diff --git a/drivers/bus/softspi.c b/drivers/bus/softspi.c index bc12d89d3b..7d687a1a2f 100644 --- a/drivers/bus/softspi.c +++ b/drivers/bus/softspi.c @@ -44,28 +44,36 @@ int mp_soft_spi_ioctl(void *self_in, uint32_t cmd) { return 0; } +static uint8_t swap_bits(uint8_t byte) { + const static uint8_t swap_table[16] = { + 0x00, 0x08, 0x04, 0x0c, 0x02, 0x0a, 0x06, 0x0e, + 0x01, 0x09, 0x05, 0x0d, 0x03, 0x0b, 0x07, 0x0f + }; + return ((swap_table[byte & 0x0f] << 4) | swap_table[byte >> 4]); +} + void mp_soft_spi_transfer(void *self_in, size_t len, const uint8_t *src, uint8_t *dest) { mp_soft_spi_obj_t *self = (mp_soft_spi_obj_t*)self_in; uint32_t delay_half = self->delay_half; - // only MSB transfer is implemented - // If a port defines MICROPY_HW_SOFTSPI_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_HW_SOFTSPI_MIN_DELAY if (delay_half == MICROPY_HW_SOFTSPI_MIN_DELAY) { for (size_t i = 0; i < len; ++i) { - uint8_t data_out = src[i]; + uint8_t data_out = self->firstbit != MICROPY_PY_MACHINE_SPI_MSB ? + src[i] : swap_bits(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); + for (int j = 0; j < 8; ++j, data_out >>= 1) { + mp_hal_pin_write(self->mosi, data_out & 1); mp_hal_pin_write(self->sck, 1 - self->polarity); data_in = (data_in << 1) | mp_hal_pin_read(self->miso); mp_hal_pin_write(self->sck, self->polarity); } if (dest != NULL) { - dest[i] = data_in; + dest[i] = self->firstbit == MICROPY_PY_MACHINE_SPI_MSB ? + data_in : swap_bits(data_in); } } return; @@ -73,10 +81,11 @@ void mp_soft_spi_transfer(void *self_in, size_t len, const uint8_t *src, uint8_t #endif for (size_t i = 0; i < len; ++i) { - uint8_t data_out = src[i]; + uint8_t data_out = self->firstbit != MICROPY_PY_MACHINE_SPI_MSB ? + src[i] : swap_bits(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); + for (int j = 0; j < 8; ++j, data_out >>= 1) { + mp_hal_pin_write(self->mosi, data_out & 1); if (self->phase == 0) { mp_hal_delay_us_fast(delay_half); mp_hal_pin_write(self->sck, 1 - self->polarity); @@ -94,7 +103,8 @@ void mp_soft_spi_transfer(void *self_in, size_t len, const uint8_t *src, uint8_t } } if (dest != NULL) { - dest[i] = data_in; + dest[i] = self->firstbit == MICROPY_PY_MACHINE_SPI_MSB ? + data_in : swap_bits(data_in); } } } diff --git a/drivers/bus/spi.h b/drivers/bus/spi.h index 6d1b9c2f83..df7f790df8 100644 --- a/drivers/bus/spi.h +++ b/drivers/bus/spi.h @@ -42,6 +42,7 @@ typedef struct _mp_soft_spi_obj_t { uint32_t delay_half; // microsecond delay for half SCK period uint8_t polarity; uint8_t phase; + uint8_t firstbit; mp_hal_pin_obj_t sck; mp_hal_pin_obj_t mosi; mp_hal_pin_obj_t miso; diff --git a/extmod/machine_spi.c b/extmod/machine_spi.c index a1d18c9052..5be30e9476 100644 --- a/extmod/machine_spi.c +++ b/extmod/machine_spi.c @@ -33,12 +33,6 @@ #include "extmod/modmachine.h" -// if a port didn't define MSB/LSB constants then provide them -#ifndef MICROPY_PY_MACHINE_SPI_MSB -#define MICROPY_PY_MACHINE_SPI_MSB (0) -#define MICROPY_PY_MACHINE_SPI_LSB (1) -#endif - /******************************************************************************/ // MicroPython bindings for generic machine.SPI @@ -154,9 +148,9 @@ static uint32_t baudrate_to_delay_half(uint32_t baudrate) { static void mp_machine_soft_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { mp_machine_soft_spi_obj_t *self = MP_OBJ_TO_PTR(self_in); - mp_printf(print, "SoftSPI(baudrate=%u, polarity=%u, phase=%u," + mp_printf(print, "SoftSPI(baudrate=%u, polarity=%u, phase=%u, firstbit=%u," " sck=" MP_HAL_PIN_FMT ", mosi=" MP_HAL_PIN_FMT ", miso=" MP_HAL_PIN_FMT ")", - baudrate_from_delay_half(self->spi.delay_half), self->spi.polarity, self->spi.phase, + baudrate_from_delay_half(self->spi.delay_half), self->spi.polarity, self->spi.phase, self->spi.firstbit, mp_hal_pin_name(self->spi.sck), mp_hal_pin_name(self->spi.mosi), mp_hal_pin_name(self->spi.miso)); } @@ -185,9 +179,7 @@ static mp_obj_t mp_machine_soft_spi_make_new(const mp_obj_type_t *type, size_t n if (args[ARG_bits].u_int != 8) { mp_raise_ValueError(MP_ERROR_TEXT("bits must be 8")); } - if (args[ARG_firstbit].u_int != MICROPY_PY_MACHINE_SPI_MSB) { - mp_raise_ValueError(MP_ERROR_TEXT("firstbit must be MSB")); - } + self->spi.firstbit = args[ARG_firstbit].u_int; if (args[ARG_sck].u_obj == MP_OBJ_NULL || args[ARG_mosi].u_obj == MP_OBJ_NULL || args[ARG_miso].u_obj == MP_OBJ_NULL) { @@ -206,11 +198,12 @@ static mp_obj_t mp_machine_soft_spi_make_new(const mp_obj_type_t *type, size_t n static void mp_machine_soft_spi_init(mp_obj_base_t *self_in, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { mp_machine_soft_spi_obj_t *self = (mp_machine_soft_spi_obj_t *)self_in; - enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_sck, ARG_mosi, ARG_miso }; + enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_firstbit, ARG_sck, ARG_mosi, ARG_miso }; static const mp_arg_t allowed_args[] = { { MP_QSTR_baudrate, MP_ARG_INT, {.u_int = -1} }, { MP_QSTR_polarity, MP_ARG_INT, {.u_int = -1} }, { MP_QSTR_phase, MP_ARG_INT, {.u_int = -1} }, + { MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} }, { MP_QSTR_sck, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_mosi, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_miso, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, @@ -227,6 +220,9 @@ static void mp_machine_soft_spi_init(mp_obj_base_t *self_in, size_t n_args, cons if (args[ARG_phase].u_int != -1) { self->spi.phase = args[ARG_phase].u_int; } + if (args[ARG_firstbit].u_int != -1) { + self->spi.firstbit = args[ARG_firstbit].u_int; + } if (args[ARG_sck].u_obj != MP_OBJ_NULL) { self->spi.sck = mp_hal_get_pin_obj(args[ARG_sck].u_obj); } diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h index 0afb12f85c..558fa6b8c6 100644 --- a/ports/esp32/mpconfigport.h +++ b/ports/esp32/mpconfigport.h @@ -136,8 +136,6 @@ #define MICROPY_PY_MACHINE_I2C_TRANSFER_WRITE1 (1) #define MICROPY_PY_MACHINE_SOFTI2C (1) #define MICROPY_PY_MACHINE_SPI (1) -#define MICROPY_PY_MACHINE_SPI_MSB (0) -#define MICROPY_PY_MACHINE_SPI_LSB (1) #define MICROPY_PY_MACHINE_SOFTSPI (1) #ifndef MICROPY_PY_MACHINE_DAC #define MICROPY_PY_MACHINE_DAC (SOC_DAC_SUPPORTED) diff --git a/py/mpconfig.h b/py/mpconfig.h index 346d0c21e1..98893ceb6d 100644 --- a/py/mpconfig.h +++ b/py/mpconfig.h @@ -1784,6 +1784,12 @@ typedef double mp_float_t; #define MICROPY_PY_MACHINE_SOFTSPI (0) #endif +// Values of SPI.MSB and SPI.LSB constants +#ifndef MICROPY_PY_MACHINE_SPI_MSB +#define MICROPY_PY_MACHINE_SPI_MSB (0) +#define MICROPY_PY_MACHINE_SPI_LSB (1) +#endif + // Whether to provide the "machine.Timer" class #ifndef MICROPY_PY_MACHINE_TIMER #define MICROPY_PY_MACHINE_TIMER (0)