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extmod/machine_spi: Factor out software SPI code from esp8266 to extmod.

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This commit is contained in:
Damien George
2016-10-03 16:43:44 +11:00
parent a22a67661a
commit d434ce3fca
3 changed files with 54 additions and 51 deletions
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37
extmod/machine_spi.c
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@@ -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;