mbed official / mbed-src

mbed library sources

Dependents:   Encrypted my_mbed lklk CyaSSL_DTLS_Cellular ... more

Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

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.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

Import librarymbed

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_LPC13XX/serial_api.c@440:8a0b45cd594f, 2014-12-16 (annotated)

Committer:
mbed_official
Date:
Tue Dec 16 08:15:08 2014 +0000
Revision:
440:8a0b45cd594f
Parent:
339:40bd4701f3e2 
Synchronized with git revision 67fbbf0b635d0c0d93fbe433306c537c2ad206aa



Full URL: https://github.com/mbedmicro/mbed/commit/67fbbf0b635d0c0d93fbe433306c537c2ad206aa/



Targets: nrf51 - updating app_timer.c from Norid'c SDKv7.1.0

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
mbed_official 227:7bd0639b8911 17 #include "mbed_assert.h"
bogdanm 13:0645d8841f51 18 #include <math.h>
bogdanm 13:0645d8841f51 19 #include <string.h>
mbed_official 140:ca60b7a31055 20 #include <stdlib.h>
bogdanm 13:0645d8841f51 21
bogdanm 13:0645d8841f51 22 #include "serial_api.h"
bogdanm 13:0645d8841f51 23 #include "cmsis.h"
bogdanm 13:0645d8841f51 24 #include "pinmap.h"
bogdanm 13:0645d8841f51 25
bogdanm 13:0645d8841f51 26 /******************************************************************************
bogdanm 13:0645d8841f51 27 * INITIALIZATION
bogdanm 13:0645d8841f51 28 ******************************************************************************/
bogdanm 13:0645d8841f51 29 #define UART_NUM 1
bogdanm 13:0645d8841f51 30
bogdanm 13:0645d8841f51 31 static const PinMap PinMap_UART_TX[] = {
bogdanm 13:0645d8841f51 32 {P0_19, UART_0, 1},
bogdanm 13:0645d8841f51 33 {P1_13, UART_0, 3},
bogdanm 13:0645d8841f51 34 {P1_27, UART_0, 2},
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 {P0_18, UART_0, 1},
bogdanm 13:0645d8841f51 40 {P1_14, UART_0, 3},
bogdanm 13:0645d8841f51 41 {P1_26, UART_0, 2},
bogdanm 13:0645d8841f51 42 {NC , NC , 0}
bogdanm 13:0645d8841f51 43 };
bogdanm 13:0645d8841f51 44
bogdanm 13:0645d8841f51 45 static uint32_t serial_irq_ids[UART_NUM] = {0};
bogdanm 13:0645d8841f51 46 static uart_irq_handler irq_handler;
bogdanm 13:0645d8841f51 47
bogdanm 13:0645d8841f51 48 int stdio_uart_inited = 0;
bogdanm 13:0645d8841f51 49 serial_t stdio_uart;
bogdanm 13:0645d8841f51 50
bogdanm 13:0645d8841f51 51 void serial_init(serial_t *obj, PinName tx, PinName rx) {
bogdanm 13:0645d8841f51 52 int is_stdio_uart = 0;
bogdanm 13:0645d8841f51 53
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);
mbed_official 227:7bd0639b8911 58 MBED_ASSERT((int)uart != NC);
bogdanm 13:0645d8841f51 59
bogdanm 13:0645d8841f51 60 obj->uart = (LPC_USART_Type *)uart;
bogdanm 13:0645d8841f51 61 LPC_SYSCON->SYSAHBCLKCTRL |= (1<<12);
bogdanm 13:0645d8841f51 62
bogdanm 13:0645d8841f51 63 // [TODO] Consider more elegant approach
bogdanm 13:0645d8841f51 64 // disconnect USBTX/RX mapping mux, for case when switching ports
bogdanm 13:0645d8841f51 65 //pin_function(USBTX, 0);
