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DM: added write_readinto to bitbangio

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This commit is contained in:
dean 2018-01-30 17:18:57 -05:00
parent 271c4bead6
commit a7f72eb2d8
3 changed files with 102 additions and 0 deletions
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33
shared-bindings/bitbangio/SPI.c
View File

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

3
shared-bindings/bitbangio/SPI.h
View File

@ -56,4 +56,7 @@ extern bool shared_module_bitbangio_spi_write(bitbangio_spi_obj_t *self, const u
// Reads in len bytes while outputting zeroes.
extern bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data, size_t len);
// Transfer out len bytes while reading len bytes
extern bool shared_module_bitbangio_spi_transfer(bitbangio_spi_obj_t *self, const uint8_t *dout, uint8_t *din, size_t len);
#endif // MICROPY_INCLUDED_SHARED_BINDINGS_BITBANGIO_SPI_H

66
shared-module/bitbangio/SPI.c
View File

@ -238,3 +238,69 @@ bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data,
}
return true;
}
// transfer
bool shared_module_bitbangio_spi_transfer(bitbangio_spi_obj_t *self, const uint8_t *dout, uint8_t *din, size_t len) {
if (len > 0 && (!self->has_mosi || !self->has_miso) ) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError,
"Cannot transfer without MOSI and MISO pins."));
}
uint32_t delay_half = self->delay_half;
// only MSB transfer is implemented
// If a port defines MICROPY_PY_MACHINE_SPI_MIN_DELAY, and the configured
// delay_half is equal to this value, then the software SPI implementation
// will run as fast as possible, limited only by CPU speed and GPIO time.
#ifdef MICROPY_PY_MACHINE_SPI_MIN_DELAY
if (delay_half <= MICROPY_PY_MACHINE_SPI_MIN_DELAY) {
for (size_t i = 0; i < len; ++i) {
uint8_t data_out = dout[i];
uint8_t data_in = 0;
for (int j = 0; j < 8; ++j, data_out <<= 1) {
common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
}
din[i] = data_in;
if (dest != NULL) {
dest[i] = data_in;
}
}
return true;
}
#endif
for (size_t i = 0; i < len; ++i) {
uint8_t data_out = dout[i];
uint8_t data_in = 0;
for (int j = 0; j < 8; ++j, data_out <<= 1) {
common_hal_digitalio_digitalinout_set_value(&self->mosi, (data_out >> 7) & 1);
if (self->phase == 0) {
common_hal_mcu_delay_us(delay_half);
common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
} else {
common_hal_digitalio_digitalinout_set_value(&self->clock, 1 - self->polarity);
common_hal_mcu_delay_us(delay_half);
}
data_in = (data_in << 1) | common_hal_digitalio_digitalinout_get_value(&self->miso);
if (self->phase == 0) {
common_hal_mcu_delay_us(delay_half);
common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
} else {
common_hal_digitalio_digitalinout_set_value(&self->clock, self->polarity);
common_hal_mcu_delay_us(delay_half);
}
}
din[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
}
return true;
}