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mbed-os/targets/TARGET_Freescale/TARGET_KLXX/TARGET_KL05Z/serial_api.c

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/* 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.
*/
#include "mbed_assert.h"
#include "serial_api.h"
// math.h required for floating point operations for baud rate calculation
#include <math.h>
#include <string.h>
#include "cmsis.h"
#include "pinmap.h"
#include "clk_freqs.h"
#include "PeripheralPins.h"
//Devices either user UART0 or UARTLP
#ifndef UARTLP_BASES
#define UARTLP_C2_RE_MASK UART0_C2_RE_MASK
#define UARTLP_C2_TE_MASK UART0_C2_TE_MASK
#define UARTLP_BDH_SBNS_MASK UART0_BDH_SBNS_MASK
#define UARTLP_BDH_SBNS_SHIFT UART0_BDH_SBNS_SHIFT
#define UARTLP_S1_TDRE_MASK UART0_S1_TDRE_MASK
#define UARTLP_S1_OR_MASK UART0_S1_OR_MASK
#define UARTLP_C2_RIE_MASK UART0_C2_RIE_MASK
#define UARTLP_C2_TIE_MASK UART0_C2_TIE_MASK
#define UARTLP_C2_SBK_MASK UART0_C2_SBK_MASK
#define UARTLP_S1_RDRF_MASK UART0_S1_RDRF_MASK
#endif
#ifdef UART2
#define UART_NUM 3
#else
#define UART_NUM 1
#endif
/******************************************************************************
* INITIALIZATION
******************************************************************************/
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) {
// 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 = (UARTLP_Type *)uart;
// enable clk
switch (uart) {
case UART_0: if (mcgpllfll_frequency() != 0) //PLL/FLL is selected
SIM->SOPT2 |= (1<<SIM_SOPT2_UART0SRC_SHIFT);
else
SIM->SOPT2 |= (2<<SIM_SOPT2_UART0SRC_SHIFT);
SIM->SCGC4 |= SIM_SCGC4_UART0_MASK; break;
#if UART_NUM > 1
case UART_1: SIM->SCGC4 |= SIM_SCGC4_UART1_MASK; break;
case UART_2: SIM->SCGC4 |= SIM_SCGC4_UART2_MASK; break;
#endif
}
// Disable UART before changing registers
obj->uart->C2 &= ~(UARTLP_C2_RE_MASK | UARTLP_C2_TE_MASK);
switch (uart) {
case UART_0: obj->index = 0; break;
#if UART_NUM > 1
case UART_1: obj->index = 1; break;
case UART_2: obj->index = 2; break;
#endif
}
// 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);
}
obj->uart->C2 |= (UARTLP_C2_RE_MASK | UARTLP_C2_TE_MASK);
if (uart == 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) {
// save C2 state
uint8_t c2_state = (obj->uart->C2 & (UARTLP_C2_RE_MASK | UARTLP_C2_TE_MASK));
// Disable UART before changing registers
obj->uart->C2 &= ~(UARTLP_C2_RE_MASK | UARTLP_C2_TE_MASK);
uint32_t PCLK;
if (obj->uart == UART0) {
if (mcgpllfll_frequency() != 0)
PCLK = mcgpllfll_frequency();
else
PCLK = extosc_frequency();
} else
PCLK = bus_frequency();
// 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);
// set BDH and BDL
obj->uart->BDH = (obj->uart->BDH & ~(0x1f)) | ((DL >> 8) & 0x1f);
obj->uart->BDL = (obj->uart->BDL & ~(0xff)) | ((DL >> 0) & 0xff);
// restore C2 state
obj->uart->C2 |= c2_state;
}
void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) {
MBED_ASSERT((stop_bits == 1) || (stop_bits == 2));
MBED_ASSERT((parity == ParityNone) || (parity == ParityOdd) || (parity == ParityEven));
MBED_ASSERT(data_bits == 8); // TODO: Support other number of data bits (also in the write method!)
