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v2.2-tranZPUter-SW-HW_700_1MB_v1.3
zSoft/teensy3/serial6_lpuart.c

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/* Teensyduino Core Library
* http://www.pjrc.com/teensy/
* Copyright (c) 2017 PJRC.COM, LLC.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* 1. The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* 2. If the Software is incorporated into a build system that allows
* selection among a list of target devices, then similar target
* devices manufactured by PJRC.COM must be included in the list of
* target devices and selectable in the same manner.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "kinetis.h"
#include "core_pins.h"
#include "HardwareSerial.h"
#ifdef HAS_KINETISK_LPUART0
#define GPIO_BITBAND_ADDR(reg, bit) (((uint32_t)&(reg) - 0x40000000) * 32 + (bit) * 4 + 0x42000000)
#define GPIO_BITBAND_PTR(reg, bit) ((uint32_t *)GPIO_BITBAND_ADDR((reg), (bit)))
#define BITBAND_SET_BIT(reg, bit) (*GPIO_BITBAND_PTR((reg), (bit)) = 1)
#define BITBAND_CLR_BIT(reg, bit) (*GPIO_BITBAND_PTR((reg), (bit)) = 0)
#define TCIE_BIT 22
#define TIE_BIT 23
////////////////////////////////////////////////////////////////
// Tunable parameters (relatively safe to edit these numbers)
////////////////////////////////////////////////////////////////
#ifndef SERIAL6_TX_BUFFER_SIZE
#define SERIAL6_TX_BUFFER_SIZE 40 // number of outgoing bytes to buffer
#endif
#ifndef SERIAL6_RX_BUFFER_SIZE
#define SERIAL6_RX_BUFFER_SIZE 64 // number of incoming bytes to buffer
#endif
#define RTS_HIGH_WATERMARK (SERIAL6_RX_BUFFER_SIZE-24) // RTS requests sender to pause
#define RTS_LOW_WATERMARK (SERIAL6_RX_BUFFER_SIZE-38) // RTS allows sender to resume
#define IRQ_PRIORITY 64 // 0 = highest priority, 255 = lowest
////////////////////////////////////////////////////////////////
// changes not recommended below this point....
////////////////////////////////////////////////////////////////
#ifdef SERIAL_9BIT_SUPPORT
static uint8_t use9Bits = 0;
#define BUFTYPE uint16_t
#else
#define BUFTYPE uint8_t
#define use9Bits 0
#endif
static volatile BUFTYPE tx_buffer[SERIAL6_TX_BUFFER_SIZE];
static volatile BUFTYPE rx_buffer[SERIAL6_RX_BUFFER_SIZE];
static volatile uint8_t transmitting = 0;
static volatile uint8_t *transmit_pin=NULL;
#define transmit_assert() *transmit_pin = 1
#define transmit_deassert() *transmit_pin = 0
static volatile uint8_t *rts_pin=NULL;
#define rts_assert() *rts_pin = 0
#define rts_deassert() *rts_pin = 1
#if SERIAL6_TX_BUFFER_SIZE > 255
static volatile uint16_t tx_buffer_head = 0;
static volatile uint16_t tx_buffer_tail = 0;
#else
static volatile uint8_t tx_buffer_head = 0;
static volatile uint8_t tx_buffer_tail = 0;
#endif
#if SERIAL6_RX_BUFFER_SIZE > 255
static volatile uint16_t rx_buffer_head = 0;
static volatile uint16_t rx_buffer_tail = 0;
#else
static volatile uint8_t rx_buffer_head = 0;
static volatile uint8_t rx_buffer_tail = 0;
#endif
static uint8_t tx_pin_num = 48;
// UART0 and UART1 are clocked by F_CPU, UART2 is clocked by F_BUS
// UART0 has 8 byte fifo, UART1 and UART2 have 1 byte buffer
void serial6_begin(uint32_t desiredBaudRate)
{
#define F_LPUART_CLOCK_SPEED 48000000 //F_BUS
// Make sure the clock for this uart is enabled, else the registers are not
// vailable.
