diff options
Diffstat (limited to 'extmod/machine_spi.c')
| -rw-r--r-- | extmod/machine_spi.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/extmod/machine_spi.c b/extmod/machine_spi.c index 1c64cf511b..3a34b7fb08 100644 --- a/extmod/machine_spi.c +++ b/extmod/machine_spi.c @@ -32,6 +32,43 @@ #if MICROPY_PY_MACHINE_SPI +void mp_machine_soft_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) { + mp_machine_soft_spi_obj_t *self = (mp_machine_soft_spi_obj_t*)self_in; + // only MSB transfer is implemented + uint32_t delay_half = 500000 / self->baudrate + 1; + for (size_t i = 0; i < len; ++i) { + uint8_t data_out = src[i]; + uint8_t data_in = 0; + for (int j = 0; j < 8; ++j, data_out <<= 1) { + mp_hal_pin_write(self->mosi, (data_out >> 7) & 1); + if (self->phase == 0) { + mp_hal_delay_us_fast(delay_half); + mp_hal_pin_write(self->sck, 1 - self->polarity); + } else { + mp_hal_pin_write(self->sck, 1 - self->polarity); + mp_hal_delay_us_fast(delay_half); + } + data_in = (data_in << 1) | mp_hal_pin_read(self->miso); + if (self->phase == 0) { + mp_hal_delay_us_fast(delay_half); + mp_hal_pin_write(self->sck, self->polarity); + } else { + mp_hal_pin_write(self->sck, self->polarity); + mp_hal_delay_us_fast(delay_half); + } + } + if (dest != NULL) { + dest[i] = data_in; + } + + // Some ports need a regular callback, but probably we don't need + // to do this every byte, or even at all. + #ifdef MICROPY_EVENT_POLL_HOOK + MICROPY_EVENT_POLL_HOOK; + #endif + } +} + STATIC void mp_machine_spi_transfer(mp_obj_t self, size_t len, const void *src, void *dest) { mp_obj_base_t *s = (mp_obj_base_t*)MP_OBJ_TO_PTR(self); mp_machine_spi_p_t *spi_p = (mp_machine_spi_p_t*)s->type->protocol; |