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neorv32/sw/lib/source/neorv32_onewire.c

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// #################################################################################################
// # << NEORV32: neorv32_onewire.c - 1-Wire Interface Controller HW Driver HW Driver (Source) >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2022, Stephan Nolting. All rights reserved. #
// # #
// # Redistribution and use in source and binary forms, with or without modification, are #
// # permitted provided that the following conditions are met: #
// # #
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
// # conditions and the following disclaimer. #
// # #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
// # conditions and the following disclaimer in the documentation and/or other materials #
// # provided with the distribution. #
// # #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
// # endorse or promote products derived from this software without specific prior written #
// # permission. #
// # #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file neorv32_onewire.c
* @brief 1-Wire Interface Controller (ONEWIRE) HW driver source file.
*
* @note These functions should only be used if the ONEWIRE unit was synthesized (IO_ONEWIRE_EN = true).
**************************************************************************/
#include "neorv32.h"
#include "neorv32_onewire.h"
/**********************************************************************//**
* Check if ONEWIRE controller was synthesized.
*
* @return 0 if ONEWIRE was not synthesized, 1 if ONEWIRE is available.
**************************************************************************/
int neorv32_onewire_available(void) {
if (NEORV32_SYSINFO->SOC & (1 << SYSINFO_SOC_IO_ONEWIRE)) {
return 1;
}
else {
return 0;
}
}
/**********************************************************************//**
* Reset, configure and enable ONEWIRE interface controller.
*
* @param[in] t_base Base tick time in ns.
* @return 0 if configuration failed, otherwise the actual t_base time in ns is returned.
**************************************************************************/
int neorv32_onewire_setup(uint32_t t_base) {
const uint8_t PRSC_LUT[4] = {2, 4, 8, 64}; // subset of system clock prescalers
// reset
NEORV32_ONEWIRE->CTRL = 0;
NEORV32_ONEWIRE->DATA = 0;
uint32_t t_tick;
uint32_t clkdiv;
uint32_t clk_prsc_sel = 0; // initial prsc = CLK/2
uint32_t t_clock_x250ps = (4 * 1000 * 1000 * 1000U) / NEORV32_SYSINFO->CLK; // t_clock in multiples of 0.25 ns
// find best base tick configuration
while (1) {
t_tick = t_clock_x250ps * PRSC_LUT[clk_prsc_sel];
clkdiv = (4*t_base) / t_tick;
if ((clkdiv > 0) && (clkdiv <= 255)) { // 8-bit
break;
}
else if (clk_prsc_sel < 3) {
clk_prsc_sel++; // try next-higher clock prescaler
}
else {
return 0; // failed
}
}
// set new configuration
uint32_t ctrl = 0;
ctrl |= 1 << ONEWIRE_CTRL_EN; // module enable
ctrl |= (clk_prsc_sel & 0x3) << ONEWIRE_CTRL_PRSC0; // clock prescaler
ctrl |= ((clkdiv - 1) & 0xff) << ONEWIRE_CTRL_CLKDIV0; // clock divider
NEORV32_ONEWIRE->CTRL = ctrl;
return (int)((t_clock_x250ps / 4) * PRSC_LUT[clk_prsc_sel] * clkdiv);
}
/**********************************************************************//**
* Enable ONEWIRE controller.
**************************************************************************/
void neorv32_onewire_enable(void) {
NEORV32_ONEWIRE->CTRL |= (1 << ONEWIRE_CTRL_EN);
}
/**********************************************************************//**
* Disable ONEWIRE controller.
**************************************************************************/
void neorv32_onewire_disable(void) {
NEORV32_ONEWIRE->CTRL &= ~(1 << ONEWIRE_CTRL_EN);
}
/**********************************************************************//**
* Get current bus state.
*
* @return 1 if bus is high, 0 if bus is low.
**************************************************************************/
int neorv32_onewire_sense(void) {
if (NEORV32_ONEWIRE->CTRL & (1 << ONEWIRE_CTRL_SENSE)) {
return 1;
}
else {
return 0;
}
}
// ----------------------------------------------------------------------------------------------------------------------------
// NON-BLOCKING functions
// ----------------------------------------------------------------------------------------------------------------------------
/**********************************************************************//**
* Check if ONEWIRE module is busy.
*
* @note This function is non-blocking.
*
* @return 0 if not busy, 1 if busy.
**************************************************************************/
int neorv32_onewire_busy(void) {
// check busy flag
if (NEORV32_ONEWIRE->CTRL & (1 << ONEWIRE_CTRL_BUSY)) {
return 1;
}
else {
return 0;
}
}
/**********************************************************************//**
* Initiate reset pulse.
*
* @note This function is non-blocking.
**************************************************************************/
void neorv32_onewire_reset(void) {
// trigger reset-pulse operation
NEORV32_ONEWIRE->CTRL |= 1 << ONEWIRE_CTRL_TRIG_RST;
}
/**********************************************************************//**
* Get bus presence (after RESET).
