+++ /dev/null
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-// math.h required for floating point operations for baud rate calculation
-#include "mbed_assert.h"
-#include <math.h>
-#include <string.h>
-#include <stdlib.h>
-
-#include "serial_api.h"
-#include "cmsis.h"
-#include "pinmap.h"
-
-/******************************************************************************
- * INITIALIZATION
- ******************************************************************************/
-#define UART_NUM 4
-
-static const PinMap PinMap_UART_TX[] = {
- {P0_0, UART_3, 2},
- {P0_2, UART_0, 1},
- {P0_10, UART_2, 1},
- {P0_15, UART_1, 1},
- {P0_25, UART_3, 3},
- {P2_0 , UART_1, 2},
- {P2_8 , UART_2, 2},
- {P4_28, UART_3, 3},
- {NC , NC , 0}
-};
-
-static const PinMap PinMap_UART_RX[] = {
- {P0_1 , UART_3, 2},
- {P0_3 , UART_0, 1},
- {P0_11, UART_2, 1},
- {P0_16, UART_1, 1},
- {P0_26, UART_3, 3},
- {P2_1 , UART_1, 2},
- {P2_9 , UART_2, 2},
- {P4_29, UART_3, 3},
- {NC , NC , 0}
-};
-
-static uint32_t serial_irq_ids[UART_NUM] = {0};
-static uart_irq_handler irq_handler;
-
-int stdio_uart_inited = 0;
-serial_t stdio_uart;
-
-void serial_init(serial_t *obj, PinName tx, PinName rx) {
- int is_stdio_uart = 0;
-
- // determine the UART to use
- UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
- UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
- UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
- MBED_ASSERT((int)uart != NC);
-
- obj->uart = (LPC_UART_TypeDef *)uart;
- // enable power
- switch (uart) {
- case UART_0: LPC_SC->PCONP |= 1 << 3; break;
- case UART_1: LPC_SC->PCONP |= 1 << 4; break;
- case UART_2: LPC_SC->PCONP |= 1 << 24; break;
- case UART_3: LPC_SC->PCONP |= 1 << 25; break;
- }
-
- // enable fifos and default rx trigger level
- obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled
- | 0 << 1 // Rx Fifo Reset
- | 0 << 2 // Tx Fifo Reset
- | 0 << 6; // Rx irq trigger level - 0 = 1 char, 1 = 4 chars, 2 = 8 chars, 3 = 14 chars
-
- // disable irqs
- obj->uart->IER = 0 << 0 // Rx Data available irq enable
- | 0 << 1 // Tx Fifo empty irq enable
- | 0 << 2; // Rx Line Status irq enable
-
- // set default baud rate and format
- serial_baud (obj, 9600);
- serial_format(obj, 8, ParityNone, 1);
-
- // pinout the chosen uart
- pinmap_pinout(tx, PinMap_UART_TX);
- pinmap_pinout(rx, PinMap_UART_RX);
-
- // set rx/tx pins in PullUp mode
- if (tx != NC) {
- pin_mode(tx, PullUp);
- }
- if (rx != NC) {
- pin_mode(rx, PullUp);
- }
-
- switch (uart) {
- case UART_0: obj->index = 0; break;
- case UART_1: obj->index = 1; break;
- case UART_2: obj->index = 2; break;
- case UART_3: obj->index = 3; break;
- }
-
- is_stdio_uart = (uart == STDIO_UART) ? (1) : (0);
-
- if (is_stdio_uart) {
- stdio_uart_inited = 1;
- memcpy(&stdio_uart, obj, sizeof(serial_t));
- }
-}
-
-void serial_free(serial_t *obj) {
- serial_irq_ids[obj->index] = 0;
-}
-
-// serial_baud
-// set the baud rate, taking in to account the current SystemFrequency
-void serial_baud(serial_t *obj, int baudrate) {
- MBED_ASSERT((int)obj->uart <= UART_3);
- // The LPC2300 and LPC1700 have a divider and a fractional divider to control the
- // baud rate. The formula is:
- //
