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bitbangio.SPI.read: Support write_value, fix some other nits

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This commit is contained in:
Jeff Epler 2021-03-26 12:06:25 -05:00
parent 2bc61b4580
commit a70b679ed5
3 changed files with 42 additions and 16 deletions
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48
shared-bindings/bitbangio/SPI.c
View File

@ -224,32 +224,53 @@ STATIC mp_obj_t bitbangio_spi_write(mp_obj_t self_in, mp_obj_t wr_buf) {
MP_DEFINE_CONST_FUN_OBJ_2(bitbangio_spi_write_obj, bitbangio_spi_write);
//| def readinto(self, buf: WriteableBuffer) -> None:
//| """Read into the buffer specified by ``buf`` while writing zeroes.
//| Requires the SPI being locked.
//| If the number of bytes to read is 0, nothing happens."""
//| def readinto(self, buffer: WriteableBuffer, *, start: int = 0, end: Optional[int] = None, write_value: int = 0) -> None:
//| """Read into ``buffer`` while writing ``write_value`` for each byte read.
//| The SPI object must be locked.
//| If the number of bytes to read is 0, nothing happens.
//|
//| :param bytearray buffer: Read data into this buffer
//| :param int start: Start of the slice of ``buffer`` to read into: ``buffer[start:end]``
//| :param int end: End of the slice; this index is not included. Defaults to ``len(buffer)``
//| :param int write_value: Value to write while reading."""
//| ...
//|
// TODO(tannewt): Add support for start and end kwargs.
STATIC mp_obj_t bitbangio_spi_readinto(size_t n_args, const mp_obj_t *args) {
bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(args[0]);
STATIC mp_obj_t bitbangio_spi_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_buffer, ARG_start, ARG_end, ARG_write_value };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
{ MP_QSTR_write_value,MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
};
bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_for_deinit(self);
check_lock(self);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
if (bufinfo.len == 0) {
mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE);
int32_t start = args[ARG_start].u_int;
size_t length = bufinfo.len;
normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
if (length == 0) {
return mp_const_none;
}
check_lock(args[0]);
bool ok = shared_module_bitbangio_spi_read(self, bufinfo.buf, bufinfo.len);
bool ok = shared_module_bitbangio_spi_read(self, ((uint8_t*)bufinfo.buf) + start, length, args[ARG_write_value].u_int);
if (!ok) {
mp_raise_OSError(MP_EIO);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_spi_readinto_obj, 2, 2, bitbangio_spi_readinto);
MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_spi_readinto_obj, 2, bitbangio_spi_readinto);
//| def write_readinto(self, buffer_out: ReadableBuffer, buffer_in: WriteableBuffer, *, out_start: int = 0, out_end: Optional[int] = None, in_start: int = 0, in_end: Optional[int] = None) -> None:
//| def write_readinto(self, buffer_out: ReadableBuffer, buffer_in: ReadableBuffer, *, out_start: int = 0, out_end: Optional[int] = None, in_start: int = 0, in_end: Optional[int] = None) -> None:
//| """Write out the data in ``buffer_out`` while simultaneously reading data into ``buffer_in``.
//| The SPI object must be locked.
//| The lengths of the slices defined by ``buffer_out[out_start:out_end]`` and ``buffer_in[in_start:in_end]``
//| must be equal.
//| If buffer slice lengths are both 0, nothing happens.
@ -274,6 +295,7 @@ STATIC mp_obj_t bitbangio_spi_write_readinto(size_t n_args, const mp_obj_t *pos_
};
bitbangio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_for_deinit(self);
check_lock(self);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

2
shared-bindings/bitbangio/SPI.h
View File

@ -54,7 +54,7 @@ extern void shared_module_bitbangio_spi_unlock(bitbangio_spi_obj_t *self);
extern bool shared_module_bitbangio_spi_write(bitbangio_spi_obj_t *self, const uint8_t *data, size_t len);
// 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);
extern bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data, size_t len, uint8_t write_value);
// 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);

8
shared-module/bitbangio/SPI.c
View File

@ -176,7 +176,7 @@ bool shared_module_bitbangio_spi_write(bitbangio_spi_obj_t *self, const uint8_t
}
// Reads in len bytes while outputting zeroes.
bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data, size_t len) {
bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data, size_t len, uint8_t write_data) {
if (len > 0 && !self->has_miso) {
mp_raise_ValueError(translate("Cannot read without MISO pin."));
}
@ -210,8 +210,12 @@ bool shared_module_bitbangio_spi_read(bitbangio_spi_obj_t *self, uint8_t *data,
common_hal_digitalio_digitalinout_set_value(&self->mosi, false);
}
for (size_t i = 0; i < len; ++i) {
uint8_t data_out = write_data;
uint8_t data_in = 0;
for (int j = 0; j < 8; ++j) {
for (int j = 0; j < 8; ++j, data_out <<= 1) {
if (self->has_mosi) {
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);