shao ziyang / mbed-src-kl05

mbed library sources

Dependents:   frdm_kl05z_gpio_test

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targets/hal/TARGET_NXP/TARGET_LPC43XX/serial_api.c@20:4263a77256ae, 2013-09-10 (annotated)

Committer:
bogdanm
Date:
Tue Sep 10 15:14:19 2013 +0300
Revision:
20:4263a77256ae
Child:
51:7838415c99e7
Sync with git revision 171dda705c947bf910926a0b73d6a4797802554d

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 20:4263a77256ae 1 /* mbed Microcontroller Library
bogdanm 20:4263a77256ae 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 20:4263a77256ae 3 *
bogdanm 20:4263a77256ae 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 20:4263a77256ae 5 * you may not use this file except in compliance with the License.
bogdanm 20:4263a77256ae 6 * You may obtain a copy of the License at
bogdanm 20:4263a77256ae 7 *
bogdanm 20:4263a77256ae 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 20:4263a77256ae 9 *
bogdanm 20:4263a77256ae 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 20:4263a77256ae 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 20:4263a77256ae 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 20:4263a77256ae 13 * See the License for the specific language governing permissions and
bogdanm 20:4263a77256ae 14 * limitations under the License.
bogdanm 20:4263a77256ae 15 *
bogdanm 20:4263a77256ae 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
bogdanm 20:4263a77256ae 17 */
bogdanm 20:4263a77256ae 18 // math.h required for floating point operations for baud rate calculation
bogdanm 20:4263a77256ae 19 #include <math.h>
bogdanm 20:4263a77256ae 20 #include <string.h>
bogdanm 20:4263a77256ae 21
bogdanm 20:4263a77256ae 22 #include "serial_api.h"
bogdanm 20:4263a77256ae 23 #include "cmsis.h"
bogdanm 20:4263a77256ae 24 #include "pinmap.h"
bogdanm 20:4263a77256ae 25 #include "error.h"
bogdanm 20:4263a77256ae 26
bogdanm 20:4263a77256ae 27 /******************************************************************************
bogdanm 20:4263a77256ae 28 * INITIALIZATION
bogdanm 20:4263a77256ae 29 ******************************************************************************/
bogdanm 20:4263a77256ae 30 static const PinMap PinMap_UART_TX[] = {
bogdanm 20:4263a77256ae 31 {UART0_TX, UART_0, (SCU_PINIO_PULLDOWN | 2)},
bogdanm 20:4263a77256ae 32 {UART1_TX, UART_1, (SCU_PINIO_PULLDOWN | 4)},
bogdanm 20:4263a77256ae 33 {UART2_TX, UART_2, (SCU_PINIO_PULLDOWN | 2)},
bogdanm 20:4263a77256ae 34 {UART3_TX, UART_3, (SCU_PINIO_PULLDOWN | 2)},
bogdanm 20:4263a77256ae 35 {NC , NC , 0}
bogdanm 20:4263a77256ae 36 };
bogdanm 20:4263a77256ae 37
bogdanm 20:4263a77256ae 38 static const PinMap PinMap_UART_RX[] = {
bogdanm 20:4263a77256ae 39 {UART0_RX, UART_0, (SCU_PINIO_PULLDOWN | 2)},
bogdanm 20:4263a77256ae 40 {UART1_RX, UART_1, (SCU_PINIO_PULLDOWN | 1)},
bogdanm 20:4263a77256ae 41 {UART2_RX, UART_2, (SCU_PINIO_PULLDOWN | 2)},
bogdanm 20:4263a77256ae 42 {UART3_RX, UART_3, (SCU_PINIO_PULLDOWN | 2)},
bogdanm 20:4263a77256ae 43 {NC , NC , 0}
bogdanm 20:4263a77256ae 44 };
bogdanm 20:4263a77256ae 45
bogdanm 20:4263a77256ae 46 #define UART_NUM 4
bogdanm 20:4263a77256ae 47
bogdanm 20:4263a77256ae 48 static uint32_t serial_irq_ids[UART_NUM] = {0};
bogdanm 20:4263a77256ae 49 static uart_irq_handler irq_handler;
bogdanm 20:4263a77256ae 50
bogdanm 20:4263a77256ae 51 int stdio_uart_inited = 0;
bogdanm 20:4263a77256ae 52 serial_t stdio_uart;
bogdanm 20:4263a77256ae 53
bogdanm 20:4263a77256ae 54 void serial_init(serial_t *obj, PinName tx, PinName rx) {
bogdanm 20:4263a77256ae 55 int is_stdio_uart = 0;
bogdanm 20:4263a77256ae 56
bogdanm 20:4263a77256ae 57 // determine the UART to use
bogdanm 20:4263a77256ae 58 UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
