shao ziyang / mbed-src-kl05

mbed library sources

Dependents:   frdm_kl05z_gpio_test

Fork of mbed-src by mbed official

targets/hal/TARGET_NXP/TARGET_LPC11XX_11CXX/serial_api.c@51:7838415c99e7, 2013-12-02 (annotated)

Committer:
mbed_official
Date:
Mon Dec 02 10:00:04 2013 +0000
Revision:
51:7838415c99e7
Parent:
30:91c1d09ada54
Child:
140:ca60b7a31055
Synchronized with git revision 6aaa1345164ad42bf681b857dc768b1b65a07595



Full URL: https://github.com/mbedmicro/mbed/commit/6aaa1345164ad42bf681b857dc768b1b65a07595/



Added (deep)sleep to KL25Z

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 30:91c1d09ada54 1 /* mbed Microcontroller Library
mbed_official 30:91c1d09ada54 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 30:91c1d09ada54 3 *
mbed_official 30:91c1d09ada54 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 30:91c1d09ada54 5 * you may not use this file except in compliance with the License.
mbed_official 30:91c1d09ada54 6 * You may obtain a copy of the License at
mbed_official 30:91c1d09ada54 7 *
mbed_official 30:91c1d09ada54 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 30:91c1d09ada54 9 *
mbed_official 30:91c1d09ada54 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 30:91c1d09ada54 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 30:91c1d09ada54 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 30:91c1d09ada54 13 * See the License for the specific language governing permissions and
mbed_official 30:91c1d09ada54 14 * limitations under the License.
mbed_official 30:91c1d09ada54 15 */
mbed_official 30:91c1d09ada54 16 // math.h required for floating point operations for baud rate calculation
mbed_official 30:91c1d09ada54 17 #include <math.h>
mbed_official 30:91c1d09ada54 18 #include <string.h>
mbed_official 30:91c1d09ada54 19
mbed_official 30:91c1d09ada54 20 #include "serial_api.h"
mbed_official 30:91c1d09ada54 21 #include "cmsis.h"
mbed_official 30:91c1d09ada54 22 #include "pinmap.h"
mbed_official 30:91c1d09ada54 23 #include "error.h"
mbed_official 30:91c1d09ada54 24
mbed_official 30:91c1d09ada54 25 /******************************************************************************
mbed_official 30:91c1d09ada54 26 * INITIALIZATION
mbed_official 30:91c1d09ada54 27 ******************************************************************************/
mbed_official 30:91c1d09ada54 28 #define UART_NUM 1
mbed_official 30:91c1d09ada54 29
mbed_official 30:91c1d09ada54 30 static const PinMap PinMap_UART_TX[] = {
mbed_official 30:91c1d09ada54 31 {P2_8 , UART_0, 0x02},
mbed_official 30:91c1d09ada54 32 {P3_5 , UART_0, 0x02},
mbed_official 30:91c1d09ada54 33 {P3_0 , UART_0, 0x03},
mbed_official 30:91c1d09ada54 34 {P1_7 , UART_0, 0x01},
mbed_official 30:91c1d09ada54 35 {NC , NC , 0x00}
mbed_official 30:91c1d09ada54 36 };
mbed_official 30:91c1d09ada54 37
mbed_official 30:91c1d09ada54 38 static const PinMap PinMap_UART_RX[] = {
mbed_official 30:91c1d09ada54 39 {P2_7 , UART_0, 0x02},
mbed_official 30:91c1d09ada54 40 {P3_4 , UART_0, 0x02},
mbed_official 30:91c1d09ada54 41 {P3_1 , UART_0, 0x03},
mbed_official 30:91c1d09ada54 42 {P1_6 , UART_0, 0x01},
