[PATCH v1 16/35] acpi: Support writing a string

[Simon Glass <sjg@chromium.org>]

ACPI supports storing a simple nul-terminated string. Add support for
this.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

Changes in v1: None

 include/acpi/acpigen.h | 10 ++++++++++
 lib/acpi/acpigen.c     |  6 ++++++
 test/dm/acpigen.c      | 32 ++++++++++++++++++++++++++++++--
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index a4edcb097b..f65de53a76 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -21,6 +21,7 @@ enum {
 	BYTE_PREFIX		= 0x0a,
 	WORD_PREFIX		= 0x0b,
 	DWORD_PREFIX		= 0x0c,
+	STRING_PREFIX		= 0x0d,
 	QWORD_PREFIX		= 0x0e,
 	PACKAGE_OP		= 0x12,
 };
@@ -147,4 +148,13 @@ char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el);
  */
 void acpigen_write_integer(struct acpi_ctx *ctx, u64 data);
 
+/**
+ * acpigen_write_string() - Write a string
+ *
+ * This writes a STRING_PREFIX followed by a nul-terminated string
+ *
+ * @ctx: ACPI context pointer
+ * @str: String to write
+ */
+void acpigen_write_string(struct acpi_ctx *ctx, const char *str);
 #endif
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index 01222533f2..275293d22c 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -145,3 +145,9 @@ void acpigen_emit_string(struct acpi_ctx *ctx, const char *str)
 	acpigen_emit_stream(ctx, str, str ? strlen(str) : 0);
 	acpigen_emit_byte(ctx, '\0'); /* NUL */
 }
+
+void acpigen_write_string(struct acpi_ctx *ctx, const char *str)
+{
+	acpigen_emit_byte(ctx, STRING_PREFIX);
+	acpigen_emit_string(ctx, str);
+}
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index 9350943a12..dc6993b7a7 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -20,6 +20,7 @@
 #include <test/ut.h>
 
 #define TEST_STRING	"frogmore"
+#define TEST_STRING2	"ranch"
 #define TEST_STREAM2	"\xfa\xde"
 
 #define TEST_INT8	0x7d
@@ -400,7 +401,7 @@ static int dm_test_acpi_len(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_acpi_len, 0);
 
-/* Test emitting a package */
+/* Test writing a package */
 static int dm_test_acpi_package(struct unit_test_state *uts)
 {
 	struct acpi_ctx *ctx;
@@ -427,7 +428,7 @@ static int dm_test_acpi_package(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_acpi_package, 0);
 
-/* Test emitting an integer */
+/* Test writing an integer */
 static int dm_test_acpi_integer(struct unit_test_state *uts)
 {
 	struct acpi_ctx *ctx;
@@ -467,3 +468,30 @@ static int dm_test_acpi_integer(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_acpi_integer, 0);
+
+/* Test writing a string */
+static int dm_test_acpi_string(struct unit_test_state *uts)
+{
+	struct acpi_ctx *ctx;
+	u8 *ptr;
+
+	ut_assertok(alloc_context(&ctx));
+
+	ptr = acpigen_get_current(ctx);
+
+	acpigen_write_string(ctx, TEST_STRING);
+	acpigen_write_string(ctx, TEST_STRING2);
+
+	ut_asserteq(2 + sizeof(TEST_STRING) + sizeof(TEST_STRING2),
+		    acpigen_get_current(ctx) - ptr);
+	ut_asserteq(STRING_PREFIX, ptr[0]);
+	ut_asserteq_str(TEST_STRING, (char *)ptr + 1);
+	ptr += 1 + sizeof(TEST_STRING);
+	ut_asserteq(STRING_PREFIX, ptr[0]);
+	ut_asserteq_str(TEST_STRING2, (char *)ptr + 1);
+
+	free_context(&ctx);
+
+	return 0;
+}
+DM_TEST(dm_test_acpi_string, 0);
-- 
2.26.2.303.gf8c07b1a785-goog