2020-01-03 15:00:20 -07:00

456 lines
12 KiB
C

// High resolution pinout can be found here:
// https://osoyoo.com/wp-content/uploads/2017/08/arduino_mega_2560_pinout.png
#include <stdint.h>
#include <stdio.h>
#include <board/cpu.h>
#include <util/delay.h>
#include <arch/gpio.h>
#include <arch/uart.h>
// Mapping of 24-pin ribbon cable to parallel pins. See schematic
#define PINS \
/* Data (KSO0 - KSO7) - bi-directional */ \
PIN(d0, 1) \
PIN(d1, 2) \
PIN(d2, 3) \
PIN(d3, 7) \
PIN(d4, 9) \
PIN(d5, 10) \
PIN(d6, 13) \
PIN(d7, 16) \
/* Wait# (KSO9) - input */ \
/* low to indicate cycle may begin, high to indicate cycle may end */ \
PIN(wait_n, 18) \
/* Write# (KSI0) - output */ \
/* low to indicate write cycle, high to indicate read cycle */ \
PIN(write_n, 4) \
/* DataStrobe# (KSI1) - output */ \
/* low indicates a data cycle */ \
PIN(data_n, 5) \
/* Reset# (KSI2) - output */ \
/* low requests device reset */ \
PIN(reset_n, 6) \
/* AddressStrobe# (KSI3) - output */ \
/* low indicates an address cycle */ \
PIN(addr_n, 8) \
/* Strap0 (KSI4) */ \
/* 1K-Ohm pull-down resistor */ \
PIN(strap_0, 11) \
/* Strap1 (KSI5) */ \
/* 1K-Ohm pull-down resistor */ \
PIN(strap_1, 12)
#define DATA_BITS \
DATA_BIT(0) \
DATA_BIT(1) \
DATA_BIT(2) \
DATA_BIT(3) \
DATA_BIT(4) \
DATA_BIT(5) \
DATA_BIT(6) \
DATA_BIT(7)
// Mapping of 24-pin ribbon cable to GPIOs
static struct Gpio GPIOS[24] = {
GPIO(L, 5), GPIO(L, 4),
GPIO(L, 7), GPIO(L, 6),
GPIO(G, 1), GPIO(G, 0),
GPIO(D, 7), GPIO(G, 2),
GPIO(C, 1), GPIO(C, 0),
GPIO(C, 3), GPIO(C, 2),
GPIO(C, 5), GPIO(C, 4),
GPIO(C, 7), GPIO(C, 6),
GPIO(A, 6), GPIO(A, 7),
GPIO(A, 4), GPIO(A, 5),
GPIO(A, 2), GPIO(A, 3),
GPIO(A, 0), GPIO(A, 1),
};
// Parallel struct definition
// See http://efplus.com/techref/io/parallel/1284/eppmode.htm
struct Parallel {
#define PIN(N, P) struct Gpio * N;
PINS
#undef PIN
};
// Parallel struct instance
static struct Parallel PORT = {
#define PIN(N, P) .N = &GPIOS[P - 1],
PINS
#undef PIN
};
// Set port to all high-impedance inputs
void parallel_hiz(struct Parallel * port) {
#define PIN(N, P) \
gpio_set_dir(port->N, false); \
gpio_set(port->N, false);
PINS
#undef PIN
}
// Set port to initial state required before being able to perform cycles
void parallel_reset(struct Parallel * port) {
parallel_hiz(port);
// Set reset line low
gpio_set_dir(port->reset_n, true);
// Wait 1 microsecond
_delay_us(1);
// Make sure strobes are high outputs
gpio_set(port->data_n, true);
gpio_set(port->addr_n, true);
gpio_set_dir(port->data_n, true);
gpio_set_dir(port->addr_n, true);
// Set write line high output
gpio_set(port->write_n, true);
gpio_set_dir(port->write_n, true);
// Pull up wait line
gpio_set(port->wait_n, true);
// Pull up data lines
#define DATA_BIT(B) gpio_set(port->d ## B, true);
DATA_BITS
#undef DATA_BIT
//TODO: something with straps
// Wait 1 microsecond
_delay_us(1);
// Set reset line high, ending reset
gpio_set(port->reset_n, true);
}
//TODO: timeout
int parallel_transaction(struct Parallel * port, uint8_t * data, int length, bool read, bool addr) {
if (!read) {
// Set write line low
gpio_set(port->write_n, false);
// Set data direction out
#define DATA_BIT(B) gpio_set_dir(port->d ## B, true);
