Yihui Xiong / mbed-src

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targets/hal/TARGET_Freescale/TARGET_K20D5M/serial_api.c@75:af844aac7b8c, 2014-01-17 (annotated)

Committer:
yihui
Date:
Fri Jan 17 03:18:47 2014 +0000
Revision:
75:af844aac7b8c
Parent:
73:299c67215126 
disable semihost and local file system

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 68:41613245dfd7 1 /* mbed Microcontroller Library
mbed_official 68:41613245dfd7 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 68:41613245dfd7 3 *
mbed_official 68:41613245dfd7 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 68:41613245dfd7 5 * you may not use this file except in compliance with the License.
mbed_official 68:41613245dfd7 6 * You may obtain a copy of the License at
mbed_official 68:41613245dfd7 7 *
mbed_official 68:41613245dfd7 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 68:41613245dfd7 9 *
mbed_official 68:41613245dfd7 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 68:41613245dfd7 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 68:41613245dfd7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 68:41613245dfd7 13 * See the License for the specific language governing permissions and
mbed_official 68:41613245dfd7 14 * limitations under the License.
mbed_official 68:41613245dfd7 15 */
mbed_official 68:41613245dfd7 16 #include "serial_api.h"
mbed_official 68:41613245dfd7 17
mbed_official 68:41613245dfd7 18 // math.h required for floating point operations for baud rate calculation
mbed_official 68:41613245dfd7 19 #include <math.h>
mbed_official 68:41613245dfd7 20
mbed_official 68:41613245dfd7 21 #include <string.h>
mbed_official 68:41613245dfd7 22
mbed_official 68:41613245dfd7 23 #include "cmsis.h"
mbed_official 68:41613245dfd7 24 #include "pinmap.h"
mbed_official 68:41613245dfd7 25 #include "error.h"
mbed_official 68:41613245dfd7 26
mbed_official 68:41613245dfd7 27 static const PinMap PinMap_UART_TX[] = {
mbed_official 68:41613245dfd7 28 {PTB17, UART_0, 3},
mbed_official 68:41613245dfd7 29 {NC , NC , 0}
mbed_official 68:41613245dfd7 30 };
mbed_official 68:41613245dfd7 31
mbed_official 68:41613245dfd7 32 static const PinMap PinMap_UART_RX[] = {
mbed_official 68:41613245dfd7 33 {PTB16, UART_0, 3},
mbed_official 68:41613245dfd7 34 {NC , NC , 0}
mbed_official 68:41613245dfd7 35 };
mbed_official 68:41613245dfd7 36
mbed_official 68:41613245dfd7 37 #define UART_NUM 3
mbed_official 68:41613245dfd7 38
mbed_official 68:41613245dfd7 39 static uint32_t serial_irq_ids[UART_NUM] = {0};
mbed_official 68:41613245dfd7 40 static uart_irq_handler irq_handler;
mbed_official 68:41613245dfd7 41
mbed_official 68:41613245dfd7 42 int stdio_uart_inited = 0;
mbed_official 68:41613245dfd7 43 serial_t stdio_uart;
mbed_official 68:41613245dfd7 44
mbed_official 68:41613245dfd7 45 void serial_init(serial_t *obj, PinName tx, PinName rx) {
mbed_official 68:41613245dfd7 46 // determine the UART to use
mbed_official 68:41613245dfd7 47 UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
mbed_official 68:41613245dfd7 48 UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
mbed_official 68:41613245dfd7 49 UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
mbed_official 68:41613245dfd7 50 if ((int)uart == NC)
mbed_official 68:41613245dfd7 51 error("Serial pinout mapping failed");
mbed_official 68:41613245dfd7 52
mbed_official 68:41613245dfd7 53 obj->uart = (UART_Type *)uart;
mbed_official 68:41613245dfd7 54 // enable clk
mbed_official 68:41613245dfd7 55 switch (uart) {
