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Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_Freescale/TARGET_KL25Z/serial_api.c@13:0645d8841f51, 2013-08-05 (annotated)

Committer:
bogdanm
Date:
Mon Aug 05 14:12:34 2013 +0300
Revision:
13:0645d8841f51
Child:
15:4892fe388435
Update mbed sources to revision 64

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 13:0645d8841f51 1 /* mbed Microcontroller Library
bogdanm 13:0645d8841f51 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 13:0645d8841f51 3 *
bogdanm 13:0645d8841f51 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 13:0645d8841f51 5 * you may not use this file except in compliance with the License.
bogdanm 13:0645d8841f51 6 * You may obtain a copy of the License at
bogdanm 13:0645d8841f51 7 *
bogdanm 13:0645d8841f51 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 13:0645d8841f51 9 *
bogdanm 13:0645d8841f51 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 13:0645d8841f51 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 13:0645d8841f51 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 13:0645d8841f51 13 * See the License for the specific language governing permissions and
bogdanm 13:0645d8841f51 14 * limitations under the License.
bogdanm 13:0645d8841f51 15 */
bogdanm 13:0645d8841f51 16 #include "serial_api.h"
bogdanm 13:0645d8841f51 17
bogdanm 13:0645d8841f51 18 // math.h required for floating point operations for baud rate calculation
bogdanm 13:0645d8841f51 19 #include <math.h>
bogdanm 13:0645d8841f51 20
bogdanm 13:0645d8841f51 21 #include <string.h>
bogdanm 13:0645d8841f51 22
bogdanm 13:0645d8841f51 23 #include "cmsis.h"
bogdanm 13:0645d8841f51 24 #include "pinmap.h"
bogdanm 13:0645d8841f51 25 #include "error.h"
bogdanm 13:0645d8841f51 26
bogdanm 13:0645d8841f51 27 /******************************************************************************
bogdanm 13:0645d8841f51 28 * INITIALIZATION
bogdanm 13:0645d8841f51 29 ******************************************************************************/
bogdanm 13:0645d8841f51 30 static const PinMap PinMap_UART_TX[] = {
bogdanm 13:0645d8841f51 31 {PTC4, UART_1, 3},
bogdanm 13:0645d8841f51 32 {PTA2, UART_0, 2},
bogdanm 13:0645d8841f51 33 {PTD5, UART_2, 3},
bogdanm 13:0645d8841f51 34 {PTD3, UART_2, 3},
bogdanm 13:0645d8841f51 35 {NC , NC , 0}
bogdanm 13:0645d8841f51 36 };
bogdanm 13:0645d8841f51 37
bogdanm 13:0645d8841f51 38 static const PinMap PinMap_UART_RX[] = {
bogdanm 13:0645d8841f51 39 {PTC3, UART_1, 3},
bogdanm 13:0645d8841f51 40 {PTA1, UART_0, 2},
bogdanm 13:0645d8841f51 41 {PTD4, UART_2, 3},
bogdanm 13:0645d8841f51 42 {PTD2, UART_2, 3},
bogdanm 13:0645d8841f51 43 {NC , NC , 0}
bogdanm 13:0645d8841f51 44 };
bogdanm 13:0645d8841f51 45
bogdanm 13:0645d8841f51 46 #define UART_NUM 3
bogdanm 13:0645d8841f51 47 static uint32_t serial_irq_ids[UART_NUM] = {0};