SIM_SCGC2 |= SIM_SCGC2_LPUART0; // Turn on the clock
// Convert the baud rate to best divisor and OSR, based off of code I found in posting
// try to find an OSR > 4 with the minimum difference from the actual disired baud rate.
uint16_t sbr, sbrTemp, osrCheck;
uint32_t osr, baudDiffCheck, calculatedBaud, baudDiff;
uint32_t clockSpeed;
// First lets figure out what the LPUART Clock speed is.
uint32_t PLLFLLSEL = SIM_SOPT2 & SIM_SOPT2_IRC48SEL; // Note: Bot bits on here
if (PLLFLLSEL == SIM_SOPT2_IRC48SEL)
clockSpeed = 48000000; // Fixed to 48mhz
else if (PLLFLLSEL == SIM_SOPT2_PLLFLLSEL)
clockSpeed = F_PLL; // Using PLL clock
else
clockSpeed = F_CPU/4; // FLL clock, guessing
osr = 4;
sbr = (clockSpeed/(desiredBaudRate * osr));
/*set sbr to 1 if the clockSpeed can not satisfy the desired baud rate*/
if(sbr == 0) {
// Maybe print something.
return; // can not initialize
}
// With integer math the divide*muliply implies the calculated baud will be >= desired baud
calculatedBaud = (clockSpeed / (osr * sbr));
baudDiff = calculatedBaud - desiredBaudRate;
// Check if better off with sbr+1
if (baudDiff != 0) {
calculatedBaud = (clockSpeed / (osr * (sbr + 1)));
baudDiffCheck = desiredBaudRate - calculatedBaud ;
if (baudDiffCheck < baudDiff) {
sbr++; // use the higher sbr
baudDiff = baudDiffCheck;
}
}
// loop to find the best osr value possible, one that generates minimum baudDiff
for (osrCheck = 5; osrCheck <= 32; osrCheck++) {
sbrTemp = (clockSpeed/(desiredBaudRate * osrCheck));
if(sbrTemp == 0)
break; // higher divisor returns 0 so can not use...
// Remember integer math so (X/Y)*Y will always be <=X
calculatedBaud = (clockSpeed / (osrCheck * sbrTemp));
baudDiffCheck = calculatedBaud - desiredBaudRate;
if (baudDiffCheck <= baudDiff) {
baudDiff = baudDiffCheck;
osr = osrCheck;
sbr = sbrTemp;
}
// Lets try the rounded up one as well
if (baudDiffCheck) {
calculatedBaud = (clockSpeed / (osrCheck * ++sbrTemp));
baudDiffCheck = desiredBaudRate - calculatedBaud;
if (baudDiffCheck <= baudDiff) {
baudDiff = baudDiffCheck;
osr = osrCheck;
sbr = sbrTemp;
}
}
}
// for lower OSR <= 7x turn on both edge sampling
uint32_t lpb = LPUART_BAUD_OSR(osr-1) | LPUART_BAUD_SBR(sbr);
if (osr < 8) {
lpb |= LPUART_BAUD_BOTHEDGE;
}
LPUART0_BAUD = lpb;
SIM_SOPT2 |= SIM_SOPT2_LPUARTSRC(1); // Lets use PLL?
rx_buffer_head = 0;
rx_buffer_tail = 0;
tx_buffer_head = 0;
tx_buffer_tail = 0;
transmitting = 0;
CORE_PIN47_CONFIG = PORT_PCR_PE | PORT_PCR_PS | PORT_PCR_PFE | PORT_PCR_MUX(5);
CORE_PIN48_CONFIG = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(5);
LPUART0_CTRL = 0;
LPUART0_MATCH = 0;
LPUART0_STAT = 0;
// Enable the transmitter, receiver and enable receiver interrupt
LPUART0_CTRL |= LPUART_CTRL_RIE | LPUART_CTRL_TE | LPUART_CTRL_RE;
NVIC_SET_PRIORITY(IRQ_LPUART0, IRQ_PRIORITY);
NVIC_ENABLE_IRQ(IRQ_LPUART0);
}
void serial6_format(uint32_t format)
{
uint32_t c;
// Bits 0-2 - Parity plus 9 bit.
c = LPUART0_CTRL;
//c = (c & ~(LPUART_CTRL_M | LPUART_CTRL_PE | LPUART_CTRL_PT)) | (format & (LPUART_CTRL_PE | LPUART_CTRL_PT)); // configure parity
//if (format & 0x04) c |= LPUART_CTRL_M; // 9 bits (might include parity)
c = (c & ~0x13) | (format & 0x03); // configure parity
if (format & 0x04) c |= 0x10; // 9 bits (might include parity)
LPUART0_CTRL = c;
if ((format & 0x0F) == 0x04) LPUART0_CTRL |= LPUART_CTRL_T8; // 8N2 is 9 bit with 9th bit always 1
// Bit 3 10 bit - Will assume that begin already cleared it.
