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mbed SDK library sources

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Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_NXP/TARGET_LPC81X/serial_api.c@46:bebbbd80dd87, 2013-11-11 (annotated)

Committer:
mbed_official
Date:
Mon Nov 11 13:30:09 2013 +0000
Revision:
46:bebbbd80dd87
Child:
64:7b352733b00a
Synchronized with git revision b2733e9b9af906952b295cd6abcf916bf79780ab

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 46:bebbbd80dd87 1 /* mbed Microcontroller Library
mbed_official 46:bebbbd80dd87 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 46:bebbbd80dd87 3 *
mbed_official 46:bebbbd80dd87 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 46:bebbbd80dd87 5 * you may not use this file except in compliance with the License.
mbed_official 46:bebbbd80dd87 6 * You may obtain a copy of the License at
mbed_official 46:bebbbd80dd87 7 *
mbed_official 46:bebbbd80dd87 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 46:bebbbd80dd87 9 *
mbed_official 46:bebbbd80dd87 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 46:bebbbd80dd87 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 46:bebbbd80dd87 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 46:bebbbd80dd87 13 * See the License for the specific language governing permissions and
mbed_official 46:bebbbd80dd87 14 * limitations under the License.
mbed_official 46:bebbbd80dd87 15 */
mbed_official 46:bebbbd80dd87 16 // math.h required for floating point operations for baud rate calculation
mbed_official 46:bebbbd80dd87 17 #include <math.h>
mbed_official 46:bebbbd80dd87 18 #include <string.h>
mbed_official 46:bebbbd80dd87 19
mbed_official 46:bebbbd80dd87 20 #include "serial_api.h"
mbed_official 46:bebbbd80dd87 21 #include "cmsis.h"
mbed_official 46:bebbbd80dd87 22 #include "pinmap.h"
mbed_official 46:bebbbd80dd87 23 #include "error.h"
mbed_official 46:bebbbd80dd87 24
mbed_official 46:bebbbd80dd87 25 /******************************************************************************
mbed_official 46:bebbbd80dd87 26 * INITIALIZATION
mbed_official 46:bebbbd80dd87 27 ******************************************************************************/
mbed_official 46:bebbbd80dd87 28 #define UART_NUM 3
mbed_official 46:bebbbd80dd87 29
mbed_official 46:bebbbd80dd87 30 static const SWM_Map SWM_UART_TX[] = {
mbed_official 46:bebbbd80dd87 31 {0, 0},
mbed_official 46:bebbbd80dd87 32 {1, 8},
mbed_official 46:bebbbd80dd87 33 {2, 16},
mbed_official 46:bebbbd80dd87 34 };
mbed_official 46:bebbbd80dd87 35
mbed_official 46:bebbbd80dd87 36 static const SWM_Map SWM_UART_RX[] = {
mbed_official 46:bebbbd80dd87 37 {0, 8},
mbed_official 46:bebbbd80dd87 38 {1, 16},
mbed_official 46:bebbbd80dd87 39 {2, 24},
mbed_official 46:bebbbd80dd87 40 };
mbed_official 46:bebbbd80dd87 41
mbed_official 46:bebbbd80dd87 42 // bit flags for used UARTs
mbed_official 46:bebbbd80dd87 43 static unsigned char uart_used = 0;
mbed_official 46:bebbbd80dd87 44 static int get_available_uart(void) {
mbed_official 46:bebbbd80dd87 45 int i;
mbed_official 46:bebbbd80dd87 46 for (i=0; i<3; i++) {
mbed_official 46:bebbbd80dd87 47 if ((uart_used & (1 << i)) == 0)
