sravan/system76-embedded-controller
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Increase parallel speed

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This commit is contained in:
Jeremy Soller 2020-01-03 10:28:24 -07:00
parent 07eb7b7ad4
commit caba9a8ff4
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GPG Key ID: E988B49EE78A7FB1
1 changed files with 52 additions and 26 deletions
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78
src/board/arduino/mega2560/parallel.c
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@ -131,27 +131,30 @@ void parallel_reset(struct Parallel * port) {
//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)) {}
// Set write line
gpio_set(port->write_n, read);
if (!read) {
// Set data
uint8_t byte = data[i];
#define DATA_BIT(B) \
gpio_set(port->d ## B, (byte & (1 << B)) > 0); \
gpio_set_dir(port->d ## B, true);
// 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
}
// Wait 1 microsecond
_delay_us(1);
if (addr) {
// Set address strobe low
gpio_set(port->addr_n, false);
@ -164,9 +167,8 @@ int parallel_transaction(struct Parallel * port, uint8_t * data, int length, boo
while (!gpio_get(port->wait_n)) {}
if (read) {
uint8_t byte = 0;
#define DATA_BIT(B) \
if (gpio_get(port->d ## B)) byte |= (1 << B);
byte = 0;
#define DATA_BIT(B) if (gpio_get(port->d ## B)) byte |= (1 << B);
DATA_BITS
#undef DATA_BIT
data[i] = byte;
@ -180,13 +182,17 @@ int parallel_transaction(struct Parallel * port, uint8_t * data, int length, boo
gpio_set(port->data_n, true);
}
// Wait 1 microsecond
_delay_us(1);
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
}
}
// Reset data lines to pull-up inputs
#define DATA_BIT(B) \
gpio_set_dir(port->d ## B, false); \
gpio_set(port->d ## B, true);
if (!read) {
// Set data direction in
#define DATA_BIT(B) gpio_set_dir(port->d ## B, false);
DATA_BITS
#undef DATA_BIT
@ -224,21 +230,44 @@ int parallel_main(void) {
struct Parallel * port = &PORT;
parallel_reset(port);
static uint8_t data[256];
static uint8_t data[128];
char command;
int length;
int i;
for (;;) {
// Read command and length
res = serial_read(data, 2);
res = serial_read(data, 3);
if (res < 0) goto err;
// Command is a character
command = (char)data[0];
// Length is received data + 1
length = (int)data[1] + 1;
length = (
((int)data[1]) |
(((int)data[2]) << 8)
) + 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 < 2) {
data[i] = (uint8_t)(
(sizeof(data) - 1) >> (i * 8)
);
} 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
@ -268,9 +297,6 @@ int parallel_main(void) {
// Read data from parallel
res = parallel_read(port, data, length);
if (res < 0) goto err;
for (res = 0; res < length; res++) {
data[res] = (uint8_t)res;
}
// Write data to serial
res = serial_write(data, length);