Joris Aerts / mbed-src

mbed library sources

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targets/hal/TARGET_NXP/TARGET_LPC81X/serial_api.c@13:0645d8841f51, 2013-08-05 (annotated)

Committer:
bogdanm
Date:
Mon Aug 05 14:12:34 2013 +0300
Revision:
13:0645d8841f51
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 // math.h required for floating point operations for baud rate calculation
bogdanm 13:0645d8841f51 17 #include <math.h>
bogdanm 13:0645d8841f51 18 #include <string.h>
bogdanm 13:0645d8841f51 19
bogdanm 13:0645d8841f51 20 #include "serial_api.h"
bogdanm 13:0645d8841f51 21 #include "cmsis.h"
bogdanm 13:0645d8841f51 22 #include "pinmap.h"
bogdanm 13:0645d8841f51 23 #include "error.h"
bogdanm 13:0645d8841f51 24
bogdanm 13:0645d8841f51 25 /******************************************************************************
bogdanm 13:0645d8841f51 26 * INITIALIZATION
bogdanm 13:0645d8841f51 27 ******************************************************************************/
bogdanm 13:0645d8841f51 28 #define UART_NUM 3
bogdanm 13:0645d8841f51 29
bogdanm 13:0645d8841f51 30 static const SWM_Map SWM_UART_TX[] = {
bogdanm 13:0645d8841f51 31 {0, 0},
bogdanm 13:0645d8841f51 32 {1, 8},
bogdanm 13:0645d8841f51 33 {2, 16},
bogdanm 13:0645d8841f51 34 };
bogdanm 13:0645d8841f51 35
bogdanm 13:0645d8841f51 36 static const SWM_Map SWM_UART_RX[] = {
bogdanm 13:0645d8841f51 37 {0, 8},
bogdanm 13:0645d8841f51 38 {1, 16},
bogdanm 13:0645d8841f51 39 {2, 24},
bogdanm 13:0645d8841f51 40 };
bogdanm 13:0645d8841f51 41
bogdanm 13:0645d8841f51 42 // bit flags for used UARTs
bogdanm 13:0645d8841f51 43 static unsigned char uart_used = 0;
bogdanm 13:0645d8841f51 44 static int get_available_uart(void) {
bogdanm 13:0645d8841f51 45 int i;
bogdanm 13:0645d8841f51 46 for (i=0; i<3; i++) {
bogdanm 13:0645d8841f51 47 if ((uart_used & (1 << i)) == 0)
bogdanm 13:0645d8841f51 48 return i;
bogdanm 13:0645d8841f51 49 }
bogdanm 13:0645d8841f51 50 return -1;
bogdanm 13:0645d8841f51 51 }
bogdanm 13:0645d8841f51 52
bogdanm 13:0645d8841f51 53 #define UART_EN (0x01<<0)
bogdanm 13:0645d8841f51 54
bogdanm 13:0645d8841f51 55 #define CTS_DELTA (0x01<<5)
bogdanm 13:0645d8841f51 56 #define RXBRK (0x01<<10)
bogdanm 13:0645d8841f51 57 #define DELTA_RXBRK (0x01<<11)
bogdanm 13:0645d8841f51 58
bogdanm 13:0645d8841f51 59 #define RXRDY (0x01<<0)
bogdanm 13:0645d8841f51 60 #define TXRDY (0x01<<2)
bogdanm 13:0645d8841f51 61
bogdanm 13:0645d8841f51 62 #define TXBRKEN (0x01<<1)
bogdanm 13:0645d8841f51 63
bogdanm 13:0645d8841f51 64 static uint32_t UARTSysClk;
