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Use new pio functions #766

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d0a5182
Use new pio functions
peterharperuk Jun 23, 2026
8469ba0
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peterharperuk Jun 24, 2026
9b5b228
Update pio/spi/spi_loopback.c
peterharperuk Jun 25, 2026
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4 changes: 2 additions & 2 deletions pio/spi/spi.pio
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Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,7 @@ static inline void pio_spi_init(PIO pio, uint sm, uint prog_offs, uint n_bits,
// and this is a cheesy way to get CPOL=1
gpio_set_outover(pin_sck, cpol ? GPIO_OVERRIDE_INVERT : GPIO_OVERRIDE_NORMAL);
// SPI is synchronous, so bypass input synchroniser to reduce input delay.
hw_set_bits(&pio->input_sync_bypass, (pin_miso >= 32) ? (1u << (pin_miso - 16)) : (1u << pin_miso));
pio_set_input_sync_bypass_with_mask64(pio, 1ull << pin_miso, 1ull << pin_miso);

pio_sm_init(pio, sm, prog_offs, &c);
pio_sm_set_enabled(pio, sm, true);
Expand Down Expand Up @@ -157,7 +157,7 @@ static inline void pio_spi_cs_init(PIO pio, uint sm, uint prog_offs, uint n_bits
pio_gpio_init(pio, pin_sck);
pio_gpio_init(pio, pin_sck + 1);
gpio_set_outover(pin_sck, cpol ? GPIO_OVERRIDE_INVERT : GPIO_OVERRIDE_NORMAL);
hw_set_bits(&pio->input_sync_bypass, (pin_miso >= 32) ? (1u << (pin_miso - 16)) : (1u << pin_miso));
pio_set_input_sync_bypass_with_mask64(pio, 1ull << pin_miso, 1ull << pin_miso);

uint entry_point = prog_offs + (cpha ? spi_cpha1_cs_offset_entry_point : spi_cpha0_cs_offset_entry_point);
pio_sm_init(pio, sm, entry_point, &c);
Expand Down
18 changes: 15 additions & 3 deletions pio/spi/spi_loopback.c
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,8 @@

#define BUF_SIZE 20

static uint32_t match_count;

void test(const pio_spi_inst_t *spi) {
static uint8_t txbuf[BUF_SIZE];
static uint8_t rxbuf[BUF_SIZE];
Expand All @@ -40,26 +42,34 @@ void test(const pio_spi_inst_t *spi) {
printf(" %02x", (int) rxbuf[i]);
mismatch = mismatch || rxbuf[i] != txbuf[i];
}
if (mismatch)
if (mismatch) {
printf("\nNope\n");
else
} else {
printf("\nOK\n");
match_count++;
}
}

int main() {
stdio_init_all();

printf("spi_loopback start\n");
pio_spi_inst_t spi[2];
#if 1
float clkdiv = 1; // as fast as possible!
#else
float clkdiv = 31.25f; // 1 MHz @ 125 clk_sys
#endif

// pio_claim_free_sm_and_add_program_for_gpio_range finds a free pio and state machine for a program and sets the gpio base correctly
const uint pin_base = MIN(PIN_SCK, MIN(PIN_MOSI, PIN_MISO));
const uint pin_count = MAX(PIN_SCK, MAX(PIN_MOSI, PIN_MISO)) - pin_base + 1;
hard_assert(pio_claim_free_sm_and_add_program_for_gpio_range(&spi_cpha0_program, &spi[0].pio, &spi[0].sm, &spi[0].offset, pin_base, pin_count, true));
hard_assert(pio_claim_free_sm_and_add_program_for_gpio_range(&spi_cpha1_program, &spi[1].pio, &spi[1].sm, &spi[1].offset, pin_base, pin_count, true));

int spi_example_runs = 0;
for (int cpha = 0; cpha <= 1; ++cpha) {
for (int cpol = 0; cpol <= 1; ++cpol) {
spi_example_runs++;
printf("CPHA = %d, CPOL = %d\n", cpha, cpol);
pio_spi_init(spi[cpha].pio, spi[cpha].sm,
spi[cpha].offset,
Expand All @@ -75,4 +85,6 @@ int main() {
sleep_ms(10);
}
}
printf("Example %s\n", match_count == spi_example_runs ? "PASSED" : "FAILED");
assert(match_count == spi_example_runs);
}
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