mbed_official 73:299c67215126 56 case UART_0: SIM->SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK;
mbed_official 68:41613245dfd7 57 SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK; SIM->SCGC4 |= SIM_SCGC4_UART0_MASK; break;
mbed_official 68:41613245dfd7 58 case UART_1: SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK; SIM->SCGC4 |= SIM_SCGC4_UART1_MASK; break;
mbed_official 68:41613245dfd7 59 case UART_2: SIM->SCGC5 |= SIM_SCGC5_PORTD_MASK; SIM->SCGC4 |= SIM_SCGC4_UART2_MASK; break;
mbed_official 68:41613245dfd7 60 }
mbed_official 68:41613245dfd7 61 // Disable UART before changing registers
mbed_official 68:41613245dfd7 62 obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
mbed_official 68:41613245dfd7 63
mbed_official 68:41613245dfd7 64 switch (uart) {
mbed_official 68:41613245dfd7 65 case UART_0: obj->index = 0; break;
mbed_official 68:41613245dfd7 66 case UART_1: obj->index = 1; break;
mbed_official 68:41613245dfd7 67 case UART_2: obj->index = 2; break;
mbed_official 68:41613245dfd7 68 }
mbed_official 68:41613245dfd7 69
mbed_official 68:41613245dfd7 70 // set default baud rate and format
mbed_official 68:41613245dfd7 71 serial_baud (obj, 9600);
mbed_official 68:41613245dfd7 72 serial_format(obj, 8, ParityNone, 1);
mbed_official 68:41613245dfd7 73
mbed_official 68:41613245dfd7 74 // pinout the chosen uart
mbed_official 68:41613245dfd7 75 pinmap_pinout(tx, PinMap_UART_TX);
mbed_official 68:41613245dfd7 76 pinmap_pinout(rx, PinMap_UART_RX);
mbed_official 68:41613245dfd7 77
mbed_official 68:41613245dfd7 78 // set rx/tx pins in PullUp mode
mbed_official 68:41613245dfd7 79 pin_mode(tx, PullUp);
mbed_official 68:41613245dfd7 80 pin_mode(rx, PullUp);
mbed_official 68:41613245dfd7 81
mbed_official 68:41613245dfd7 82 obj->uart->C2 |= (UART_C2_RE_MASK | UART_C2_TE_MASK);
mbed_official 68:41613245dfd7 83
mbed_official 68:41613245dfd7 84 if (uart == STDIO_UART) {
mbed_official 68:41613245dfd7 85 stdio_uart_inited = 1;
mbed_official 68:41613245dfd7 86 memcpy(&stdio_uart, obj, sizeof(serial_t));
mbed_official 68:41613245dfd7 87 }
mbed_official 68:41613245dfd7 88 }
mbed_official 68:41613245dfd7 89
mbed_official 68:41613245dfd7 90 void serial_free(serial_t *obj) {
mbed_official 68:41613245dfd7 91 serial_irq_ids[obj->index] = 0;
mbed_official 68:41613245dfd7 92 }
mbed_official 68:41613245dfd7 93
mbed_official 68:41613245dfd7 94 void serial_baud(serial_t *obj, int baudrate) {
mbed_official 68:41613245dfd7 95 // save C2 state
mbed_official 68:41613245dfd7 96 uint32_t c2_state = (obj->uart->C2 & (UART_C2_RE_MASK | UART_C2_TE_MASK));
mbed_official 68:41613245dfd7 97
mbed_official 68:41613245dfd7 98 // Disable UART before changing registers
mbed_official 68:41613245dfd7 99 obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
mbed_official 68:41613245dfd7 100
mbed_official 73:299c67215126 101 uint32_t PCLK = (obj->uart == UART0) ? SystemCoreClock : SystemCoreClock/2;
mbed_official 68:41613245dfd7 102
mbed_official 68:41613245dfd7 103 // First we check to see if the basic divide with no DivAddVal/MulVal
mbed_official 68:41613245dfd7 104 // ratio gives us an integer result. If it does, we set DivAddVal = 0,
mbed_official 68:41613245dfd7 105 // MulVal = 1. Otherwise, we search the valid ratio value range to find
mbed_official 68:41613245dfd7 106 // the closest match. This could be more elegant, using search methods
mbed_official 68:41613245dfd7 107 // and/or lookup tables, but the brute force method is not that much
mbed_official 68:41613245dfd7 108 // slower, and is more maintainable.