bogdanm 13:0645d8841f51 66 //pin_function(USBRX, 0);
bogdanm 13:0645d8841f51 67
bogdanm 13:0645d8841f51 68 // enable fifos and default rx trigger level
bogdanm 13:0645d8841f51 69 obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled
bogdanm 13:0645d8841f51 70 | 0 << 1 // Rx Fifo Reset
bogdanm 13:0645d8841f51 71 | 0 << 2 // Tx Fifo Reset
bogdanm 13:0645d8841f51 72 | 0 << 6; // Rx irq trigger level - 0 = 1 char, 1 = 4 chars, 2 = 8 chars, 3 = 14 chars
bogdanm 13:0645d8841f51 73
bogdanm 13:0645d8841f51 74 // disable irqs
bogdanm 13:0645d8841f51 75 obj->uart->IER = 0 << 0 // Rx Data available irq enable
bogdanm 13:0645d8841f51 76 | 0 << 1 // Tx Fifo empty irq enable
bogdanm 13:0645d8841f51 77 | 0 << 2; // Rx Line Status irq enable
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
mbed_official 339:40bd4701f3e2 88 if (tx != NC) {
mbed_official 339:40bd4701f3e2 89 pin_mode(tx, PullUp);
mbed_official 339:40bd4701f3e2 90 }
mbed_official 339:40bd4701f3e2 91 if (rx != NC) {
mbed_official 339:40bd4701f3e2 92 pin_mode(rx, PullUp);
mbed_official 339:40bd4701f3e2 93 }
bogdanm 13:0645d8841f51 94
bogdanm 13:0645d8841f51 95 switch (uart) {
bogdanm 13:0645d8841f51 96 case UART_0: obj->index = 0; break;
bogdanm 13:0645d8841f51 97 }
bogdanm 13:0645d8841f51 98
bogdanm 13:0645d8841f51 99 is_stdio_uart = (uart == STDIO_UART) ? (1) : (0);
bogdanm 13:0645d8841f51 100
bogdanm 13:0645d8841f51 101 if (is_stdio_uart) {
bogdanm 13:0645d8841f51 102 stdio_uart_inited = 1;
bogdanm 13:0645d8841f51 103 memcpy(&stdio_uart, obj, sizeof(serial_t));
bogdanm 13:0645d8841f51 104 }
bogdanm 13:0645d8841f51 105 }
bogdanm 13:0645d8841f51 106
bogdanm 13:0645d8841f51 107 void serial_free(serial_t *obj) {
bogdanm 13:0645d8841f51 108 serial_irq_ids[obj->index] = 0;
bogdanm 13:0645d8841f51 109 }
bogdanm 13:0645d8841f51 110
bogdanm 13:0645d8841f51 111 // serial_baud
bogdanm 13:0645d8841f51 112 // set the baud rate, taking in to account the current SystemFrequency
bogdanm 13:0645d8841f51 113 void serial_baud(serial_t *obj, int baudrate) {
bogdanm 13:0645d8841f51 114 LPC_SYSCON->UARTCLKDIV = 0x1;
bogdanm 13:0645d8841f51 115 uint32_t PCLK = SystemCoreClock;
bogdanm 13:0645d8841f51 116 // First we check to see if the basic divide with no DivAddVal/MulVal
bogdanm 13:0645d8841f51 117 // ratio gives us an integer result. If it does, we set DivAddVal = 0,
bogdanm 13:0645d8841f51 118 // MulVal = 1. Otherwise, we search the valid ratio value range to find
bogdanm 13:0645d8841f51 119 // the closest match. This could be more elegant, using search methods
bogdanm 13:0645d8841f51 120 // and/or lookup tables, but the brute force method is not that much
bogdanm 13:0645d8841f51 121 // slower, and is more maintainable.
bogdanm 13:0645d8841f51 122 uint16_t DL = PCLK / (16 * baudrate);
bogdanm 13:0645d8841f51 123
bogdanm 13:0645d8841f51 124 uint8_t DivAddVal = 0;
bogdanm 13:0645d8841f51 125 uint8_t MulVal = 1;
bogdanm 13:0645d8841f51 126 int hit = 0;
bogdanm 13:0645d8841f51 127 uint16_t dlv;
