Diff: targets/TARGET_NORDIC/TARGET_MCU_NRF51822/serial_api.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/serial_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,306 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2013 Nordic Semiconductor
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+// math.h required for floating point operations for baud rate calculation
+//#include <math.h>
+#include <string.h>
+#include "mbed_assert.h"
+
+#include "serial_api.h"
+#include "cmsis.h"
+#include "pinmap.h"
+
+/******************************************************************************
+ * INITIALIZATION
+ ******************************************************************************/
+#define UART_NUM    1
+
+static uint32_t serial_irq_ids[UART_NUM] = {0};
+static uart_irq_handler irq_handler;
+static const int acceptedSpeeds[18][2] = {
+    {1200, UART_BAUDRATE_BAUDRATE_Baud1200},
+    {2400, UART_BAUDRATE_BAUDRATE_Baud2400},
+    {4800, UART_BAUDRATE_BAUDRATE_Baud4800},
+    {9600, UART_BAUDRATE_BAUDRATE_Baud9600},
+    {14400, UART_BAUDRATE_BAUDRATE_Baud14400},
+    {19200, UART_BAUDRATE_BAUDRATE_Baud19200},
+    {28800, UART_BAUDRATE_BAUDRATE_Baud28800},
+    {31250, (0x00800000UL) /* 31250 baud */},
+    {38400, UART_BAUDRATE_BAUDRATE_Baud38400},
+    {56000, (0x00E51000UL) /* 56000 baud */},
+    {57600, UART_BAUDRATE_BAUDRATE_Baud57600},
+    {76800, UART_BAUDRATE_BAUDRATE_Baud76800},
+    {115200, UART_BAUDRATE_BAUDRATE_Baud115200},
+    {230400, UART_BAUDRATE_BAUDRATE_Baud230400},
+    {250000, UART_BAUDRATE_BAUDRATE_Baud250000},
+    {460800, UART_BAUDRATE_BAUDRATE_Baud460800},
+    {921600, UART_BAUDRATE_BAUDRATE_Baud921600},
+    {1000000, UART_BAUDRATE_BAUDRATE_Baud1M}
+};
+
+int stdio_uart_inited = 0;
+serial_t stdio_uart;
+
+
+void serial_init(serial_t *obj, PinName tx, PinName rx) {
+    UARTName uart = UART_0;
+    obj->uart = (NRF_UART_Type *)uart;
+
+    //pin configurations --
+    NRF_GPIO->OUT |= (1 << tx);
+    NRF_GPIO->OUT |= (1 << RTS_PIN_NUMBER);
+    NRF_GPIO->DIR |= (1 << tx); //TX_PIN_NUMBER);
+    NRF_GPIO->DIR |= (1 << RTS_PIN_NUMBER);
+
+    NRF_GPIO->DIR &= ~(1 << rx); //RX_PIN_NUMBER);
+    NRF_GPIO->DIR &= ~(1 << CTS_PIN_NUMBER);
+
+
+    // set default baud rate and format
+    serial_baud  (obj, 9600);
+    serial_format(obj, 8, ParityNone, 1);
+
+    obj->uart->ENABLE        = (UART_ENABLE_ENABLE_Enabled << UART_ENABLE_ENABLE_Pos);
+    obj->uart->TASKS_STARTTX = 1;
+    obj->uart->TASKS_STARTRX = 1;
+    obj->uart->EVENTS_RXDRDY = 0;
+    // dummy write needed or TXDRDY trails write rather than leads write.
+    //  pins are disconnected so nothing is physically transmitted on the wire
+    obj->uart->PSELTXD = 0xFFFFFFFF;
+    obj->uart->EVENTS_TXDRDY = 0;
+    obj->uart->TXD = 0;
+    while (obj->uart->EVENTS_TXDRDY != 1);
+
+    obj->index = 0;
+    
+    obj->uart->PSELRTS = RTS_PIN_NUMBER;
+    obj->uart->PSELTXD = tx; //TX_PIN_NUMBER;
+    obj->uart->PSELCTS = CTS_PIN_NUMBER;
+    obj->uart->PSELRXD = rx; //RX_PIN_NUMBER;
+
+    // set rx/tx pins in PullUp mode
+    if (tx != NC) {
+        pin_mode(tx, PullUp);
+    }
+    if (rx != NC) {
+        pin_mode(rx, PullUp);
+    }
+
+    if (uart == STDIO_UART) {
+        stdio_uart_inited = 1;
+        memcpy(&stdio_uart, obj, sizeof(serial_t));
+    }
+}
+
+void serial_free(serial_t *obj)
+{
+    serial_irq_ids[obj->index] = 0;
+}
+
+// serial_baud
+// set the baud rate, taking in to account the current SystemFrequency
+void serial_baud(serial_t *obj, int baudrate)
+{
+    if (baudrate<=1200) {
+        obj->uart->BAUDRATE = UART_BAUDRATE_BAUDRATE_Baud1200;
+        return;
+    }
+
+    for (int i = 1; i<17; i++) {
+        if (baudrate<acceptedSpeeds[i][0]) {
+            obj->uart->BAUDRATE = acceptedSpeeds[i - 1][1];
+            return;
+        }
+    }
+    obj->uart->BAUDRATE = UART_BAUDRATE_BAUDRATE_Baud1M;
+}
+
+void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits)
+{
+    // 0: 1 stop bits, 1: 2 stop bits
+    // int parity_enable, parity_select;
+    switch (parity) {
+        case ParityNone:
+            obj->uart->CONFIG = 0;
+            break;
+        default:
+            obj->uart->CONFIG = (UART_CONFIG_PARITY_Included << UART_CONFIG_PARITY_Pos);
+            return;