bogdanm 13:0645d8841f51 65
bogdanm 13:0645d8841f51 66 static uint32_t serial_irq_ids[UART_NUM] = {0};
bogdanm 13:0645d8841f51 67 static uart_irq_handler irq_handler;
bogdanm 13:0645d8841f51 68
bogdanm 13:0645d8841f51 69 int stdio_uart_inited = 0;
bogdanm 13:0645d8841f51 70 serial_t stdio_uart;
bogdanm 13:0645d8841f51 71
bogdanm 13:0645d8841f51 72 void serial_init(serial_t *obj, PinName tx, PinName rx) {
bogdanm 13:0645d8841f51 73 int is_stdio_uart = 0;
bogdanm 13:0645d8841f51 74
bogdanm 13:0645d8841f51 75 int uart_n = get_available_uart();
bogdanm 13:0645d8841f51 76 if (uart_n == -1) {
bogdanm 13:0645d8841f51 77 error("No available UART");
bogdanm 13:0645d8841f51 78 }
bogdanm 13:0645d8841f51 79 obj->index = uart_n;
bogdanm 13:0645d8841f51 80 obj->uart = (LPC_USART_TypeDef *)(LPC_USART0_BASE + (0x4000 * uart_n));
bogdanm 13:0645d8841f51 81 uart_used |= (1 << uart_n);
bogdanm 13:0645d8841f51 82
bogdanm 13:0645d8841f51 83 const SWM_Map *swm;
bogdanm 13:0645d8841f51 84 uint32_t regVal;
bogdanm 13:0645d8841f51 85
bogdanm 13:0645d8841f51 86 swm = &SWM_UART_TX[uart_n];
bogdanm 13:0645d8841f51 87 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
bogdanm 13:0645d8841f51 88 LPC_SWM->PINASSIGN[swm->n] = regVal | (tx << swm->offset);
bogdanm 13:0645d8841f51 89
bogdanm 13:0645d8841f51 90 swm = &SWM_UART_RX[uart_n];
bogdanm 13:0645d8841f51 91 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
bogdanm 13:0645d8841f51 92 LPC_SWM->PINASSIGN[swm->n] = regVal | (rx << swm->offset);
bogdanm 13:0645d8841f51 93
bogdanm 13:0645d8841f51 94 /* uart clock divided by 1 */
bogdanm 13:0645d8841f51 95 LPC_SYSCON->UARTCLKDIV = 1;
bogdanm 13:0645d8841f51 96
bogdanm 13:0645d8841f51 97 /* disable uart interrupts */
bogdanm 13:0645d8841f51 98 NVIC_DisableIRQ((IRQn_Type)(UART0_IRQn + uart_n));
bogdanm 13:0645d8841f51 99
bogdanm 13:0645d8841f51 100 /* Enable UART clock */
bogdanm 13:0645d8841f51 101 LPC_SYSCON->SYSAHBCLKCTRL |= (1 << (14 + uart_n));
bogdanm 13:0645d8841f51 102
bogdanm 13:0645d8841f51 103 /* Peripheral reset control to UART, a "1" bring it out of reset. */
bogdanm 13:0645d8841f51 104 LPC_SYSCON->PRESETCTRL &= ~(0x1 << (3 + uart_n));
bogdanm 13:0645d8841f51 105 LPC_SYSCON->PRESETCTRL |= (0x1 << (3 + uart_n));
bogdanm 13:0645d8841f51 106
bogdanm 13:0645d8841f51 107 UARTSysClk = SystemCoreClock / LPC_SYSCON->UARTCLKDIV;
bogdanm 13:0645d8841f51 108
bogdanm 13:0645d8841f51 109 // set default baud rate and format
bogdanm 13:0645d8841f51 110 serial_baud (obj, 9600);
bogdanm 13:0645d8841f51 111 serial_format(obj, 8, ParityNone, 1);