bogdanm 13:0645d8841f51 48 static uart_irq_handler irq_handler;
bogdanm 13:0645d8841f51 49
bogdanm 13:0645d8841f51 50 int stdio_uart_inited = 0;
bogdanm 13:0645d8841f51 51 serial_t stdio_uart;
bogdanm 13:0645d8841f51 52
bogdanm 13:0645d8841f51 53 void serial_init(serial_t *obj, PinName tx, PinName rx) {
bogdanm 13:0645d8841f51 54 // determine the UART to use
bogdanm 13:0645d8841f51 55 UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
bogdanm 13:0645d8841f51 56 UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
bogdanm 13:0645d8841f51 57 UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
bogdanm 13:0645d8841f51 58 if ((int)uart == NC) {
bogdanm 13:0645d8841f51 59 error("Serial pinout mapping failed");
bogdanm 13:0645d8841f51 60 }
bogdanm 13:0645d8841f51 61
bogdanm 13:0645d8841f51 62 obj->uart = (UARTLP_Type *)uart;
bogdanm 13:0645d8841f51 63 // enable clk
bogdanm 13:0645d8841f51 64 switch (uart) {
bogdanm 13:0645d8841f51 65 case UART_0: SIM->SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK | (1<<SIM_SOPT2_UART0SRC_SHIFT);
bogdanm 13:0645d8841f51 66 SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK; SIM->SCGC4 |= SIM_SCGC4_UART0_MASK; break;
bogdanm 13:0645d8841f51 67 case UART_1: SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK; SIM->SCGC4 |= SIM_SCGC4_UART1_MASK; break;
bogdanm 13:0645d8841f51 68 case UART_2: SIM->SCGC5 |= SIM_SCGC5_PORTD_MASK; SIM->SCGC4 |= SIM_SCGC4_UART2_MASK; break;
bogdanm 13:0645d8841f51 69 }
bogdanm 13:0645d8841f51 70 // Disable UART before changing registers
bogdanm 13:0645d8841f51 71 obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
bogdanm 13:0645d8841f51 72
bogdanm 13:0645d8841f51 73 switch (uart) {
bogdanm 13:0645d8841f51 74 case UART_0: obj->index = 0; break;
bogdanm 13:0645d8841f51 75 case UART_1: obj->index = 1; break;
bogdanm 13:0645d8841f51 76 case UART_2: obj->index = 2; break;
bogdanm 13:0645d8841f51 77 }
bogdanm 13:0645d8841f51 78
bogdanm 13:0645d8841f51 79 // set default baud rate and format
bogdanm 13:0645d8841f51 80 serial_baud (obj, 9600);
bogdanm 13:0645d8841f51 81 serial_format(obj, 8, ParityNone, 1);
bogdanm 13:0645d8841f51 82
bogdanm 13:0645d8841f51 83 // pinout the chosen uart
bogdanm 13:0645d8841f51 84 pinmap_pinout(tx, PinMap_UART_TX);
bogdanm 13:0645d8841f51 85 pinmap_pinout(rx, PinMap_UART_RX);
bogdanm 13:0645d8841f51 86
bogdanm 13:0645d8841f51 87 // set rx/tx pins in PullUp mode
bogdanm 13:0645d8841f51 88 pin_mode(tx, PullUp);
bogdanm 13:0645d8841f51 89 pin_mode(rx, PullUp);
bogdanm 13:0645d8841f51 90
bogdanm 13:0645d8841f51 91 obj->uart->C2 |= (UART_C2_RE_MASK | UART_C2_TE_MASK);
bogdanm 13:0645d8841f51 92
bogdanm 13:0645d8841f51 93 if (uart == STDIO_UART) {
bogdanm 13:0645d8841f51 94 stdio_uart_inited = 1;
bogdanm 13:0645d8841f51 95 memcpy(&stdio_uart, obj, sizeof(serial_t));
bogdanm 13:0645d8841f51 96 }
bogdanm 13:0645d8841f51 97 }
