esp8266: Add limited (untested) UART support.

Author: tannewt

esp8266/Makefile

@@ -117,6 +117,7 @@ SRC_COMMON_HAL = \
 	nativeio/PWMOut.c \
 	nativeio/SPI.c \
 	nativeio/TouchIn.c \
+	nativeio/UART.c \
 	neopixel_write/__init__.c \
 	time/__init__.c \
 	board/__init__.c

esp8266/common-hal/nativeio/UART.c

@@ -0,0 +1,120 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "common-hal/microcontroller/__init__.h"
+#include "shared-bindings/microcontroller/__init__.h"
+#include "shared-bindings/nativeio/UART.h"
+
+#include "ets_sys.h"
+#include "uart.h"
+
+#include "py/nlr.h"
+
+// UartDev is defined and initialized in rom code.
+extern UartDevice UartDev;
+
+void common_hal_nativeio_uart_construct(nativeio_uart_obj_t *self,
+        const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx, uint32_t baudrate,
+        uint8_t bits, uart_parity_t parity, uint8_t stop, uint32_t timeout,
+        uint8_t receiver_buffer_size) {
+    if (rx != NULL || tx != &pin_GPIO2) {
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "Only tx supported on UART1 (GPIO2)."));
+    }
+    // set baudrate
+    UartDev.baut_rate = baudrate;
+
+    // set data bits
+    switch (bits) {
+        case 5:
+            UartDev.data_bits = UART_FIVE_BITS;
+            break;
+        case 6:
+            UartDev.data_bits = UART_SIX_BITS;
+            break;
+        case 7:
+            UartDev.data_bits = UART_SEVEN_BITS;
+            break;
+        case 8:
+            UartDev.data_bits = UART_EIGHT_BITS;
+            break;
+        default:
+            nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid data bits"));
+            break;
+    }
+
+    if (parity == PARITY_NONE) {
+        UartDev.parity = UART_NONE_BITS;
+        UartDev.exist_parity = UART_STICK_PARITY_DIS;
+    } else {
+        UartDev.exist_parity = UART_STICK_PARITY_EN;
+        if (parity == PARITY_ODD) {
+            UartDev.parity = UART_ODD_BITS;
+        } else {
+            UartDev.parity = UART_EVEN_BITS;
+        }
+    }
+
+    switch (stop) {
+        case 1:
+            UartDev.stop_bits = UART_ONE_STOP_BIT;
+            break;
+        case 2:
+            UartDev.stop_bits = UART_TWO_STOP_BIT;
+            break;
+        default:
+            nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid stop bits"));
+            break;
+    }
+
+    uart_setup(UART1);
+}
+
+void common_hal_nativeio_uart_deinit(nativeio_uart_obj_t *self) {
+    PIN_FUNC_SELECT(FUNC_U1TXD_BK, 0);
+}
+
+size_t common_hal_nativeio_uart_read(nativeio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
+    return 0;
+}
+
+// Write characters.
+size_t common_hal_nativeio_uart_write(nativeio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
+    // write the data
+    for (size_t i = 0; i < len; ++i) {
+        uart_tx_one_char(UART1, *data++);
+    }
+
+    // return number of bytes written
+    return len;
+}
+
+uint32_t common_hal_nativeio_uart_rx_characters_available(nativeio_uart_obj_t *self) {
+    return 0;
+}
+
+bool common_hal_nativeio_uart_ready_to_tx(nativeio_uart_obj_t *self) {
+    return true;
+}

esp8266/common-hal/nativeio/types.h

@@ -71,4 +71,8 @@ typedef struct {
     mp_obj_base_t base;
 } nativeio_touchin_obj_t;
 
+typedef struct {
+  mp_obj_base_t base;
+} nativeio_uart_obj_t;
+
 #endif // __MICROPY_INCLUDED_ATMEL_SAMD_COMMON_HAL_NATIVEIO_TYPES_H__