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uart_ow: add ow specific context and store search state there

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Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Jon Trulson
2016-04-15 12:52:21 -06:00
committed by Brendan Le Foll
parent a702cdf4d5
commit f6d9cf57c9
2 changed files with 58 additions and 41 deletions
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10
api/mraa/uart_ow.h
View File

@@ -62,9 +62,17 @@ extern "C" {
#include <stdio.h> #include <stdio.h>
#include "common.h" #include "common.h"
#include "uart.h"
/* for now, we simply use the normal MRAA UART context */ /* for now, we simply use the normal MRAA UART context */
typedef struct _uart* mraa_uart_ow_context; typedef struct _mraa_uart_ow {
mraa_uart_context uart;
/* search state */
unsigned char ROM_NO[8]; /* 8 byte (64b) rom code */
int LastDiscrepancy;
int LastFamilyDiscrepancy;
mraa_boolean_t LastDeviceFlag;
} *mraa_uart_ow_context;
/* 8 bytes (64 bits) for a device rom code */ /* 8 bytes (64 bits) for a device rom code */
static const int MRAA_UART_OW_ROMCODE_SIZE = 8; static const int MRAA_UART_OW_ROMCODE_SIZE = 8;

89
src/uart_ow/uart_ow.c
View File

@@ -40,17 +40,11 @@
#include "uart_ow.h" #include "uart_ow.h"
#include "mraa_internal.h" #include "mraa_internal.h"
// global search state
static unsigned char ROM_NO[8]; /* 8 byte (64b) rom code */
static int LastDiscrepancy;
static int LastFamilyDiscrepancy;
static mraa_boolean_t LastDeviceFlag;
// low-level read byte // low-level read byte
static mraa_result_t static mraa_result_t
_ow_read_byte(mraa_uart_ow_context dev, uint8_t *ch) _ow_read_byte(mraa_uart_ow_context dev, uint8_t *ch)
{ {
while (!mraa_uart_read(dev, (char*) ch, 1)) while (!mraa_uart_read(dev->uart, (char*) ch, 1))
; ;
return MRAA_SUCCESS; return MRAA_SUCCESS;
@@ -60,7 +54,7 @@ _ow_read_byte(mraa_uart_ow_context dev, uint8_t *ch)
static int static int
_ow_write_byte(mraa_uart_ow_context dev, const char ch) _ow_write_byte(mraa_uart_ow_context dev, const char ch)
{ {
return mraa_uart_write(dev, &ch, 1); return mraa_uart_write(dev->uart, &ch, 1);
} }
// Here we setup a very simple termios with the minimum required // Here we setup a very simple termios with the minimum required
@@ -69,7 +63,7 @@ _ow_write_byte(mraa_uart_ow_context dev, const char ch)
// high speed (115200 bd) for actual data communications. // high speed (115200 bd) for actual data communications.
// //
static mraa_result_t static mraa_result_t
_ow_set_speed(mraa_uart_context dev, mraa_boolean_t speed) _ow_set_speed(mraa_uart_ow_context dev, mraa_boolean_t speed)
{ {
if (!dev) { if (!dev) {
@@ -89,10 +83,10 @@ _ow_set_speed(mraa_uart_context dev, mraa_boolean_t speed)
.c_cflag = baud | CS8 | CLOCAL | CREAD, .c_iflag = 0, .c_oflag = 0, .c_lflag = NOFLSH, .c_cc = { 0 }, .c_cflag = baud | CS8 | CLOCAL | CREAD, .c_iflag = 0, .c_oflag = 0, .c_lflag = NOFLSH, .c_cc = { 0 },
}; };
tcflush(dev->fd, TCIFLUSH); tcflush(dev->uart->fd, TCIFLUSH);
// TCSANOW is required // TCSANOW is required
if (tcsetattr(dev->fd, TCSANOW, &termio) < 0) { if (tcsetattr(dev->uart->fd, TCSANOW, &termio) < 0) {
syslog(LOG_ERR, "uart_ow: tcsetattr() failed"); syslog(LOG_ERR, "uart_ow: tcsetattr() failed");
return MRAA_ERROR_INVALID_RESOURCE; return MRAA_ERROR_INVALID_RESOURCE;
} }
@@ -121,13 +115,13 @@ _ow_search(mraa_uart_ow_context dev)
search_result = 0; search_result = 0;
// if the last call was not the last device // if the last call was not the last device
if (!LastDeviceFlag) { if (!dev->LastDeviceFlag) {
// 1-Wire reset // 1-Wire reset
if (mraa_uart_ow_reset(dev) != MRAA_SUCCESS) { if (mraa_uart_ow_reset(dev) != MRAA_SUCCESS) {
// reset the search // reset the search
LastDiscrepancy = 0; dev->LastDiscrepancy = 0;
LastDeviceFlag = 0; dev->LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0; dev->LastFamilyDiscrepancy = 0;
return 0; return 0;
} }
@@ -150,26 +144,26 @@ _ow_search(mraa_uart_ow_context dev)
else { else {
// if this discrepancy if before the Last Discrepancy // if this discrepancy if before the Last Discrepancy
// on a previous next then pick the same as last time // on a previous next then pick the same as last time
if (id_bit_number < LastDiscrepancy) if (id_bit_number < dev->LastDiscrepancy)
search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0); search_direction = ((dev->ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
else else
// if equal to last pick 1, if not then pick 0 // if equal to last pick 1, if not then pick 0
search_direction = (id_bit_number == LastDiscrepancy); search_direction = (id_bit_number == dev->LastDiscrepancy);
