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Diffstat (limited to 'peripheral/libmraa/src/uart_ow/uart_ow.c')
-rw-r--r--peripheral/libmraa/src/uart_ow/uart_ow.c519
1 files changed, 0 insertions, 519 deletions
diff --git a/peripheral/libmraa/src/uart_ow/uart_ow.c b/peripheral/libmraa/src/uart_ow/uart_ow.c
deleted file mode 100644
index 759ba2f..0000000
--- a/peripheral/libmraa/src/uart_ow/uart_ow.c
+++ /dev/null
@@ -1,519 +0,0 @@
-/*
- * Author: Jon Trulson <jtrulson@ics.com>
- * Copyright (c) 2016 Intel Corporation
- *
- * Portions (search) copyright:
- * Copyright (C) 2004 Dallas Semiconductor Corporation, All Rights Reserved.
- *
- * For the crc8 algorithm:
- * Copyright (c) 2002 Colin O'Flynn
- *
- * 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:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * 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 <stdlib.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <string.h>
-#include <termios.h>
-#include <fcntl.h>
-#include <errno.h>
-
-#include "uart.h"
-#include "uart_ow.h"
-#include "mraa_internal.h"
-
-// low-level read byte
-static mraa_result_t
-_ow_read_byte(mraa_uart_ow_context dev, uint8_t *ch)
-{
- while (!mraa_uart_read(dev->uart, (char*) ch, 1))
- ;
-
- return MRAA_SUCCESS;
-}
-
-// low-level write byte
-static int
-_ow_write_byte(mraa_uart_ow_context dev, const char ch)
-{
- return mraa_uart_write(dev->uart, &ch, 1);
-}
-
-// Here we setup a very simple termios with the minimum required
-// settings. We use this to also change speed from high to low. We
-// use the low speed (9600 bd) for emitting the reset pulse, and
-// high speed (115200 bd) for actual data communications.
-//
-static mraa_result_t
-_ow_set_speed(mraa_uart_ow_context dev, mraa_boolean_t speed)
-{
-
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: set_speed: context is NULL");
- return MRAA_ERROR_INVALID_HANDLE;
- }
-
- static speed_t baud;
- if (speed) {
- baud = B115200;
- }
- else {
- baud = B9600;
- }
-
- struct termios termio = {
- .c_cflag = baud | CS8 | CLOCAL | CREAD, .c_iflag = 0, .c_oflag = 0, .c_lflag = NOFLSH, .c_cc = { 0 },
- };
-
- tcflush(dev->uart->fd, TCIFLUSH);
-
- // TCSANOW is required
- if (tcsetattr(dev->uart->fd, TCSANOW, &termio) < 0) {
- syslog(LOG_ERR, "uart_ow: tcsetattr() failed");
- return MRAA_ERROR_INVALID_RESOURCE;
- }
-
- return MRAA_SUCCESS;
-}
-
-// Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
-// search state.