mbed_official 30:91c1d09ada54 43 {NC , NC , 0x00}
mbed_official 30:91c1d09ada54 44 };
mbed_official 30:91c1d09ada54 45
mbed_official 30:91c1d09ada54 46 static uint32_t serial_irq_ids[UART_NUM] = {0};
mbed_official 30:91c1d09ada54 47 static uart_irq_handler irq_handler;
mbed_official 30:91c1d09ada54 48
mbed_official 30:91c1d09ada54 49 int stdio_uart_inited = 0;
mbed_official 30:91c1d09ada54 50 serial_t stdio_uart;
mbed_official 30:91c1d09ada54 51
mbed_official 30:91c1d09ada54 52 void serial_init(serial_t *obj, PinName tx, PinName rx) {
mbed_official 30:91c1d09ada54 53 int is_stdio_uart = 0;
mbed_official 30:91c1d09ada54 54
mbed_official 30:91c1d09ada54 55 // determine the UART to use
mbed_official 30:91c1d09ada54 56 UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
mbed_official 30:91c1d09ada54 57 UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
mbed_official 30:91c1d09ada54 58 UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
mbed_official 30:91c1d09ada54 59 if ((int)uart == NC) {
mbed_official 30:91c1d09ada54 60 error("Serial pinout mapping failed");
mbed_official 30:91c1d09ada54 61 }
mbed_official 30:91c1d09ada54 62
mbed_official 30:91c1d09ada54 63 obj->uart = (LPC_UART_TypeDef *)uart;
mbed_official 30:91c1d09ada54 64 LPC_SYSCON->SYSAHBCLKCTRL |= (1<<12);
mbed_official 30:91c1d09ada54 65
mbed_official 30:91c1d09ada54 66 // enable fifos and default rx trigger level
mbed_official 30:91c1d09ada54 67 obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled
mbed_official 30:91c1d09ada54 68 | 0 << 1 // Rx Fifo Reset
mbed_official 30:91c1d09ada54 69 | 0 << 2 // Tx Fifo Reset
mbed_official 30:91c1d09ada54 70 | 0 << 6; // Rx irq trigger level - 0 = 1 char, 1 = 4 chars, 2 = 8 chars, 3 = 14 chars
mbed_official 30:91c1d09ada54 71
mbed_official 30:91c1d09ada54 72 // disable irqs
mbed_official 30:91c1d09ada54 73 obj->uart->IER = 0 << 0 // Rx Data available irq enable
mbed_official 30:91c1d09ada54 74 | 0 << 1 // Tx Fifo empty irq enable
mbed_official 30:91c1d09ada54 75 | 0 << 2; // Rx Line Status irq enable
mbed_official 30:91c1d09ada54 76
mbed_official 30:91c1d09ada54 77 // set default baud rate and format
mbed_official 30:91c1d09ada54 78 serial_baud (obj, 9600);
mbed_official 30:91c1d09ada54 79 serial_format(obj, 8, ParityNone, 1);
mbed_official 30:91c1d09ada54 80
mbed_official 30:91c1d09ada54 81 // pinout the chosen uart
mbed_official 30:91c1d09ada54 82 pinmap_pinout(tx, PinMap_UART_TX);
mbed_official 30:91c1d09ada54 83 pinmap_pinout(rx, PinMap_UART_RX);
mbed_official 30:91c1d09ada54 84
mbed_official 30:91c1d09ada54 85 // set rx/tx pins in PullUp mode
mbed_official 30:91c1d09ada54 86 pin_mode(tx, PullUp);
mbed_official 30:91c1d09ada54 87 pin_mode(rx, PullUp);
mbed_official 30:91c1d09ada54 88
mbed_official 30:91c1d09ada54 89 switch (uart) {
mbed_official 30:91c1d09ada54 90 case UART_0: obj->index = 0; break;
mbed_official 30:91c1d09ada54 91 }
mbed_official 30:91c1d09ada54 92
mbed_official 30:91c1d09ada54 93 is_stdio_uart = (uart == STDIO_UART) ? (1) : (0);
mbed_official 30:91c1d09ada54 94
mbed_official 30:91c1d09ada54 95 if (is_stdio_uart) {