// if 0 was picked then record its position in LastZero // if 0 was picked then record its position in LastZero
if (search_direction == 0) { if (search_direction == 0) {
last_zero = id_bit_number; last_zero = id_bit_number;
// check for Last discrepancy in family // check for Last discrepancy in family
if (last_zero < 9) if (last_zero < 9)
LastFamilyDiscrepancy = last_zero; dev->LastFamilyDiscrepancy = last_zero;
} }
} }
// set or clear the bit in the ROM byte rom_byte_number // set or clear the bit in the ROM byte rom_byte_number
// with mask rom_byte_mask // with mask rom_byte_mask
if (search_direction == 1) if (search_direction == 1)
ROM_NO[rom_byte_number] |= rom_byte_mask; dev->ROM_NO[rom_byte_number] |= rom_byte_mask;
else else
ROM_NO[rom_byte_number] &= ~rom_byte_mask; dev->ROM_NO[rom_byte_number] &= ~rom_byte_mask;
// serial number search direction write bit // serial number search direction write bit
mraa_uart_ow_bit(dev, search_direction); mraa_uart_ow_bit(dev, search_direction);
@@ -192,21 +186,21 @@ _ow_search(mraa_uart_ow_context dev)
if (id_bit_number >= 65) { if (id_bit_number >= 65) {
// search successful so set // search successful so set
// LastDiscrepancy,LastDeviceFlag,search_result // LastDiscrepancy,LastDeviceFlag,search_result
LastDiscrepancy = last_zero; dev->LastDiscrepancy = last_zero;
// check for last device // check for last device
if (LastDiscrepancy == 0) if (dev->LastDiscrepancy == 0)
LastDeviceFlag = 1; dev->LastDeviceFlag = 1;
} }
search_result = 1; search_result = 1;
} }
// if no device found then reset counters so next 'search' will be // if no device found then reset counters so next 'search' will be
// like a first // like a first
if (!search_result || !ROM_NO[0]) { if (!search_result || !dev->ROM_NO[0]) {
LastDiscrepancy = 0; dev->LastDiscrepancy = 0;
LastDeviceFlag = 0; dev->LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0; dev->LastFamilyDiscrepancy = 0;
search_result = 0; search_result = 0;
} }
@@ -222,9 +216,9 @@ static mraa_boolean_t
_ow_first(mraa_uart_ow_context dev) _ow_first(mraa_uart_ow_context dev)
{ {
// reset the search state // reset the search state
LastDiscrepancy = 0; dev->LastDiscrepancy = 0;
LastDeviceFlag = 0; dev->LastDeviceFlag = 0;
LastFamilyDiscrepancy = 0; dev->LastFamilyDiscrepancy = 0;
return _ow_search(dev); return _ow_search(dev);
} }
@@ -246,13 +240,20 @@ _ow_next(mraa_uart_ow_context dev)
mraa_uart_ow_context mraa_uart_ow_context
mraa_uart_ow_init(int index) mraa_uart_ow_init(int index)
{ {
mraa_uart_ow_context dev = mraa_uart_init(index); mraa_uart_ow_context dev = calloc(1, sizeof(struct _mraa_uart_ow));
if (!dev) if (!dev)
return NULL; 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 // now get the fd, and set it up for non-blocking operation
if (fcntl(dev->fd, F_SETFL, O_NONBLOCK) == -1) { if (fcntl(dev->uart->fd, F_SETFL, O_NONBLOCK) == -1) {
syslog(LOG_ERR, "uart_ow: failed to set non-blocking on fd"); syslog(LOG_ERR, "uart_ow: failed to set non-blocking on fd");
mraa_uart_ow_stop(dev); mraa_uart_ow_stop(dev);
return NULL; return NULL;
@@ -264,13 +265,19 @@ mraa_uart_ow_init(int index)
mraa_uart_ow_context mraa_uart_ow_context
mraa_uart_ow_init_raw(const char* path) mraa_uart_ow_init_raw(const char* path)
{ {
mraa_uart_ow_context dev = mraa_uart_init_raw(path); mraa_uart_ow_context dev = calloc(1, sizeof(struct _mraa_uart_ow));
if (!dev) if (!dev)
return NULL; 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 // now get the fd, and set it up for non-blocking operation
if (fcntl(dev->fd, F_SETFL, O_NONBLOCK) == -1) { if (fcntl(dev->uart->fd, F_SETFL, O_NONBLOCK) == -1) {
syslog(LOG_ERR, "uart_ow: failed to set non-blocking on fd"); syslog(LOG_ERR, "uart_ow: failed to set non-blocking on fd");
mraa_uart_ow_stop(dev); mraa_uart_ow_stop(dev);
return NULL; return NULL;
@@ -282,13 +289,15 @@ mraa_uart_ow_init_raw(const char* path)
mraa_result_t mraa_result_t
mraa_uart_ow_stop(mraa_uart_ow_context dev) mraa_uart_ow_stop(mraa_uart_ow_context dev)
{ {
return mraa_uart_stop(dev); mraa_result_t rv = mraa_uart_stop(dev->uart);
free(dev);
return rv;
} }
const char* const char*
mraa_uart_ow_get_dev_path(mraa_uart_ow_context dev) mraa_uart_ow_get_dev_path(mraa_uart_ow_context dev)
{ {
return mraa_uart_get_dev_path(dev); return mraa_uart_get_dev_path(dev->uart);
} }
int int
@@ -438,7 +447,7 @@ mraa_uart_ow_rom_search(mraa_uart_ow_context dev, mraa_boolean_t start, uint8_t*
// found one. Copy into id and return 1 // found one. Copy into id and return 1
int i; int i;
for (i = 0; i < MRAA_UART_OW_ROMCODE_SIZE; i++) for (i = 0; i < MRAA_UART_OW_ROMCODE_SIZE; i++)
id[i] = ROM_NO[i]; id[i] = dev->ROM_NO[i];
return MRAA_SUCCESS; return MRAA_SUCCESS;
} else } else