mbed_official 46:bebbbd80dd87 48 return i;
mbed_official 46:bebbbd80dd87 49 }
mbed_official 46:bebbbd80dd87 50 return -1;
mbed_official 46:bebbbd80dd87 51 }
mbed_official 46:bebbbd80dd87 52
mbed_official 46:bebbbd80dd87 53 #define UART_EN (0x01<<0)
mbed_official 46:bebbbd80dd87 54
mbed_official 46:bebbbd80dd87 55 #define CTS_DELTA (0x01<<5)
mbed_official 46:bebbbd80dd87 56 #define RXBRK (0x01<<10)
mbed_official 46:bebbbd80dd87 57 #define DELTA_RXBRK (0x01<<11)
mbed_official 46:bebbbd80dd87 58
mbed_official 46:bebbbd80dd87 59 #define RXRDY (0x01<<0)
mbed_official 46:bebbbd80dd87 60 #define TXRDY (0x01<<2)
mbed_official 46:bebbbd80dd87 61
mbed_official 46:bebbbd80dd87 62 #define TXBRKEN (0x01<<1)
mbed_official 46:bebbbd80dd87 63
mbed_official 46:bebbbd80dd87 64 static uint32_t UARTSysClk;
mbed_official 46:bebbbd80dd87 65
mbed_official 46:bebbbd80dd87 66 static uint32_t serial_irq_ids[UART_NUM] = {0};
mbed_official 46:bebbbd80dd87 67 static uart_irq_handler irq_handler;
mbed_official 46:bebbbd80dd87 68
mbed_official 46:bebbbd80dd87 69 int stdio_uart_inited = 0;
mbed_official 46:bebbbd80dd87 70 serial_t stdio_uart;
mbed_official 46:bebbbd80dd87 71
mbed_official 46:bebbbd80dd87 72 void serial_init(serial_t *obj, PinName tx, PinName rx) {
mbed_official 46:bebbbd80dd87 73 int is_stdio_uart = 0;
mbed_official 46:bebbbd80dd87 74
mbed_official 46:bebbbd80dd87 75 int uart_n = get_available_uart();
mbed_official 46:bebbbd80dd87 76 if (uart_n == -1) {
mbed_official 46:bebbbd80dd87 77 error("No available UART");
mbed_official 46:bebbbd80dd87 78 }
mbed_official 46:bebbbd80dd87 79 obj->index = uart_n;
mbed_official 46:bebbbd80dd87 80 obj->uart = (LPC_USART_TypeDef *)(LPC_USART0_BASE + (0x4000 * uart_n));
mbed_official 46:bebbbd80dd87 81 uart_used |= (1 << uart_n);
mbed_official 46:bebbbd80dd87 82
mbed_official 46:bebbbd80dd87 83 const SWM_Map *swm;
mbed_official 46:bebbbd80dd87 84 uint32_t regVal;
mbed_official 46:bebbbd80dd87 85
mbed_official 46:bebbbd80dd87 86 swm = &SWM_UART_TX[uart_n];
mbed_official 46:bebbbd80dd87 87 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 46:bebbbd80dd87 88 LPC_SWM->PINASSIGN[swm->n] = regVal | (tx << swm->offset);
mbed_official 46:bebbbd80dd87 89
mbed_official 46:bebbbd80dd87 90 swm = &SWM_UART_RX[uart_n];
mbed_official 46:bebbbd80dd87 91 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 46:bebbbd80dd87 92 LPC_SWM->PINASSIGN[swm->n] = regVal | (rx << swm->offset);
mbed_official 46:bebbbd80dd87 93
mbed_official 46:bebbbd80dd87 94 /* uart clock divided by 1 */
mbed_official 46:bebbbd80dd87 95 LPC_SYSCON->UARTCLKDIV = 1;
mbed_official 46:bebbbd80dd87 96
mbed_official 46:bebbbd80dd87 97 /* disable uart interrupts */
mbed_official 46:bebbbd80dd87 98 NVIC_DisableIRQ((IRQn_Type)(UART0_IRQn + uart_n));
mbed_official 46:bebbbd80dd87 99
mbed_official 46:bebbbd80dd87 100 /* Enable UART clock */
mbed_official 46:bebbbd80dd87 101 LPC_SYSCON->SYSAHBCLKCTRL |= (1 << (14 + uart_n));
mbed_official 46:bebbbd80dd87 102
mbed_official 46:bebbbd80dd87 103 /* Peripheral reset control to UART, a "1" bring it out of reset. */
mbed_official 46:bebbbd80dd87 104 LPC_SYSCON->PRESETCTRL &= ~(0x1 << (3 + uart_n));
mbed_official 46:bebbbd80dd87 105 LPC_SYSCON->PRESETCTRL |= (0x1 << (3 + uart_n));