mbed_official 68:41613245dfd7 109 uint16_t DL = PCLK / (16 * baudrate);
mbed_official 68:41613245dfd7 110
mbed_official 68:41613245dfd7 111 // set BDH and BDL
mbed_official 68:41613245dfd7 112 obj->uart->BDH = (obj->uart->BDH & ~(0x1f)) | ((DL >> 8) & 0x1f);
mbed_official 68:41613245dfd7 113 obj->uart->BDL = (obj->uart->BDL & ~(0xff)) | ((DL >> 0) & 0xff);
mbed_official 68:41613245dfd7 114
mbed_official 68:41613245dfd7 115 // restore C2 state
mbed_official 68:41613245dfd7 116 obj->uart->C2 |= c2_state;
mbed_official 68:41613245dfd7 117 }
mbed_official 68:41613245dfd7 118
mbed_official 68:41613245dfd7 119 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
mbed_official 68:41613245dfd7 120
mbed_official 68:41613245dfd7 121 // save C2 state
mbed_official 68:41613245dfd7 122 uint32_t c2_state = (obj->uart->C2 & (UART_C2_RE_MASK | UART_C2_TE_MASK));
mbed_official 68:41613245dfd7 123
mbed_official 68:41613245dfd7 124 // Disable UART before changing registers
mbed_official 68:41613245dfd7 125 obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
mbed_official 68:41613245dfd7 126
mbed_official 68:41613245dfd7 127 // 8 data bits = 0 ... 9 data bits = 1
mbed_official 68:41613245dfd7 128 if ((data_bits < 8) || (data_bits > 9))
mbed_official 68:41613245dfd7 129 error("Invalid number of bits (%d) in serial format, should be 8..9\r\n", data_bits);
mbed_official 68:41613245dfd7 130
mbed_official 68:41613245dfd7 131 data_bits -= 8;
mbed_official 68:41613245dfd7 132
mbed_official 68:41613245dfd7 133 uint32_t parity_enable, parity_select;
mbed_official 68:41613245dfd7 134 switch (parity) {
mbed_official 68:41613245dfd7 135 case ParityNone: parity_enable = 0; parity_select = 0; break;
mbed_official 68:41613245dfd7 136 case ParityOdd : parity_enable = 1; parity_select = 1; data_bits++; break;
mbed_official 68:41613245dfd7 137 case ParityEven: parity_enable = 1; parity_select = 0; data_bits++; break;
mbed_official 68:41613245dfd7 138 default:
mbed_official 68:41613245dfd7 139 error("Invalid serial parity setting\r\n");
mbed_official 68:41613245dfd7 140 return;
mbed_official 68:41613245dfd7 141 }
mbed_official 68:41613245dfd7 142
mbed_official 68:41613245dfd7 143 // 1 stop bits = 0, 2 stop bits = 1
mbed_official 68:41613245dfd7 144 if ((stop_bits != 1) && (stop_bits != 2))
mbed_official 68:41613245dfd7 145 error("Invalid stop bits specified\r\n");
mbed_official 68:41613245dfd7 146 stop_bits -= 1;
mbed_official 68:41613245dfd7 147
mbed_official 68:41613245dfd7 148 uint32_t m10 = 0;
mbed_official 68:41613245dfd7 149
mbed_official 68:41613245dfd7 150 // 9 data bits + parity
mbed_official 68:41613245dfd7 151 if (data_bits == 2) {
mbed_official 68:41613245dfd7 152 // only uart0 supports 10 bit communication
mbed_official 68:41613245dfd7 153 if (obj->index != 0)
mbed_official 68:41613245dfd7 154 error("Invalid number of bits (9) to be used with parity\r\n");
mbed_official 68:41613245dfd7 155 data_bits = 0;
mbed_official 68:41613245dfd7 156 m10 = 1;
mbed_official 68:41613245dfd7 157 }
mbed_official 68:41613245dfd7 158
mbed_official 68:41613245dfd7 159 // data bits, parity and parity mode
mbed_official 68:41613245dfd7 160 obj->uart->C1 = ((data_bits << 4)
mbed_official 68:41613245dfd7 161 | (parity_enable << 1)
mbed_official 68:41613245dfd7 162 | (parity_select << 0));
mbed_official 68:41613245dfd7 163
mbed_official 68:41613245dfd7 164 //enable 10bit mode if needed
