Diff: source/hic_hal/freescale/k20dx/uart.c

Revision:

0:01f31e923fe2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/hic_hal/freescale/k20dx/uart.c	Tue Apr 07 12:55:42 2020 +0200
@@ -0,0 +1,247 @@
+/**
+ * @file    uart.c
+ * @brief   
+ *
+ * DAPLink Interface Firmware
+ * Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+
+#include "string.h"
+
+#include "MK20D5.h"
+#include "uart.h"
+#include "util.h"
+#include "cortex_m.h"
+#include "circ_buf.h"
+#include "settings.h" // for config_get_overflow_detect
+
+extern uint32_t SystemCoreClock;
+
+static void clear_buffers(void);
+
+#define RX_OVRF_MSG         "<DAPLink:Overflow>\n"
+#define RX_OVRF_MSG_SIZE    (sizeof(RX_OVRF_MSG) - 1)
+#define BUFFER_SIZE         (512)
+
+
+circ_buf_t write_buffer;
+uint8_t write_buffer_data[BUFFER_SIZE];
+circ_buf_t read_buffer;
+uint8_t read_buffer_data[BUFFER_SIZE];
+
+void clear_buffers(void)
+{
+    util_assert(!(UART1->C2 & UART_C2_TIE_MASK));
+    circ_buf_init(&write_buffer, write_buffer_data, sizeof(write_buffer_data));
+    circ_buf_init(&read_buffer, read_buffer_data, sizeof(read_buffer_data));
+}
+
+int32_t uart_initialize(void)
+{
+    NVIC_DisableIRQ(UART1_RX_TX_IRQn);
+    // enable clk PORTC
+    SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK;
+    // enable clk uart
+    SIM->SCGC4 |= SIM_SCGC4_UART1_MASK;
+
+    // disable interrupt
+    NVIC_DisableIRQ(UART1_RX_TX_IRQn);
+    // transmitter and receiver disabled
+    UART1->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
+    // disable interrupt
+    UART1->C2 &= ~(UART_C2_RIE_MASK | UART_C2_TIE_MASK);
+    
+    clear_buffers();
+
+    // Enable receiver and transmitter
+    UART1->C2 |= UART_C2_RE_MASK | UART_C2_TE_MASK;
+    // alternate 3: UART1
+    PORTC->PCR[3] = (3 << 8);
+    PORTC->PCR[4] = (3 << 8);
+    // Enable receive interrupt
+    UART1->C2 |= UART_C2_RIE_MASK;
+    NVIC_ClearPendingIRQ(UART1_RX_TX_IRQn);
+    NVIC_EnableIRQ(UART1_RX_TX_IRQn);
+    return 1;
+}
+
+int32_t uart_uninitialize(void)
+{
+    // transmitter and receiver disabled
+    UART1->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
+    // disable interrupt
+    UART1->C2 &= ~(UART_C2_RIE_MASK | UART_C2_TIE_MASK);
+    clear_buffers();
+    return 1;
+}
+
+int32_t uart_reset(void)
+{
+    // disable interrupt
+    NVIC_DisableIRQ(UART1_RX_TX_IRQn);
+    // disable TIE interrupt
+    UART1->C2 &= ~(UART_C2_TIE_MASK);
+    clear_buffers();
+    // enable interrupt
+    NVIC_EnableIRQ(UART1_RX_TX_IRQn);
+    return 1;
+}
+
+int32_t uart_set_configuration(UART_Configuration *config)
+{
+    uint8_t data_bits = 8;
+    uint8_t parity_enable = 0;
+    uint8_t parity_type = 0;
+    uint32_t dll;
+    // disable interrupt
+    NVIC_DisableIRQ(UART1_RX_TX_IRQn);
+    UART1->C2 &= ~(UART_C2_RIE_MASK | UART_C2_TIE_MASK);
+    // Disable receiver and transmitter while updating
+    UART1->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
+    clear_buffers();
+
+    // set data bits, stop bits, parity
+    if ((config->DataBits < 8) || (config->DataBits > 9)) {
+        data_bits = 8;
+    }
+
+    data_bits -= 8;
+
+    if (config->Parity == 1) {
+        parity_enable = 1;
+        parity_type = 1;
+        data_bits++;
+    } else if (config->Parity == 2) {
+        parity_enable = 1;
+        parity_type = 0;
+        data_bits++;
+    }
+