bogdanm 13:0645d8841f51 112
bogdanm 13:0645d8841f51 113 /* Clear all status bits. */
bogdanm 13:0645d8841f51 114 obj->uart->STAT = CTS_DELTA | DELTA_RXBRK;
bogdanm 13:0645d8841f51 115
bogdanm 13:0645d8841f51 116 /* enable uart interrupts */
bogdanm 13:0645d8841f51 117 NVIC_EnableIRQ((IRQn_Type)(UART0_IRQn + uart_n));
bogdanm 13:0645d8841f51 118
bogdanm 13:0645d8841f51 119 /* Enable UART interrupt */
bogdanm 13:0645d8841f51 120 // obj->uart->INTENSET = RXRDY | TXRDY | DELTA_RXBRK;
bogdanm 13:0645d8841f51 121
bogdanm 13:0645d8841f51 122 /* Enable UART */
bogdanm 13:0645d8841f51 123 obj->uart->CFG |= UART_EN;
bogdanm 13:0645d8841f51 124
bogdanm 13:0645d8841f51 125 is_stdio_uart = ((tx == USBTX) && (rx == USBRX));
bogdanm 13:0645d8841f51 126
bogdanm 13:0645d8841f51 127 if (is_stdio_uart) {
bogdanm 13:0645d8841f51 128 stdio_uart_inited = 1;
bogdanm 13:0645d8841f51 129 memcpy(&stdio_uart, obj, sizeof(serial_t));
bogdanm 13:0645d8841f51 130 }
bogdanm 13:0645d8841f51 131 }
bogdanm 13:0645d8841f51 132
bogdanm 13:0645d8841f51 133 void serial_free(serial_t *obj) {
bogdanm 13:0645d8841f51 134 uart_used &= ~(1 << obj->index);
bogdanm 13:0645d8841f51 135 serial_irq_ids[obj->index] = 0;
bogdanm 13:0645d8841f51 136 }
bogdanm 13:0645d8841f51 137
bogdanm 13:0645d8841f51 138 // serial_baud
bogdanm 13:0645d8841f51 139 // set the baud rate, taking in to account the current SystemFrequency
bogdanm 13:0645d8841f51 140 void serial_baud(serial_t *obj, int baudrate) {
bogdanm 13:0645d8841f51 141 /* Integer divider:
bogdanm 13:0645d8841f51 142 BRG = UARTSysClk/(Baudrate * 16) - 1
bogdanm 13:0645d8841f51 143
bogdanm 13:0645d8841f51 144 Frational divider:
bogdanm 13:0645d8841f51 145 FRG = ((UARTSysClk / (Baudrate * 16 * (BRG + 1))) - 1)
bogdanm 13:0645d8841f51 146
bogdanm 13:0645d8841f51 147 where
bogdanm 13:0645d8841f51 148 FRG = (LPC_SYSCON->UARTFRDADD + 1) / (LPC_SYSCON->UARTFRDSUB + 1)
bogdanm 13:0645d8841f51 149
bogdanm 13:0645d8841f51 150 (1) The easiest way is set SUB value to 256, -1 encoded, thus SUB
bogdanm 13:0645d8841f51 151 register is 0xFF.
bogdanm 13:0645d8841f51 152 (2) In ADD register value, depending on the value of UartSysClk,
bogdanm 13:0645d8841f51 153 baudrate, BRG register value, and SUB register value, be careful
bogdanm 13:0645d8841f51 154 about the order of multiplier and divider and make sure any
bogdanm 13:0645d8841f51 155 multiplier doesn't exceed 32-bit boundary and any divider doesn't get
bogdanm 13:0645d8841f51 156 down below one(integer 0).
bogdanm 13:0645d8841f51 157 (3) ADD should be always less than SUB.
