Merge pull request #1186 from dhalbert/uart-enhancements3.0.2

UART enhancements

8 files changed, 103 insertions, 65 deletions

diff --git a/ports/atmel-samd/Makefile b/ports/atmel-samd/Makefile
index 62f058c3d..865210e2f 100644
--- a/ports/atmel-samd/Makefile
+++ b/ports/atmel-samd/Makefile
@@ -115,7 +115,7 @@ else
   # -finline-limit=80 or so is similar to not having it on.
   # There is no simple default value, though.
   ifdef INTERNAL_FLASH_FILESYSTEM
-    CFLAGS += -finline-limit=55
+    CFLAGS += -finline-limit=50
   endif
   ifdef CFLAGS_INLINE_LIMIT
     CFLAGS += -finline-limit=$(CFLAGS_INLINE_LIMIT)
diff --git a/ports/atmel-samd/board_busses.c b/ports/atmel-samd/board_busses.c
index 4bf1a40fa..6a4c4a84d 100644
--- a/ports/atmel-samd/board_busses.c
+++ b/ports/atmel-samd/board_busses.c
@@ -33,81 +33,96 @@
 #include "samd/pins.h"
 #include "py/runtime.h"
 
-#if !defined(DEFAULT_I2C_BUS_SDA) || !defined(DEFAULT_I2C_BUS_SCL)
-    STATIC mp_obj_t board_i2c(void) {
-        mp_raise_NotImplementedError("No default I2C bus");
-        return NULL;
-    }
-#else
-    STATIC mp_obj_t i2c_singleton = NULL;
+#define BOARD_I2C (defined(DEFAULT_I2C_BUS_SDA) && defined(DEFAULT_I2C_BUS_SCL))
+#define BOARD_SPI (defined(DEFAULT_SPI_BUS_SCK) && defined(DEFAULT_SPI_BUS_MISO) && defined(DEFAULT_SPI_BUS_MOSI))
+#define BOARD_UART (defined(DEFAULT_UART_BUS_RX) && defined(DEFAULT_UART_BUS_TX))
 
-    STATIC mp_obj_t board_i2c(void) {
+#if BOARD_I2C
+STATIC mp_obj_t i2c_singleton = NULL;
 
-        if (i2c_singleton == NULL) {
-            busio_i2c_obj_t *self = m_new_obj(busio_i2c_obj_t);
-            self->base.type = &busio_i2c_type;
+STATIC mp_obj_t board_i2c(void) {
 
-            assert_pin_free(DEFAULT_I2C_BUS_SDA);
-            assert_pin_free(DEFAULT_I2C_BUS_SCL);
-            common_hal_busio_i2c_construct(self, DEFAULT_I2C_BUS_SCL, DEFAULT_I2C_BUS_SDA, 400000, 0);
-            i2c_singleton = (mp_obj_t)self;
-        }
-        return i2c_singleton;
+    if (i2c_singleton == NULL) {
+        busio_i2c_obj_t *self = m_new_obj(busio_i2c_obj_t);
+        self->base.type = &busio_i2c_type;
 
+        assert_pin_free(DEFAULT_I2C_BUS_SDA);
+        assert_pin_free(DEFAULT_I2C_BUS_SCL);
+        common_hal_busio_i2c_construct(self, DEFAULT_I2C_BUS_SCL, DEFAULT_I2C_BUS_SDA, 400000, 0);
+        i2c_singleton = (mp_obj_t)self;
     }
+    return i2c_singleton;
+}
+#else
+STATIC mp_obj_t board_i2c(void) {
+    mp_raise_NotImplementedError("No default I2C bus");
+    return NULL;
+}
 #endif
 MP_DEFINE_CONST_FUN_OBJ_0(board_i2c_obj, board_i2c);
 
