Fix GPIO16 Board Reset; Updated Usage

ports/esp8266/common-hal/analogio/AnalogIn.c

@@ -36,14 +36,12 @@
 
 #include "user_interface.h"
 
-volatile bool adc_in_use __attribute__((aligned(4))) = false;
-
 void common_hal_analogio_analogin_construct(analogio_analogin_obj_t* self,
         const mcu_pin_obj_t *pin) {
     if (pin != &pin_TOUT) {
         nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Pin %q does not have ADC capabilities", pin->name));
     }
-    adc_in_use = true;
+    claim_pin(pin);
 }
 
 bool common_hal_analogio_analogin_deinited(analogio_analogin_obj_t* self) {
@@ -54,7 +52,7 @@ void common_hal_analogio_analogin_deinit(analogio_analogin_obj_t* self) {
     if (common_hal_analogio_analogin_deinited(self)) {
         return;
     }
-    adc_in_use = false;
+    reset_pin(&pin_TOUT);
     self->deinited = true;
 }
 

ports/esp8266/common-hal/digitalio/DigitalInOut.c

@@ -33,11 +33,21 @@
 #include "py/mphal.h"
 
 #include "shared-bindings/digitalio/DigitalInOut.h"
+#include "common-hal/microcontroller/Pin.h"
+
+extern volatile bool gpio16_in_use;
 
 digitalinout_result_t common_hal_digitalio_digitalinout_construct(
         digitalio_digitalinout_obj_t* self, const mcu_pin_obj_t* pin) {
     self->pin = pin;
-    PIN_FUNC_SELECT(self->pin->peripheral, self->pin->gpio_function);
+    if (self->pin->gpio_number == 16) {
+        WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1); 	// mux configuration for XPD_DCDC and rtc_gpio0 connection
+        WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);	//mux configuration for out enable
+        WRITE_PERI_REG(RTC_GPIO_ENABLE, READ_PERI_REG(RTC_GPIO_ENABLE) & ~1);	//out disable
+        claim_pin(pin);
+    } else {    
+        PIN_FUNC_SELECT(self->pin->peripheral, self->pin->gpio_function);
+    }    
     return DIGITALINOUT_OK;
 }
 
@@ -54,6 +64,8 @@ void common_hal_digitalio_digitalinout_deinit(digitalio_digitalinout_obj_t* self
         gpio_output_set(0x0, 0x0, 0x0, pin_mask);
         PIN_FUNC_SELECT(self->pin->peripheral, 0);
         PIN_PULLUP_DIS(self->pin->peripheral);
+    } else {
+        reset_pin(self->pin);
     }
     self->pin = mp_const_none;
 }
@@ -96,6 +108,23 @@ digitalio_direction_t common_hal_digitalio_digitalinout_get_direction(
 
 void common_hal_digitalio_digitalinout_set_value(
         digitalio_digitalinout_obj_t* self, bool value) {
+    if (self->pin->gpio_number == 16) {
+        if (self->open_drain && value) {
+            // configure GPIO16 as input with output register holding 0
+            WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1);
+            WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);
+            WRITE_PERI_REG(RTC_GPIO_ENABLE, (READ_PERI_REG(RTC_GPIO_ENABLE) & ~1)); // input
+            WRITE_PERI_REG(RTC_GPIO_OUT, (READ_PERI_REG(RTC_GPIO_OUT) & 1)); // out=1
+            return;
+        } else {
+            int out_en = self->output;
+            WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1);
+            WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);
+            WRITE_PERI_REG(RTC_GPIO_ENABLE, (READ_PERI_REG(RTC_GPIO_ENABLE) & ~1) | out_en);
+            WRITE_PERI_REG(RTC_GPIO_OUT, (READ_PERI_REG(RTC_GPIO_OUT) & ~1) | value);
+            return;
+        }
+    }
     if (value) {
         if (self->open_drain) {
             // Disable output.
@@ -125,11 +154,19 @@ bool common_hal_digitalio_digitalinout_get_value(
         }
         return GPIO_INPUT_GET(self->pin->gpio_number);
     } else {
-        uint32_t pin_mask = 1 << self->pin->gpio_number;
-        if (self->open_drain && ((*PIN_DIR) & pin_mask) == 0) {
-            return true;
+        if (self->pin->gpio_number == 16) {
+            if (self->open_drain && READ_PERI_REG(RTC_GPIO_ENABLE) == 0) {
+                return true;
+            } else {
+                return READ_PERI_REG(RTC_GPIO_OUT) & 1;
+            }
         } else {
-            return ((*PIN_OUT) & pin_mask) != 0;
+            uint32_t pin_mask = 1 << self->pin->gpio_number;
+            if (self->open_drain && ((*PIN_DIR) & pin_mask) == 0) {
+                return true;
+            } else {
+                return ((*PIN_OUT) & pin_mask) != 0;
+            }
         }
     }
 }
@@ -163,8 +200,14 @@ void common_hal_digitalio_digitalinout_set_pull(
         return;
     }
     if (self->pin->gpio_number == 16) {
-        nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError,
-            "Pin does not support pull."));
+        // PULL_DOWN is the only hardware pull direction available on GPIO16.
+        // since we don't support pull down, just return without attempting
+        // to set pull (which won't work anyway). If PULL_UP is requested,
+        // raise the exception so the user knows PULL_UP is not available
+        if (pull != PULL_NONE){
+            nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError,
+            "GPIO16 does not support pull up."));
+        }
         return;
     }
     if (pull == PULL_NONE) {