bogdanm 13:0645d8841f51 158 */
bogdanm 13:0645d8841f51 159 obj->uart->BRG = UARTSysClk / 16 / baudrate - 1;
bogdanm 13:0645d8841f51 160
bogdanm 13:0645d8841f51 161 LPC_SYSCON->UARTFRGDIV = 0xFF;
bogdanm 13:0645d8841f51 162 LPC_SYSCON->UARTFRGMULT = ( ((UARTSysClk / 16) * (LPC_SYSCON->UARTFRGDIV + 1)) /
bogdanm 13:0645d8841f51 163 (baudrate * (obj->uart->BRG + 1))
bogdanm 13:0645d8841f51 164 ) - (LPC_SYSCON->UARTFRGDIV + 1);
bogdanm 13:0645d8841f51 165
bogdanm 13:0645d8841f51 166 }
bogdanm 13:0645d8841f51 167
bogdanm 13:0645d8841f51 168 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
bogdanm 13:0645d8841f51 169 // 0: 1 stop bits, 1: 2 stop bits
bogdanm 13:0645d8841f51 170 if (stop_bits != 1 && stop_bits != 2) {
bogdanm 13:0645d8841f51 171 error("Invalid stop bits specified");
bogdanm 13:0645d8841f51 172 }
bogdanm 13:0645d8841f51 173 stop_bits -= 1;
bogdanm 13:0645d8841f51 174
bogdanm 13:0645d8841f51 175 // 0: 7 data bits ... 2: 9 data bits
bogdanm 13:0645d8841f51 176 if (data_bits < 7 || data_bits > 9) {
bogdanm 13:0645d8841f51 177 error("Invalid number of bits (%d) in serial format, should be 7..9", data_bits);
bogdanm 13:0645d8841f51 178 }
bogdanm 13:0645d8841f51 179 data_bits -= 7;
bogdanm 13:0645d8841f51 180
bogdanm 13:0645d8841f51 181 int paritysel;
bogdanm 13:0645d8841f51 182 switch (parity) {
bogdanm 13:0645d8841f51 183 case ParityNone: paritysel = 0; break;
bogdanm 13:0645d8841f51 184 case ParityEven: paritysel = 2; break;
bogdanm 13:0645d8841f51 185 case ParityOdd : paritysel = 3; break;
bogdanm 13:0645d8841f51 186 default:
bogdanm 13:0645d8841f51 187 error("Invalid serial parity setting");
bogdanm 13:0645d8841f51 188 return;
bogdanm 13:0645d8841f51 189 }
bogdanm 13:0645d8841f51 190
bogdanm 13:0645d8841f51 191 obj->uart->CFG = (data_bits << 2)
bogdanm 13:0645d8841f51 192 | (paritysel << 4)
bogdanm 13:0645d8841f51 193 | (stop_bits << 6);
bogdanm 13:0645d8841f51 194 }
bogdanm 13:0645d8841f51 195
bogdanm 13:0645d8841f51 196 /******************************************************************************
bogdanm 13:0645d8841f51 197 * INTERRUPTS HANDLING
bogdanm 13:0645d8841f51 198 ******************************************************************************/
bogdanm 13:0645d8841f51 199 static inline void uart_irq(uint32_t iir, uint32_t index) {
bogdanm 13:0645d8841f51 200 // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling
bogdanm 13:0645d8841f51 201 SerialIrq irq_type;
bogdanm 13:0645d8841f51 202 switch (iir) {
bogdanm 13:0645d8841f51 203 case 1: irq_type = TxIrq; break;
bogdanm 13:0645d8841f51 204 case 2: irq_type = RxIrq; break;
bogdanm 13:0645d8841f51 205 default: return;
bogdanm 13:0645d8841f51 206 }
bogdanm 13:0645d8841f51 207
bogdanm 13:0645d8841f51 208 if (serial_irq_ids[index] != 0)
bogdanm 13:0645d8841f51 209 irq_handler(serial_irq_ids[index], irq_type);
bogdanm 13:0645d8841f51 210 }
bogdanm 13:0645d8841f51 211
bogdanm 13:0645d8841f51 212 void uart0_irq() {uart_irq((LPC_USART0->STAT & (1 << 2)) ? 2 : 1, 0);}
bogdanm 13:0645d8841f51 213 void uart1_irq() {uart_irq((LPC_USART1->STAT & (1 << 2)) ? 2 : 1, 1);}
bogdanm 13:0645d8841f51 214 void uart2_irq() {uart_irq((LPC_USART2->STAT & (1 << 2)) ? 2 : 1, 2);}
bogdanm 13:0645d8841f51 215
bogdanm 13:0645d8841f51 216 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
bogdanm 13:0645d8841f51 217 irq_handler = handler;
