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deanm1278deanm1278
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DM: added write_readinto to bitbangio
1 parent 271c4be commit a7f72eb

3 files changed

Lines changed: 102 additions & 0 deletions

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‎shared-bindings/bitbangio/SPI.c‎

Lines changed: 33 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -236,6 +236,38 @@ STATIC mp_obj_t bitbangio_spi_readinto(size_t n_args, const mp_obj_t *args) {
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}
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MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_spi_readinto_obj, 2, 2, bitbangio_spi_readinto);
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//| .. method:: SPI.write_readinto(buf_in, buf_out)
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//|
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//| Write out the data in ``buffer_out`` while simultaneously reading data into ``buffer_in``.
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STATIC mp_obj_t bitbangio_spi_write_readinto(size_t n_args, const mp_obj_t *args) {
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bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(args[0]);
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raise_error_if_deinited(shared_module_bitbangio_spi_deinited(self));
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mp_buffer_info_t bufinfoin;
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mp_get_buffer_raise(args[2], &bufinfoin, MP_BUFFER_WRITE);
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if (bufinfoin.len == 0) {
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return mp_const_none;
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}
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mp_buffer_info_t bufinfoout;
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mp_get_buffer_raise(args[1], &bufinfoout, MP_BUFFER_READ);
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if (bufinfoout.len != bufinfoin.len) {
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mp_raise_ValueError("buffers must be of equal length");
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}
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bool ok = shared_module_bitbangio_spi_transfer(self,
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((uint8_t*)bufinfoout.buf),
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((uint8_t*)bufinfoin.buf),
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bufinfoin.len);
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if (!ok) {
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mp_raise_OSError(MP_EIO);
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}
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return mp_const_none;
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}
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MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_spi_write_readinto_obj, 3, 3, bitbangio_spi_write_readinto);
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STATIC const mp_rom_map_elem_t bitbangio_spi_locals_dict_table[] = {
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{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&bitbangio_spi_deinit_obj) },
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{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
@@ -247,6 +279,7 @@ STATIC const mp_rom_map_elem_t bitbangio_spi_locals_dict_table[] = {
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248280
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&bitbangio_spi_readinto_obj) },
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{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&bitbangio_spi_write_obj) },
282+
{ MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&bitbangio_spi_write_readinto_obj) },
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};
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STATIC MP_DEFINE_CONST_DICT(bitbangio_spi_locals_dict, bitbangio_spi_locals_dict_table);
252285

‎shared-bindings/bitbangio/SPI.h‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -56,4 +56,7 @@ extern bool shared_module_bitbangio_spi_write(bitbangio_spi_obj_t *self, const u
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// Reads in len bytes while outputting zeroes.
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extern bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data, size_t len);
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59+
// Transfer out len bytes while reading len bytes
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extern bool shared_module_bitbangio_spi_transfer(bitbangio_spi_obj_t *self, const uint8_t *dout, uint8_t *din, size_t len);
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#endif // MICROPY_INCLUDED_SHARED_BINDINGS_BITBANGIO_SPI_H

‎shared-module/bitbangio/SPI.c‎

Lines changed: 66 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -238,3 +238,69 @@ bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data,
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}
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return true;
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}
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// transfer
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bool shared_module_bitbangio_spi_transfer(bitbangio_spi_obj_t *self, const uint8_t *dout, uint8_t *din, size_t len) {
244+
if (len > 0 && (!self->has_mosi || !self->has_miso) ) {
245+
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError,
246+
"Cannot transfer without MOSI and MISO pins."));
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}
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uint32_t delay_half = self->delay_half;
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// only MSB transfer is implemented
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// If a port defines MICROPY_PY_MACHINE_SPI_MIN_DELAY, and the configured
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// delay_half is equal to this value, then the software SPI implementation
254+
// will run as fast as possible, limited only by CPU speed and GPIO time.
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#ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
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if (delay_half <= MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
257+
for (size_t i = 0; i < len; ++i) {
258+
uint8_t data_out = dout[i];
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uint8_t data_in = 0;
260+
for (int j = 0; j < 8; ++j, data_out <<= 1) {
261+
common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
262+
common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
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data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
264+
common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
265+
}
266+
din[i] = data_in;
267+
268+
if (dest != NULL) {
269+
dest[i] = data_in;
270+
}
271+
}
272+
return true;
273+
}
274+
#endif
275+
276+
for (size_t i = 0; i < len; ++i) {
277+
uint8_t data_out = dout[i];
278+
uint8_t data_in = 0;
279+
for (int j = 0; j < 8; ++j, data_out <<= 1) {
280+
common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
281+
if (self->phase == 0) {
282+
common_hal_mcu_delay_us(delay_half);
283+
common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
284+
} else {
285+
common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
286+
common_hal_mcu_delay_us(delay_half);
287+
}
288+
data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
289+
if (self->phase == 0) {
290+
common_hal_mcu_delay_us(delay_half);
291+
common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
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} else {
293+
common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
294+
common_hal_mcu_delay_us(delay_half);
295+
}
296+
}
297+
din[i] = data_in;
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299+
// Some ports need a regular callback, but probably we don't need
300+
// to do this every byte, or even at all.
301+
#ifdef MICROPY_EVENT_POLL_HOOK
302+
MICROPY_EVENT_POLL_HOOK;
303+
#endif
304+
}
305+
return true;
306+
}

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