DATA_BITS
#undef DATA_BIT
}
int i;
uint8_t byte;
for (i = 0; i < length; i++) {
// Wait for wait line to be low
while (gpio_get(port->wait_n)) {}
if (!read) {
// Set data low where necessary
byte = data[i];
#define DATA_BIT(B) if (!(byte & (1 << B))) gpio_set(port->d ## B, false);
DATA_BITS
#undef DATA_BIT
}
if (addr) {
// Set address strobe low
gpio_set(port->addr_n, false);
} else {
// Set data strobe low
gpio_set(port->data_n, false);
}
// Wait for wait line to be high
while (!gpio_get(port->wait_n)) {}
if (read) {
byte = 0;
#define DATA_BIT(B) if (gpio_get(port->d ## B)) byte |= (1 << B);
DATA_BITS
#undef DATA_BIT
data[i] = byte;
}
if (addr) {
// Set address strobe high
gpio_set(port->addr_n, true);
} else {
// Set data strobe high
gpio_set(port->data_n, true);
}
if (!read) {
// Set data high where necessary
#define DATA_BIT(B) if (!(byte & (1 << B))) gpio_set(port->d ## B, true);
DATA_BITS
#undef DATA_BIT
}
}
if (!read) {
// Set data direction in
#define DATA_BIT(B) gpio_set_dir(port->d ## B, false);
DATA_BITS
#undef DATA_BIT
// Set write line high
gpio_set(port->write_n, true);
}
return i;
}
#define parallel_get_address(P, D, L) parallel_transaction(P, D, L, true, true)
#define parallel_set_address(P, D, L) parallel_transaction(P, D, L, false, true)
#define parallel_read(P, D, L) parallel_transaction(P, D, L, true, false)
#define parallel_write(P, D, L) parallel_transaction(P, D, L, false, false)
static uint8_t ADDRESS_INDAR1 = 0x05;
static uint8_t ADDRESS_INDDR = 0x08;
static uint8_t ZERO = 0x00;
static uint8_t SPI_ENABLE = 0xFE;
static uint8_t SPI_DATA = 0xFD;
// Disable chip
int parallel_spi_reset(struct Parallel *port) {
int res;
res = parallel_set_address(port, &ADDRESS_INDAR1, 1);
if (res < 0) return res;
res = parallel_write(port, &SPI_ENABLE, 1);
if (res < 0) return res;
res = parallel_set_address(port, &ADDRESS_INDDR, 1);
if (res < 0) return res;
return parallel_write(port, &ZERO, 1);
}
// Enable chip and read or write data
int parallel_spi_transaction(struct Parallel *port, uint8_t * data, int length, bool read) {
int res;
res = parallel_set_address(port, &ADDRESS_INDAR1, 1);
if (res < 0) return res;
res = parallel_write(port, &SPI_DATA, 1);
if (res < 0) return res;
res = parallel_set_address(port, &ADDRESS_INDDR, 1);
if (res < 0) return res;
return parallel_transaction(port, data, length, read, false);
}
#define parallel_spi_read(P, D, L) parallel_spi_transaction(P, D, L, true)
#define parallel_spi_write(P, D, L) parallel_spi_transaction(P, D, L, false)
// "Hardware" accelerated SPI programming, requires ECINDARs to be set
int parallel_spi_program(struct Parallel * port, uint8_t * data, int length, bool initialized) {
static uint8_t aai[6] = { 0xAD, 0, 0, 0, 0, 0 };
int res;
int i;
uint8_t status;
for(i = 0; (i + 1) < length; i+=2) {
// Disable chip to begin command
res = parallel_spi_reset(port);
if (res < 0) return res;
if (!initialized) {
// If not initialized, the start address must be sent
aai[1] = 0;
aai[2] = 0;
aai[3] = 0;
aai[4] = data[i];
aai[5] = data[i + 1];
res = parallel_spi_write(port, aai, 6);
if (res < 0) return res;
initialized = true;
} else {
aai[1] = data[i];
aai[2] = data[i + 1];
