unleashed-firmware/lib/one_wire/one_wire_slave.c

320 lines
8.4 KiB
C

#include "one_wire_slave.h"
#include "one_wire_slave_i.h"
#include "one_wire_device.h"
#include <furi.h>
#include <furi_hal_delay.h>
#include <furi_hal_ibutton.h>
#define OWS_RESET_MIN 270
#define OWS_RESET_MAX 960
#define OWS_PRESENCE_TIMEOUT 20
#define OWS_PRESENCE_MIN 100
#define OWS_PRESENCE_MAX 480
#define OWS_MSG_HIGH_TIMEOUT 15000
#define OWS_SLOT_MAX 135
#define OWS_READ_MIN 20
#define OWS_READ_MAX 60
#define OWS_WRITE_ZERO 30
typedef enum {
NO_ERROR = 0,
VERY_LONG_RESET,
VERY_SHORT_RESET,
PRESENCE_LOW_ON_LINE,
AWAIT_TIMESLOT_TIMEOUT_HIGH,
INCORRECT_ONEWIRE_CMD,
FIRST_BIT_OF_BYTE_TIMEOUT,
RESET_IN_PROGRESS
} OneWireSlaveError;
struct OneWireSlave {
OneWireSlaveError error;
OneWireDevice* device;
OneWireSlaveResultCallback result_cb;
void* result_cb_ctx;
};
/*********************** PRIVATE ***********************/
uint32_t onewire_slave_wait_while_gpio_is(OneWireSlave* bus, uint32_t time, const bool pin_value) {
UNUSED(bus);
uint32_t start = DWT->CYCCNT;
uint32_t time_ticks = time * furi_hal_delay_instructions_per_microsecond();
uint32_t time_captured;
do {
time_captured = DWT->CYCCNT;
if(furi_hal_ibutton_pin_get_level() != pin_value) {
uint32_t remaining_time = time_ticks - (time_captured - start);
remaining_time /= furi_hal_delay_instructions_per_microsecond();
return remaining_time;
}
} while((time_captured - start) < time_ticks);
return 0;
}
bool onewire_slave_show_presence(OneWireSlave* bus) {
// wait while master delay presence check
onewire_slave_wait_while_gpio_is(bus, OWS_PRESENCE_TIMEOUT, true);
// show presence
furi_hal_ibutton_pin_low();
furi_hal_delay_us(OWS_PRESENCE_MIN);
furi_hal_ibutton_pin_high();
// somebody also can show presence
const uint32_t wait_low_time = OWS_PRESENCE_MAX - OWS_PRESENCE_MIN;
// so we will wait
if(onewire_slave_wait_while_gpio_is(bus, wait_low_time, false) == 0) {
bus->error = PRESENCE_LOW_ON_LINE;
return false;
}
return true;
}
bool onewire_slave_receive_bit(OneWireSlave* bus) {
// wait while bus is low
uint32_t time = OWS_SLOT_MAX;
time = onewire_slave_wait_while_gpio_is(bus, time, false);
if(time == 0) {
bus->error = RESET_IN_PROGRESS;
return false;
}
// wait while bus is high
time = OWS_MSG_HIGH_TIMEOUT;
time = onewire_slave_wait_while_gpio_is(bus, time, true);
if(time == 0) {
bus->error = AWAIT_TIMESLOT_TIMEOUT_HIGH;
return false;
}
// wait a time of zero
time = OWS_READ_MIN;
time = onewire_slave_wait_while_gpio_is(bus, time, false);
return (time > 0);
}
bool onewire_slave_send_bit(OneWireSlave* bus, bool value) {
const bool write_zero = !value;
// wait while bus is low
uint32_t time = OWS_SLOT_MAX;
time = onewire_slave_wait_while_gpio_is(bus, time, false);
if(time == 0) {
bus->error = RESET_IN_PROGRESS;
return false;
}
// wait while bus is high
time = OWS_MSG_HIGH_TIMEOUT;
time = onewire_slave_wait_while_gpio_is(bus, time, true);
if(time == 0) {
bus->error = AWAIT_TIMESLOT_TIMEOUT_HIGH;
return false;
}
// choose write time
if(write_zero) {
furi_hal_ibutton_pin_low();
time = OWS_WRITE_ZERO;
} else {
time = OWS_READ_MAX;
}
// hold line for ZERO or ONE time
furi_hal_delay_us(time);
furi_hal_ibutton_pin_high();
return true;
}
void onewire_slave_cmd_search_rom(OneWireSlave* bus) {
const uint8_t key_bytes = 8;
uint8_t* key = onewire_device_get_id_p(bus->device);
for(uint8_t i = 0; i < key_bytes; i++) {
uint8_t key_byte = key[i];
for(uint8_t j = 0; j < 8; j++) {
bool bit = (key_byte >> j) & 0x01;
if(!onewire_slave_send_bit(bus, bit)) return;
if(!onewire_slave_send_bit(bus, !bit)) return;
onewire_slave_receive_bit(bus);
if(bus->error != NO_ERROR) return;
}
}
}