mbed_official 46:bebbbd80dd87 106
mbed_official 46:bebbbd80dd87 107 UARTSysClk = SystemCoreClock / LPC_SYSCON->UARTCLKDIV;
mbed_official 46:bebbbd80dd87 108
mbed_official 46:bebbbd80dd87 109 // set default baud rate and format
mbed_official 46:bebbbd80dd87 110 serial_baud (obj, 9600);
mbed_official 46:bebbbd80dd87 111 serial_format(obj, 8, ParityNone, 1);
mbed_official 46:bebbbd80dd87 112
mbed_official 46:bebbbd80dd87 113 /* Clear all status bits. */
mbed_official 46:bebbbd80dd87 114 obj->uart->STAT = CTS_DELTA | DELTA_RXBRK;
mbed_official 46:bebbbd80dd87 115
mbed_official 46:bebbbd80dd87 116 /* enable uart interrupts */
mbed_official 46:bebbbd80dd87 117 NVIC_EnableIRQ((IRQn_Type)(UART0_IRQn + uart_n));
mbed_official 46:bebbbd80dd87 118
mbed_official 46:bebbbd80dd87 119 /* Enable UART interrupt */
mbed_official 46:bebbbd80dd87 120 // obj->uart->INTENSET = RXRDY | TXRDY | DELTA_RXBRK;
mbed_official 46:bebbbd80dd87 121
mbed_official 46:bebbbd80dd87 122 /* Enable UART */
mbed_official 46:bebbbd80dd87 123 obj->uart->CFG |= UART_EN;
mbed_official 46:bebbbd80dd87 124
mbed_official 46:bebbbd80dd87 125 is_stdio_uart = ((tx == USBTX) && (rx == USBRX));
mbed_official 46:bebbbd80dd87 126
mbed_official 46:bebbbd80dd87 127 if (is_stdio_uart) {
mbed_official 46:bebbbd80dd87 128 stdio_uart_inited = 1;
mbed_official 46:bebbbd80dd87 129 memcpy(&stdio_uart, obj, sizeof(serial_t));
mbed_official 46:bebbbd80dd87 130 }
mbed_official 46:bebbbd80dd87 131 }
mbed_official 46:bebbbd80dd87 132
mbed_official 46:bebbbd80dd87 133 void serial_free(serial_t *obj) {
mbed_official 46:bebbbd80dd87 134 uart_used &= ~(1 << obj->index);
mbed_official 46:bebbbd80dd87 135 serial_irq_ids[obj->index] = 0;
mbed_official 46:bebbbd80dd87 136 }
mbed_official 46:bebbbd80dd87 137
mbed_official 46:bebbbd80dd87 138 // serial_baud
mbed_official 46:bebbbd80dd87 139 // set the baud rate, taking in to account the current SystemFrequency
mbed_official 46:bebbbd80dd87 140 void serial_baud(serial_t *obj, int baudrate) {
mbed_official 46:bebbbd80dd87 141 /* Integer divider:
mbed_official 46:bebbbd80dd87 142 BRG = UARTSysClk/(Baudrate * 16) - 1
mbed_official 46:bebbbd80dd87 143
mbed_official 46:bebbbd80dd87 144 Frational divider:
mbed_official 46:bebbbd80dd87 145 FRG = ((UARTSysClk / (Baudrate * 16 * (BRG + 1))) - 1)
mbed_official 46:bebbbd80dd87 146
mbed_official 46:bebbbd80dd87 147 where
mbed_official 46:bebbbd80dd87 148 FRG = (LPC_SYSCON->UARTFRDADD + 1) / (LPC_SYSCON->UARTFRDSUB + 1)
mbed_official 46:bebbbd80dd87 149
mbed_official 46:bebbbd80dd87 150 (1) The easiest way is set SUB value to 256, -1 encoded, thus SUB
mbed_official 46:bebbbd80dd87 151 register is 0xFF.
mbed_official 46:bebbbd80dd87 152 (2) In ADD register value, depending on the value of UartSysClk,
mbed_official 46:bebbbd80dd87 153 baudrate, BRG register value, and SUB register value, be careful
mbed_official 46:bebbbd80dd87 154 about the order of multiplier and divider and make sure any
mbed_official 46:bebbbd80dd87 155 multiplier doesn't exceed 32-bit boundary and any divider doesn't get
mbed_official 46:bebbbd80dd87 156 down below one(integer 0).
mbed_official 46:bebbbd80dd87 157 (3) ADD should be always less than SUB.