*
* @note This function is non-blocking.
*
* @return 0 if at lest one device is present, -1 otherwise
**************************************************************************/
int neorv32_onewire_reset_get_presence(void) {
// check presence bit
if (NEORV32_ONEWIRE->CTRL & (1 << ONEWIRE_CTRL_PRESENCE)) {
return 0;
}
else {
return -1;
}
}
/**********************************************************************//**
* Initiate single-bit read.
*
* @note This function is non-blocking.
**************************************************************************/
void neorv32_onewire_read_bit(void) {
// output all-one
NEORV32_ONEWIRE->DATA = 0xff;
// trigger bit operation
NEORV32_ONEWIRE->CTRL |= (1 << ONEWIRE_CTRL_TRIG_BIT);
}
/**********************************************************************//**
* Get bit from previous single-bit read operation
*
* @note This function is non-blocking.
*
* @return Read bit in bit 0.
**************************************************************************/
uint8_t neorv32_onewire_read_bit_get(void) {
// return read bit
if (NEORV32_ONEWIRE->DATA & (1 << 7)) { // LSB first -> read bit is in MSB
return 1;
}
else {
return 0;
}
}
/**********************************************************************//**
* Initiate single-bit write.
*
* @note This function is non-blocking.
*
* @param[in] bit Bit to be send.
**************************************************************************/
void neorv32_onewire_write_bit(uint8_t bit) {
// set replicated bit
if (bit) {
NEORV32_ONEWIRE->DATA = 0xff;
}
else {
NEORV32_ONEWIRE->DATA = 0x00;
}
// trigger bit operation
NEORV32_ONEWIRE->CTRL |= (1 << ONEWIRE_CTRL_TRIG_BIT);
}
/**********************************************************************//**
* Initiate read byte.
*
* @note This function is non-blocking.
**************************************************************************/
void neorv32_onewire_read_byte(void) {
// output all-one
NEORV32_ONEWIRE->DATA = 0xff;
//trigger byte operation
NEORV32_ONEWIRE->CTRL |= (1 << ONEWIRE_CTRL_TRIG_BYTE);
}
/**********************************************************************//**
* Get data from previous read byte operation.
*
* @note This function is non-blocking.
*
* @return Read byte.
**************************************************************************/
uint8_t neorv32_onewire_read_byte_get(void) {
// return read bit
return (uint8_t)(NEORV32_ONEWIRE->DATA);
}
/**********************************************************************//**
* Initiate write byte.
*
* @note This function is non-blocking.
*
* @param[in] byte Byte to be send.
**************************************************************************/
void neorv32_onewire_write_byte(uint8_t byte) {
// TX data
NEORV32_ONEWIRE->DATA = (uint32_t)byte;
// and trigger byte operation
NEORV32_ONEWIRE->CTRL |= (1 << ONEWIRE_CTRL_TRIG_BYTE);
}
// ----------------------------------------------------------------------------------------------------------------------------
// BLOCKING functions
// ----------------------------------------------------------------------------------------------------------------------------
/**********************************************************************//**
* Generate reset pulse and check if any bus device is present.
*
* @warning This function is blocking!
*
* @return 0 if at lest one device is present, -1 otherwise
**************************************************************************/
int neorv32_onewire_reset_blocking(void) {
// trigger reset-pulse operation
neorv32_onewire_reset();
// wait for operation to complete
while (neorv32_onewire_busy());
// check presence bit
return neorv32_onewire_reset_get_presence();
}
/**********************************************************************//**
* Read single bit.
*
* @warning This function is blocking!
*
* @return Read bit in bit 0.
**************************************************************************/
uint8_t neorv32_onewire_read_bit_blocking(void) {
// trigger read-bit operation
neorv32_onewire_read_bit();
// wait for operation to complete
while (neorv32_onewire_busy());
// return read bit
return neorv32_onewire_read_bit_get();
}
/**********************************************************************//**
* Write single bit.
*
* @warning This function is blocking!
*
* @param[in] bit Bit to be send.
**************************************************************************/
void neorv32_onewire_write_bit_blocking(uint8_t bit) {
// start single-bit write
neorv32_onewire_write_bit(bit);
// wait for operation to complete
while (neorv32_onewire_busy());
}
/**********************************************************************//**
* Read byte.
*
* @warning This function is blocking!
*
* @return Read byte.
**************************************************************************/
uint8_t neorv32_onewire_read_byte_blocking(void) {
// initiate read byte
neorv32_onewire_read_byte();
// wait for operation to complete
while (neorv32_onewire_busy());
// return read byte
return neorv32_onewire_read_byte_get();
}
/**********************************************************************//**
* Write byte.
*
* @warning This function is blocking!
*
* @param[in] byte Byte to be send.
**************************************************************************/
void neorv32_onewire_write_byte_blocking(uint8_t byte) {
// initiate write byte
neorv32_onewire_write_byte(byte);
// wait for operation to complete
while (neorv32_onewire_busy());
}
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