Update stm32 gpio driver

Restores functionality to the stm32 gpio driver by updating mailbox message
parsing to match updates to the the erlang and elixir drivers. Modifies the
`pin() type` in both versions of the gpio driver to accommodate tuples used
in the stm32 port.

Signed-off-by: Winford <[email protected]>

Author: Winford

libs/eavmlib/src/gpio.erl

@@ -43,6 +43,9 @@
 %%
 %% This module provides functions for interacting with micro-controller GPIO
 %% (General Purpose Input and Output) pins.
+%%
+%% Note: `-type pin()' used in this driver refers to a pin number on Espressif
+%% chips, or a tuple {GPIO_GROUP, PIN} for stm32 chips.
 %% @end
 %%-----------------------------------------------------------------------------
 -module(gpio).
@@ -62,7 +65,7 @@
 ]).
 
 -type gpio() :: pid().
--type pin() :: non_neg_integer().
+-type pin() :: non_neg_integer() | {atom(), non_neg_integer()}.
 -type direction() :: input | output | output_od.
 -type pull() :: up | down | up_down | floating.
 -type low_level() :: low | 0.

libs/exavmlib/lib/GPIO.ex

@@ -28,8 +28,10 @@ defmodule GPIO do
   Valid GPIO pin number.
 
   The actual number of pins that are broken out vary by board and module.
+  For espressif chips this a the pin number marked on the board or data sheet.
+  For stm32 chips this is a tuple {GPIO_GROUP, PIN_NUMBER}.
   """
-  @type gpio_pin() :: non_neg_integer()
+  @type gpio_pin() :: non_neg_integer() | {atom(), non_neg_integer()}
 
   @typedoc """
   Event type describing the voltage that will trigger an interrupt.

src/platforms/stm32/src/lib/gpiodriver.c

@@ -27,6 +27,8 @@
 #include <mailbox.h>
 #include <term.h>
 
+// Uncomment to enable trace
+//#define ENABLE_TRACE 1
 #include <trace.h>
 
 #include "platform_defaultatoms.h"
@@ -36,6 +38,15 @@ static uint32_t port_atom_to_gpio_port(Context *ctx, term port_atom);
 static uint16_t gpio_port_to_rcc_port(uint32_t gpio_port);
 static char gpio_port_to_name(uint32_t gpio_port);
 
+static term create_pair(Context *ctx, term term1, term term2)
+{
+    term ret = term_alloc_tuple(2, ctx);
+    term_put_tuple_element(ret, 0, term1);
+    term_put_tuple_element(ret, 1, term2);
+
+    return ret;
+}
+
 void gpiodriver_init(Context *ctx)
 {
     ctx->native_handler = consume_gpio_mailbox;
@@ -49,17 +60,18 @@ static void consume_gpio_mailbox(Context *ctx)
     Message *message = mailbox_dequeue(ctx);
     term msg = message->message;
     term pid = term_get_tuple_element(msg, 0);
-    term cmd = term_get_tuple_element(msg, 1);
+    term req = term_get_tuple_element(msg, 2);
+    term cmd = term_get_tuple_element(req, 0);
 
     int local_process_id = term_to_local_process_id(pid);
     Context *target = globalcontext_get_process(ctx->global, local_process_id);
 
     if (cmd == SET_LEVEL_ATOM) {
-        term gpio_tuple = term_get_tuple_element(msg, 2);
+        term gpio_tuple = term_get_tuple_element(req, 1);
         term gpio_port_atom = term_get_tuple_element(gpio_tuple, 0);
         uint32_t gpio_port = port_atom_to_gpio_port(ctx, gpio_port_atom);
         int32_t gpio_pin_num = term_to_int32(term_get_tuple_element(gpio_tuple, 1));
-        int32_t level = term_to_int32(term_get_tuple_element(msg, 3));
+        int32_t level = term_to_int32(term_get_tuple_element(req, 2));
 
         if (level != 0) {
             gpio_set(gpio_port, 1 << gpio_pin_num);
@@ -70,11 +82,11 @@ static void consume_gpio_mailbox(Context *ctx)
         ret = OK_ATOM;
 
     } else if (cmd == SET_DIRECTION_ATOM) {
-        term gpio_tuple = term_get_tuple_element(msg, 2);
+        term gpio_tuple = term_get_tuple_element(req, 1);
         term gpio_port_atom = term_get_tuple_element(gpio_tuple, 0);
         uint32_t gpio_port = port_atom_to_gpio_port(ctx, gpio_port_atom);
         int32_t gpio_pin_num = term_to_int32(term_get_tuple_element(gpio_tuple, 1));
-        term direction = term_get_tuple_element(msg, 3);
+        term direction = term_get_tuple_element(req, 2);
 
         uint16_t rcc_port = gpio_port_to_rcc_port(gpio_port);
         // Set direction implicitly enables the port of the GPIO
@@ -100,9 +112,16 @@ static void consume_gpio_mailbox(Context *ctx)
         ret = ERROR_ATOM;
     }
 
-    free(message);
+    term ret_msg;
+    if (UNLIKELY(memory_ensure_free(ctx, 3) != MEMORY_GC_OK)) {
+        ret_msg = OUT_OF_MEMORY_ATOM;
+    } else {
+        term ref = term_get_tuple_element(msg, 1);
+        ret_msg = create_pair(ctx, ref, ret);
+    }
 
-    mailbox_send(target, ret);
+    mailbox_send(target, ret_msg);
+    mailbox_destroy_message(message);
 }
 
 static uint32_t port_atom_to_gpio_port(Context *ctx, term port_atom)