-// Return 1 : device found, ROM number in ROM_NO buffer
-// 0 : device not found, end of search
-//
-static mraa_boolean_t
-_ow_search(mraa_uart_ow_context dev)
-{
- int id_bit_number;
- int last_zero, rom_byte_number, search_result;
- int id_bit, cmp_id_bit;
- unsigned char rom_byte_mask, search_direction;
-
- // initialize for search
- id_bit_number = 1;
- last_zero = 0;
- rom_byte_number = 0;
- rom_byte_mask = 1;
- search_result = 0;
-
- // if the last call was not the last device
- if (!dev->LastDeviceFlag) {
- // 1-Wire reset
- if (mraa_uart_ow_reset(dev) != MRAA_SUCCESS) {
- // reset the search
- dev->LastDiscrepancy = 0;
- dev->LastDeviceFlag = 0;
- dev->LastFamilyDiscrepancy = 0;
- return 0;
- }
-
- // issue the search command
- mraa_uart_ow_write_byte(dev, MRAA_UART_OW_CMD_SEARCH_ROM);
-
- // loop to do the search
- do {
- // read a bit and its complement
- id_bit = mraa_uart_ow_bit(dev, 1);
- cmp_id_bit = mraa_uart_ow_bit(dev, 1);
-
- // check for no devices on 1-wire
- if ((id_bit == 1) && (cmp_id_bit == 1))
- break;
- else {
- // all devices coupled have 0 or 1
- if (id_bit != cmp_id_bit)
- search_direction = id_bit; // bit write value for search
- else {
- // if this discrepancy if before the Last Discrepancy
- // on a previous next then pick the same as last time
- if (id_bit_number < dev->LastDiscrepancy)
- search_direction = ((dev->ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
- else
- // if equal to last pick 1, if not then pick 0
- search_direction = (id_bit_number == dev->LastDiscrepancy);
- // if 0 was picked then record its position in LastZero
- if (search_direction == 0) {
- last_zero = id_bit_number;
- // check for Last discrepancy in family
- if (last_zero < 9)
- dev->LastFamilyDiscrepancy = last_zero;
- }
- }
-
- // set or clear the bit in the ROM byte rom_byte_number
- // with mask rom_byte_mask
- if (search_direction == 1)
- dev->ROM_NO[rom_byte_number] |= rom_byte_mask;
- else
- dev->ROM_NO[rom_byte_number] &= ~rom_byte_mask;
-
- // serial number search direction write bit
- mraa_uart_ow_bit(dev, search_direction);
-
- // increment the byte counter id_bit_number
- // and shift the mask rom_byte_mask
- id_bit_number++;
- rom_byte_mask <<= 1;
- // if the mask is 0 then go to new SerialNum byte
- // rom_byte_number and reset
- if (rom_byte_mask == 0) {
- rom_byte_number++;
- rom_byte_mask = 1;
- }
- }
- } while (rom_byte_number < 8);
-
- // loop until through all ROM bytes 0-7
- // if the search was successful then
- if (id_bit_number >= 65) {
- // search successful so set
- // LastDiscrepancy,LastDeviceFlag,search_result
- dev->LastDiscrepancy = last_zero;
-
- // check for last device
- if (dev->LastDiscrepancy == 0)
- dev->LastDeviceFlag = 1;
- }
- search_result = 1;
- }
-
- // if no device found then reset counters so next 'search' will be
- // like a first
- if (!search_result || !dev->ROM_NO[0]) {
- dev->LastDiscrepancy = 0;
- dev->LastDeviceFlag = 0;
- dev->LastFamilyDiscrepancy = 0;
- search_result = 0;
- }
-
- return search_result;
-}
-
-//--------------------------------------------------------------------------
-// Find the 'first' devices on the 1-Wire bus
-// Return 1 : device found, ROM number in ROM_NO buffer
-// 0 : no device present
-//
-static mraa_boolean_t
-_ow_first(mraa_uart_ow_context dev)
-{
- // reset the search state
- dev->LastDiscrepancy = 0;
- dev->LastDeviceFlag = 0;
- dev->LastFamilyDiscrepancy = 0;
-
- return _ow_search(dev);
-}
-
-//--------------------------------------------------------------------------
-// Find the 'next' devices on the 1-Wire bus
-// Return 1 : device found, ROM number in ROM_NO buffer
-// 0 : device not found, end of search
-//
-static mraa_boolean_t
-_ow_next(mraa_uart_ow_context dev)
-{
- // leave the search state alone
- return _ow_search(dev);
-}
-
-// Start of exported mraa functionality