bogdanm 20:4263a77256ae 59 UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
bogdanm 20:4263a77256ae 60 UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
bogdanm 20:4263a77256ae 61 if ((int)uart == NC) {
bogdanm 20:4263a77256ae 62 error("Serial pinout mapping failed");
bogdanm 20:4263a77256ae 63 }
bogdanm 20:4263a77256ae 64
bogdanm 20:4263a77256ae 65 obj->uart = (LPC_USART_T *)uart;
bogdanm 20:4263a77256ae 66
bogdanm 20:4263a77256ae 67 // enable fifos and default rx trigger level
bogdanm 20:4263a77256ae 68 obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled
bogdanm 20:4263a77256ae 69 | 0 << 1 // Rx Fifo Reset
bogdanm 20:4263a77256ae 70 | 0 << 2 // Tx Fifo Reset
bogdanm 20:4263a77256ae 71 | 0 << 6; // Rx irq trigger level - 0 = 1 char, 1 = 4 chars, 2 = 8 chars, 3 = 14 chars
bogdanm 20:4263a77256ae 72
bogdanm 20:4263a77256ae 73 // disable irqs
bogdanm 20:4263a77256ae 74 obj->uart->IER = 0 << 0 // Rx Data available irq enable
bogdanm 20:4263a77256ae 75 | 0 << 1 // Tx Fifo empty irq enable
bogdanm 20:4263a77256ae 76 | 0 << 2; // Rx Line Status irq enable
bogdanm 20:4263a77256ae 77
bogdanm 20:4263a77256ae 78 // set default baud rate and format
bogdanm 20:4263a77256ae 79 serial_baud (obj, 9600);
bogdanm 20:4263a77256ae 80 serial_format(obj, 8, ParityNone, 1);
bogdanm 20:4263a77256ae 81
bogdanm 20:4263a77256ae 82 // pinout the chosen uart
bogdanm 20:4263a77256ae 83 pinmap_pinout(tx, PinMap_UART_TX);
bogdanm 20:4263a77256ae 84 pinmap_pinout(rx, PinMap_UART_RX);
bogdanm 20:4263a77256ae 85
bogdanm 20:4263a77256ae 86 // set rx/tx pins in PullUp mode
bogdanm 20:4263a77256ae 87 pin_mode(tx, PullUp);
bogdanm 20:4263a77256ae 88 pin_mode(rx, PullUp);
bogdanm 20:4263a77256ae 89
bogdanm 20:4263a77256ae 90 switch (uart) {
bogdanm 20:4263a77256ae 91 case UART_0: obj->index = 0; break;
bogdanm 20:4263a77256ae 92 case UART_1: obj->index = 1; break;
bogdanm 20:4263a77256ae 93 case UART_2: obj->index = 2; break;
bogdanm 20:4263a77256ae 94 #if (UART_NUM > 3)
bogdanm 20:4263a77256ae 95 case UART_3: obj->index = 3; break;
bogdanm 20:4263a77256ae 96 #endif
bogdanm 20:4263a77256ae 97 #if (UART_NUM > 4)
bogdanm 20:4263a77256ae 98 case UART_4: obj->index = 4; break;
bogdanm 20:4263a77256ae 99 #endif
bogdanm 20:4263a77256ae 100 }
bogdanm 20:4263a77256ae 101
bogdanm 20:4263a77256ae 102 is_stdio_uart = (uart == STDIO_UART) ? (1) : (0);
bogdanm 20:4263a77256ae 103
bogdanm 20:4263a77256ae 104 if (is_stdio_uart) {
bogdanm 20:4263a77256ae 105 stdio_uart_inited = 1;
bogdanm 20:4263a77256ae 106 memcpy(&stdio_uart, obj, sizeof(serial_t));
bogdanm 20:4263a77256ae 107 }
bogdanm 20:4263a77256ae 108 }
bogdanm 20:4263a77256ae 109
bogdanm 20:4263a77256ae 110 void serial_free(serial_t *obj) {
bogdanm 20:4263a77256ae 111 serial_irq_ids[obj->index] = 0;
bogdanm 20:4263a77256ae 112 }
bogdanm 20:4263a77256ae 113
bogdanm 20:4263a77256ae 114 // serial_baud
bogdanm 20:4263a77256ae 115 // set the baud rate, taking in to account the current SystemFrequency
bogdanm 20:4263a77256ae 116 void serial_baud(serial_t *obj, int baudrate) {
bogdanm 20:4263a77256ae 117 uint32_t PCLK = SystemCoreClock;
bogdanm 20:4263a77256ae 118
bogdanm 20:4263a77256ae 119 // First we check to see if the basic divide with no DivAddVal/MulVal
bogdanm 20:4263a77256ae 120 // ratio gives us an integer result. If it does, we set DivAddVal = 0,
bogdanm 20:4263a77256ae 121 // MulVal = 1. Otherwise, we search the valid ratio value range to find
bogdanm 20:4263a77256ae 122 // the closest match. This could be more elegant, using search methods
bogdanm 20:4263a77256ae 123 // and/or lookup tables, but the brute force method is not that much
bogdanm 20:4263a77256ae 124 // slower, and is more maintainable.