mbed_official 30:91c1d09ada54 96 stdio_uart_inited = 1;
mbed_official 30:91c1d09ada54 97 memcpy(&stdio_uart, obj, sizeof(serial_t));
mbed_official 30:91c1d09ada54 98 }
mbed_official 30:91c1d09ada54 99 }
mbed_official 30:91c1d09ada54 100
mbed_official 30:91c1d09ada54 101 void serial_free(serial_t *obj) {
mbed_official 30:91c1d09ada54 102 serial_irq_ids[obj->index] = 0;
mbed_official 30:91c1d09ada54 103 }
mbed_official 30:91c1d09ada54 104
mbed_official 30:91c1d09ada54 105 // serial_baud
mbed_official 30:91c1d09ada54 106 // set the baud rate, taking in to account the current SystemFrequency
mbed_official 30:91c1d09ada54 107 void serial_baud(serial_t *obj, int baudrate) {
mbed_official 30:91c1d09ada54 108 LPC_SYSCON->UARTCLKDIV = 0x1;
mbed_official 30:91c1d09ada54 109 uint32_t PCLK = SystemCoreClock;
mbed_official 30:91c1d09ada54 110 // First we check to see if the basic divide with no DivAddVal/MulVal
mbed_official 30:91c1d09ada54 111 // ratio gives us an integer result. If it does, we set DivAddVal = 0,
mbed_official 30:91c1d09ada54 112 // MulVal = 1. Otherwise, we search the valid ratio value range to find
mbed_official 30:91c1d09ada54 113 // the closest match. This could be more elegant, using search methods
mbed_official 30:91c1d09ada54 114 // and/or lookup tables, but the brute force method is not that much
mbed_official 30:91c1d09ada54 115 // slower, and is more maintainable.
mbed_official 30:91c1d09ada54 116 uint16_t DL = PCLK / (16 * baudrate);
mbed_official 30:91c1d09ada54 117
mbed_official 30:91c1d09ada54 118 uint8_t DivAddVal = 0;
mbed_official 30:91c1d09ada54 119 uint8_t MulVal = 1;
mbed_official 30:91c1d09ada54 120 int hit = 0;
mbed_official 30:91c1d09ada54 121 uint16_t dlv;
mbed_official 30:91c1d09ada54 122 uint8_t mv, dav;
mbed_official 30:91c1d09ada54 123 if ((PCLK % (16 * baudrate)) != 0) { // Checking for zero remainder
mbed_official 51:7838415c99e7 124 int err_best = baudrate, b;
mbed_official 51:7838415c99e7 125 for (mv = 1; mv < 16 && !hit; mv++)
mbed_official 51:7838415c99e7 126 {
mbed_official 51:7838415c99e7 127 for (dav = 0; dav < mv; dav++)
mbed_official 51:7838415c99e7 128 {
mbed_official 51:7838415c99e7 129 // baudrate = PCLK / (16 * dlv * (1 + (DivAdd / Mul))
mbed_official 51:7838415c99e7 130 // solving for dlv, we get dlv = mul * PCLK / (16 * baudrate * (divadd + mul))
mbed_official 51:7838415c99e7 131 // mul has 4 bits, PCLK has 27 so we have 1 bit headroom which can be used for rounding
mbed_official 51:7838415c99e7 132 // 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 133 // note: X / 32 doesn't round correctly. Instead, we use ((X / 16) + 1) / 2 for correct rounding
mbed_official 51:7838415c99e7 134
mbed_official 51:7838415c99e7 135 if ((mv * PCLK * 2) & 0x80000000) // 1 bit headroom
mbed_official 51:7838415c99e7 136 dlv = ((((2 * mv * PCLK) / (baudrate * (dav + mv))) / 16) + 1) / 2;
mbed_official 51:7838415c99e7 137 else // 2 bits headroom, use more precision
mbed_official 51:7838415c99e7 138 dlv = ((((4 * mv * PCLK) / (baudrate * (dav + mv))) / 32) + 1) / 2;
mbed_official 51:7838415c99e7 139
