some drying things up (GPIO init in particular)

platform/pin_utils.c

@@ -271,3 +271,43 @@ void deinit_unit_pins(Unit *unit)
         }
     }
 }
+
+
+error_t configure_gpio_alternate(char port_name, uint8_t pin_num, uint32_t af)
+{
+    bool suc = true;
+    GPIO_TypeDef *port = port2periph(port_name, &suc);
+    uint32_t ll_pin = pin2ll(pin_num, &suc);
+    if (!suc) return E_BAD_CONFIG;
+
+    if (pin_num < 8)
+        LL_GPIO_SetAFPin_0_7(port, ll_pin, af);
+    else
+        LL_GPIO_SetAFPin_8_15(port, ll_pin, af);
+
+    LL_GPIO_SetPinMode(port, ll_pin, LL_GPIO_MODE_ALTERNATE);
+
+    return E_SUCCESS;
+}
+
+error_t configure_sparse_pins(char port_name, uint16_t mask, GPIO_TypeDef **port_dest, uint32_t mode, uint32_t otype)
+{
+    bool suc = true;
+    GPIO_TypeDef *port = port2periph(port_name, &suc);
+    if (!suc) return E_BAD_CONFIG;
+
+    for (int i = 0; i < 16; i++) {
+        if (mask & (1<<i)) {
+            uint32_t ll_pin = pin2ll((uint8_t) i, &suc);
+            LL_GPIO_SetPinMode(port, ll_pin, mode);
+            LL_GPIO_SetPinOutputType(port, ll_pin, otype);
+            LL_GPIO_SetPinSpeed(port, ll_pin, LL_GPIO_SPEED_FREQ_HIGH);
+        }
+    }
+
+    if (port_dest != NULL) {
+        *port_dest = port;
+    }
+
+    return E_SUCCESS;
+}

platform/pin_utils.h

@@ -75,4 +75,7 @@ uint16_t port_pack(uint16_t spread, uint16_t mask);
  */
 void deinit_unit_pins(Unit *unit);
 
+error_t configure_gpio_alternate(char port_name, uint8_t pin_num, uint32_t af);
+error_t configure_sparse_pins(char port_name, uint16_t mask, GPIO_TypeDef **port_dest, uint32_t mode, uint32_t otype);
+
 #endif //GEX_PIN_UTILS_H