Flipper/Applications/Official/DEV_FW/source/grnch/flipperzero-i2ctools-main/i2csniffer.c
2022-12-28 22:34:27 -08:00

102 lines
3.3 KiB
C

#include "i2csniffer.h"
void clear_sniffer_buffers(i2cSniffer* i2c_sniffer) {
furi_assert(i2c_sniffer);
for(uint8_t i = 0; i < MAX_RECORDS; i++) {
for(uint8_t j = 0; j < MAX_MESSAGE_SIZE; j++) {
i2c_sniffer->frames[i].ack[j] = false;
i2c_sniffer->frames[i].data[j] = 0;
}
i2c_sniffer->frames[i].bit_index = 0;
i2c_sniffer->frames[i].data_index = 0;
}
i2c_sniffer->frame_index = 0;
i2c_sniffer->state = I2C_BUS_FREE;
i2c_sniffer->first = true;
}
void start_interrupts(i2cSniffer* i2c_sniffer) {
furi_assert(i2c_sniffer);
furi_hal_gpio_init(pinSCL, GpioModeInterruptRise, GpioPullNo, GpioSpeedHigh);
furi_hal_gpio_add_int_callback(pinSCL, SCLcallback, i2c_sniffer);
// Add Rise and Fall Interrupt on SDA pin
furi_hal_gpio_init(pinSDA, GpioModeInterruptRiseFall, GpioPullNo, GpioSpeedHigh);
furi_hal_gpio_add_int_callback(pinSDA, SDAcallback, i2c_sniffer);
}
void stop_interrupts() {
furi_hal_gpio_remove_int_callback(pinSCL);
furi_hal_gpio_remove_int_callback(pinSDA);
// Reset GPIO pins to default state
furi_hal_gpio_init(pinSCL, GpioModeAnalog, GpioPullNo, GpioSpeedLow);
furi_hal_gpio_init(pinSDA, GpioModeAnalog, GpioPullNo, GpioSpeedLow);
}
// Called on Fallin/Rising SDA
// Used to monitor i2c bus state
void SDAcallback(void* _i2c_sniffer) {
i2cSniffer* i2c_sniffer = _i2c_sniffer;
// SCL is low maybe cclock strecching
if(furi_hal_gpio_read(pinSCL) == false) {
return;
}
// Check for stop condition: SDA rising while SCL is High
if(i2c_sniffer->state == I2C_BUS_STARTED) {
if(furi_hal_gpio_read(pinSDA) == true) {
i2c_sniffer->state = I2C_BUS_FREE;
}
}
// Check for start condition: SDA falling while SCL is high
else if(furi_hal_gpio_read(pinSDA) == false) {
i2c_sniffer->state = I2C_BUS_STARTED;
if(i2c_sniffer->first) {
i2c_sniffer->first = false;
return;
}
i2c_sniffer->frame_index++;
if(i2c_sniffer->frame_index >= MAX_RECORDS) {
clear_sniffer_buffers(i2c_sniffer);
}
}
return;
}
// Called on Rising SCL
// Used to read bus datas
void SCLcallback(void* _i2c_sniffer) {
i2cSniffer* i2c_sniffer = _i2c_sniffer;
if(i2c_sniffer->state == I2C_BUS_FREE) {
return;
}
uint8_t frame = i2c_sniffer->frame_index;
uint8_t bit = i2c_sniffer->frames[frame].bit_index;
uint8_t data_idx = i2c_sniffer->frames[frame].data_index;
if(bit < 8) {
i2c_sniffer->frames[frame].data[data_idx] <<= 1;
i2c_sniffer->frames[frame].data[data_idx] |= (int)furi_hal_gpio_read(pinSDA);
i2c_sniffer->frames[frame].bit_index++;
} else {
i2c_sniffer->frames[frame].ack[data_idx] = !furi_hal_gpio_read(pinSDA);
i2c_sniffer->frames[frame].data_index++;
i2c_sniffer->frames[frame].bit_index = 0;
}
}
i2cSniffer* i2c_sniffer_alloc() {
i2cSniffer* i2c_sniffer = malloc(sizeof(i2cSniffer));
i2c_sniffer->started = false;
i2c_sniffer->row_index = 0;
i2c_sniffer->menu_index = 0;
clear_sniffer_buffers(i2c_sniffer);
return i2c_sniffer;
}
void i2c_sniffer_free(i2cSniffer* i2c_sniffer) {
furi_assert(i2c_sniffer);
if(i2c_sniffer->started) {
stop_interrupts();
}
free(i2c_sniffer);
}