mbed_official 51:7838415c99e7 140 // datasheet says if DLL==DLM==0, then 1 is used instead since divide by zero is ungood
mbed_official 51:7838415c99e7 141 if (dlv == 0)
mbed_official 51:7838415c99e7 142 dlv = 1;
mbed_official 51:7838415c99e7 143
mbed_official 51:7838415c99e7 144 // datasheet says if dav > 0 then DL must be >= 2
mbed_official 51:7838415c99e7 145 if ((dav > 0) && (dlv < 2))
mbed_official 51:7838415c99e7 146 dlv = 2;
mbed_official 51:7838415c99e7 147
mbed_official 51:7838415c99e7 148 // integer rearrangement of the baudrate equation (with rounding)
mbed_official 51:7838415c99e7 149 b = ((PCLK * mv / (dlv * (dav + mv) * 8)) + 1) / 2;
mbed_official 51:7838415c99e7 150
mbed_official 51:7838415c99e7 151 // check to see how we went
mbed_official 51:7838415c99e7 152 b = abs(b - baudrate);
mbed_official 51:7838415c99e7 153 if (b < err_best)
mbed_official 51:7838415c99e7 154 {
mbed_official 51:7838415c99e7 155 err_best = b;
mbed_official 51:7838415c99e7 156
mbed_official 51:7838415c99e7 157 DL = dlv;
mbed_official 51:7838415c99e7 158 MulVal = mv;
mbed_official 51:7838415c99e7 159 DivAddVal = dav;
mbed_official 51:7838415c99e7 160
mbed_official 51:7838415c99e7 161 if (b == baudrate)
mbed_official 51:7838415c99e7 162 {
mbed_official 51:7838415c99e7 163 hit = 1;
mbed_official 51:7838415c99e7 164 break;
mbed_official 30:91c1d09ada54 165 }
mbed_official 30:91c1d09ada54 166 }
mbed_official 30:91c1d09ada54 167 }
mbed_official 30:91c1d09ada54 168 }
mbed_official 30:91c1d09ada54 169 }
mbed_official 30:91c1d09ada54 170
mbed_official 30:91c1d09ada54 171 // set LCR[DLAB] to enable writing to divider registers
mbed_official 30:91c1d09ada54 172 obj->uart->LCR |= (1 << 7);
mbed_official 30:91c1d09ada54 173
mbed_official 30:91c1d09ada54 174 // set divider values
mbed_official 30:91c1d09ada54 175 obj->uart->DLM = (DL >> 8) & 0xFF;
mbed_official 30:91c1d09ada54 176 obj->uart->DLL = (DL >> 0) & 0xFF;
mbed_official 30:91c1d09ada54 177 obj->uart->FDR = (uint32_t) DivAddVal << 0
mbed_official 30:91c1d09ada54 178 | (uint32_t) MulVal << 4;
mbed_official 30:91c1d09ada54 179
mbed_official 30:91c1d09ada54 180 // clear LCR[DLAB]
mbed_official 30:91c1d09ada54 181 obj->uart->LCR &= ~(1 << 7);
mbed_official 30:91c1d09ada54 182 }
mbed_official 30:91c1d09ada54 183
mbed_official 30:91c1d09ada54 184 void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
mbed_official 30:91c1d09ada54 185 // 0: 1 stop bits, 1: 2 stop bits
mbed_official 30:91c1d09ada54 186 if (stop_bits != 1 && stop_bits != 2) {
mbed_official 30:91c1d09ada54 187 error("Invalid stop bits specified");
mbed_official 30:91c1d09ada54 188 }
mbed_official 30:91c1d09ada54 189 stop_bits -= 1;
mbed_official 30:91c1d09ada54 190
mbed_official 30:91c1d09ada54 191 // 0: 5 data bits ... 3: 8 data bits
mbed_official 30:91c1d09ada54 192 if (data_bits < 5 || data_bits > 8) {
mbed_official 30:91c1d09ada54 193 error("Invalid number of bits (%d) in serial format, should be 5..8", data_bits);
mbed_official 30:91c1d09ada54 194 }
mbed_official 30:91c1d09ada54 195 data_bits -= 5;
mbed_official 30:91c1d09ada54 196