bogdanm 13:0645d8841f51 98
bogdanm 13:0645d8841f51 99 void serial_free(serial_t *obj) {
bogdanm 13:0645d8841f51 100 serial_irq_ids[obj->index] = 0;
bogdanm 13:0645d8841f51 101 }
bogdanm 13:0645d8841f51 102
bogdanm 13:0645d8841f51 103 // serial_baud
bogdanm 13:0645d8841f51 104 //
bogdanm 13:0645d8841f51 105 // set the baud rate, taking in to account the current SystemFrequency
bogdanm 13:0645d8841f51 106 //
bogdanm 13:0645d8841f51 107 // The LPC2300 and LPC1700 have a divider and a fractional divider to control the
bogdanm 13:0645d8841f51 108 // baud rate. The formula is:
bogdanm 13:0645d8841f51 109 //
bogdanm 13:0645d8841f51 110 // Baudrate = (1 / PCLK) * 16 * DL * (1 + DivAddVal / MulVal)
bogdanm 13:0645d8841f51 111 // where:
bogdanm 13:0645d8841f51 112 // 1 < MulVal <= 15
bogdanm 13:0645d8841f51 113 // 0 <= DivAddVal < 14
bogdanm 13:0645d8841f51 114 // DivAddVal < MulVal
bogdanm 13:0645d8841f51 115 //
bogdanm 13:0645d8841f51 116 void serial_baud(serial_t *obj, int baudrate) {
bogdanm 13:0645d8841f51 117
bogdanm 13:0645d8841f51 118 // save C2 state
bogdanm 13:0645d8841f51 119 uint8_t c2_state = (obj->uart->C2 & (UART_C2_RE_MASK | UART_C2_TE_MASK));
bogdanm 13:0645d8841f51 120
bogdanm 13:0645d8841f51 121 // Disable UART before changing registers
bogdanm 13:0645d8841f51 122 obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
bogdanm 13:0645d8841f51 123
bogdanm 13:0645d8841f51 124 // [TODO] not hardcode this value
bogdanm 13:0645d8841f51 125 uint32_t PCLK = (obj->uart == UART0) ? 48000000u : 24000000u;
bogdanm 13:0645d8841f51 126
bogdanm 13:0645d8841f51 127 // First we check to see if the basic divide with no DivAddVal/MulVal
bogdanm 13:0645d8841f51 128 // ratio gives us an integer result. If it does, we set DivAddVal = 0,
bogdanm 13:0645d8841f51 129 // MulVal = 1. Otherwise, we search the valid ratio value range to find
bogdanm 13:0645d8841f51 130 // the closest match. This could be more elegant, using search methods
bogdanm 13:0645d8841f51 131 // and/or lookup tables, but the brute force method is not that much
bogdanm 13:0645d8841f51 132 // slower, and is more maintainable.
bogdanm 13:0645d8841f51 133 uint16_t DL = PCLK / (16 * baudrate);
bogdanm 13:0645d8841f51 134
bogdanm 13:0645d8841f51 135 // set BDH and BDL
bogdanm 13:0645d8841f51 136 obj->uart->BDH = (obj->uart->BDH & ~(0x1f)) | ((DL >> 8) & 0x1f);
bogdanm 13:0645d8841f51 137 obj->uart->BDL = (obj->uart->BDL & ~(0xff)) | ((DL >> 0) & 0xff);
bogdanm 13:0645d8841f51 138
bogdanm 13:0645d8841f51 139 // restore C2 state
bogdanm 13:0645d8841f51 140 obj->uart->C2 |= c2_state;
bogdanm 13:0645d8841f51 141 }
bogdanm 13:0645d8841f51 142
bogdanm 13:0645d8841f51 143 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
bogdanm 13:0645d8841f51 144 uint8_t m10 = 0;
bogdanm 13:0645d8841f51 145
bogdanm 13:0645d8841f51 146 // save C2 state