res = parallel_spi_write(port, aai, 3);
if (res < 0) return res;
}
// Wait for SPI busy flag to clear
for (;;) {
// Disable chip to begin command
res = parallel_spi_reset(port);
if (res < 0) return res;
status = 0x05;
res = parallel_spi_write(port, &status, 1);
if (res < 0) return res;
res = parallel_spi_read(port, &status, 1);
if (res < 0) return res;
if (!(status & 1)) break;
}
}
return i;
}
int serial_transaction(uint8_t * data, int length, bool read) {
int i;
for (i = 0; i < length; i++) {
if (read) {
data[i] = (uint8_t)uart_read(uart_stdio);
} else {
uart_write(uart_stdio, (unsigned char)data[i]);
}
}
return i;
}
#define serial_read(D, L) serial_transaction(D, L, true)
#define serial_write(D, L) serial_transaction(D, L, false)
int parallel_main(void) {
int res = 0;
struct Parallel * port = &PORT;
parallel_reset(port);
static uint8_t data[128];
char command;
int length;
int i;
uint8_t address;
bool set_address = false;
bool program_aai = false;
for (;;) {
// Read command and length
res = serial_read(data, 2);
if (res < 0) goto err;
// Command is a character
command = (char)data[0];
// Special address prefix
if (command == 'A') {
// Prepare to set address on next parallel cycle
address = data[1];
set_address = true;
continue;
} else if (command != 'P') {
// End accelerated programming
program_aai = false;
}
// Length is received data + 1
length = ((int)data[1]) + 1;
// Truncate length to size of data
if (length > sizeof(data)) length = sizeof(data);
switch (command) {
// Buffer size
case 'B':
// Fill buffer size - 1
for (i = 0; i < length; i++) {
if (i == 0) {
data[i] = (uint8_t)(sizeof(data) - 1);
} else {
data[i] = 0;
}
}
// Write data to serial
res = serial_write(data, length);
if (res < 0) goto err;
break;
// Echo
case 'E':
// Read data from serial
res = serial_read(data, length);
if (res < 0) goto err;
// Write data to serial
res = serial_write(data, length);
if (res < 0) goto err;
break;
// Read data
case 'R':
// Update parallel address if necessary
if (set_address) {
res = parallel_set_address(port, &address, 1);
if (res < 0) goto err;
set_address = false;
}
// Read data from parallel
res = parallel_read(port, data, length);
if (res < 0) goto err;
// Write data to serial
res = serial_write(data, length);
if (res < 0) goto err;
break;
// Accelerated program function
case 'P':
// Read data from serial
res = serial_read(data, length);
if (res < 0) goto err;
// Run accelerated programming function
res = parallel_spi_program(port, data, length, program_aai);
if (res < 0) goto err;
program_aai = true;
// Send ACK of data length
data[0] = (uint8_t)(length - 1);
res = serial_write(data, 1);
if (res < 0) goto err;
break;
// Write data
case 'W':
// Read data from serial
res = serial_read(data, length);
if (res < 0) goto err;
// Update parallel address if necessary
if (set_address) {
res = parallel_set_address(port, &address, 1);
if (res < 0) goto err;
set_address = false;
}
// Write data to parallel
res = parallel_write(port, data, length);
if (res < 0) goto err;
// Send ACK of data length
data[0] = (uint8_t)(length - 1);
res = serial_write(data, 1);
if (res < 0) goto err;
break;
}
}
err:
parallel_hiz(port);
return res;
}