+    }
+    //no Flow Control
+}
+
+//******************************************************************************
+// * INTERRUPT HANDLING
+//******************************************************************************
+static inline void uart_irq(uint32_t iir, uint32_t index)
+{
+    SerialIrq irq_type;
+    switch (iir) {
+        case 1:
+            irq_type = TxIrq;
+            break;
+        case 2:
+            irq_type = RxIrq;
+            break;
+
+        default:
+            return;
+    }
+
+    if (serial_irq_ids[index] != 0) {
+        irq_handler(serial_irq_ids[index], irq_type);
+    }
+}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+void UART0_IRQHandler()
+{
+    uint32_t irtype = 0;
+
+    if((NRF_UART0->INTENSET & 0x80) && NRF_UART0->EVENTS_TXDRDY) {
+        irtype = 1;
+    } else if((NRF_UART0->INTENSET & 0x04) && NRF_UART0->EVENTS_RXDRDY) {
+        irtype = 2;
+    }
+    uart_irq(irtype, 0);
+}
+
+#ifdef __cplusplus
+}
+#endif
+void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id)
+{
+    irq_handler                = handler;
+    serial_irq_ids[obj->index] = id;
+}
+
+void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable)
+{
+    IRQn_Type irq_n = (IRQn_Type)0;
+
+    switch ((int)obj->uart) {
+        case UART_0:
+            irq_n = UART0_IRQn;
+            break;
+    }
+
+    if (enable) {
+        switch (irq) {
+            case RxIrq:
+                obj->uart->INTENSET = (UART_INTENSET_RXDRDY_Msk);
+                break;
+            case TxIrq:
+                obj->uart->INTENSET = (UART_INTENSET_TXDRDY_Msk);
+                break;
+        }
+        NVIC_SetPriority(irq_n, 3);
+        NVIC_EnableIRQ(irq_n);
+    } else { // disable
+        // maseked writes to INTENSET dont disable and masked writes to
+        //  INTENCLR seemed to clear the entire register, not bits.
+        //  Added INTEN to memory map and seems to allow set and clearing of specific bits as desired
+        int all_disabled = 0;
+        switch (irq) {
+            case RxIrq:
+                obj->uart->INTENCLR = (UART_INTENCLR_RXDRDY_Msk);
+                all_disabled        =  (obj->uart->INTENCLR & (UART_INTENCLR_TXDRDY_Msk)) == 0;
+                break;
+            case TxIrq:
+                obj->uart->INTENCLR = (UART_INTENCLR_TXDRDY_Msk);
+                all_disabled        =  (obj->uart->INTENCLR & (UART_INTENCLR_RXDRDY_Msk)) == 0;
+                break;
+        }
+
+        if (all_disabled) {
+            NVIC_DisableIRQ(irq_n);
+        }
+    }
+}
+
+//******************************************************************************
+//* READ/WRITE
+//******************************************************************************
+int serial_getc(serial_t *obj)
+{
+    while (!serial_readable(obj)) {
+    }
+
+    obj->uart->EVENTS_RXDRDY = 0;
+
+    return (uint8_t)obj->uart->RXD;
+}
+
+void serial_putc(serial_t *obj, int c)
+{
+    while (!serial_writable(obj)) {
+    }
+
+    obj->uart->EVENTS_TXDRDY = 0;
+    obj->uart->TXD = (uint8_t)c;
+}
+
+int serial_readable(serial_t *obj)
+{
+    return (obj->uart->EVENTS_RXDRDY == 1);
+}
+
+int serial_writable(serial_t *obj)
+{
+    return (obj->uart->EVENTS_TXDRDY == 1);
+}
+
+void serial_break_set(serial_t *obj)
+{
+    obj->uart->TASKS_SUSPEND = 1;
+}
+
+void serial_break_clear(serial_t *obj)
+{
+    obj->uart->TASKS_STARTTX = 1;
+    obj->uart->TASKS_STARTRX = 1;
+}
+
+void serial_set_flow_control(serial_t *obj, FlowControl type, PinName rxflow, PinName txflow)
+{
+
+    if (type == FlowControlRTSCTS || type == FlowControlRTS) {
+        NRF_GPIO->DIR |= (1<<rxflow);
+        pin_mode(rxflow, PullUp);
+        obj->uart->PSELRTS = rxflow;
+
+        obj->uart->CONFIG |= 0x01; // Enable HWFC
+    }
+
+    if (type == FlowControlRTSCTS || type == FlowControlCTS) {
+        NRF_GPIO->DIR &= ~(1<<txflow);
+        pin_mode(txflow, PullUp);
+        obj->uart->PSELCTS = txflow;
+
+        obj->uart->CONFIG |= 0x01; // Enable HWFC;
+    }
+
+    if (type == FlowControlNone) {
+        obj->uart->PSELRTS = 0xFFFFFFFF; // Disable RTS
+        obj->uart->PSELCTS = 0xFFFFFFFF; // Disable CTS
+
+        obj->uart->CONFIG &= ~0x01; // Enable HWFC;
+    }
+}
+
+void serial_clear(serial_t *obj) {
+}