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Merge pull request #404 from pewpew-game/fix-spi-empty-read-write

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Allow empty reads and writes for busio.SPI
This commit is contained in:
Dan Halbert 2017-11-03 12:40:15 -04:00 committed by GitHub
commit 4869599f89
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 23 additions and 6 deletions
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7
shared-bindings/bitbangio/I2C.c
View File

@ -157,6 +157,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_unlock_obj, bitbangio_i2c_obj_unlock);
//|
//| Read into ``buffer`` from the slave specified by ``address``.
//| The number of bytes read will be the length of ``buffer``.
//| At least one byte must be read.
//|
//| If ``start`` or ``end`` is provided, then the buffer will be sliced
//| as if ``buffer[start:end]``. This will not cause an allocation like
@ -186,6 +187,9 @@ STATIC mp_obj_t bitbangio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_a
int32_t start = args[ARG_start].u_int;
uint32_t length = bufinfo.len;
normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
if (length == 0) {
mp_raise_ValueError("Buffer must be at least length 1");
}
uint8_t status = shared_module_bitbangio_i2c_read(self,
args[ARG_address].u_int,
((uint8_t*)bufinfo.buf) + start,
@ -206,6 +210,9 @@ MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_readfrom_into_obj, 3, bitbangio_i2c_rea
//| as if ``buffer[start:end]``. This will not cause an allocation like
//| ``buffer[start:end]`` will so it saves memory.
//|
//| Writing a buffer or slice of length zero is permitted, as it can be used
//| to poll for the existence of a device.
//|
//| :param int address: 7-bit device address
//| :param bytearray buffer: buffer containing the bytes to write
//| :param int start: Index to start writing from

11
shared-bindings/bitbangio/SPI.c
View File

@ -191,6 +191,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_spi_unlock_obj, bitbangio_spi_obj_unlock);
//| .. method:: SPI.write(buf)
//|
//| Write the data contained in ``buf``. Requires the SPI being locked.
//| If the buffer is empty, nothing happens.
//|
// TODO(tannewt): Add support for start and end kwargs.
STATIC mp_obj_t bitbangio_spi_write(mp_obj_t self_in, mp_obj_t wr_buf) {
@ -198,6 +199,9 @@ STATIC mp_obj_t bitbangio_spi_write(mp_obj_t self_in, mp_obj_t wr_buf) {
raise_error_if_deinited(shared_module_bitbangio_spi_deinited(self));
mp_buffer_info_t src;
mp_get_buffer_raise(wr_buf, &src, MP_BUFFER_READ);
if (src.len == 0) {
return mp_const_none;
}
check_lock(self);
bool ok = shared_module_bitbangio_spi_write(self, src.buf, src.len);
if (!ok) {
@ -210,7 +214,9 @@ MP_DEFINE_CONST_FUN_OBJ_2(bitbangio_spi_write_obj, bitbangio_spi_write);
//| .. method:: SPI.readinto(buf)
//|
//| Read into the buffer specified by ``buf`` while writing zeroes. Requires the SPI being locked.
//| 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.
//|
// 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) {
@ -218,6 +224,9 @@ STATIC mp_obj_t bitbangio_spi_readinto(size_t n_args, const mp_obj_t *args) {
raise_error_if_deinited(shared_module_bitbangio_spi_deinited(self));
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_WRITE);
if (bufinfo.len == 0) {
return mp_const_none;
}
check_lock(args[0]);
bool ok = shared_module_bitbangio_spi_read(self, bufinfo.buf, bufinfo.len);
if (!ok) {

11
shared-bindings/busio/SPI.c
View File

@ -207,7 +207,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_unlock_obj, busio_spi_obj_unlock);
//| .. method:: SPI.write(buffer, \*, start=0, end=len(buffer))
//|
//| Write the data contained in ``buf``. Requires the SPI being locked.
//| At least one byte must be written.
//| If the buffer is empty, nothing happens.
//|
//| :param bytearray buffer: buffer containing the bytes to write
//| :param int start: Index to start writing from
@ -233,7 +233,7 @@ STATIC mp_obj_t busio_spi_write(size_t n_args, const mp_obj_t *pos_args, mp_map_
normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
if (length == 0) {
mp_raise_ValueError("Buffer must be at least length 1");
return mp_const_none;
}
bool ok = common_hal_busio_spi_write(self, ((uint8_t*)bufinfo.buf) + start, length);
@ -247,8 +247,9 @@ MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_write_obj, 2, busio_spi_write);
//| .. method:: SPI.readinto(buffer, \*, start=0, end=len(buffer), write_value=0)
//|
//| Read into the buffer specified by ``buf`` while writing zeroes. Requires the SPI being locked.
//| At least one byte must be read.
//| 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.
//|
//| :param bytearray buffer: buffer to write into
//| :param int start: Index to start writing at
@ -276,7 +277,7 @@ STATIC mp_obj_t busio_spi_readinto(size_t n_args, const mp_obj_t *pos_args, mp_m
normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
if (length == 0) {
mp_raise_ValueError("Buffer must be at least length 1");
return mp_const_none;
}
bool ok = common_hal_busio_spi_read(self, ((uint8_t*)bufinfo.buf) + start, length, args[ARG_write_value].u_int);