mbed_official 68:41613245dfd7 165 if (obj->index == 0) {
mbed_official 68:41613245dfd7 166 obj->uart->C4 &= ~UART_C4_M10_MASK;
mbed_official 68:41613245dfd7 167 obj->uart->C4 |= (m10 << UART_C4_M10_SHIFT);
mbed_official 68:41613245dfd7 168 }
mbed_official 68:41613245dfd7 169
mbed_official 68:41613245dfd7 170 // stop bits
mbed_official 68:41613245dfd7 171 obj->uart->BDH &= ~UART_BDH_SBR_MASK;
mbed_official 68:41613245dfd7 172 obj->uart->BDH |= (stop_bits << UART_BDH_SBR_SHIFT);
mbed_official 68:41613245dfd7 173
mbed_official 68:41613245dfd7 174 // restore C2 state
mbed_official 68:41613245dfd7 175 obj->uart->C2 |= c2_state;
mbed_official 68:41613245dfd7 176 }
mbed_official 68:41613245dfd7 177
mbed_official 68:41613245dfd7 178 /******************************************************************************
mbed_official 68:41613245dfd7 179 * INTERRUPTS HANDLING
mbed_official 68:41613245dfd7 180 ******************************************************************************/
mbed_official 68:41613245dfd7 181 static inline void uart_irq(uint8_t status, uint32_t index) {
mbed_official 68:41613245dfd7 182 if (serial_irq_ids[index] != 0) {
mbed_official 68:41613245dfd7 183 if (status & UART_S1_TDRE_MASK)
mbed_official 68:41613245dfd7 184 irq_handler(serial_irq_ids[index], TxIrq);
mbed_official 68:41613245dfd7 185
mbed_official 68:41613245dfd7 186 if (status & UART_S1_RDRF_MASK)
mbed_official 68:41613245dfd7 187 irq_handler(serial_irq_ids[index], RxIrq);
mbed_official 68:41613245dfd7 188 }
mbed_official 68:41613245dfd7 189 }
mbed_official 68:41613245dfd7 190
mbed_official 68:41613245dfd7 191 void uart0_irq() {uart_irq(UART0->S1, 0);}
mbed_official 68:41613245dfd7 192 void uart1_irq() {uart_irq(UART1->S1, 1);}
mbed_official 68:41613245dfd7 193 void uart2_irq() {uart_irq(UART2->S1, 2);}
mbed_official 68:41613245dfd7 194
mbed_official 68:41613245dfd7 195 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
mbed_official 68:41613245dfd7 196 irq_handler = handler;
mbed_official 68:41613245dfd7 197 serial_irq_ids[obj->index] = id;
mbed_official 68:41613245dfd7 198 }
mbed_official 68:41613245dfd7 199
mbed_official 68:41613245dfd7 200 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
mbed_official 68:41613245dfd7 201 IRQn_Type irq_n = (IRQn_Type)0;
mbed_official 68:41613245dfd7 202 uint32_t vector = 0;
mbed_official 68:41613245dfd7 203 switch ((int)obj->uart) {
mbed_official 68:41613245dfd7 204 case UART_0:
mbed_official 68:41613245dfd7 205 irq_n=UART0_RX_TX_IRQn;
mbed_official 68:41613245dfd7 206 vector = (uint32_t)&uart0_irq;
mbed_official 68:41613245dfd7 207 break;
mbed_official 68:41613245dfd7 208 case UART_1:
mbed_official 68:41613245dfd7 209 irq_n=UART1_RX_TX_IRQn;
mbed_official 68:41613245dfd7 210 vector = (uint32_t)&uart1_irq;
mbed_official 68:41613245dfd7 211 break;
mbed_official 68:41613245dfd7 212 case UART_2:
mbed_official 68:41613245dfd7 213 irq_n=UART2_RX_TX_IRQn;
mbed_official 68:41613245dfd7 214 vector = (uint32_t)&uart2_irq;
mbed_official 68:41613245dfd7 215 break;
mbed_official 68:41613245dfd7 216 }
mbed_official 68:41613245dfd7 217
mbed_official 68:41613245dfd7 218 if (enable) {
mbed_official 68:41613245dfd7 219 switch (irq) {
mbed_official 68:41613245dfd7 220 case RxIrq:
mbed_official 68:41613245dfd7 221 obj->uart->C2 |= (UART_C2_RIE_MASK);
mbed_official 68:41613245dfd7 222 break;
mbed_official 68:41613245dfd7 223 case TxIrq:
mbed_official 68:41613245dfd7 224 obj->uart->C2 |= (UART_C2_TIE_MASK);
mbed_official 68:41613245dfd7 225 break;
mbed_official 68:41613245dfd7 226 }
mbed_official 68:41613245dfd7 227 NVIC_SetVector(irq_n, vector);
mbed_official 68:41613245dfd7 228 NVIC_EnableIRQ(irq_n);
mbed_official 68:41613245dfd7 229
mbed_official 68:41613245dfd7 230 } else { // disable
mbed_official 68:41613245dfd7 231 int all_disabled = 0;
mbed_official 68:41613245dfd7 232 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
mbed_official 68:41613245dfd7 233 switch (irq) {
mbed_official 68:41613245dfd7 234 case RxIrq:
mbed_official 68:41613245dfd7 235 obj->uart->C2 &= ~(UART_C2_RIE_MASK);
mbed_official 68:41613245dfd7 236 break;
mbed_official 68:41613245dfd7 237 case TxIrq:
mbed_official 68:41613245dfd7 238 obj->uart->C2 &= ~(UART_C2_TIE_MASK);
mbed_official 68:41613245dfd7 239 break;
mbed_official 68:41613245dfd7 240 }
mbed_official 68:41613245dfd7 241 switch (other_irq) {
mbed_official 68:41613245dfd7 242 case RxIrq:
mbed_official 68:41613245dfd7 243 all_disabled = (obj->uart->C2 & (UART_C2_RIE_MASK)) == 0;
mbed_official 68:41613245dfd7 244 break;
mbed_official 68:41613245dfd7 245 case TxIrq:
mbed_official 68:41613245dfd7 246 all_disabled = (obj->uart->C2 & (UART_C2_TIE_MASK)) == 0;
mbed_official 68:41613245dfd7 247 break;
mbed_official 68:41613245dfd7 248 }
mbed_official 68:41613245dfd7 249 if (all_disabled)
mbed_official 68:41613245dfd7 250 NVIC_DisableIRQ(irq_n);
mbed_official 68:41613245dfd7 251 }
mbed_official 68:41613245dfd7 252 }
mbed_official 68:41613245dfd7 253
mbed_official 68:41613245dfd7 254 int serial_getc(serial_t *obj) {
mbed_official 68:41613245dfd7 255 while (!serial_readable(obj));
mbed_official 68:41613245dfd7 256 return obj->uart->D;
mbed_official 68:41613245dfd7 257 }
mbed_official 68:41613245dfd7 258
mbed_official 68:41613245dfd7 259 void serial_putc(serial_t *obj, int c) {
mbed_official 68:41613245dfd7 260 while (!serial_writable(obj));
mbed_official 68:41613245dfd7 261 obj->uart->D = c;
mbed_official 68:41613245dfd7 262 }
mbed_official 68:41613245dfd7 263
mbed_official 68:41613245dfd7 264 int serial_readable(serial_t *obj) {
mbed_official 68:41613245dfd7 265
mbed_official 68:41613245dfd7 266 return (obj->uart->S1 & UART_S1_RDRF_MASK);
mbed_official 68:41613245dfd7 267 }
mbed_official 68:41613245dfd7 268
mbed_official 68:41613245dfd7 269 int serial_writable(serial_t *obj) {
mbed_official 68:41613245dfd7 270
mbed_official 68:41613245dfd7 271 return (obj->uart->S1 & UART_S1_TDRE_MASK);
mbed_official 68:41613245dfd7 272 }
mbed_official 68:41613245dfd7 273
mbed_official 68:41613245dfd7 274 void serial_clear(serial_t *obj) {
mbed_official 68:41613245dfd7 275 }
mbed_official 68:41613245dfd7 276
mbed_official 68:41613245dfd7 277 void serial_pinout_tx(PinName tx) {
mbed_official 68:41613245dfd7 278 pinmap_pinout(tx, PinMap_UART_TX);
mbed_official 68:41613245dfd7 279 }
mbed_official 68:41613245dfd7 280
mbed_official 68:41613245dfd7 281 void serial_break_set(serial_t *obj) {
mbed_official 68:41613245dfd7 282 obj->uart->C2 |= UART_C2_SBK_MASK;
mbed_official 68:41613245dfd7 283 }
mbed_official 68:41613245dfd7 284
mbed_official 68:41613245dfd7 285 void serial_break_clear(serial_t *obj) {
mbed_official 68:41613245dfd7 286 obj->uart->C2 &= ~UART_C2_SBK_MASK;
mbed_official 68:41613245dfd7 287 }
mbed_official 68:41613245dfd7 288