bogdanm 13:0645d8841f51 128 uint8_t mv, dav;
bogdanm 13:0645d8841f51 129 if ((PCLK % (16 * baudrate)) != 0) { // Checking for zero remainder
mbed_official 51:7838415c99e7 130 int err_best = baudrate, b;
mbed_official 51:7838415c99e7 131 for (mv = 1; mv < 16 && !hit; mv++)
mbed_official 51:7838415c99e7 132 {
mbed_official 51:7838415c99e7 133 for (dav = 0; dav < mv; dav++)
mbed_official 51:7838415c99e7 134 {
mbed_official 51:7838415c99e7 135 // baudrate = PCLK / (16 * dlv * (1 + (DivAdd / Mul))
mbed_official 51:7838415c99e7 136 // solving for dlv, we get dlv = mul * PCLK / (16 * baudrate * (divadd + mul))
mbed_official 51:7838415c99e7 137 // mul has 4 bits, PCLK has 27 so we have 1 bit headroom which can be used for rounding
mbed_official 51:7838415c99e7 138 // for many values of mul and PCLK we have 2 or more bits of headroom which can be used to improve precision
mbed_official 51:7838415c99e7 139 // note: X / 32 doesn't round correctly. Instead, we use ((X / 16) + 1) / 2 for correct rounding
mbed_official 51:7838415c99e7 140
mbed_official 51:7838415c99e7 141 if ((mv * PCLK * 2) & 0x80000000) // 1 bit headroom
mbed_official 51:7838415c99e7 142 dlv = ((((2 * mv * PCLK) / (baudrate * (dav + mv))) / 16) + 1) / 2;
mbed_official 51:7838415c99e7 143 else // 2 bits headroom, use more precision
mbed_official 51:7838415c99e7 144 dlv = ((((4 * mv * PCLK) / (baudrate * (dav + mv))) / 32) + 1) / 2;
mbed_official 51:7838415c99e7 145
mbed_official 51:7838415c99e7 146 // datasheet says if DLL==DLM==0, then 1 is used instead since divide by zero is ungood
mbed_official 51:7838415c99e7 147 if (dlv == 0)
mbed_official 51:7838415c99e7 148 dlv = 1;
mbed_official 51:7838415c99e7 149
mbed_official 51:7838415c99e7 150 // datasheet says if dav > 0 then DL must be >= 2
mbed_official 51:7838415c99e7 151 if ((dav > 0) && (dlv < 2))
mbed_official 51:7838415c99e7 152 dlv = 2;
mbed_official 51:7838415c99e7 153
mbed_official 51:7838415c99e7 154 // integer rearrangement of the baudrate equation (with rounding)
mbed_official 51:7838415c99e7 155 b = ((PCLK * mv / (dlv * (dav + mv) * 8)) + 1) / 2;
mbed_official 51:7838415c99e7 156
mbed_official 51:7838415c99e7 157 // check to see how we went
mbed_official 51:7838415c99e7 158 b = abs(b - baudrate);
mbed_official 51:7838415c99e7 159 if (b < err_best)
mbed_official 51:7838415c99e7 160 {
mbed_official 51:7838415c99e7 161 err_best = b;
mbed_official 51:7838415c99e7 162
mbed_official 51:7838415c99e7 163 DL = dlv;
mbed_official 51:7838415c99e7 164 MulVal = mv;
mbed_official 51:7838415c99e7 165 DivAddVal = dav;
mbed_official 51:7838415c99e7 166
mbed_official 51:7838415c99e7 167 if (b == baudrate)
mbed_official 51:7838415c99e7 168 {
mbed_official 51:7838415c99e7 169 hit = 1;
mbed_official 51:7838415c99e7 170 break;
bogdanm 13:0645d8841f51 171 }
bogdanm 13:0645d8841f51 172 }
bogdanm 13:0645d8841f51 173 }
bogdanm 13:0645d8841f51 174 }
bogdanm 13:0645d8841f51 175 }
bogdanm 13:0645d8841f51 176