bool onewire_slave_receive_and_process_cmd(OneWireSlave* bus) {
uint8_t cmd;
onewire_slave_receive(bus, &cmd, 1);
if(bus->error == RESET_IN_PROGRESS) return true;
if(bus->error != NO_ERROR) return false;
switch(cmd) {
case 0xF0:
// SEARCH ROM
onewire_slave_cmd_search_rom(bus);
return true;
case 0x0F:
case 0x33:
// READ ROM
onewire_device_send_id(bus->device);
return true;
default: // Unknown command
bus->error = INCORRECT_ONEWIRE_CMD;
}
if(bus->error == RESET_IN_PROGRESS) return true;
return (bus->error == NO_ERROR);
}
bool onewire_slave_bus_start(OneWireSlave* bus) {
bool result = true;
if(bus->device == NULL) {
result = false;
} else {
FURI_CRITICAL_ENTER();
furi_hal_ibutton_start_drive_in_isr();
bus->error = NO_ERROR;
if(onewire_slave_show_presence(bus)) {
// TODO think about multiple command cycles
onewire_slave_receive_and_process_cmd(bus);
result = (bus->error == NO_ERROR || bus->error == INCORRECT_ONEWIRE_CMD);
} else {
result = false;
}
furi_hal_ibutton_start_interrupt_in_isr();
FURI_CRITICAL_EXIT();
}
return result;
}
static void exti_cb(void* context) {
OneWireSlave* bus = context;
volatile bool input_state = furi_hal_ibutton_pin_get_level();
static uint32_t pulse_start = 0;
if(input_state) {
uint32_t pulse_length =
(DWT->CYCCNT - pulse_start) / furi_hal_delay_instructions_per_microsecond();
if(pulse_length >= OWS_RESET_MIN) {
if(pulse_length <= OWS_RESET_MAX) {
// reset cycle ok
bool result = onewire_slave_bus_start(bus);
if(result && bus->result_cb != NULL) {
bus->result_cb(bus->result_cb_ctx);
}
} else {
bus->error = VERY_LONG_RESET;
}
} else {
bus->error = VERY_SHORT_RESET;
}
} else {
//FALL event
pulse_start = DWT->CYCCNT;
}
};
/*********************** PUBLIC ***********************/
OneWireSlave* onewire_slave_alloc() {
OneWireSlave* bus = malloc(sizeof(OneWireSlave));
bus->error = NO_ERROR;
bus->device = NULL;
bus->result_cb = NULL;
bus->result_cb_ctx = NULL;
return bus;
}
void onewire_slave_free(OneWireSlave* bus) {
onewire_slave_stop(bus);
free(bus);
}
void onewire_slave_start(OneWireSlave* bus) {
furi_hal_ibutton_add_interrupt(exti_cb, bus);
furi_hal_ibutton_start_interrupt();
}
void onewire_slave_stop(OneWireSlave* bus) {
UNUSED(bus);
furi_hal_ibutton_stop();
furi_hal_ibutton_remove_interrupt();
}
void onewire_slave_attach(OneWireSlave* bus, OneWireDevice* device) {
bus->device = device;
onewire_device_attach(device, bus);
}
void onewire_slave_detach(OneWireSlave* bus) {
if(bus->device != NULL) {
onewire_device_detach(bus->device);
}
bus->device = NULL;
}
void onewire_slave_set_result_callback(
OneWireSlave* bus,
OneWireSlaveResultCallback result_cb,
void* context) {
bus->result_cb = result_cb;
bus->result_cb_ctx = context;
}
bool onewire_slave_send(OneWireSlave* bus, const uint8_t* address, const uint8_t data_length) {
uint8_t bytes_sent = 0;
furi_hal_ibutton_pin_high();
// bytes loop
for(; bytes_sent < data_length; ++bytes_sent) {
const uint8_t data_byte = address[bytes_sent];
// bit loop
for(uint8_t bit_mask = 0x01; bit_mask != 0; bit_mask <<= 1) {
if(!onewire_slave_send_bit(bus, bit_mask & data_byte)) {
// if we cannot send first bit
if((bit_mask == 0x01) && (bus->error == AWAIT_TIMESLOT_TIMEOUT_HIGH))
bus->error = FIRST_BIT_OF_BYTE_TIMEOUT;
return false;
}
}
}
return true;
}
bool onewire_slave_receive(OneWireSlave* bus, uint8_t* data, const uint8_t data_length) {
uint8_t bytes_received = 0;
furi_hal_ibutton_pin_high();
for(; bytes_received < data_length; ++bytes_received) {
uint8_t value = 0;
for(uint8_t bit_mask = 0x01; bit_mask != 0; bit_mask <<= 1) {
if(onewire_slave_receive_bit(bus)) value |= bit_mask;
}
data[bytes_received] = value;
}
return (bytes_received != data_length);
}