- // Baudrate = (1 / PCLK) * 16 * DL * (1 + DivAddVal / MulVal)
- // where:
- // 1 < MulVal <= 15
- // 0 <= DivAddVal < 14
- // DivAddVal < MulVal
- //
- // set pclk to /1
- switch ((int)obj->uart) {
- case UART_0: LPC_SC->PCLKSEL0 &= ~(0x3 << 6); LPC_SC->PCLKSEL0 |= (0x1 << 6); break;
- case UART_1: LPC_SC->PCLKSEL0 &= ~(0x3 << 8); LPC_SC->PCLKSEL0 |= (0x1 << 8); break;
- case UART_2: LPC_SC->PCLKSEL1 &= ~(0x3 << 16); LPC_SC->PCLKSEL1 |= (0x1 << 16); break;
- case UART_3: LPC_SC->PCLKSEL1 &= ~(0x3 << 18); LPC_SC->PCLKSEL1 |= (0x1 << 18); break;
- default: break;
- }
-
- uint32_t PCLK = SystemCoreClock;
-
- // First we check to see if the basic divide with no DivAddVal/MulVal
- // ratio gives us an integer result. If it does, we set DivAddVal = 0,
- // MulVal = 1. Otherwise, we search the valid ratio value range to find
- // the closest match. This could be more elegant, using search methods
- // and/or lookup tables, but the brute force method is not that much
- // slower, and is more maintainable.
- uint16_t DL = PCLK / (16 * baudrate);
-
- uint8_t DivAddVal = 0;
- uint8_t MulVal = 1;
- int hit = 0;
- uint16_t dlv;
- uint8_t mv, dav;
- if ((PCLK % (16 * baudrate)) != 0) { // Checking for zero remainder
- int err_best = baudrate, b;
- for (mv = 1; mv < 16 && !hit; mv++)
- {
- for (dav = 0; dav < mv; dav++)
- {
- // baudrate = PCLK / (16 * dlv * (1 + (DivAdd / Mul))
- // solving for dlv, we get dlv = mul * PCLK / (16 * baudrate * (divadd + mul))
- // mul has 4 bits, PCLK has 27 so we have 1 bit headroom which can be used for rounding
- // for many values of mul and PCLK we have 2 or more bits of headroom which can be used to improve precision
- // note: X / 32 doesn't round correctly. Instead, we use ((X / 16) + 1) / 2 for correct rounding
-
- if ((mv * PCLK * 2) & 0x80000000) // 1 bit headroom
- dlv = ((((2 * mv * PCLK) / (baudrate * (dav + mv))) / 16) + 1) / 2;
- else // 2 bits headroom, use more precision
- dlv = ((((4 * mv * PCLK) / (baudrate * (dav + mv))) / 32) + 1) / 2;
-
- // datasheet says if DLL==DLM==0, then 1 is used instead since divide by zero is ungood
- if (dlv == 0)
- dlv = 1;
-
- // datasheet says if dav > 0 then DL must be >= 2
- if ((dav > 0) && (dlv < 2))
- dlv = 2;
-
- // integer rearrangement of the baudrate equation (with rounding)
- b = ((PCLK * mv / (dlv * (dav + mv) * 8)) + 1) / 2;
-
- // check to see how we went
- b = abs(b - baudrate);
- if (b < err_best)
- {
- err_best = b;
-
- DL = dlv;
- MulVal = mv;
- DivAddVal = dav;
-
- if (b == baudrate)
- {
- hit = 1;
- break;
- }
- }
- }
- }
- }
-
- // set LCR[DLAB] to enable writing to divider registers
- obj->uart->LCR |= (1 << 7);
-
- // set divider values
- obj->uart->DLM = (DL >> 8) & 0xFF;
- obj->uart->DLL = (DL >> 0) & 0xFF;
- obj->uart->FDR = (uint32_t) DivAddVal << 0
- | (uint32_t) MulVal << 4;
-
- // clear LCR[DLAB]
- obj->uart->LCR &= ~(1 << 7);
-}
-
-void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
- MBED_ASSERT((stop_bits == 1) || (stop_bits == 2)); // 0: 1 stop bits, 1: 2 stop bits
- MBED_ASSERT((data_bits > 4) && (data_bits < 9)); // 0: 5 data bits ... 3: 8 data bits
- MBED_ASSERT((parity == ParityNone) || (parity == ParityOdd) || (parity == ParityEven) ||
