diff options
| -rw-r--r-- | shared-bindings/bitbangio/SPI.c | 33 | ||||
| -rw-r--r-- | shared-bindings/bitbangio/SPI.h | 3 | ||||
| -rw-r--r-- | shared-module/bitbangio/SPI.c | 66 |
3 files changed, 102 insertions, 0 deletions
diff --git a/shared-bindings/bitbangio/SPI.c b/shared-bindings/bitbangio/SPI.c index 5442b9ea2..3675db9bc 100644 --- a/shared-bindings/bitbangio/SPI.c +++ b/shared-bindings/bitbangio/SPI.c @@ -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); diff --git a/shared-bindings/bitbangio/SPI.h b/shared-bindings/bitbangio/SPI.h index 0ce329798..c4b10b666 100644 --- a/shared-bindings/bitbangio/SPI.h +++ b/shared-bindings/bitbangio/SPI.h @@ -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 diff --git a/shared-module/bitbangio/SPI.c b/shared-module/bitbangio/SPI.c index 0576a6e56..f65cbeaec 100644 --- a/shared-module/bitbangio/SPI.c +++ b/shared-module/bitbangio/SPI.c @@ -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; +} |