+    // does not support 10 bit data comm
+    if (data_bits == 2) {
+        data_bits = 0;
+        parity_enable = 0;
+        parity_type = 0;
+    }
+
+    // data bits, parity and parity mode
+    UART1->C1 = data_bits << UART_C1_M_SHIFT
+                | parity_enable << UART_C1_PE_SHIFT
+                | parity_type << UART_C1_PT_SHIFT;
+    dll =  SystemCoreClock / (16 * config->Baudrate);
+    // set baudrate
+    UART1->BDH = (UART1->BDH & ~(UART_BDH_SBR_MASK)) | ((dll >> 8) & UART_BDH_SBR_MASK);
+    UART1->BDL = (UART1->BDL & ~(UART_BDL_SBR_MASK)) | (dll & UART_BDL_SBR_MASK);
+    // Enable transmitter and receiver
+    UART1->C2 |= UART_C2_RE_MASK | UART_C2_TE_MASK;
+    // Enable UART interrupt
+    NVIC_ClearPendingIRQ(UART1_RX_TX_IRQn);
+    NVIC_EnableIRQ(UART1_RX_TX_IRQn);
+    UART1->C2 |= UART_C2_RIE_MASK;
+    return 1;
+}
+
+int32_t uart_get_configuration(UART_Configuration *config)
+{
+    return 1;
+}
+
+int32_t uart_write_free(void)
+{
+    return circ_buf_count_free(&write_buffer);
+}
+
+int32_t uart_write_data(uint8_t *data, uint16_t size)
+{
+    cortex_int_state_t state;
+    uint32_t cnt;
+
+    cnt = circ_buf_write(&write_buffer, data, size);
+
+    // Atomically enable TX
+    state = cortex_int_get_and_disable();
+    if (circ_buf_count_used(&write_buffer)) {
+        UART1->C2 |= UART_C2_TIE_MASK;
+    }
+    cortex_int_restore(state);
+
+    return cnt;
+}
+
+int32_t uart_read_data(uint8_t *data, uint16_t size)
+{
+    return circ_buf_read(&read_buffer, data, size);
+}
+
+void uart_enable_flow_control(bool enabled)
+{
+    // Flow control not implemented for this platform
+}
+
+void UART1_RX_TX_IRQHandler(void)
+{
+    uint32_t s1;
+    volatile uint8_t errorData;
+    // read interrupt status
+    s1 = UART1->S1;
+    // mask off interrupts that are not enabled
+    if (!(UART1->C2 & UART_C2_RIE_MASK)) {
+        s1 &= ~UART_S1_RDRF_MASK;
+    }
+    if (!(UART1->C2 & UART_C2_TIE_MASK)) {
+        s1 &= ~UART_S1_TDRE_MASK;
+    }
+
+    // handle character to transmit
+    if (s1 & UART_S1_TDRE_MASK) {
+        // Assert that there is data in the buffer
+        util_assert(circ_buf_count_used(&write_buffer) > 0);
+
+        // Send out data
+        UART1->D = circ_buf_pop(&write_buffer);
+        // Turn off the transmitter if that was the last byte
+        if (circ_buf_count_used(&write_buffer) == 0) {
+            // disable TIE interrupt
+            UART1->C2 &= ~(UART_C2_TIE_MASK);
+        }
+    }
+
+    // handle received character
+    if (s1 & UART_S1_RDRF_MASK) {
+        if ((s1 & UART_S1_NF_MASK) || (s1 & UART_S1_FE_MASK)) {
+            errorData = UART1->D;
+        } else {
+            uint32_t free;
+            uint8_t data;
+            
+            data = UART1->D;
+            free = circ_buf_count_free(&read_buffer);
+            if (free > RX_OVRF_MSG_SIZE) {
+                circ_buf_push(&read_buffer, data);
+            } else if (config_get_overflow_detect()) {
+                if (RX_OVRF_MSG_SIZE == free) {
+                    circ_buf_write(&read_buffer, (uint8_t*)RX_OVRF_MSG, RX_OVRF_MSG_SIZE);
+                } else {
+                    // Drop newest
+                }
+            } else {
+                // Drop oldest
+                circ_buf_pop(&read_buffer);
+                circ_buf_push(&read_buffer, data);
+            }
+        }
+    }
+}