// save C2 state
uint8_t c2_state = (obj->uart->C2 & (UARTLP_C2_RE_MASK | UARTLP_C2_TE_MASK));
// Disable UART before changing registers
obj->uart->C2 &= ~(UARTLP_C2_RE_MASK | UARTLP_C2_TE_MASK);
uint8_t parity_enable, parity_select;
switch (parity) {
case ParityNone: parity_enable = 0; parity_select = 0; break;
case ParityOdd : parity_enable = 1; parity_select = 1; data_bits++; break;
case ParityEven: parity_enable = 1; parity_select = 0; data_bits++; break;
default:
break;
}
stop_bits -= 1;
// data bits, parity and parity mode
obj->uart->C1 = ((parity_enable << 1)
| (parity_select << 0));
// stop bits
obj->uart->BDH &= ~UARTLP_BDH_SBNS_MASK;
obj->uart->BDH |= (stop_bits << UARTLP_BDH_SBNS_SHIFT);
// restore C2 state
obj->uart->C2 |= c2_state;
}
/******************************************************************************
* INTERRUPTS HANDLING
******************************************************************************/
static inline void uart_irq(uint8_t status, uint32_t index) {
if (serial_irq_ids[index] != 0) {
if (status & UARTLP_S1_TDRE_MASK)
irq_handler(serial_irq_ids[index], TxIrq);
if (status & UARTLP_S1_RDRF_MASK)
irq_handler(serial_irq_ids[index], RxIrq);
}
}
void uart0_irq() {
uart_irq(UART0->S1, 0);
if (UART0->S1 & UARTLP_S1_OR_MASK)
UART0->S1 |= UARTLP_S1_OR_MASK;
}
#if UART_NUM > 1
void uart1_irq() {uart_irq(UART1->S1, 1);}
void uart2_irq() {uart_irq(UART2->S1, 2);}
#endif
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;
#if UART_NUM > 1
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;
#endif
}
if (enable) {
switch (irq) {
case RxIrq: obj->uart->C2 |= (UARTLP_C2_RIE_MASK); break;
case TxIrq: obj->uart->C2 |= (UARTLP_C2_TIE_MASK); break;
}
NVIC_SetVector(irq_n, vector);
NVIC_EnableIRQ(irq_n);
} else { // disable
int all_disabled = 0;
SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);
switch (irq) {
case RxIrq: obj->uart->C2 &= ~(UARTLP_C2_RIE_MASK); break;
case TxIrq: obj->uart->C2 &= ~(UARTLP_C2_TIE_MASK); break;
}
switch (other_irq) {
case RxIrq: all_disabled = (obj->uart->C2 & (UARTLP_C2_RIE_MASK)) == 0; break;
case TxIrq: all_disabled = (obj->uart->C2 & (UARTLP_C2_TIE_MASK)) == 0; break;
}
if (all_disabled)
NVIC_DisableIRQ(irq_n);
}
}
/******************************************************************************
* READ/WRITE
******************************************************************************/
int serial_getc(serial_t *obj) {
while (!serial_readable(obj));
return obj->uart->D;
}
void serial_putc(serial_t *obj, int c) {
while (!serial_writable(obj));
obj->uart->D = c;
}
int serial_readable(serial_t *obj) {
// check overrun
if (obj->uart->S1 & UARTLP_S1_OR_MASK) {
obj->uart->S1 |= UARTLP_S1_OR_MASK;
}
return (obj->uart->S1 & UARTLP_S1_RDRF_MASK);
}
int serial_writable(serial_t *obj) {
// check overrun
if (obj->uart->S1 & UARTLP_S1_OR_MASK) {
obj->uart->S1 |= UARTLP_S1_OR_MASK;
}
return (obj->uart->S1 & UARTLP_S1_TDRE_MASK);
}
void serial_clear(serial_t *obj) {
}
void serial_pinout_tx(PinName tx) {
pinmap_pinout(tx, PinMap_UART_TX);
}
void serial_break_set(serial_t *obj) {
obj->uart->C2 |= UARTLP_C2_SBK_MASK;
}
void serial_break_clear(serial_t *obj) {
obj->uart->C2 &= ~UARTLP_C2_SBK_MASK;
}
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