ports/esp8266/common-hal/microcontroller/Pin.c

@@ -32,23 +32,49 @@
 
 #include "eagle_soc.h"
 
-extern volatile bool adc_in_use;
+bool adc_in_use;
+bool gpio16_in_use;
 
 bool common_hal_mcu_pin_is_free(const mcu_pin_obj_t* pin) {
     if (pin == &pin_TOUT) {
         return !adc_in_use;
     }
-    if (pin->gpio_number == NO_GPIO || pin->gpio_number == SPECIAL_CASE) {
+    if (pin == &pin_XPD_DCDC) {
+        return !gpio16_in_use;
+    }
+    if (pin->gpio_number == NO_GPIO) {
         return false;
     }
     return (READ_PERI_REG(pin->peripheral) &
                 (PERIPHS_IO_MUX_FUNC<<PERIPHS_IO_MUX_FUNC_S)) == 0 &&
              (GPIO_REG_READ(GPIO_ENABLE_ADDRESS) & (1 << pin->gpio_number)) == 0 &&
-             (READ_PERI_REG(pin->peripheral) & PERIPHS_IO_MUX_PULLUP) == 0;
+             (READ_PERI_REG(pin->peripheral) & PERIPHS_IO_MUX_PULLUP) == 0;     
+}
+
+void claim_pin(const mcu_pin_obj_t* pin) {
+    if (pin == &pin_XPD_DCDC) {
+        gpio16_in_use = true;
+    }
+    if (pin == &pin_TOUT) {
+        adc_in_use = true;
+    }
+}
+
+void reset_pin(const mcu_pin_obj_t* pin) {
+    if (pin == &pin_XPD_DCDC) {
+        // Set GPIO16 as input
+        WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1); 	// mux configuration for XPD_DCDC and rtc_gpio0 connection
+        WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);	//mux configuration for out enable
+        WRITE_PERI_REG(RTC_GPIO_ENABLE, READ_PERI_REG(RTC_GPIO_ENABLE) & ~1);	//out disable
+        gpio16_in_use = false;
+    }
+    if (pin == &pin_TOUT) {
+        adc_in_use = false;
+    }
 }
 
 void reset_pins(void) {
-    for (int i = 0; i < 17; i++) {
+    for (int i = 0; i < 16; i++) {
         // 5 is RXD, 6 is TXD
         if ((i > 4 && i < 13) || i == 12) {
             continue;
@@ -59,4 +85,11 @@ void reset_pins(void) {
         // Disable the pin.
         gpio_output_set(0x0, 0x0, 0x0, 1 << i);
     }
-}
+    // Set GPIO16 as input
+    WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1); 	// mux configuration for XPD_DCDC and rtc_gpio0 connection
+    WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);	//mux configuration for out enable
+    WRITE_PERI_REG(RTC_GPIO_ENABLE, READ_PERI_REG(RTC_GPIO_ENABLE) & ~1);	//out disable
+
+    adc_in_use = false;
+    gpio16_in_use = false;
+}

ports/esp8266/common-hal/microcontroller/Pin.h

@@ -41,6 +41,8 @@ typedef struct {
 #define NO_GPIO 0xff
 #define SPECIAL_CASE 0xfe
 
+void claim_pin(const mcu_pin_obj_t* pin);
+void reset_pin(const mcu_pin_obj_t* pin);
 void reset_pins(void);
 
 #endif  // MICROPY_INCLUDED_ESP8266_COMMON_HAL_MICROCONTROLLER_PIN_H