flipperzero-firmware/lib/one_wire/one_wire_host.c
Nikolay Minaylov 2f3ea9494e
HAL to LL migration: GPIO, HSEM, AES (#1069)
* gpio, hsem, crypto: switch from HAL to LL/registers
* Moved GPIO initialization to furi_hal
* More HAL removed
* All HAL modules disabled
* HAL is finally removed
* hal_gpio -> furi_hal_gpio, main.h removed
* Bootloader build fix
* RTOS config moved to freertos-glue
* delay -> furi_hal_delay

Co-authored-by: あく <alleteam@gmail.com>
2022-03-30 18:23:40 +03:00

262 lines
7.5 KiB
C

#include <furi.h>
#include <furi_hal.h>
#include "one_wire_host.h"
#include "one_wire_host_timing.h"
struct OneWireHost {
// global search state
unsigned char saved_rom[8];
uint8_t last_discrepancy;
uint8_t last_family_discrepancy;
bool last_device_flag;
};
OneWireHost* onewire_host_alloc() {
OneWireHost* host = malloc(sizeof(OneWireHost));
onewire_host_reset_search(host);
return host;
}
void onewire_host_free(OneWireHost* host) {
onewire_host_stop(host);
free(host);
}
bool onewire_host_reset(OneWireHost* host) {
uint8_t r;
uint8_t retries = 125;
// wait until the gpio is high
furi_hal_ibutton_pin_high();
do {
if(--retries == 0) return 0;
furi_hal_delay_us(2);
} while(!furi_hal_ibutton_pin_get_level());
// pre delay
furi_hal_delay_us(OWH_RESET_DELAY_PRE);
// drive low
furi_hal_ibutton_pin_low();
furi_hal_delay_us(OWH_RESET_DRIVE);
// release
furi_hal_ibutton_pin_high();
furi_hal_delay_us(OWH_RESET_RELEASE);
// read and post delay
r = !furi_hal_ibutton_pin_get_level();
furi_hal_delay_us(OWH_RESET_DELAY_POST);
return r;
}
bool onewire_host_read_bit(OneWireHost* host) {
bool result;
// drive low
furi_hal_ibutton_pin_low();
furi_hal_delay_us(OWH_READ_DRIVE);
// release
furi_hal_ibutton_pin_high();
furi_hal_delay_us(OWH_READ_RELEASE);
// read and post delay
result = furi_hal_ibutton_pin_get_level();
furi_hal_delay_us(OWH_READ_DELAY_POST);
return result;
}
uint8_t onewire_host_read(OneWireHost* host) {
uint8_t result = 0;
for(uint8_t bitMask = 0x01; bitMask; bitMask <<= 1) {
if(onewire_host_read_bit(host)) {
result |= bitMask;
}
}
return result;
}
void onewire_host_read_bytes(OneWireHost* host, uint8_t* buffer, uint16_t count) {
for(uint16_t i = 0; i < count; i++) {
buffer[i] = onewire_host_read(host);
}
}
void onewire_host_write_bit(OneWireHost* host, bool value) {
if(value) {
// drive low
furi_hal_ibutton_pin_low();
furi_hal_delay_us(OWH_WRITE_1_DRIVE);
// release
furi_hal_ibutton_pin_high();
furi_hal_delay_us(OWH_WRITE_1_RELEASE);
} else {
// drive low
furi_hal_ibutton_pin_low();
furi_hal_delay_us(OWH_WRITE_0_DRIVE);
// release
furi_hal_ibutton_pin_high();
furi_hal_delay_us(OWH_WRITE_0_RELEASE);
}
}
void onewire_host_write(OneWireHost* host, uint8_t value) {
uint8_t bitMask;
for(bitMask = 0x01; bitMask; bitMask <<= 1) {
onewire_host_write_bit(host, (bitMask & value) ? 1 : 0);
}
}
void onewire_host_skip(OneWireHost* host) {
onewire_host_write(host, 0xCC);
}
void onewire_host_start(OneWireHost* host) {
furi_hal_ibutton_start_drive();
}
void onewire_host_stop(OneWireHost* host) {
furi_hal_ibutton_stop();
}
void onewire_host_reset_search(OneWireHost* host) {
host->last_discrepancy = 0;
host->last_device_flag = false;
host->last_family_discrepancy = 0;
for(int i = 7;; i--) {
host->saved_rom[i] = 0;
if(i == 0) break;
}
}
void onewire_host_target_search(OneWireHost* host, uint8_t family_code) {
host->saved_rom[0] = family_code;
for(uint8_t i = 1; i < 8; i++) host->saved_rom[i] = 0;
host->last_discrepancy = 64;
host->last_family_discrepancy = 0;
host->last_device_flag = false;
}
uint8_t onewire_host_search(OneWireHost* host, uint8_t* newAddr, OneWireHostSearchMode mode) {
uint8_t id_bit_number;
uint8_t last_zero, rom_byte_number, search_result;
uint8_t 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 one
if(!host->last_device_flag) {
// 1-Wire reset
if(!onewire_host_reset(host)) {
// reset the search
host->last_discrepancy = 0;
host->last_device_flag = false;
host->last_family_discrepancy = 0;
return false;
}
// issue the search command
switch(mode) {
case CONDITIONAL_SEARCH:
onewire_host_write(host, 0xEC);
break;
case NORMAL_SEARCH:
onewire_host_write(host, 0xF0);
break;
}
// loop to do the search
do {
// read a bit and its complement
id_bit = onewire_host_read_bit(host);
cmp_id_bit = onewire_host_read_bit(host);
// 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 < host->last_discrepancy)
search_direction =
((host->saved_rom[rom_byte_number] & rom_byte_mask) > 0);
else
// if equal to last pick 1, if not then pick 0
search_direction = (id_bit_number == host->last_discrepancy);
// 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) host->last_family_discrepancy = last_zero;
}
}
// set or clear the bit in the ROM byte rom_byte_number
// with mask rom_byte_mask
if(search_direction == 1)
host->saved_rom[rom_byte_number] |= rom_byte_mask;
else
host->saved_rom[rom_byte_number] &= ~rom_byte_mask;
// serial number search direction write bit
onewire_host_write_bit(host, 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 mask
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 last_Discrepancy, last_device_flag, search_result
host->last_discrepancy = last_zero;
// check for last device
if(host->last_discrepancy == 0) host->last_device_flag = true;
search_result = true;
}
}
// if no device found then reset counters so next 'search' will be like a first
if(!search_result || !host->saved_rom[0]) {
host->last_discrepancy = 0;
host->last_device_flag = false;
host->last_family_discrepancy = 0;
search_result = false;
} else {
for(int i = 0; i < 8; i++) newAddr[i] = host->saved_rom[i];
}
return search_result;
}