mbed_official 46:bebbbd80dd87 158 */
mbed_official 46:bebbbd80dd87 159 obj->uart->BRG = UARTSysClk / 16 / baudrate - 1;
mbed_official 46:bebbbd80dd87 160
mbed_official 46:bebbbd80dd87 161 LPC_SYSCON->UARTFRGDIV = 0xFF;
mbed_official 46:bebbbd80dd87 162 LPC_SYSCON->UARTFRGMULT = ( ((UARTSysClk / 16) * (LPC_SYSCON->UARTFRGDIV + 1)) /
mbed_official 46:bebbbd80dd87 163 (baudrate * (obj->uart->BRG + 1))
mbed_official 46:bebbbd80dd87 164 ) - (LPC_SYSCON->UARTFRGDIV + 1);
mbed_official 46:bebbbd80dd87 165
mbed_official 46:bebbbd80dd87 166 }
mbed_official 46:bebbbd80dd87 167
mbed_official 46:bebbbd80dd87 168 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
mbed_official 46:bebbbd80dd87 169 // 0: 1 stop bits, 1: 2 stop bits
mbed_official 46:bebbbd80dd87 170 if (stop_bits != 1 && stop_bits != 2) {
mbed_official 46:bebbbd80dd87 171 error("Invalid stop bits specified");
mbed_official 46:bebbbd80dd87 172 }
mbed_official 46:bebbbd80dd87 173 stop_bits -= 1;
mbed_official 46:bebbbd80dd87 174
mbed_official 46:bebbbd80dd87 175 // 0: 7 data bits ... 2: 9 data bits
mbed_official 46:bebbbd80dd87 176 if (data_bits < 7 || data_bits > 9) {
mbed_official 46:bebbbd80dd87 177 error("Invalid number of bits (%d) in serial format, should be 7..9", data_bits);
mbed_official 46:bebbbd80dd87 178 }
mbed_official 46:bebbbd80dd87 179 data_bits -= 7;
mbed_official 46:bebbbd80dd87 180
mbed_official 46:bebbbd80dd87 181 int paritysel;
mbed_official 46:bebbbd80dd87 182 switch (parity) {
mbed_official 46:bebbbd80dd87 183 case ParityNone: paritysel = 0; break;
mbed_official 46:bebbbd80dd87 184 case ParityEven: paritysel = 2; break;
mbed_official 46:bebbbd80dd87 185 case ParityOdd : paritysel = 3; break;
mbed_official 46:bebbbd80dd87 186 default:
mbed_official 46:bebbbd80dd87 187 error("Invalid serial parity setting");
mbed_official 46:bebbbd80dd87 188 return;
mbed_official 46:bebbbd80dd87 189 }
mbed_official 46:bebbbd80dd87 190
mbed_official 46:bebbbd80dd87 191 obj->uart->CFG = (data_bits << 2)
mbed_official 46:bebbbd80dd87 192 | (paritysel << 4)
mbed_official 46:bebbbd80dd87 193 | (stop_bits << 6);
mbed_official 46:bebbbd80dd87 194 }
mbed_official 46:bebbbd80dd87 195
mbed_official 46:bebbbd80dd87 196 /******************************************************************************
mbed_official 46:bebbbd80dd87 197 * INTERRUPTS HANDLING
mbed_official 46:bebbbd80dd87 198 ******************************************************************************/
mbed_official 46:bebbbd80dd87 199 static inline void uart_irq(uint32_t iir, uint32_t index) {
mbed_official 46:bebbbd80dd87 200 // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling
mbed_official 46:bebbbd80dd87 201 SerialIrq irq_type;
mbed_official 46:bebbbd80dd87 202 switch (iir) {
mbed_official 46:bebbbd80dd87 203 case 1: irq_type = TxIrq; break;
mbed_official 46:bebbbd80dd87 204 case 2: irq_type = RxIrq; break;
mbed_official 46:bebbbd80dd87 205 default: return;
mbed_official 46:bebbbd80dd87 206 }
mbed_official 46:bebbbd80dd87 207
mbed_official 46:bebbbd80dd87 208 if (serial_irq_ids[index] != 0)
mbed_official 46:bebbbd80dd87 209 irq_handler(serial_irq_ids[index], irq_type);
mbed_official 46:bebbbd80dd87 210 }
mbed_official 46:bebbbd80dd87 211
mbed_official 46:bebbbd80dd87 212 void uart0_irq() {uart_irq((LPC_USART0->STAT & (1 << 2)) ? 2 : 1, 0);}
mbed_official 46:bebbbd80dd87 213 void uart1_irq() {uart_irq((LPC_USART1->STAT & (1 << 2)) ? 2 : 1, 1);}
mbed_official 46:bebbbd80dd87 214 void uart2_irq() {uart_irq((LPC_USART2->STAT & (1 << 2)) ? 2 : 1, 2);}
mbed_official 46:bebbbd80dd87 215
mbed_official 46:bebbbd80dd87 216 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
mbed_official 46:bebbbd80dd87 217 irq_handler = handler;