-
-mraa_uart_ow_context
-mraa_uart_ow_init(int index)
-{
- mraa_uart_ow_context dev = calloc(1, sizeof(struct _mraa_uart_ow));
- if (!dev)
- return NULL;
-
- dev->uart = mraa_uart_init(index);
- if (!dev->uart)
- {
- free(dev);
- return NULL;
- }
-
-
- // now get the fd, and set it up for non-blocking operation
- if (fcntl(dev->uart->fd, F_SETFL, O_NONBLOCK) == -1) {
- syslog(LOG_ERR, "uart_ow: failed to set non-blocking on fd");
- mraa_uart_ow_stop(dev);
- return NULL;
- }
-
- return dev;
-}
-
-mraa_uart_ow_context
-mraa_uart_ow_init_raw(const char* path)
-{
- mraa_uart_ow_context dev = calloc(1, sizeof(struct _mraa_uart_ow));
- if (!dev)
- return NULL;
-
- dev->uart = mraa_uart_init_raw(path);
- if (!dev->uart)
- {
- free(dev);
- return NULL;
- }
-
- // now get the fd, and set it up for non-blocking operation
- if (fcntl(dev->uart->fd, F_SETFL, O_NONBLOCK) == -1) {
- syslog(LOG_ERR, "uart_ow: failed to set non-blocking on fd");
- mraa_uart_ow_stop(dev);
- return NULL;
- }
-
- return dev;
-}
-
-mraa_result_t
-mraa_uart_ow_stop(mraa_uart_ow_context dev)
-{
- mraa_result_t rv = mraa_uart_stop(dev->uart);
- free(dev);
- return rv;
-}
-
-const char*
-mraa_uart_ow_get_dev_path(mraa_uart_ow_context dev)
-{
- return mraa_uart_get_dev_path(dev->uart);
-}
-
-int
-mraa_uart_ow_bit(mraa_uart_ow_context dev, uint8_t bit)
-{
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: ow_bit: context is NULL");
- return -1;
- }
-
- int ret = 0;
- uint8_t ch;
- if (bit) {
- ret = _ow_write_byte(dev, 0xff); /* write a 1 bit */
- }
- else {
- ret = _ow_write_byte(dev, 0x00); /* write a 0 bit */
- }
-
- /* return the bit present on the bus (0xff is a '1', anything else
- * (typically 0xfc or 0x00) is a 0
- */
- if (_ow_read_byte(dev, &ch) == -1 || ret == -1) {
- return -1;
- }
- return (ch == 0xff);
-}
-
-int
-mraa_uart_ow_write_byte(mraa_uart_ow_context dev, uint8_t byte)
-{
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: write_byte: context is NULL");
- return -1;
- }
-
- /* writing bytes - each bit on the byte to send corresponds to a
- * byte on the uart. At the same time, we read bits (uart bytes)
- * from the bus and build a byte to return. This is possible due to
- * the way we wire the UART TX/RX pins together, similar to a
- * loopback connection, except the devices on the 1-wire bus have
- * the ability to modify the returning bitstream.
- */
-
- uint8_t bit;
- int i;
- for (i = 0; i < 8; i++) {
- bit = mraa_uart_ow_bit(dev, byte & 0x01);
- /* prep for next bit to send, and clear space for bit read */
- byte >>= 1;
- /* store read bit in the msb */
- if (bit)
- byte |= 0x80;
- }
-
- /* return the new byte read */
- return byte;
-}
-
-int
-mraa_uart_ow_read_byte(mraa_uart_ow_context dev)
-{
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: read_byte: context is NULL");
- return -1;
- }
-
- /* we read by sending 0xff, so the bus is released on the initial
- * low pulse (uart start bit) for every timeslot, when the device
- * will then send it's bits
- */
- return mraa_uart_ow_write_byte(dev, 0xff);
-}
-
-mraa_result_t
-mraa_uart_ow_reset(mraa_uart_ow_context dev)
-{
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: reset: context is NULL");
- return MRAA_ERROR_INVALID_HANDLE;
- }
-
- uint8_t rv;
-
- /* To emit a proper reset pulse, we set low speed (9600 baud) for
- * the reset pulse and send 0xf0 to pull the line down for the
- * minimum amount of time.
- *
- * From the Maxim whitepaper:
- *
- * Transmitting an 0xF0 from the UART forms a proper Reset
- * pulse. The receive value depends on whether one or more 1-Wire
- * slave devices are present, their internal timing of each slave
- * device present, and the UART's detection timing within each bit
- * window. If no device is present, the receive value will equal the
- * transmit value. Otherwise the receive value can vary.