bogdanm 13:0645d8841f51 147 uint8_t c2_state = (obj->uart->C2 & (UART_C2_RE_MASK | UART_C2_TE_MASK));
bogdanm 13:0645d8841f51 148
bogdanm 13:0645d8841f51 149 // Disable UART before changing registers
bogdanm 13:0645d8841f51 150 obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
bogdanm 13:0645d8841f51 151
bogdanm 13:0645d8841f51 152 // 8 data bits = 0 ... 9 data bits = 1
bogdanm 13:0645d8841f51 153 if ((data_bits < 8) || (data_bits > 9)) {
bogdanm 13:0645d8841f51 154 error("Invalid number of bits (%d) in serial format, should be 8..9\r\n", data_bits);
bogdanm 13:0645d8841f51 155 }
bogdanm 13:0645d8841f51 156 data_bits -= 8;
bogdanm 13:0645d8841f51 157
bogdanm 13:0645d8841f51 158 uint8_t parity_enable, parity_select;
bogdanm 13:0645d8841f51 159 switch (parity) {
bogdanm 13:0645d8841f51 160 case ParityNone: parity_enable = 0; parity_select = 0; break;
bogdanm 13:0645d8841f51 161 case ParityOdd : parity_enable = 1; parity_select = 1; data_bits++; break;
bogdanm 13:0645d8841f51 162 case ParityEven: parity_enable = 1; parity_select = 0; data_bits++; break;
bogdanm 13:0645d8841f51 163 default:
bogdanm 13:0645d8841f51 164 error("Invalid serial parity setting\r\n");
bogdanm 13:0645d8841f51 165 return;
bogdanm 13:0645d8841f51 166 }
bogdanm 13:0645d8841f51 167
bogdanm 13:0645d8841f51 168 // 1 stop bits = 0, 2 stop bits = 1
bogdanm 13:0645d8841f51 169 if ((stop_bits != 1) && (stop_bits != 2)) {
bogdanm 13:0645d8841f51 170 error("Invalid stop bits specified\r\n");
bogdanm 13:0645d8841f51 171 }
bogdanm 13:0645d8841f51 172 stop_bits -= 1;
bogdanm 13:0645d8841f51 173
bogdanm 13:0645d8841f51 174 // 9 data bits + parity
bogdanm 13:0645d8841f51 175 if (data_bits == 2) {
bogdanm 13:0645d8841f51 176 // only uart0 supports 10 bit communication
bogdanm 13:0645d8841f51 177 if (obj->index != 0) {
bogdanm 13:0645d8841f51 178 error("Invalid number of bits (9) to be used with parity\r\n");
bogdanm 13:0645d8841f51 179 }
bogdanm 13:0645d8841f51 180 data_bits = 0;
bogdanm 13:0645d8841f51 181 m10 = 1;
bogdanm 13:0645d8841f51 182 }
bogdanm 13:0645d8841f51 183
bogdanm 13:0645d8841f51 184 // data bits, parity and parity mode
bogdanm 13:0645d8841f51 185 obj->uart->C1 = ((data_bits << 4)
bogdanm 13:0645d8841f51 186 | (parity_enable << 1)
bogdanm 13:0645d8841f51 187 | (parity_select << 0));
bogdanm 13:0645d8841f51 188
bogdanm 13:0645d8841f51 189 // enable 10bit mode if needed
bogdanm 13:0645d8841f51 190 if (obj->index == 0) {
bogdanm 13:0645d8841f51 191 obj->uart->C4 &= ~UARTLP_C4_M10_MASK;
bogdanm 13:0645d8841f51 192 obj->uart->C4 |= (m10 << UARTLP_C4_M10_SHIFT);
bogdanm 13:0645d8841f51 193 }
bogdanm 13:0645d8841f51 194
bogdanm 13:0645d8841f51 195 // stop bits
bogdanm 13:0645d8841f51 196 obj->uart->BDH &= ~UART_BDH_SBNS_MASK;
bogdanm 13:0645d8841f51 197 obj->uart->BDH |= (stop_bits << UART_BDH_SBNS_SHIFT);
bogdanm 13:0645d8841f51 198