-#if !defined(DEFAULT_SPI_BUS_SCK) || !defined(DEFAULT_SPI_BUS_MISO) || !defined(DEFAULT_SPI_BUS_MOSI)
-    STATIC mp_obj_t board_spi(void) {
-        mp_raise_NotImplementedError("No default SPI bus");
-        return NULL;
+#if BOARD_SPI
+STATIC mp_obj_t spi_singleton = NULL;
+
+STATIC mp_obj_t board_spi(void) {
+    if (spi_singleton == NULL) {
+        busio_spi_obj_t *self = m_new_obj(busio_spi_obj_t);
+        self->base.type = &busio_spi_type;
+        assert_pin_free(DEFAULT_SPI_BUS_SCK);
+        assert_pin_free(DEFAULT_SPI_BUS_MOSI);
+        assert_pin_free(DEFAULT_SPI_BUS_MISO);
+        const mcu_pin_obj_t* clock = MP_OBJ_TO_PTR(DEFAULT_SPI_BUS_SCK);
+        const mcu_pin_obj_t* mosi = MP_OBJ_TO_PTR(DEFAULT_SPI_BUS_MOSI);
+        const mcu_pin_obj_t* miso = MP_OBJ_TO_PTR(DEFAULT_SPI_BUS_MISO);
+        common_hal_busio_spi_construct(self, clock, mosi, miso);
+        spi_singleton = (mp_obj_t)self;
     }
+    return spi_singleton;
+}
 #else
-    STATIC mp_obj_t spi_singleton = NULL;
-
-    STATIC mp_obj_t board_spi(void) {
-
-        if (spi_singleton == NULL) {
-            busio_spi_obj_t *self = m_new_obj(busio_spi_obj_t);
-            self->base.type = &busio_spi_type;
-            assert_pin_free(DEFAULT_SPI_BUS_SCK);
-            assert_pin_free(DEFAULT_SPI_BUS_MOSI);
-            assert_pin_free(DEFAULT_SPI_BUS_MISO);
-            const mcu_pin_obj_t* clock = MP_OBJ_TO_PTR(DEFAULT_SPI_BUS_SCK);
-            const mcu_pin_obj_t* mosi = MP_OBJ_TO_PTR(DEFAULT_SPI_BUS_MOSI);
-            const mcu_pin_obj_t* miso = MP_OBJ_TO_PTR(DEFAULT_SPI_BUS_MISO);
-            common_hal_busio_spi_construct(self, clock, mosi, miso);
-            spi_singleton = (mp_obj_t)self;
-        }
-        return spi_singleton;
-    }
+STATIC mp_obj_t board_spi(void) {
+    mp_raise_NotImplementedError("No default SPI bus");
+    return NULL;
+}
 #endif
 MP_DEFINE_CONST_FUN_OBJ_0(board_spi_obj, board_spi);
 
-#if !defined(DEFAULT_UART_BUS_RX) || !defined(DEFAULT_UART_BUS_TX)
-    STATIC mp_obj_t board_uart(void) {
-        mp_raise_NotImplementedError("No default UART bus");
-        return NULL;
-    }
-#else
-    STATIC mp_obj_t uart_singleton = NULL;
+#if BOARD_UART
+STATIC mp_obj_t uart_singleton = NULL;
 
-    STATIC mp_obj_t board_uart(void) {
-        if (uart_singleton == NULL) {
-            busio_uart_obj_t *self = m_new_obj(busio_uart_obj_t);
-            self->base.type = &busio_uart_type;
+STATIC mp_obj_t board_uart(void) {
+    if (uart_singleton == NULL) {
+        busio_uart_obj_t *self = m_new_obj(busio_uart_obj_t);
+        self->base.type = &busio_uart_type;
 
-            assert_pin_free(DEFAULT_UART_BUS_RX);
-            assert_pin_free(DEFAULT_UART_BUS_TX);
+        assert_pin_free(DEFAULT_UART_BUS_RX);
+        assert_pin_free(DEFAULT_UART_BUS_TX);
 
-            const mcu_pin_obj_t* rx = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_RX);
-            const mcu_pin_obj_t* tx = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_TX);
+        const mcu_pin_obj_t* rx = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_RX);
+        const mcu_pin_obj_t* tx = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_TX);
 
-            common_hal_busio_uart_construct(self, tx, rx, 9600, 8, PARITY_NONE, 1, 1000, 64);
-            uart_singleton = (mp_obj_t)self;
-        }
-        return uart_singleton;
+        common_hal_busio_uart_construct(self, tx, rx, 9600, 8, PARITY_NONE, 1, 1000, 64);
+        uart_singleton = (mp_obj_t)self;
     }
+    return uart_singleton;
+}
+#else
+STATIC mp_obj_t board_uart(void) {
+    mp_raise_NotImplementedError("No default UART bus");
+    return NULL;
+}
 #endif
 MP_DEFINE_CONST_FUN_OBJ_0(board_uart_obj, board_uart);
+
+
+void reset_board_busses(void) {
+#if BOARD_I2C
+    i2c_singleton = NULL;
+#endif
+#if BOARD_SPI
+    spi_singleton = NULL;
+#endif
+#if BOARD_UART
+    uart_singleton = NULL;
+#endif
+}
diff --git a/ports/atmel-samd/board_busses.h b/ports/atmel-samd/board_busses.h
index a368885a5..08dd1aae1 100644
--- a/ports/atmel-samd/board_busses.h
+++ b/ports/atmel-samd/board_busses.h
@@ -36,4 +36,6 @@ extern mp_obj_fun_builtin_fixed_t board_spi_obj;
 void board_uart(void);
 extern mp_obj_fun_builtin_fixed_t board_uart_obj;
 