- */
- if (_ow_set_speed(dev, 0) != MRAA_SUCCESS) {
- return MRAA_ERROR_INVALID_HANDLE;
- }
-
- /* pull the data line low */
- _ow_write_byte(dev, 0xf0);
-
- _ow_read_byte(dev, &rv);
-
- /* back up to high speed for normal data transmissions */
- if (_ow_set_speed(dev, 1) != MRAA_SUCCESS) {
- return MRAA_ERROR_INVALID_HANDLE;
- }
-
- /* shorted data line */
- if (rv == 0x00)
- return MRAA_ERROR_UART_OW_SHORTED;
-
- /* no devices detected (no presence pulse) */
- if (rv == 0xf0)
- return MRAA_ERROR_UART_OW_NO_DEVICES;
-
- /* otherwise, at least one device is present */
- return MRAA_SUCCESS;
-}
-
-
-mraa_result_t
-mraa_uart_ow_rom_search(mraa_uart_ow_context dev, mraa_boolean_t start, uint8_t* id)
-{
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: rom_search: context is NULL");
- return MRAA_ERROR_INVALID_HANDLE;
- }
-
- // bail if there aren't any devices, or some other error occurs
- mraa_result_t rv;
- if ((rv = mraa_uart_ow_reset(dev)) != MRAA_SUCCESS)
- return rv;
-
- mraa_boolean_t result;
-
- // see if we are starting from scratch
- if (start)
- result = _ow_first(dev);
- else
- result = _ow_next(dev);
-
- if (result) {
- // found one. Copy into id and return 1
- int i;
- for (i = 0; i < MRAA_UART_OW_ROMCODE_SIZE; i++)
- id[i] = dev->ROM_NO[i];
-
- return MRAA_SUCCESS;
- } else
- return MRAA_ERROR_UART_OW_NO_DEVICES;
-}
-
-mraa_result_t
-mraa_uart_ow_command(mraa_uart_ow_context dev, uint8_t command, uint8_t* id)
-{
- if (!dev) {
- syslog(LOG_ERR, "uart_ow: ow_command: context is NULL");
- return MRAA_ERROR_INVALID_HANDLE;
- }
-
- /* send reset pulse first */
- mraa_result_t rv = mraa_uart_ow_reset(dev);
-
- if (rv != MRAA_SUCCESS)
- return rv;
-
- if (id) {
- /* send the match rom command */
- mraa_uart_ow_write_byte(dev, MRAA_UART_OW_CMD_MATCH_ROM);
-
- /* sending to a specific device, so send out the full romcode */
- int i;
- for (i = 0; i < MRAA_UART_OW_ROMCODE_SIZE; i++)
- mraa_uart_ow_write_byte(dev, id[i]);
- } else {
- /* send to all devices (or a single device if it's the only one
- * on the bus)
- */
- mraa_uart_ow_write_byte(dev, MRAA_UART_OW_CMD_SKIP_ROM);
- }
-
- mraa_uart_ow_write_byte(dev, command);
-
- return MRAA_SUCCESS;
-}
-
-uint8_t
-mraa_uart_ow_crc8(uint8_t* buffer, uint16_t length)
-{
- // 0x18 = X ^ 8 + X ^ 5 + X ^ 4 + X ^ 0
- static const uint8_t CRC8POLY = 0x18;
-
- uint8_t crc = 0x00;
- uint16_t loop_count;
- uint8_t bit_counter;
- uint8_t data;
- uint8_t feedback_bit;
-
- for (loop_count = 0; loop_count != length; loop_count++) {
- data = buffer[loop_count];
- bit_counter = 8;
- do {
- feedback_bit = (crc ^ data) & 0x01;
- if (feedback_bit == 0x01)
- crc = crc ^ CRC8POLY;
- crc = (crc >> 1) & 0x7F;
- if (feedback_bit == 0x01)
- crc = crc | 0x80;
- data = data >> 1;
- bit_counter--;
- } while (bit_counter > 0);
- }
-
- return crc;
-}
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