bogdanm 13:0645d8841f51 177 // set LCR[DLAB] to enable writing to divider registers
bogdanm 13:0645d8841f51 178 obj->uart->LCR |= (1 << 7);
bogdanm 13:0645d8841f51 179
bogdanm 13:0645d8841f51 180 // set divider values
bogdanm 13:0645d8841f51 181 obj->uart->DLM = (DL >> 8) & 0xFF;
bogdanm 13:0645d8841f51 182 obj->uart->DLL = (DL >> 0) & 0xFF;
bogdanm 13:0645d8841f51 183 obj->uart->FDR = (uint32_t) DivAddVal << 0
bogdanm 13:0645d8841f51 184 | (uint32_t) MulVal << 4;
bogdanm 13:0645d8841f51 185
bogdanm 13:0645d8841f51 186 // clear LCR[DLAB]
bogdanm 13:0645d8841f51 187 obj->uart->LCR &= ~(1 << 7);
bogdanm 13:0645d8841f51 188 }
bogdanm 13:0645d8841f51 189
bogdanm 13:0645d8841f51 190 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
mbed_official 227:7bd0639b8911 191 MBED_ASSERT((stop_bits == 1) || (stop_bits == 2)); // 0: 1 stop bits, 1: 2 stop bits
mbed_official 227:7bd0639b8911 192 MBED_ASSERT((data_bits > 4) && (data_bits < 9)); // 0: 5 data bits ... 3: 8 data bits
mbed_official 227:7bd0639b8911 193 MBED_ASSERT((parity == ParityNone) || (parity == ParityOdd) || (parity == ParityEven) ||
mbed_official 227:7bd0639b8911 194 (parity == ParityForced1) || (parity == ParityForced0));
mbed_official 227:7bd0639b8911 195
bogdanm 13:0645d8841f51 196 stop_bits -= 1;
bogdanm 13:0645d8841f51 197 data_bits -= 5;
bogdanm 13:0645d8841f51 198
bogdanm 13:0645d8841f51 199 int parity_enable, parity_select;
bogdanm 13:0645d8841f51 200 switch (parity) {
bogdanm 13:0645d8841f51 201 case ParityNone: parity_enable = 0; parity_select = 0; break;
bogdanm 13:0645d8841f51 202 case ParityOdd : parity_enable = 1; parity_select = 0; break;
bogdanm 13:0645d8841f51 203 case ParityEven: parity_enable = 1; parity_select = 1; break;
bogdanm 13:0645d8841f51 204 case ParityForced1: parity_enable = 1; parity_select = 2; break;
bogdanm 13:0645d8841f51 205 case ParityForced0: parity_enable = 1; parity_select = 3; break;
bogdanm 13:0645d8841f51 206 default:
mbed_official 227:7bd0639b8911 207 break;
bogdanm 13:0645d8841f51 208 }
bogdanm 13:0645d8841f51 209
bogdanm 13:0645d8841f51 210 obj->uart->LCR = data_bits << 0
bogdanm 13:0645d8841f51 211 | stop_bits << 2
bogdanm 13:0645d8841f51 212 | parity_enable << 3
bogdanm 13:0645d8841f51 213 | parity_select << 4;
bogdanm 13:0645d8841f51 214 }
bogdanm 13:0645d8841f51 215
bogdanm 13:0645d8841f51 216 /******************************************************************************
bogdanm 13:0645d8841f51 217 * INTERRUPTS HANDLING
bogdanm 13:0645d8841f51 218 ******************************************************************************/
bogdanm 13:0645d8841f51 219 static inline void uart_irq(uint32_t iir, uint32_t index) {
bogdanm 13:0645d8841f51 220 // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling
bogdanm 13:0645d8841f51 221 SerialIrq irq_type;
bogdanm 13:0645d8841f51 222 switch (iir) {
bogdanm 13:0645d8841f51 223 case 1: irq_type = TxIrq; break;
bogdanm 13:0645d8841f51 224 case 2: irq_type = RxIrq; break;
bogdanm 13:0645d8841f51 225 default: return;
