esp8266: Convert mp_hal_pin_obj_t from pin ptr to simple integer.

Most pin I/O can be done just knowing the pin number as a simple
integer, and it's more efficient this way (code size, speed) because it
doesn't require a memory lookup to get the pin id from the pin object.

If the full pin object is needed then it can be easily looked up in the
pin table.

esp8266/esp_mphal.c

@@ -212,3 +212,15 @@ void dupterm_task_init() {
 void mp_hal_signal_dupterm_input(void) {
     system_os_post(DUPTERM_TASK_ID, 0, 0);
 }
+
+void mp_hal_pin_config_od(mp_hal_pin_obj_t pin_id) {
+    const pyb_pin_obj_t *pin = &pyb_pin_obj[pin_id];
+    ETS_GPIO_INTR_DISABLE();
+    PIN_FUNC_SELECT(pin->periph, pin->func);
+    GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN(pin->phys_port)),
+        GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN(pin->phys_port)))
+        | GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE)); // open drain
+    GPIO_REG_WRITE(GPIO_ENABLE_ADDRESS,
+        GPIO_REG_READ(GPIO_ENABLE_ADDRESS) | (1 << pin->phys_port));
+    ETS_GPIO_INTR_ENABLE();
+}

esp8266/esp_mphal.h

@@ -63,20 +63,11 @@ void ets_event_poll(void);
 #include "etshal.h"
 #include "gpio.h"
 #include "esp8266/modpyb.h"
-#define mp_hal_pin_obj_t pyb_pin_obj_t*
-#define mp_hal_get_pin_obj(o) mp_obj_get_pin_obj(o)
-#define mp_hal_pin_config_od(p) do { \
-        ETS_GPIO_INTR_DISABLE(); \
-        PIN_FUNC_SELECT((p)->periph, (p)->func); \
-        GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN((p)->phys_port)), \
-            GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN((p)->phys_port))) \
-            | GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE)); /* open drain */ \
-        GPIO_REG_WRITE(GPIO_ENABLE_ADDRESS, \
-            GPIO_REG_READ(GPIO_ENABLE_ADDRESS) | (1 << (p)->phys_port)); \
-        ETS_GPIO_INTR_ENABLE(); \
-    } while (0)
-#define mp_hal_pin_low(p) gpio_output_set(0, 1 << (p)->phys_port, 1 << (p)->phys_port, 0)
-#define mp_hal_pin_od_high(p) gpio_output_set(1 << (p)->phys_port, 0, 1 << (p)->phys_port, 0)
-#define mp_hal_pin_read(p) GPIO_INPUT_GET(GPIO_ID_PIN((p)->phys_port))
+#define mp_hal_pin_obj_t uint32_t
+#define mp_hal_get_pin_obj(o) mp_obj_get_pin(o)
+void mp_hal_pin_config_od(mp_hal_pin_obj_t pin);
+#define mp_hal_pin_low(p) gpio_output_set(0, 1 << (p), 1 << (p), 0)
+#define mp_hal_pin_od_high(p) gpio_output_set(1 << (p), 0, 1 << (p), 0)
+#define mp_hal_pin_read(p) GPIO_INPUT_GET(GPIO_ID_PIN((p)))
 
 #endif // _INCLUDED_MPHAL_H_

esp8266/modpyb.h

@@ -18,6 +18,8 @@ typedef struct _pyb_pin_obj_t {
     uint32_t periph;
 } pyb_pin_obj_t;
 
+const pyb_pin_obj_t pyb_pin_obj[16 + 1];
+
 void pin_init0(void);
 void pin_intr_handler_iram(void *arg);
 void pin_intr_handler(uint32_t);

esp8266/modpybpin.c

@@ -59,7 +59,7 @@ typedef struct _pin_irq_obj_t {
     uint16_t phys_port;
 } pin_irq_obj_t;
 
-STATIC const pyb_pin_obj_t pyb_pin_obj[16 + 1] = {
+const pyb_pin_obj_t pyb_pin_obj[16 + 1] = {
     {{&pyb_pin_type}, 0, FUNC_GPIO0, PERIPHS_IO_MUX_GPIO0_U},
     {{&pyb_pin_type}, 1, FUNC_GPIO1, PERIPHS_IO_MUX_U0TXD_U},
     {{&pyb_pin_type}, 2, FUNC_GPIO2, PERIPHS_IO_MUX_GPIO2_U},