bogdanm 20:4263a77256ae 125 uint16_t DL = PCLK / (16 * baudrate);
bogdanm 20:4263a77256ae 126
bogdanm 20:4263a77256ae 127 uint8_t DivAddVal = 0;
bogdanm 20:4263a77256ae 128 uint8_t MulVal = 1;
bogdanm 20:4263a77256ae 129 int hit = 0;
bogdanm 20:4263a77256ae 130 uint16_t dlv;
bogdanm 20:4263a77256ae 131 uint8_t mv, dav;
bogdanm 20:4263a77256ae 132 if ((PCLK % (16 * baudrate)) != 0) { // Checking for zero remainder
bogdanm 20:4263a77256ae 133 float err_best = (float) baudrate;
bogdanm 20:4263a77256ae 134 uint16_t dlmax = DL;
bogdanm 20:4263a77256ae 135 for ( dlv = (dlmax/2); (dlv <= dlmax) && !hit; dlv++) {
bogdanm 20:4263a77256ae 136 for ( mv = 1; mv <= 15; mv++) {
bogdanm 20:4263a77256ae 137 for ( dav = 1; dav < mv; dav++) {
bogdanm 20:4263a77256ae 138 float ratio = 1.0f + ((float) dav / (float) mv);
bogdanm 20:4263a77256ae 139 float calcbaud = (float)PCLK / (16.0f * (float) dlv * ratio);
bogdanm 20:4263a77256ae 140 float err = fabs(((float) baudrate - calcbaud) / (float) baudrate);
bogdanm 20:4263a77256ae 141 if (err < err_best) {
bogdanm 20:4263a77256ae 142 DL = dlv;
bogdanm 20:4263a77256ae 143 DivAddVal = dav;
bogdanm 20:4263a77256ae 144 MulVal = mv;
bogdanm 20:4263a77256ae 145 err_best = err;
bogdanm 20:4263a77256ae 146 if (err < 0.001f) {
bogdanm 20:4263a77256ae 147 hit = 1;
bogdanm 20:4263a77256ae 148 }
bogdanm 20:4263a77256ae 149 }
bogdanm 20:4263a77256ae 150 }
bogdanm 20:4263a77256ae 151 }
bogdanm 20:4263a77256ae 152 }
bogdanm 20:4263a77256ae 153 }
bogdanm 20:4263a77256ae 154
bogdanm 20:4263a77256ae 155 // set LCR[DLAB] to enable writing to divider registers
bogdanm 20:4263a77256ae 156 obj->uart->LCR |= (1 << 7);
bogdanm 20:4263a77256ae 157
bogdanm 20:4263a77256ae 158 // set divider values
bogdanm 20:4263a77256ae 159 obj->uart->DLM = (DL >> 8) & 0xFF;
bogdanm 20:4263a77256ae 160 obj->uart->DLL = (DL >> 0) & 0xFF;
bogdanm 20:4263a77256ae 161 obj->uart->FDR = (uint32_t) DivAddVal << 0
bogdanm 20:4263a77256ae 162 | (uint32_t) MulVal << 4;
bogdanm 20:4263a77256ae 163
bogdanm 20:4263a77256ae 164 // clear LCR[DLAB]
bogdanm 20:4263a77256ae 165 obj->uart->LCR &= ~(1 << 7);
bogdanm 20:4263a77256ae 166 }
bogdanm 20:4263a77256ae 167
bogdanm 20:4263a77256ae 168 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
bogdanm 20:4263a77256ae 169 // 0: 1 stop bits, 1: 2 stop bits
bogdanm 20:4263a77256ae 170 if (stop_bits != 1 && stop_bits != 2) {
bogdanm 20:4263a77256ae 171 error("Invalid stop bits specified");
bogdanm 20:4263a77256ae 172 }
bogdanm 20:4263a77256ae 173 stop_bits -= 1;
bogdanm 20:4263a77256ae 174
bogdanm 20:4263a77256ae 175 // 0: 5 data bits ... 3: 8 data bits
bogdanm 20:4263a77256ae 176 if (data_bits < 5 || data_bits > 8) {
bogdanm 20:4263a77256ae 177 error("Invalid number of bits (%d) in serial format, should be 5..8", data_bits);
bogdanm 20:4263a77256ae 178 }
bogdanm 20:4263a77256ae 179 data_bits -= 5;
bogdanm 20:4263a77256ae 180
bogdanm 20:4263a77256ae 181 int parity_enable, parity_select;