bogdanm 13:0645d8841f51 218 serial_irq_ids[obj->index] = id;
bogdanm 13:0645d8841f51 219 }
bogdanm 13:0645d8841f51 220
bogdanm 13:0645d8841f51 221 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
bogdanm 13:0645d8841f51 222 IRQn_Type irq_n = (IRQn_Type)0;
bogdanm 13:0645d8841f51 223 uint32_t vector = 0;
bogdanm 13:0645d8841f51 224 switch ((int)obj->uart) {
bogdanm 13:0645d8841f51 225 case LPC_USART0_BASE: irq_n=UART0_IRQn; vector = (uint32_t)&uart0_irq; break;
bogdanm 13:0645d8841f51 226 case LPC_USART1_BASE: irq_n=UART1_IRQn; vector = (uint32_t)&uart1_irq; break;
bogdanm 13:0645d8841f51 227 case LPC_USART2_BASE: irq_n=UART2_IRQn; vector = (uint32_t)&uart2_irq; break;
bogdanm 13:0645d8841f51 228 }
bogdanm 13:0645d8841f51 229
bogdanm 13:0645d8841f51 230 if (enable) {
bogdanm 13:0645d8841f51 231 obj->uart->INTENSET = (1 << ((irq == RxIrq) ? 0 : 2));
bogdanm 13:0645d8841f51 232 NVIC_SetVector(irq_n, vector);
bogdanm 13:0645d8841f51 233 NVIC_EnableIRQ(irq_n);
bogdanm 13:0645d8841f51 234 } else { // disable
bogdanm 13:0645d8841f51 235 int all_disabled = 0;
bogdanm 13:0645d8841f51 236 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
bogdanm 13:0645d8841f51 237 obj->uart->INTENSET &= ~(1 << ((irq == RxIrq) ? 0 : 2));
bogdanm 13:0645d8841f51 238 all_disabled = (obj->uart->INTENSET & (1 << ((other_irq == RxIrq) ? 0 : 2))) == 0;
bogdanm 13:0645d8841f51 239 if (all_disabled)
bogdanm 13:0645d8841f51 240 NVIC_DisableIRQ(irq_n);
bogdanm 13:0645d8841f51 241 }
bogdanm 13:0645d8841f51 242 }
bogdanm 13:0645d8841f51 243
bogdanm 13:0645d8841f51 244 /******************************************************************************
bogdanm 13:0645d8841f51 245 * READ/WRITE
bogdanm 13:0645d8841f51 246 ******************************************************************************/
bogdanm 13:0645d8841f51 247 int serial_getc(serial_t *obj) {
bogdanm 13:0645d8841f51 248 while (!serial_readable(obj));
bogdanm 13:0645d8841f51 249 return obj->uart->RXDATA;
bogdanm 13:0645d8841f51 250 }
bogdanm 13:0645d8841f51 251
bogdanm 13:0645d8841f51 252 void serial_putc(serial_t *obj, int c) {
bogdanm 13:0645d8841f51 253 while (!serial_writable(obj));
bogdanm 13:0645d8841f51 254 obj->uart->TXDATA = c;
bogdanm 13:0645d8841f51 255 }
bogdanm 13:0645d8841f51 256
bogdanm 13:0645d8841f51 257 int serial_readable(serial_t *obj) {
bogdanm 13:0645d8841f51 258 return obj->uart->STAT & RXRDY;
bogdanm 13:0645d8841f51 259 }
bogdanm 13:0645d8841f51 260
bogdanm 13:0645d8841f51 261 int serial_writable(serial_t *obj) {
bogdanm 13:0645d8841f51 262 return obj->uart->STAT & TXRDY;
bogdanm 13:0645d8841f51 263 }
bogdanm 13:0645d8841f51 264
bogdanm 13:0645d8841f51 265 void serial_clear(serial_t *obj) {
bogdanm 13:0645d8841f51 266 // [TODO]
bogdanm 13:0645d8841f51 267 }
bogdanm 13:0645d8841f51 268
bogdanm 13:0645d8841f51 269 void serial_pinout_tx(PinName tx) {
bogdanm 13:0645d8841f51 270
bogdanm 13:0645d8841f51 271 }
bogdanm 13:0645d8841f51 272
bogdanm 13:0645d8841f51 273 void serial_break_set(serial_t *obj) {
bogdanm 13:0645d8841f51 274 obj->uart->CTRL |= TXBRKEN;
bogdanm 13:0645d8841f51 275 }
bogdanm 13:0645d8841f51 276
bogdanm 13:0645d8841f51 277 void serial_break_clear(serial_t *obj) {
bogdanm 13:0645d8841f51 278 obj->uart->CTRL &= ~TXBRKEN;
bogdanm 13:0645d8841f51 279 }
bogdanm 13:0645d8841f51 280