bogdanm 13:0645d8841f51 226 }
bogdanm 13:0645d8841f51 227
bogdanm 13:0645d8841f51 228 if (serial_irq_ids[index] != 0)
bogdanm 13:0645d8841f51 229 irq_handler(serial_irq_ids[index], irq_type);
bogdanm 13:0645d8841f51 230 }
bogdanm 13:0645d8841f51 231
bogdanm 13:0645d8841f51 232 void uart0_irq() {uart_irq((LPC_USART->IIR >> 1) & 0x7, 0);}
bogdanm 13:0645d8841f51 233
bogdanm 13:0645d8841f51 234 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
bogdanm 13:0645d8841f51 235 irq_handler = handler;
bogdanm 13:0645d8841f51 236 serial_irq_ids[obj->index] = id;
bogdanm 13:0645d8841f51 237 }
bogdanm 13:0645d8841f51 238
bogdanm 13:0645d8841f51 239 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
bogdanm 13:0645d8841f51 240 IRQn_Type irq_n = (IRQn_Type)0;
bogdanm 13:0645d8841f51 241 uint32_t vector = 0;
bogdanm 13:0645d8841f51 242 switch ((int)obj->uart) {
bogdanm 13:0645d8841f51 243 case UART_0: irq_n=USART_IRQn ; vector = (uint32_t)&uart0_irq; break;
bogdanm 13:0645d8841f51 244 }
bogdanm 13:0645d8841f51 245
bogdanm 13:0645d8841f51 246 if (enable) {
bogdanm 13:0645d8841f51 247 obj->uart->IER |= 1 << irq;
bogdanm 13:0645d8841f51 248 NVIC_SetVector(irq_n, vector);
bogdanm 13:0645d8841f51 249 NVIC_EnableIRQ(irq_n);
bogdanm 13:0645d8841f51 250 } else { // disable
bogdanm 13:0645d8841f51 251 int all_disabled = 0;
bogdanm 13:0645d8841f51 252 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
bogdanm 13:0645d8841f51 253
bogdanm 13:0645d8841f51 254 obj->uart->IER &= ~(1 << irq);
bogdanm 13:0645d8841f51 255 all_disabled = (obj->uart->IER & (1 << other_irq)) == 0;
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->RBR;
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->THR = c;
bogdanm 13:0645d8841f51 273 }
bogdanm 13:0645d8841f51 274
bogdanm 13:0645d8841f51 275 int serial_readable(serial_t *obj) {
bogdanm 13:0645d8841f51 276 return obj->uart->LSR & 0x01;
bogdanm 13:0645d8841f51 277 }
bogdanm 13:0645d8841f51 278
bogdanm 13:0645d8841f51 279 int serial_writable(serial_t *obj) {
bogdanm 13:0645d8841f51 280 return obj->uart->LSR & 0x20;
bogdanm 13:0645d8841f51 281 }
bogdanm 13:0645d8841f51 282
bogdanm 13:0645d8841f51 283 void serial_clear(serial_t *obj) {
bogdanm 13:0645d8841f51 284 obj->uart->FCR = 1 << 1 // rx FIFO reset
bogdanm 13:0645d8841f51 285 | 1 << 2 // tx FIFO reset
bogdanm 13:0645d8841f51 286 | 0 << 6; // interrupt depth
bogdanm 13:0645d8841f51 287 }
bogdanm 13:0645d8841f51 288
bogdanm 13:0645d8841f51 289 void serial_pinout_tx(PinName tx) {
bogdanm 13:0645d8841f51 290 pinmap_pinout(tx, PinMap_UART_TX);
bogdanm 13:0645d8841f51 291 }
bogdanm 13:0645d8841f51 292
bogdanm 13:0645d8841f51 293 void serial_break_set(serial_t *obj) {
bogdanm 13:0645d8841f51 294 obj->uart->LCR |= (1 << 6);
bogdanm 13:0645d8841f51 295 }
bogdanm 13:0645d8841f51 296
bogdanm 13:0645d8841f51 297 void serial_break_clear(serial_t *obj) {
bogdanm 13:0645d8841f51 298 obj->uart->LCR &= ~(1 << 6);
bogdanm 13:0645d8841f51 299 }
bogdanm 13:0645d8841f51 300