bogdanm 20:4263a77256ae 182 switch (parity) {
bogdanm 20:4263a77256ae 183 case ParityNone: parity_enable = 0; parity_select = 0; break;
bogdanm 20:4263a77256ae 184 case ParityOdd : parity_enable = 1; parity_select = 0; break;
bogdanm 20:4263a77256ae 185 case ParityEven: parity_enable = 1; parity_select = 1; break;
bogdanm 20:4263a77256ae 186 case ParityForced1: parity_enable = 1; parity_select = 2; break;
bogdanm 20:4263a77256ae 187 case ParityForced0: parity_enable = 1; parity_select = 3; break;
bogdanm 20:4263a77256ae 188 default:
bogdanm 20:4263a77256ae 189 error("Invalid serial parity setting");
bogdanm 20:4263a77256ae 190 return;
bogdanm 20:4263a77256ae 191 }
bogdanm 20:4263a77256ae 192
bogdanm 20:4263a77256ae 193 obj->uart->LCR = data_bits << 0
bogdanm 20:4263a77256ae 194 | stop_bits << 2
bogdanm 20:4263a77256ae 195 | parity_enable << 3
bogdanm 20:4263a77256ae 196 | parity_select << 4;
bogdanm 20:4263a77256ae 197 }
bogdanm 20:4263a77256ae 198
bogdanm 20:4263a77256ae 199 /******************************************************************************
bogdanm 20:4263a77256ae 200 * INTERRUPTS HANDLING
bogdanm 20:4263a77256ae 201 ******************************************************************************/
bogdanm 20:4263a77256ae 202 static inline void uart_irq(uint32_t iir, uint32_t index) {
bogdanm 20:4263a77256ae 203 // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling
bogdanm 20:4263a77256ae 204 SerialIrq irq_type;
bogdanm 20:4263a77256ae 205 switch (iir) {
bogdanm 20:4263a77256ae 206 case 1: irq_type = TxIrq; break;
bogdanm 20:4263a77256ae 207 case 2: irq_type = RxIrq; break;
bogdanm 20:4263a77256ae 208 default: return;
bogdanm 20:4263a77256ae 209 }
bogdanm 20:4263a77256ae 210
bogdanm 20:4263a77256ae 211 if (serial_irq_ids[index] != 0)
bogdanm 20:4263a77256ae 212 irq_handler(serial_irq_ids[index], irq_type);
bogdanm 20:4263a77256ae 213 }
bogdanm 20:4263a77256ae 214
bogdanm 20:4263a77256ae 215 void uart0_irq() {uart_irq((LPC_USART0->IIR >> 1) & 0x7, 0);}
bogdanm 20:4263a77256ae 216 void uart1_irq() {uart_irq((LPC_UART1->IIR >> 1) & 0x7, 1);}
bogdanm 20:4263a77256ae 217 void uart2_irq() {uart_irq((LPC_USART2->IIR >> 1) & 0x7, 2);}
bogdanm 20:4263a77256ae 218 void uart3_irq() {uart_irq((LPC_USART3->IIR >> 1) & 0x7, 3);}
bogdanm 20:4263a77256ae 219
bogdanm 20:4263a77256ae 220 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
bogdanm 20:4263a77256ae 221 irq_handler = handler;
bogdanm 20:4263a77256ae 222 serial_irq_ids[obj->index] = id;
bogdanm 20:4263a77256ae 223 }
bogdanm 20:4263a77256ae 224
bogdanm 20:4263a77256ae 225 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
bogdanm 20:4263a77256ae 226 IRQn_Type irq_n = (IRQn_Type)0;
bogdanm 20:4263a77256ae 227 uint32_t vector = 0;
bogdanm 20:4263a77256ae 228 switch ((int)obj->uart) {
bogdanm 20:4263a77256ae 229 case UART_0: irq_n=USART0_IRQn; vector = (uint32_t)&uart0_irq; break;
bogdanm 20:4263a77256ae 230 case UART_1: irq_n=UART1_IRQn; vector = (uint32_t)&uart1_irq; break;