- (parity == ParityForced1) || (parity == ParityForced0));
-
- stop_bits -= 1;
- data_bits -= 5;
-
- int parity_enable = 0, parity_select = 0;
- switch (parity) {
- case ParityNone: parity_enable = 0; parity_select = 0; break;
- case ParityOdd : parity_enable = 1; parity_select = 0; break;
- case ParityEven: parity_enable = 1; parity_select = 1; break;
- case ParityForced1: parity_enable = 1; parity_select = 2; break;
- case ParityForced0: parity_enable = 1; parity_select = 3; break;
- default:
- break;
- }
-
- obj->uart->LCR = data_bits << 0
- | stop_bits << 2
- | parity_enable << 3
- | parity_select << 4;
-}
-
-/******************************************************************************
- * INTERRUPTS HANDLING
- ******************************************************************************/
-static inline void uart_irq(uint32_t iir, uint32_t index) {
- // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling
- SerialIrq irq_type;
- switch (iir) {
- case 1: irq_type = TxIrq; break;
- case 2: irq_type = RxIrq; break;
- default: return;
- }
-
- if (serial_irq_ids[index] != 0)
- irq_handler(serial_irq_ids[index], irq_type);
-}
-
-void uart0_irq() {uart_irq((LPC_UART0->IIR >> 1) & 0x7, 0);}
-void uart1_irq() {uart_irq((LPC_UART1->IIR >> 1) & 0x7, 1);}
-void uart2_irq() {uart_irq((LPC_UART2->IIR >> 1) & 0x7, 2);}
-void uart3_irq() {uart_irq((LPC_UART3->IIR >> 1) & 0x7, 3);}
-
-void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
- irq_handler = handler;
- serial_irq_ids[obj->index] = id;
-}
-
-void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
- IRQn_Type irq_n = (IRQn_Type)0;
- uint32_t vector = 0;
- switch ((int)obj->uart) {
- case UART_0: irq_n=UART0_IRQn; vector = (uint32_t)&uart0_irq; break;
- case UART_1: irq_n=UART1_IRQn; vector = (uint32_t)&uart1_irq; break;
- case UART_2: irq_n=UART2_IRQn; vector = (uint32_t)&uart2_irq; break;
- case UART_3: irq_n=UART3_IRQn; vector = (uint32_t)&uart3_irq; break;
- }
-
- if (enable) {
- obj->uart->IER |= 1 << irq;
- NVIC_SetVector(irq_n, vector);
- NVIC_EnableIRQ(irq_n);
- } else { // disable
- int all_disabled = 0;
- SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
- obj->uart->IER &= ~(1 << irq);
- all_disabled = (obj->uart->IER & (1 << other_irq)) == 0;
- if (all_disabled)
- NVIC_DisableIRQ(irq_n);
- }
-}
-
-/******************************************************************************
- * READ/WRITE
- ******************************************************************************/
-int serial_getc(serial_t *obj) {
- while (!serial_readable(obj));
- return obj->uart->RBR;
-}
-
-void serial_putc(serial_t *obj, int c) {
- while (!serial_writable(obj));
- obj->uart->THR = c;
-}
-
-int serial_readable(serial_t *obj) {
- return obj->uart->LSR & 0x01;
-}
-
-int serial_writable(serial_t *obj) {
- return obj->uart->LSR & 0x20;
-}
-
-void serial_clear(serial_t *obj) {
- obj->uart->FCR = 1 << 1 // rx FIFO reset
- | 1 << 2 // tx FIFO reset
- | 0 << 6; // interrupt depth
-}
-
-void serial_pinout_tx(PinName tx) {
- pinmap_pinout(tx, PinMap_UART_TX);
-}
-
-void serial_break_set(serial_t *obj) {
- obj->uart->LCR |= (1 << 6);
-}
-
-void serial_break_clear(serial_t *obj) {
- obj->uart->LCR &= ~(1 << 6);
-}
-