bogdanm 13:0645d8841f51 199 // restore C2 state
bogdanm 13:0645d8841f51 200 obj->uart->C2 |= c2_state;
bogdanm 13:0645d8841f51 201 }
bogdanm 13:0645d8841f51 202
bogdanm 13:0645d8841f51 203 /******************************************************************************
bogdanm 13:0645d8841f51 204 * INTERRUPTS HANDLING
bogdanm 13:0645d8841f51 205 ******************************************************************************/
bogdanm 13:0645d8841f51 206 static inline void uart_irq(uint8_t status, uint32_t index) {
bogdanm 13:0645d8841f51 207 if (serial_irq_ids[index] != 0) {
bogdanm 13:0645d8841f51 208 if (status & UART_S1_TDRE_MASK)
bogdanm 13:0645d8841f51 209 irq_handler(serial_irq_ids[index], TxIrq);
bogdanm 13:0645d8841f51 210
bogdanm 13:0645d8841f51 211 if (status & UART_S1_RDRF_MASK)
bogdanm 13:0645d8841f51 212 irq_handler(serial_irq_ids[index], RxIrq);
bogdanm 13:0645d8841f51 213 }
bogdanm 13:0645d8841f51 214 }
bogdanm 13:0645d8841f51 215
bogdanm 13:0645d8841f51 216 void uart0_irq() {
bogdanm 13:0645d8841f51 217 uart_irq(UART0->S1, 0);
bogdanm 13:0645d8841f51 218 if (UART0->S1 & UART_S1_OR_MASK)
bogdanm 13:0645d8841f51 219 UART0->S1 |= UART_S1_OR_MASK;
bogdanm 13:0645d8841f51 220 }
bogdanm 13:0645d8841f51 221 void uart1_irq() {uart_irq(UART1->S1, 1);}
bogdanm 13:0645d8841f51 222 void uart2_irq() {uart_irq(UART2->S1, 2);}
bogdanm 13:0645d8841f51 223
bogdanm 13:0645d8841f51 224 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
bogdanm 13:0645d8841f51 225 irq_handler = handler;
bogdanm 13:0645d8841f51 226 serial_irq_ids[obj->index] = id;
bogdanm 13:0645d8841f51 227 }
bogdanm 13:0645d8841f51 228
bogdanm 13:0645d8841f51 229 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
bogdanm 13:0645d8841f51 230 IRQn_Type irq_n = (IRQn_Type)0;
bogdanm 13:0645d8841f51 231 uint32_t vector = 0;
bogdanm 13:0645d8841f51 232 switch ((int)obj->uart) {
bogdanm 13:0645d8841f51 233 case UART_0: irq_n=UART0_IRQn; vector = (uint32_t)&uart0_irq; break;
bogdanm 13:0645d8841f51 234 case UART_1: irq_n=UART1_IRQn; vector = (uint32_t)&uart1_irq; break;
bogdanm 13:0645d8841f51 235 case UART_2: irq_n=UART2_IRQn; vector = (uint32_t)&uart2_irq; break;
bogdanm 13:0645d8841f51 236 }
bogdanm 13:0645d8841f51 237
bogdanm 13:0645d8841f51 238 if (enable) {
bogdanm 13:0645d8841f51 239 switch (irq) {
bogdanm 13:0645d8841f51 240 case RxIrq: obj->uart->C2 |= (UART_C2_RIE_MASK); break;
bogdanm 13:0645d8841f51 241 case TxIrq: obj->uart->C2 |= (UART_C2_TIE_MASK); break;
bogdanm 13:0645d8841f51 242 }
bogdanm 13:0645d8841f51 243 NVIC_SetVector(irq_n, vector);
bogdanm 13:0645d8841f51 244 NVIC_EnableIRQ(irq_n);
bogdanm 13:0645d8841f51 245
bogdanm 13:0645d8841f51 246 } else { // disable
bogdanm 13:0645d8841f51 247 int all_disabled = 0;
bogdanm 13:0645d8841f51 248 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
bogdanm 13:0645d8841f51 249 switch (irq) {
