// Resets stack
static void red_stack_reset(void) {
// Change mux of reset pin to output
gpio_mux_configure(_red_stack_reset_stack_pin, GPIO_MUX_OUTPUT);
gpio_output_clear(_red_stack_reset_stack_pin);
SLEEP_NS(0, 1000*1000*100); // Clear reset pin for 100ms to force reset
gpio_output_set(_red_stack_reset_stack_pin);
SLEEP_NS(1, 1000*1000*500); // Wait 1.5s so slaves can start properly
// Change mux back to interrupt, so we can see if a human presses reset
gpio_mux_configure(_red_stack_reset_stack_pin, GPIO_MUX_6);
}
// Initialize TX/RX state
void init_tx_rx_state(void) {
_tx_pin.port_index = GPIO_PORT_C;
_tx_pin.pin_index = GPIO_PIN_19;
_rx_pin.port_index = GPIO_PORT_B;
_rx_pin.pin_index = GPIO_PIN_13;
gpio_mux_configure(_tx_pin, GPIO_MUX_OUTPUT);
gpio_mux_configure(_rx_pin, GPIO_MUX_OUTPUT);
// By default, RX = always on and TX = enabled on demand
gpio_output_clear(_tx_pin);
gpio_output_clear(_rx_pin);
log_debug("RS485: Initialized RS485 TX/RX state");
}
static void red_extension_configure_pin(ExtensionPinConfiguration *config, int extension) {
gpio_mux_configure(config->pin[extension], config->mux);
if (config->value == 0) {
gpio_output_clear(config->pin[extension]);
} else {
gpio_output_set(config->pin[extension]); // This should enable pull-up in case of input
}
}
static int red_stack_init_spi(void) {
uint8_t slave;
const uint8_t mode = RED_STACK_SPI_CONFIG_MODE;
const uint8_t lsb_first = RED_STACK_SPI_CONFIG_LSB_FIRST;
const uint8_t bits_per_word = RED_STACK_SPI_CONFIG_BITS_PER_WORD;
const uint32_t max_speed_hz = RED_STACK_SPI_CONFIG_MAX_SPEED_HZ;
// Set Master High pin to low (so Master Bricks above RED Brick can
// configure themselves as slave)
gpio_mux_configure(_red_stack_master_high_pin, GPIO_MUX_OUTPUT);
gpio_output_clear(_red_stack_master_high_pin);
// Initialize slaves
for (slave = 0; slave < RED_STACK_SPI_MAX_SLAVES; slave++) {
_red_stack.slaves[slave].stack_address = slave;
_red_stack.slaves[slave].status = RED_STACK_SLAVE_STATUS_ABSENT;
_red_stack.slaves[slave].slave_select_pin = _red_stack_slave_select_pins[slave];
_red_stack.slaves[slave].sequence_number_master = 1;
_red_stack.slaves[slave].sequence_number_slave = 0;
// Bring slave in initial state (deselected)
gpio_mux_configure(_red_stack.slaves[slave].slave_select_pin, GPIO_MUX_OUTPUT);
red_stack_spi_deselect(&_red_stack.slaves[slave]);
}
// Reset slaves and wait for slaves to be ready
red_stack_reset();
// Open spidev
_red_stack_spi_fd = open(_red_stack_spi_device, O_RDWR);
if (_red_stack_spi_fd < 0) {
log_error("Could not open %s", _red_stack_spi_device);
return -1;
}
if (ioctl(_red_stack_spi_fd, SPI_IOC_WR_MODE, &mode) < 0) {
log_error("Could not configure SPI mode");
return -1;
}
if (ioctl(_red_stack_spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &max_speed_hz) < 0) {
log_error("Could not configure SPI max speed");
return -1;
}
if (ioctl(_red_stack_spi_fd, SPI_IOC_WR_BITS_PER_WORD, &bits_per_word) < 0) {
log_error("Could not configure SPI bits per word");
return -1;
}
if (ioctl(_red_stack_spi_fd, SPI_IOC_WR_LSB_FIRST, &lsb_first) < 0) {
log_error("Could not configure SPI lsb first");
return -1;
}
// Create SPI packet transceive thread
// FIXME: maybe handshake thread start?
thread_create(&_red_stack_spi_thread, red_stack_spi_thread, NULL);
return 0;
}