Files
lowobservable.coax/interface2/firmware/src/ice40.cpp
2021-03-29 16:38:10 -05:00

114 lines
3.3 KiB
C++

// Copyright (c) 2020, Andrew Kay
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#include "pins.h"
#include "ice40.h"
ICE40::ICE40()
{
_isConfigured = false;
}
inline void clock()
{
LL_GPIO_ResetOutputPin(ICE40_SCK_GPIO_Port, ICE40_SCK_Pin);
for (int index = 0; index < 4; index++) {
asm volatile("nop\n\t");
}
LL_GPIO_SetOutputPin(ICE40_SCK_GPIO_Port, ICE40_SCK_Pin);
}
bool ICE40::configure(const uint8_t *bitstream, size_t bitstreamCount)
{
_isConfigured = false;
// Configure GPIO.
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
HAL_GPIO_WritePin(GPIOA, ICE40_CS_Pin | ICE40_SCK_Pin | ICE40_SDI_Pin, GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOB, ICE40_CRESET_Pin, GPIO_PIN_RESET);
GPIO_InitTypeDef gpioInit = { 0 };
gpioInit.Pin = ICE40_CS_Pin | ICE40_SCK_Pin | ICE40_SDI_Pin;
gpioInit.Mode = GPIO_MODE_OUTPUT_PP;
gpioInit.Pull = GPIO_NOPULL;
gpioInit.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOA, &gpioInit);
gpioInit.Pin = ICE40_CRESET_Pin;
gpioInit.Mode = GPIO_MODE_OUTPUT_PP;
gpioInit.Pull = GPIO_NOPULL;
gpioInit.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &gpioInit);
gpioInit.Pin = ICE40_CDONE_Pin;
gpioInit.Mode = GPIO_MODE_INPUT;
gpioInit.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOB, &gpioInit);
// Set initial GPIO state.
HAL_GPIO_WritePin(ICE40_CS_GPIO_Port, ICE40_CS_Pin | ICE40_SCK_Pin, GPIO_PIN_SET);
HAL_GPIO_WritePin(ICE40_CRESET_GPIO_Port, ICE40_CRESET_Pin, GPIO_PIN_SET);
// Assert CS and reset.
HAL_GPIO_WritePin(ICE40_CS_GPIO_Port, ICE40_CS_Pin, GPIO_PIN_RESET);
HAL_GPIO_WritePin(ICE40_CRESET_GPIO_Port, ICE40_CRESET_Pin, GPIO_PIN_RESET);
HAL_Delay(1);
HAL_GPIO_WritePin(ICE40_CRESET_GPIO_Port, ICE40_CRESET_Pin, GPIO_PIN_SET);
HAL_Delay(1);
// Send the bitstream.
for (size_t index = 0; index < bitstreamCount; index++) {
uint8_t byte = bitstream[index];
for (int bitIndex = 7; bitIndex >= 0; bitIndex--) {
if ((byte >> bitIndex) & 0x01) {
LL_GPIO_SetOutputPin(ICE40_SDI_GPIO_Port, ICE40_SDI_Pin);
} else {
LL_GPIO_ResetOutputPin(ICE40_SDI_GPIO_Port, ICE40_SDI_Pin);
}
clock();
}
}
// Check done.
bool done = LL_GPIO_IsInputPinSet(ICE40_CDONE_GPIO_Port, ICE40_CDONE_Pin);
if (done) {
for (int index = 0; index < 49; index++) {
clock();
}
}
// Deassert CS.
HAL_GPIO_WritePin(ICE40_CS_GPIO_Port, ICE40_CS_Pin, GPIO_PIN_SET);
_isConfigured = done;
return _isConfigured;
}