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Allow for inverted SPI CS logic (#23699)

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Dasky 2024-09-09 23:44:35 +01:00 • committed by GitHub
parent 3aaa086ac8
commit 2c7bf34d09
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GPG key ID: B5690EEEBB952194
4 changed files with 128 additions and 70 deletions
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84
platforms/avr/drivers/spi_master.c
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@ -36,9 +36,18 @@
# define SPI_TIMEOUT 100
#endif
static pin_t currentSlavePin = NO_PIN;
static uint8_t currentSlaveConfig = 0;
static bool currentSlave2X = false;
static pin_t current_slave_pin = NO_PIN;
static bool current_cs_active_low = true;
static uint8_t current_slave_config = 0;
static bool current_slave_2x = false;
static inline void spi_select(void) {
gpio_write_pin(current_slave_pin, current_cs_active_low ? 0 : 1);
}
static inline void spi_unselect(void) {
gpio_write_pin(current_slave_pin, current_cs_active_low ? 1 : 0);
}
void spi_init(void) {
gpio_write_pin_high(SPI_SS_PIN);
@ -50,63 +59,74 @@ void spi_init(void) {
}
bool spi_start(pin_t slavePin, bool lsbFirst, uint8_t mode, uint16_t divisor) {
if (currentSlavePin != NO_PIN || slavePin == NO_PIN) {
spi_start_config_t start_config = {0};
start_config.slave_pin = slavePin;
start_config.lsb_first = lsbFirst;
start_config.mode = mode;
start_config.divisor = divisor;
start_config.cs_active_low = true;
return spi_start_extended(&start_config);
}
bool spi_start_extended(spi_start_config_t *start_config) {
if (current_slave_pin != NO_PIN || start_config->slave_pin == NO_PIN) {
return false;
}
currentSlaveConfig = 0;
current_slave_config = 0;
if (lsbFirst) {
currentSlaveConfig |= _BV(DORD);
if (start_config->lsb_first) {
current_slave_config |= _BV(DORD);
}
switch (mode) {
switch (start_config->mode) {
case 1:
currentSlaveConfig |= _BV(CPHA);
current_slave_config |= _BV(CPHA);
break;
case 2:
currentSlaveConfig |= _BV(CPOL);
current_slave_config |= _BV(CPOL);
break;
case 3:
currentSlaveConfig |= (_BV(CPOL) | _BV(CPHA));
current_slave_config |= (_BV(CPOL) | _BV(CPHA));
break;
}
uint16_t roundedDivisor = 1;
while (roundedDivisor < divisor) {
while (roundedDivisor < start_config->divisor) {
roundedDivisor <<= 1;
}
switch (roundedDivisor) {
case 16:
currentSlaveConfig |= _BV(SPR0);
current_slave_config |= _BV(SPR0);
break;
case 64:
currentSlaveConfig |= _BV(SPR1);
current_slave_config |= _BV(SPR1);
break;
case 128:
currentSlaveConfig |= (_BV(SPR1) | _BV(SPR0));
current_slave_config |= (_BV(SPR1) | _BV(SPR0));
break;
case 2:
currentSlave2X = true;
current_slave_2x = true;
break;
case 8:
currentSlave2X = true;
currentSlaveConfig |= _BV(SPR0);
current_slave_2x = true;
current_slave_config |= _BV(SPR0);
break;
case 32:
currentSlave2X = true;
currentSlaveConfig |= _BV(SPR1);
current_slave_2x = true;
current_slave_config |= _BV(SPR1);
break;
}
SPCR |= currentSlaveConfig;
if (currentSlave2X) {
SPCR |= current_slave_config;
if (current_slave_2x) {
SPSR |= _BV(SPI2X);
}
currentSlavePin = slavePin;
gpio_set_pin_output(currentSlavePin);
gpio_write_pin_low(currentSlavePin);
current_slave_pin = start_config->slave_pin;
current_cs_active_low = start_config->cs_active_low;
gpio_set_pin_output(current_slave_pin);
spi_select();
return true;
}
@ -168,13 +188,13 @@ spi_status_t spi_receive(uint8_t *data, uint16_t length) {
}
void spi_stop(void) {
if (currentSlavePin != NO_PIN) {
gpio_set_pin_output(currentSlavePin);
gpio_write_pin_high(currentSlavePin);
currentSlavePin = NO_PIN;
if (current_slave_pin != NO_PIN) {
gpio_set_pin_output(current_slave_pin);
spi_unselect();
current_slave_pin = NO_PIN;
SPSR &= ~(_BV(SPI2X));
SPCR &= ~(currentSlaveConfig);
currentSlaveConfig = 0;
currentSlave2X = false;
SPCR &= ~(current_slave_config);
current_slave_config = 0;
current_slave_2x = false;
}
}