ToUUID(uuid)
+ *
+ * ACPI 6.3 Section 19.6.142 table 19-438 defines a special output order for the
+ * bytes that make up a UUID Buffer object:
+ *
+ * UUID byte order for input to this function:
+ * aabbccdd-eeff-gghh-iijj-kkllmmnnoopp
+ *
+ * UUID byte order output by this function:
+ * ddccbbaa-ffee-hhgg-iijj-kkllmmnnoopp
+ */
+int acpigen_write_uuid(struct acpi_ctx *ctx, const char *uuid)
+{
+ u8 buf[UUID_BIN_LEN];
+ int ret;
+
+ /* Parse UUID string into bytes */
+ ret = uuid_str_to_bin(uuid, buf, UUID_STR_FORMAT_GUID);
+ if (ret)
+ return log_msg_ret("bad hex", -EINVAL);
+
+ /* BufferOp */
+ acpigen_emit_byte(ctx, BUFFER_OP);
+ acpigen_write_len_f(ctx);
+
+ /* Buffer length in bytes */
+ acpigen_write_word(ctx, UUID_BIN_LEN);
+
+ /* Output UUID in expected order */
+ acpigen_emit_stream(ctx, (char *)buf, UUID_BIN_LEN);
+
+ acpigen_pop_len(ctx);
+
+ return 0;
+}