[v1,15/35] acpi: Support writing an integer

diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index 52e0b75128..a4edcb097b 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -16,6 +16,12 @@  struct acpi_ctx;
 
 /* ACPI Op/Prefix codes */
 enum {
+	ZERO_OP			= 0x00,
+	ONE_OP			= 0x01,
+	BYTE_PREFIX		= 0x0a,
+	WORD_PREFIX		= 0x0b,
+	DWORD_PREFIX		= 0x0c,
+	QWORD_PREFIX		= 0x0e,
 	PACKAGE_OP		= 0x12,
 };
 
@@ -130,4 +136,15 @@  void acpigen_pop_len(struct acpi_ctx *ctx);
  */
 char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el);
 
+/**
+ * acpigen_write_integer() - Write an integer
+ *
+ * This writes an operation (BYTE_OP, WORD_OP, DWORD_OP, QWORD_OP depending on
+ * the integer size) and an integer value. Note that WORD means 16 bits in ACPI.
+ *
+ * @ctx: ACPI context pointer
+ * @data: Integer to write
+ */
+void acpigen_write_integer(struct acpi_ctx *ctx, u64 data);
+
 #endif
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index ca9e96597e..01222533f2 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -81,6 +81,57 @@  char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el)
 	return p;
 }
 
+void acpigen_write_byte(struct acpi_ctx *ctx, unsigned int data)
+{
+	acpigen_emit_byte(ctx, BYTE_PREFIX);
+	acpigen_emit_byte(ctx, data & 0xff);
+}
+
+void acpigen_write_word(struct acpi_ctx *ctx, unsigned int data)
+{
+	acpigen_emit_byte(ctx, WORD_PREFIX);
+	acpigen_emit_word(ctx, data);
+}
+
+void acpigen_write_dword(struct acpi_ctx *ctx, unsigned int data)
+{
+	acpigen_emit_byte(ctx, DWORD_PREFIX);
+	acpigen_emit_dword(ctx, data);
+}
+
+void acpigen_write_qword(struct acpi_ctx *ctx, u64 data)
+{
+	acpigen_emit_byte(ctx, QWORD_PREFIX);
+	acpigen_emit_dword(ctx, data & 0xffffffff);
+	acpigen_emit_dword(ctx, (data >> 32) & 0xffffffff);
+}
+
+void acpigen_write_zero(struct acpi_ctx *ctx)
+{
+	acpigen_emit_byte(ctx, ZERO_OP);
+}
+
+void acpigen_write_one(struct acpi_ctx *ctx)
+{
+	acpigen_emit_byte(ctx, ONE_OP);
+}
+
+void acpigen_write_integer(struct acpi_ctx *ctx, u64 data)
+{
+	if (data == 0)
+		acpigen_write_zero(ctx);
+	else if (data == 1)
+		acpigen_write_one(ctx);
+	else if (data <= 0xff)
+		acpigen_write_byte(ctx, (unsigned char)data);
+	else if (data <= 0xffff)
+		acpigen_write_word(ctx, (unsigned int)data);
+	else if (data <= 0xffffffff)
+		acpigen_write_dword(ctx, (unsigned int)data);
+	else
+		acpigen_write_qword(ctx, data);
+}
+
 void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size)
 {
 	int i;
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index be81068759..9350943a12 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -22,6 +22,11 @@ 
 #define TEST_STRING	"frogmore"
 #define TEST_STREAM2	"\xfa\xde"
 
+#define TEST_INT8	0x7d
+#define TEST_INT16	0x2345
+#define TEST_INT32	0x12345678
+#define TEST_INT64	0x4567890123456
+
 static int alloc_context_size(struct acpi_ctx **ctxp, int size)
 {
 	struct acpi_ctx *ctx;
@@ -421,3 +426,44 @@  static int dm_test_acpi_package(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_acpi_package, 0);
+
+/* Test emitting an integer */
+static int dm_test_acpi_integer(struct unit_test_state *uts)
+{
+	struct acpi_ctx *ctx;
+	u8 *ptr;
+
+	ut_assertok(alloc_context(&ctx));
+
+	ptr = acpigen_get_current(ctx);
+
+	acpigen_write_integer(ctx, 0);
+	acpigen_write_integer(ctx, 1);
+	acpigen_write_integer(ctx, TEST_INT8);
+	acpigen_write_integer(ctx, TEST_INT16);
+	acpigen_write_integer(ctx, TEST_INT32);
+	acpigen_write_integer(ctx, TEST_INT64);
+
+	ut_asserteq(6 + 1 + 2 + 4 + 8, acpigen_get_current(ctx) - ptr);
+
+	ut_asserteq(ZERO_OP, ptr[0]);
+
+	ut_asserteq(ONE_OP, ptr[1]);
+
+	ut_asserteq(BYTE_PREFIX, ptr[2]);
+	ut_asserteq(TEST_INT8, ptr[3]);
+
+	ut_asserteq(WORD_PREFIX, ptr[4]);
+	ut_asserteq(TEST_INT16, get_unaligned((u16 *)(ptr + 5)));
+
+	ut_asserteq(DWORD_PREFIX, ptr[7]);
+	ut_asserteq(TEST_INT32, get_unaligned((u32 *)(ptr + 8)));
+
+	ut_asserteq(QWORD_PREFIX, ptr[12]);
+	ut_asserteq_64(TEST_INT64, get_unaligned((u64 *)(ptr + 13)));
+
+	free_context(&ctx);
+
+	return 0;
+}
+DM_TEST(dm_test_acpi_integer, 0);