+void reset_board_busses(void);
+
 #endif  // MICROPY_INCLUDED_ATMEL_SAMD_BOARD_BUSSES_H
diff --git a/ports/atmel-samd/common-hal/busio/UART.c b/ports/atmel-samd/common-hal/busio/UART.c
index 20e662ec6..b8b0ce74c 100644
--- a/ports/atmel-samd/common-hal/busio/UART.c
+++ b/ports/atmel-samd/common-hal/busio/UART.c
@@ -254,7 +254,7 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
     uint64_t start_ticks = ticks_ms;
 
     // Busy-wait until timeout or until we've read enough chars.
-    while (ticks_ms - start_ticks < self->timeout_ms) {
+    while (ticks_ms - start_ticks <= self->timeout_ms) {
         // Read as many chars as we can right now, up to len.
         size_t num_read = io_read(io, data, len);
 
@@ -273,6 +273,10 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
 #ifdef MICROPY_VM_HOOK_LOOP
         MICROPY_VM_HOOK_LOOP
 #endif
+       // If we are zero timeout, make sure we don't loop again (in the event
+       // we read in under 1ms)
+       if (self->timeout_ms == 0)
+            break;
     }
 
     if (total_read == 0) {
@@ -345,7 +349,18 @@ void common_hal_busio_uart_set_baudrate(busio_uart_obj_t *self, uint32_t baudrat
 }
 
 uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
-    return self->buffer_size;
+    // This assignment is only here because the usart_async routines take a *const argument.
+    struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    struct usart_async_status async_status;
+    usart_async_get_status(usart_desc_p, &async_status);
+    return async_status.rxcnt;
+}
+
+void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
+    // This assignment is only here because the usart_async routines take a *const argument.
+    struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    usart_async_flush_rx_buffer(usart_desc_p);
+
 }
 
 bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
diff --git a/ports/atmel-samd/common-hal/busio/UART.h b/ports/atmel-samd/common-hal/busio/UART.h
index 685755a5d..f94df040f 100644
--- a/ports/atmel-samd/common-hal/busio/UART.h
+++ b/ports/atmel-samd/common-hal/busio/UART.h
@@ -42,10 +42,6 @@ typedef struct {
     bool rx_error;
     uint32_t baudrate;
     uint32_t timeout_ms;
-    // Index of the oldest received character.
-    uint32_t buffer_start;
-    // Index of the next available spot to store a character.
-    uint32_t buffer_size;
     uint32_t buffer_length;
     uint8_t* buffer;
 } busio_uart_obj_t;
diff --git a/ports/atmel-samd/supervisor/port.c b/ports/atmel-samd/supervisor/port.c
index 422bf1f64..a63b85a9f 100644
--- a/ports/atmel-samd/supervisor/port.c
+++ b/ports/atmel-samd/supervisor/port.c
@@ -61,6 +61,7 @@
 #include "samd/external_interrupts.h"
 #include "samd/dma.h"
 #include "shared-bindings/rtc/__init__.h"
+#include "board_busses.h"
 #include "tick.h"
 #include "usb.h"
 
@@ -270,6 +271,8 @@ void reset_port(void) {
 
     reset_all_pins();
 
+    reset_board_busses();
+
     // Output clocks for debugging.
     // not supported by SAMD51G; uncomment for SAMD51J or update for 51G
     // #ifdef SAMD51
diff --git a/ports/esp8266/common-hal/busio/UART.c b/ports/esp8266/common-hal/busio/UART.c
index 9b5d86ef5..8b5bb49d4 100644
--- a/ports/esp8266/common-hal/busio/UART.c
+++ b/ports/esp8266/common-hal/busio/UART.c
@@ -137,6 +137,9 @@ uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
     return 0;
 }
 
+void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
+}
+
 bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
     return true;
 }
diff --git a/ports/nrf/common-hal/busio/UART.c b/ports/nrf/common-hal/busio/UART.c
index dbc6a8533..08b4bcd16 100644
--- a/ports/nrf/common-hal/busio/UART.c
+++ b/ports/nrf/common-hal/busio/UART.c
@@ -83,6 +83,10 @@ uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
     return 0;
 }
 
+void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
+    mp_raise_NotImplementedError("busio.UART not yet implemented");
+}
+
 bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
     mp_raise_NotImplementedError("busio.UART not yet implemented");
     return false;