if (format & 0x08)
LPUART0_BAUD |= LPUART_BAUD_M10;
// Bit 4 RXINVERT
c = LPUART0_STAT & ~LPUART_STAT_RXINV;
if (format & 0x10) c |= LPUART_STAT_RXINV; // rx invert
LPUART0_STAT = c;
// Bit 5 TXINVERT
c = LPUART0_CTRL & ~LPUART_CTRL_TXINV;
if (format & 0x20) c |= LPUART_CTRL_TXINV; // tx invert
LPUART0_CTRL = c;
// For T3.6 See about turning on 2 stop bit mode
if ( format & 0x100) LPUART0_BAUD |= LPUART_BAUD_SBNS;
}
void serial6_end(void)
{
if (!(SIM_SCGC2 & SIM_SCGC2_LPUART0)) return;
while (transmitting) yield(); // wait for buffered data to send
NVIC_DISABLE_IRQ(IRQ_LPUART0);
LPUART0_CTRL = 0;
CORE_PIN47_CONFIG = PORT_PCR_PE | PORT_PCR_PS | PORT_PCR_MUX(1);
CORE_PIN48_CONFIG = PORT_PCR_PE | PORT_PCR_PS | PORT_PCR_MUX(1);
rx_buffer_head = 0;
rx_buffer_tail = 0;
if (rts_pin) rts_deassert();
}
void serial6_set_transmit_pin(uint8_t pin)
{
while (transmitting) ;
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
transmit_pin = portOutputRegister(pin);
}
void serial6_set_tx(uint8_t pin, uint8_t opendrain)
{
uint32_t cfg;
if (opendrain) pin |= 128;
if (pin == tx_pin_num) return;
if ((SIM_SCGC2 & SIM_SCGC2_LPUART0)) {
switch (tx_pin_num & 127) {
case 48: CORE_PIN48_CONFIG = 0; break; // PTE24
}
if (opendrain) {
cfg = PORT_PCR_DSE | PORT_PCR_ODE;
} else {
cfg = PORT_PCR_DSE | PORT_PCR_SRE;
}
switch (pin & 127) {
case 48: CORE_PIN48_CONFIG = cfg | PORT_PCR_MUX(5); break;
}
}
tx_pin_num = pin;
}
void serial6_set_rx(uint8_t pin)
{
}
int serial6_set_rts(uint8_t pin)
{
if (!(SIM_SCGC2 & SIM_SCGC2_LPUART0)) return 0;
if (pin < CORE_NUM_DIGITAL) {
rts_pin = portOutputRegister(pin);
pinMode(pin, OUTPUT);
rts_assert();
} else {
rts_pin = NULL;
return 0;
}
return 1;
}
int serial6_set_cts(uint8_t pin)
{
if (!(SIM_SCGC2 & SIM_SCGC2_LPUART0)) return 0;
if (pin == 56) {
CORE_PIN56_CONFIG = PORT_PCR_MUX(5) | PORT_PCR_PE; // weak pulldown
} else {
UART5_MODEM &= ~UART_MODEM_TXCTSE;
return 0;
}
UART5_MODEM |= UART_MODEM_TXCTSE;
return 1;
}
void serial6_putchar(uint32_t c)
{
uint32_t head, n;
if (!(SIM_SCGC2 & SIM_SCGC2_LPUART0)) return;
if (transmit_pin) transmit_assert();
head = tx_buffer_head;
if (++head >= SERIAL6_TX_BUFFER_SIZE) head = 0;
while (tx_buffer_tail == head) {
int priority = nvic_execution_priority();
if (priority <= IRQ_PRIORITY) {
if ((LPUART0_STAT & LPUART_STAT_TDRE)) {
uint32_t tail = tx_buffer_tail;
if (++tail >= SERIAL6_TX_BUFFER_SIZE) tail = 0;
n = tx_buffer[tail];
//if (use9Bits) UART5_C3 = (UART5_C3 & ~0x40) | ((n & 0x100) >> 2);
LPUART0_DATA = n;
tx_buffer_tail = tail;
}
} else if (priority >= 256) {
yield(); // wait
}
}
tx_buffer[head] = c;
transmitting = 1;
tx_buffer_head = head;
//LPUART0_CTRL |= LPUART_CTRL_TIE; // enable the transmit interrupt
BITBAND_SET_BIT(LPUART0_CTRL, TIE_BIT);
}
void serial6_write(const void *buf, unsigned int count)
{
const uint8_t *p = (const uint8_t *)buf;
while (count-- > 0) serial6_putchar(*p++);
}