mbed_official 46:bebbbd80dd87 218 serial_irq_ids[obj->index] = id;
mbed_official 46:bebbbd80dd87 219 }
mbed_official 46:bebbbd80dd87 220
mbed_official 46:bebbbd80dd87 221 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
mbed_official 46:bebbbd80dd87 222 IRQn_Type irq_n = (IRQn_Type)0;
mbed_official 46:bebbbd80dd87 223 uint32_t vector = 0;
mbed_official 46:bebbbd80dd87 224 switch ((int)obj->uart) {
mbed_official 46:bebbbd80dd87 225 case LPC_USART0_BASE: irq_n=UART0_IRQn; vector = (uint32_t)&uart0_irq; break;
mbed_official 46:bebbbd80dd87 226 case LPC_USART1_BASE: irq_n=UART1_IRQn; vector = (uint32_t)&uart1_irq; break;
mbed_official 46:bebbbd80dd87 227 case LPC_USART2_BASE: irq_n=UART2_IRQn; vector = (uint32_t)&uart2_irq; break;
mbed_official 46:bebbbd80dd87 228 }
mbed_official 46:bebbbd80dd87 229
mbed_official 46:bebbbd80dd87 230 if (enable) {
mbed_official 46:bebbbd80dd87 231 obj->uart->INTENSET = (1 << ((irq == RxIrq) ? 0 : 2));
mbed_official 46:bebbbd80dd87 232 NVIC_SetVector(irq_n, vector);
mbed_official 46:bebbbd80dd87 233 NVIC_EnableIRQ(irq_n);
mbed_official 46:bebbbd80dd87 234 } else { // disable
mbed_official 46:bebbbd80dd87 235 int all_disabled = 0;
mbed_official 46:bebbbd80dd87 236 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
mbed_official 46:bebbbd80dd87 237 obj->uart->INTENSET &= ~(1 << ((irq == RxIrq) ? 0 : 2));
mbed_official 46:bebbbd80dd87 238 all_disabled = (obj->uart->INTENSET & (1 << ((other_irq == RxIrq) ? 0 : 2))) == 0;
mbed_official 46:bebbbd80dd87 239 if (all_disabled)
mbed_official 46:bebbbd80dd87 240 NVIC_DisableIRQ(irq_n);
mbed_official 46:bebbbd80dd87 241 }
mbed_official 46:bebbbd80dd87 242 }
mbed_official 46:bebbbd80dd87 243
mbed_official 46:bebbbd80dd87 244 /******************************************************************************
mbed_official 46:bebbbd80dd87 245 * READ/WRITE
mbed_official 46:bebbbd80dd87 246 ******************************************************************************/
mbed_official 46:bebbbd80dd87 247 int serial_getc(serial_t *obj) {
mbed_official 46:bebbbd80dd87 248 while (!serial_readable(obj));
mbed_official 46:bebbbd80dd87 249 return obj->uart->RXDATA;
mbed_official 46:bebbbd80dd87 250 }
mbed_official 46:bebbbd80dd87 251
mbed_official 46:bebbbd80dd87 252 void serial_putc(serial_t *obj, int c) {
mbed_official 46:bebbbd80dd87 253 while (!serial_writable(obj));
mbed_official 46:bebbbd80dd87 254 obj->uart->TXDATA = c;
mbed_official 46:bebbbd80dd87 255 }
mbed_official 46:bebbbd80dd87 256
mbed_official 46:bebbbd80dd87 257 int serial_readable(serial_t *obj) {
mbed_official 46:bebbbd80dd87 258 return obj->uart->STAT & RXRDY;
mbed_official 46:bebbbd80dd87 259 }
mbed_official 46:bebbbd80dd87 260
mbed_official 46:bebbbd80dd87 261 int serial_writable(serial_t *obj) {
mbed_official 46:bebbbd80dd87 262 return obj->uart->STAT & TXRDY;
mbed_official 46:bebbbd80dd87 263 }
mbed_official 46:bebbbd80dd87 264
mbed_official 46:bebbbd80dd87 265 void serial_clear(serial_t *obj) {
mbed_official 46:bebbbd80dd87 266 // [TODO]
mbed_official 46:bebbbd80dd87 267 }
mbed_official 46:bebbbd80dd87 268
mbed_official 46:bebbbd80dd87 269 void serial_pinout_tx(PinName tx) {
mbed_official 46:bebbbd80dd87 270
mbed_official 46:bebbbd80dd87 271 }
mbed_official 46:bebbbd80dd87 272
mbed_official 46:bebbbd80dd87 273 void serial_break_set(serial_t *obj) {
mbed_official 46:bebbbd80dd87 274 obj->uart->CTRL |= TXBRKEN;
mbed_official 46:bebbbd80dd87 275 }
mbed_official 46:bebbbd80dd87 276
mbed_official 46:bebbbd80dd87 277 void serial_break_clear(serial_t *obj) {
mbed_official 46:bebbbd80dd87 278 obj->uart->CTRL &= ~TXBRKEN;
mbed_official 46:bebbbd80dd87 279 }
mbed_official 46:bebbbd80dd87 280