acpigen: Add and use acpigen_write_device.

The sequence of bytes to create a method is used several times in codebase.
Put it into a function with logical arguments rather than duplicating magic
bytes everywhere.

Change-Id: I2c33fa403832eb1cfadfbf8d9adef5b63fb9cb24
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/7348
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Tested-by: build bot (Jenkins)

3 files changed, 16 insertions, 10 deletions

diff --git a/src/arch/x86/boot/acpigen.c b/src/arch/x86/boot/acpigen.c
index 0eee78a141..f714d5985b 100644
--- a/src/arch/x86/boot/acpigen.c
+++ b/src/arch/x86/boot/acpigen.c
@@ -408,6 +408,19 @@ int acpigen_write_method(const char *name, int nargs)
 	return len;
 }
 
+int acpigen_write_device(const char *name)
+{
+	int len;
+
+	/* method op */
+	len = acpigen_emit_byte(0x5b);
+	len += acpigen_emit_byte(0x82);
+	len += acpigen_write_len_f();
+	len += acpigen_emit_namestring(name);
+
+	return len;
+}
+
 /*
  * Generates a func with max supported P-states.
  */
diff --git a/src/arch/x86/include/arch/acpigen.h b/src/arch/x86/include/arch/acpigen.h
index babfb4014b..e07a0f5c22 100644
--- a/src/arch/x86/include/arch/acpigen.h
+++ b/src/arch/x86/include/arch/acpigen.h
@@ -44,6 +44,7 @@ int acpigen_write_name_qword(const char *name, uint64_t val);
 int acpigen_write_name_byte(const char *name, uint8_t val);
 int acpigen_write_scope(const char *name);
 int acpigen_write_method(const char *name, int nargs);
+int acpigen_write_device(const char *name);
 int acpigen_write_PPC(u8 nr);
 int acpigen_write_PPC_NVS(void);
 int acpigen_write_empty_PCT(void);
diff --git a/src/drivers/lenovo/wacom.c b/src/drivers/lenovo/wacom.c
index 2f73a6d8e0..ce49535cc3 100644
--- a/src/drivers/lenovo/wacom.c
+++ b/src/drivers/lenovo/wacom.c
@@ -98,11 +98,7 @@ drivers_lenovo_serial_ports_ssdt_generate(const char *scope,
 	acpigen_write_scope(scope);
 
 	if (drivers_lenovo_is_wacom_present()) {
-		/* Device op.  */
-		acpigen_emit_byte(0x5b);
-		acpigen_emit_byte(0x82);
-		acpigen_write_len_f();
-		acpigen_emit_namestring("DTR");
+		acpigen_write_device("DTR");
 
 		acpigen_write_name("_HID");
 		acpigen_emit_eisaid("WACF004");
@@ -125,11 +121,7 @@ drivers_lenovo_serial_ports_ssdt_generate(const char *scope,
 	}
 
 	if (have_dock_serial) {
-		/* Device op.  */
-		acpigen_emit_byte(0x5b);
-		acpigen_emit_byte(0x82);
-		acpigen_write_len_f();
-		acpigen_emit_namestring("COMA");
+		acpigen_write_device("COMA");
 
 		acpigen_write_name("_HID");
 		acpigen_emit_eisaid("PNP0501");