void serial6_flush(void)
{
while (transmitting) yield(); // wait
}
int serial6_write_buffer_free(void)
{
uint32_t head, tail;
head = tx_buffer_head;
tail = tx_buffer_tail;
if (head >= tail) return SERIAL6_TX_BUFFER_SIZE - 1 - head + tail;
return tail - head - 1;
}
int serial6_available(void)
{
uint32_t head, tail;
head = rx_buffer_head;
tail = rx_buffer_tail;
if (head >= tail) return head - tail;
return SERIAL6_RX_BUFFER_SIZE + head - tail;
}
int serial6_getchar(void)
{
uint32_t head, tail;
int c;
head = rx_buffer_head;
tail = rx_buffer_tail;
if (head == tail) return -1;
if (++tail >= SERIAL6_RX_BUFFER_SIZE) tail = 0;
c = rx_buffer[tail];
rx_buffer_tail = tail;
if (rts_pin) {
int avail;
if (head >= tail) avail = head - tail;
else avail = SERIAL6_RX_BUFFER_SIZE + head - tail;
if (avail <= RTS_LOW_WATERMARK) rts_assert();
}
return c;
}
int serial6_peek(void)
{
uint32_t head, tail;
head = rx_buffer_head;
tail = rx_buffer_tail;
if (head == tail) return -1;
if (++tail >= SERIAL6_RX_BUFFER_SIZE) tail = 0;
return rx_buffer[tail];
}
void serial6_clear(void)
{
rx_buffer_head = rx_buffer_tail;
if (rts_pin) rts_assert();
}
// status interrupt combines
// Transmit data below watermark LPUART_STAT_TDRE
// Transmit complete LPUART_STAT_TC
// Idle line LPUART_STAT_IDLE
// Receive data above watermark LPUART_STAT_RDRF
// LIN break detect UART_S2_LBKDIF
// RxD pin active edge UART_S2_RXEDGIF
void lpuart0_status_isr(void)
{
uint32_t head, tail, n;
uint32_t c;
if (LPUART0_STAT & LPUART_STAT_RDRF) {
// if (use9Bits && (UART5_C3 & 0x80)) {
// n = UART5_D | 0x100;
// } else {
// n = UART5_D;
// }
n = LPUART0_DATA & 0x3ff; // use only the 10 data bits
head = rx_buffer_head + 1;
if (head >= SERIAL6_RX_BUFFER_SIZE) head = 0;
if (head != rx_buffer_tail) {
rx_buffer[head] = n;
rx_buffer_head = head;
}
if (rts_pin) {
int avail;
tail = tx_buffer_tail;
if (head >= tail) avail = head - tail;
else avail = SERIAL6_RX_BUFFER_SIZE + head - tail;
if (avail >= RTS_HIGH_WATERMARK) rts_deassert();
}
}
c = LPUART0_CTRL;
if ((c & LPUART_CTRL_TIE) && (LPUART0_STAT & LPUART_STAT_TDRE)) {
head = tx_buffer_head;
tail = tx_buffer_tail;
if (head == tail) {
BITBAND_CLR_BIT(LPUART0_CTRL, TIE_BIT);
BITBAND_SET_BIT(LPUART0_CTRL, TCIE_BIT);
//LPUART0_CTRL &= ~LPUART_CTRL_TIE;
//LPUART0_CTRL |= LPUART_CTRL_TCIE; // Actually wondering if we can just leave this one on...
} else {
if (++tail >= SERIAL6_TX_BUFFER_SIZE) tail = 0;
n = tx_buffer[tail];
//if (use9Bits) UART5_C3 = (UART5_C3 & ~0x40) | ((n & 0x100) >> 2);
LPUART0_DATA = n;
tx_buffer_tail = tail;
}
}
if ((c & LPUART_CTRL_TCIE) && (LPUART0_STAT & LPUART_STAT_TC)) {
transmitting = 0;
if (transmit_pin) transmit_deassert();
BITBAND_CLR_BIT(LPUART0_CTRL, TCIE_BIT);
// LPUART0_CTRL &= ~LPUART_CTRL_TCIE; // Actually wondering if we can just leave this one on...
}
}
#endif // HAS_KINETISK_LPUART0
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