bogdanm 20:4263a77256ae 231 case UART_2: irq_n=USART2_IRQn; vector = (uint32_t)&uart2_irq; break;
bogdanm 20:4263a77256ae 232 case UART_3: irq_n=USART3_IRQn; vector = (uint32_t)&uart3_irq; break;
bogdanm 20:4263a77256ae 233 }
bogdanm 20:4263a77256ae 234
bogdanm 20:4263a77256ae 235 if (enable) {
bogdanm 20:4263a77256ae 236 obj->uart->IER |= 1 << irq;
bogdanm 20:4263a77256ae 237 NVIC_SetVector(irq_n, vector);
bogdanm 20:4263a77256ae 238 NVIC_EnableIRQ(irq_n);
bogdanm 20:4263a77256ae 239 } else { // disable
bogdanm 20:4263a77256ae 240 int all_disabled = 0;
bogdanm 20:4263a77256ae 241 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
bogdanm 20:4263a77256ae 242 obj->uart->IER &= ~(1 << irq);
bogdanm 20:4263a77256ae 243 all_disabled = (obj->uart->IER & (1 << other_irq)) == 0;
bogdanm 20:4263a77256ae 244 if (all_disabled)
bogdanm 20:4263a77256ae 245 NVIC_DisableIRQ(irq_n);
bogdanm 20:4263a77256ae 246 }
bogdanm 20:4263a77256ae 247 }
bogdanm 20:4263a77256ae 248
bogdanm 20:4263a77256ae 249 /******************************************************************************
bogdanm 20:4263a77256ae 250 * READ/WRITE
bogdanm 20:4263a77256ae 251 ******************************************************************************/
bogdanm 20:4263a77256ae 252 int serial_getc(serial_t *obj) {
bogdanm 20:4263a77256ae 253 while (!serial_readable(obj));
bogdanm 20:4263a77256ae 254 return obj->uart->RBR;
bogdanm 20:4263a77256ae 255 }
bogdanm 20:4263a77256ae 256
bogdanm 20:4263a77256ae 257 void serial_putc(serial_t *obj, int c) {
bogdanm 20:4263a77256ae 258 while (!serial_writable(obj));
bogdanm 20:4263a77256ae 259 obj->uart->THR = c;
bogdanm 20:4263a77256ae 260 }
bogdanm 20:4263a77256ae 261
bogdanm 20:4263a77256ae 262 int serial_readable(serial_t *obj) {
bogdanm 20:4263a77256ae 263 return obj->uart->LSR & 0x01;
bogdanm 20:4263a77256ae 264 }
bogdanm 20:4263a77256ae 265
bogdanm 20:4263a77256ae 266 int serial_writable(serial_t *obj) {
bogdanm 20:4263a77256ae 267 return obj->uart->LSR & 0x20;
bogdanm 20:4263a77256ae 268 }
bogdanm 20:4263a77256ae 269
bogdanm 20:4263a77256ae 270 void serial_clear(serial_t *obj) {
bogdanm 20:4263a77256ae 271 obj->uart->FCR = 1 << 1 // rx FIFO reset
bogdanm 20:4263a77256ae 272 | 1 << 2 // tx FIFO reset
bogdanm 20:4263a77256ae 273 | 0 << 6; // interrupt depth
bogdanm 20:4263a77256ae 274 }
bogdanm 20:4263a77256ae 275
bogdanm 20:4263a77256ae 276 void serial_pinout_tx(PinName tx) {
bogdanm 20:4263a77256ae 277 pinmap_pinout(tx, PinMap_UART_TX);
bogdanm 20:4263a77256ae 278 }
bogdanm 20:4263a77256ae 279
bogdanm 20:4263a77256ae 280 void serial_break_set(serial_t *obj) {
bogdanm 20:4263a77256ae 281 obj->uart->LCR |= (1 << 6);
bogdanm 20:4263a77256ae 282 }
bogdanm 20:4263a77256ae 283
bogdanm 20:4263a77256ae 284 void serial_break_clear(serial_t *obj) {
bogdanm 20:4263a77256ae 285 obj->uart->LCR &= ~(1 << 6);
bogdanm 20:4263a77256ae 286 }
bogdanm 20:4263a77256ae 287