bogdanm 13:0645d8841f51 250 case RxIrq: obj->uart->C2 &= ~(UART_C2_RIE_MASK); break;
bogdanm 13:0645d8841f51 251 case TxIrq: obj->uart->C2 &= ~(UART_C2_TIE_MASK); break;
bogdanm 13:0645d8841f51 252 }
bogdanm 13:0645d8841f51 253 switch (other_irq) {
bogdanm 13:0645d8841f51 254 case RxIrq: all_disabled = (obj->uart->C2 & (UART_C2_RIE_MASK)) == 0; break;
bogdanm 13:0645d8841f51 255 case TxIrq: all_disabled = (obj->uart->C2 & (UART_C2_TIE_MASK)) == 0; break;
bogdanm 13:0645d8841f51 256 }
bogdanm 13:0645d8841f51 257 if (all_disabled)
bogdanm 13:0645d8841f51 258 NVIC_DisableIRQ(irq_n);
bogdanm 13:0645d8841f51 259 }
bogdanm 13:0645d8841f51 260 }
bogdanm 13:0645d8841f51 261
bogdanm 13:0645d8841f51 262 /******************************************************************************
bogdanm 13:0645d8841f51 263 * READ/WRITE
bogdanm 13:0645d8841f51 264 ******************************************************************************/
bogdanm 13:0645d8841f51 265 int serial_getc(serial_t *obj) {
bogdanm 13:0645d8841f51 266 while (!serial_readable(obj));
bogdanm 13:0645d8841f51 267 return obj->uart->D;
bogdanm 13:0645d8841f51 268 }
bogdanm 13:0645d8841f51 269
bogdanm 13:0645d8841f51 270 void serial_putc(serial_t *obj, int c) {
bogdanm 13:0645d8841f51 271 while (!serial_writable(obj));
bogdanm 13:0645d8841f51 272 obj->uart->D = c;
bogdanm 13:0645d8841f51 273 }
bogdanm 13:0645d8841f51 274
bogdanm 13:0645d8841f51 275 int serial_readable(serial_t *obj) {
bogdanm 13:0645d8841f51 276 // check overrun
bogdanm 13:0645d8841f51 277 if (obj->uart->S1 & UART_S1_OR_MASK) {
bogdanm 13:0645d8841f51 278 obj->uart->S1 |= UART_S1_OR_MASK;
bogdanm 13:0645d8841f51 279 }
bogdanm 13:0645d8841f51 280 return (obj->uart->S1 & UART_S1_RDRF_MASK);
bogdanm 13:0645d8841f51 281 }
bogdanm 13:0645d8841f51 282
bogdanm 13:0645d8841f51 283 int serial_writable(serial_t *obj) {
bogdanm 13:0645d8841f51 284 // check overrun
bogdanm 13:0645d8841f51 285 if (obj->uart->S1 & UART_S1_OR_MASK) {
bogdanm 13:0645d8841f51 286 obj->uart->S1 |= UART_S1_OR_MASK;
bogdanm 13:0645d8841f51 287 }
bogdanm 13:0645d8841f51 288 return (obj->uart->S1 & UART_S1_TDRE_MASK);
bogdanm 13:0645d8841f51 289 }
bogdanm 13:0645d8841f51 290
bogdanm 13:0645d8841f51 291 void serial_clear(serial_t *obj) {
bogdanm 13:0645d8841f51 292 }
bogdanm 13:0645d8841f51 293
bogdanm 13:0645d8841f51 294 void serial_pinout_tx(PinName tx) {
bogdanm 13:0645d8841f51 295 pinmap_pinout(tx, PinMap_UART_TX);
bogdanm 13:0645d8841f51 296 }
bogdanm 13:0645d8841f51 297
bogdanm 13:0645d8841f51 298 void serial_break_set(serial_t *obj) {
bogdanm 13:0645d8841f51 299 obj->uart->C2 |= UART_C2_SBK_MASK;
bogdanm 13:0645d8841f51 300 }
bogdanm 13:0645d8841f51 301
bogdanm 13:0645d8841f51 302 void serial_break_clear(serial_t *obj) {
bogdanm 13:0645d8841f51 303 obj->uart->C2 &= ~UART_C2_SBK_MASK;
bogdanm 13:0645d8841f51 304 }
bogdanm 13:0645d8841f51 305