mbed_official 30:91c1d09ada54 197 int parity_enable, parity_select;
mbed_official 30:91c1d09ada54 198 switch (parity) {
mbed_official 30:91c1d09ada54 199 case ParityNone: parity_enable = 0; parity_select = 0; break;
mbed_official 30:91c1d09ada54 200 case ParityOdd : parity_enable = 1; parity_select = 0; break;
mbed_official 30:91c1d09ada54 201 case ParityEven: parity_enable = 1; parity_select = 1; break;
mbed_official 30:91c1d09ada54 202 case ParityForced1: parity_enable = 1; parity_select = 2; break;
mbed_official 30:91c1d09ada54 203 case ParityForced0: parity_enable = 1; parity_select = 3; break;
mbed_official 30:91c1d09ada54 204 default:
mbed_official 30:91c1d09ada54 205 error("Invalid serial parity setting");
mbed_official 30:91c1d09ada54 206 return;
mbed_official 30:91c1d09ada54 207 }
mbed_official 30:91c1d09ada54 208
mbed_official 30:91c1d09ada54 209 obj->uart->LCR = data_bits << 0
mbed_official 30:91c1d09ada54 210 | stop_bits << 2
mbed_official 30:91c1d09ada54 211 | parity_enable << 3
mbed_official 30:91c1d09ada54 212 | parity_select << 4;
mbed_official 30:91c1d09ada54 213 }
mbed_official 30:91c1d09ada54 214
mbed_official 30:91c1d09ada54 215 /******************************************************************************
mbed_official 30:91c1d09ada54 216 * INTERRUPTS HANDLING
mbed_official 30:91c1d09ada54 217 ******************************************************************************/
mbed_official 30:91c1d09ada54 218 static inline void uart_irq(uint32_t iir, uint32_t index) {
mbed_official 30:91c1d09ada54 219 // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling
mbed_official 30:91c1d09ada54 220 SerialIrq irq_type;
mbed_official 30:91c1d09ada54 221 switch (iir) {
mbed_official 30:91c1d09ada54 222 case 1: irq_type = TxIrq; break;
mbed_official 30:91c1d09ada54 223 case 2: irq_type = RxIrq; break;
mbed_official 30:91c1d09ada54 224 default: return;
mbed_official 30:91c1d09ada54 225 }
mbed_official 30:91c1d09ada54 226
mbed_official 30:91c1d09ada54 227 if (serial_irq_ids[index] != 0)
mbed_official 30:91c1d09ada54 228 irq_handler(serial_irq_ids[index], irq_type);
mbed_official 30:91c1d09ada54 229 }
mbed_official 30:91c1d09ada54 230
mbed_official 30:91c1d09ada54 231 void uart0_irq() {uart_irq((LPC_UART->IIR >> 1) & 0x7, 0);}
mbed_official 30:91c1d09ada54 232
mbed_official 30:91c1d09ada54 233 void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
mbed_official 30:91c1d09ada54 234 irq_handler = handler;
mbed_official 30:91c1d09ada54 235 serial_irq_ids[obj->index] = id;
mbed_official 30:91c1d09ada54 236 }
mbed_official 30:91c1d09ada54 237
mbed_official 30:91c1d09ada54 238 void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
mbed_official 30:91c1d09ada54 239 IRQn_Type irq_n = (IRQn_Type)0;
mbed_official 30:91c1d09ada54 240 uint32_t vector = 0;
mbed_official 30:91c1d09ada54 241 switch ((int)obj->uart) {
mbed_official 30:91c1d09ada54 242 case UART_0:
mbed_official 30:91c1d09ada54 243 irq_n=UART_IRQn;
mbed_official 30:91c1d09ada54 244 vector = (uint32_t)&uart0_irq;
mbed_official 30:91c1d09ada54 245 break;
mbed_official 30:91c1d09ada54 246 default:
mbed_official 30:91c1d09ada54 247 return;
mbed_official 30:91c1d09ada54 248 }
mbed_official 30:91c1d09ada54 249
mbed_official 30:91c1d09ada54 250 if (enable) {
mbed_official 30:91c1d09ada54 251 obj->uart->IER |= 1 << irq;
mbed_official 30:91c1d09ada54 252 NVIC_SetVector(irq_n, vector);
mbed_official 30:91c1d09ada54 253 NVIC_EnableIRQ(irq_n);
mbed_official 30:91c1d09ada54 254 } else { // disable
mbed_official 30:91c1d09ada54 255 int all_disabled = 0;
mbed_official 30:91c1d09ada54 256 SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
mbed_official 30:91c1d09ada54 257
mbed_official 30:91c1d09ada54 258 obj->uart->IER &= ~(1 << irq);
mbed_official 30:91c1d09ada54 259 all_disabled = (obj->uart->IER & (1 << other_irq)) == 0;
mbed_official 30:91c1d09ada54 260
mbed_official 30:91c1d09ada54 261 if (all_disabled)
mbed_official 30:91c1d09ada54 262 NVIC_DisableIRQ(irq_n);
mbed_official 30:91c1d09ada54 263 }
mbed_official 30:91c1d09ada54 264 }
mbed_official 30:91c1d09ada54 265
mbed_official 30:91c1d09ada54 266 /******************************************************************************
mbed_official 30:91c1d09ada54 267 * READ/WRITE
mbed_official 30:91c1d09ada54 268 ******************************************************************************/
mbed_official 30:91c1d09ada54 269 int serial_getc(serial_t *obj) {
mbed_official 30:91c1d09ada54 270 while (!serial_readable(obj));
mbed_official 30:91c1d09ada54 271 return obj->uart->RBR;
mbed_official 30:91c1d09ada54 272 }
mbed_official 30:91c1d09ada54 273
mbed_official 30:91c1d09ada54 274 void serial_putc(serial_t *obj, int c) {
mbed_official 30:91c1d09ada54 275 while (!serial_writable(obj));
mbed_official 30:91c1d09ada54 276 obj->uart->THR = c;
mbed_official 30:91c1d09ada54 277 }
mbed_official 30:91c1d09ada54 278
mbed_official 30:91c1d09ada54 279 int serial_readable(serial_t *obj) {
mbed_official 30:91c1d09ada54 280 return obj->uart->LSR & 0x01;
mbed_official 30:91c1d09ada54 281 }
mbed_official 30:91c1d09ada54 282
mbed_official 30:91c1d09ada54 283 int serial_writable(serial_t *obj) {
mbed_official 30:91c1d09ada54 284 return obj->uart->LSR & 0x20;
mbed_official 30:91c1d09ada54 285 }
mbed_official 30:91c1d09ada54 286
mbed_official 30:91c1d09ada54 287 void serial_clear(serial_t *obj) {
mbed_official 30:91c1d09ada54 288 obj->uart->FCR = 1 << 1 // rx FIFO reset
mbed_official 30:91c1d09ada54 289 | 1 << 2 // tx FIFO reset
mbed_official 30:91c1d09ada54 290 | 0 << 6; // interrupt depth
mbed_official 30:91c1d09ada54 291 }
mbed_official 30:91c1d09ada54 292
mbed_official 30:91c1d09ada54 293 void serial_pinout_tx(PinName tx) {
mbed_official 30:91c1d09ada54 294 pinmap_pinout(tx, PinMap_UART_TX);
mbed_official 30:91c1d09ada54 295 }
mbed_official 30:91c1d09ada54 296
mbed_official 30:91c1d09ada54 297 void serial_break_clear(serial_t *obj) {
mbed_official 30:91c1d09ada54 298 obj->uart->LCR &= ~(1 << 6);
mbed_official 30:91c1d09ada54 299 }
mbed_official 30:91c1d09ada54 300
mbed_official 30:91c1d09ada54 301 void serial_break_set(serial_t *obj) {
mbed_official 30:91c1d09ada54 302 obj->uart->LCR |= 1 << 6;
mbed_official 30:91c1d09ada54 303 }