extmod/machine_i2s: Factor ports' I2S Python bindings to common code.

This factors the basic top-level I2S class code from the ports into
extmod/machine_i2s.c:
- I2S class definition and method table.
- The init and deinit method wrappers.
- The make_new code.

Further factoring will follow.

Signed-off-by: Damien George <damien@micropython.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/extmod/modmachine.h b/extmod/modmachine.h
index 22bd0d625..b0235dcf6 100644
--- a/extmod/modmachine.h
+++ b/extmod/modmachine.h
@@ -30,6 +30,7 @@
 #include "py/obj.h"
 
 // A port must provide these types, but they are otherwise opaque.
+typedef struct _machine_i2s_obj_t machine_i2s_obj_t;
 typedef struct _machine_pwm_obj_t machine_pwm_obj_t;
 typedef struct _machine_wdt_obj_t machine_wdt_obj_t;
 
@@ -37,6 +38,7 @@ typedef struct _machine_wdt_obj_t machine_wdt_obj_t;
 // Their Python bindings are implemented in extmod, and their implementation
 // is provided by a port.
 extern const mp_obj_type_t machine_i2c_type;
+extern const mp_obj_type_t machine_i2s_type;
 extern const mp_obj_type_t machine_pwm_type;
 extern const mp_obj_type_t machine_spi_type;
 extern const mp_obj_type_t machine_timer_type;