merge from 2.2.0 + fix up board defs

3 files changed, 94 insertions, 9 deletions

diff --git a/shared-bindings/busio/I2C.c b/shared-bindings/busio/I2C.c
index cdc960f80..b0954d6c8 100644
--- a/shared-bindings/busio/I2C.c
+++ b/shared-bindings/busio/I2C.c
@@ -171,6 +171,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_unlock_obj, busio_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
@@ -201,6 +202,10 @@ STATIC mp_obj_t busio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_args,
     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 = common_hal_busio_i2c_read(self, args[ARG_address].u_int, ((uint8_t*)bufinfo.buf) + start, length);
     if (status != 0) {
         mp_raise_OSError(status);
@@ -219,6 +224,9 @@ MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_readfrom_into_obj, 3, busio_i2c_readfrom_in
 //|      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
diff --git a/shared-bindings/busio/SPI.c b/shared-bindings/busio/SPI.c
index 12f888f23..c4c139105 100644
--- a/shared-bindings/busio/SPI.c
+++ b/shared-bindings/busio/SPI.c
@@ -206,11 +206,12 @@ 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.
+//|     Write the data contained in ``buffer``. The SPI object must be locked.
+//|     If the buffer is empty, nothing happens.
 //|
-//|     :param bytearray buffer: buffer containing the bytes to write
-//|     :param int start: Index to start writing from
-//|     :param int end: Index to read up to but not include
+//|     :param bytearray buffer: Write out the data in this buffer
+//|     :param int start: Start of the slice of ``buffer`` to write out: ``buffer[start:end]``
+//|     :param int end: End of the slice; this index is not included
 //|
 STATIC mp_obj_t busio_spi_write(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_buffer, ARG_start, ARG_end };
@@ -231,6 +232,10 @@ STATIC mp_obj_t busio_spi_write(size_t n_args, const mp_obj_t *pos_args, mp_map_
     uint32_t length = bufinfo.len;
     normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
 
+    if (length == 0) {
+        return mp_const_none;
+    }
+
     bool ok = common_hal_busio_spi_write(self, ((uint8_t*)bufinfo.buf) + start, length);
     if (!ok) {
         mp_raise_OSError(MP_EIO);
@@ -242,12 +247,14 @@ 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.
+//|     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: buffer to write into
-//|     :param int start: Index to start writing at
-//|     :param int end: Index to write up to but not include
-//|     :param int write_value: Value to write reading. (Usually ignored.)
+//|     :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 
+//|     :param int write_value: Value to write while reading. (Usually ignored.)
 //|
 STATIC mp_obj_t busio_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 };
@@ -269,6 +276,10 @@ STATIC mp_obj_t busio_spi_readinto(size_t n_args, const mp_obj_t *pos_args, mp_m
     uint32_t length = bufinfo.len;
     normalize_buffer_bounds(&start, args[ARG_end].u_int, &length);
 
+    if (length == 0) {
+        return mp_const_none;
+    }
+
     bool ok = common_hal_busio_spi_read(self, ((uint8_t*)bufinfo.buf) + start, length, args[ARG_write_value].u_int);
     if (!ok) {
         mp_raise_OSError(MP_EIO);
@@ -277,6 +288,68 @@ STATIC mp_obj_t busio_spi_readinto(size_t n_args, const mp_obj_t *pos_args, mp_m
 }
 MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_readinto_obj, 2, busio_spi_readinto);
 
+//|   .. method:: SPI.write_readinto(buffer_out, buffer_in, \*, out_start=0, out_end=len(buffer_out), in_start=0, in_end=len(buffer_in))
+//|
+//|     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.
+//|
+//|     :param bytearray buffer_out: Write out the data in this buffer
+//|     :param bytearray buffer_in: Read data into this buffer
+//|     :param int out_start: Start of the slice of buffer_out to write out: ``buffer_out[out_start:out_end]``
+//|     :param int out_end: End of the slice; this index is not included 
+//|     :param int in_start: Start of the slice of ``buffer_in`` to read into: ``buffer_in[in_start:in_end]``
+//|     :param int in_end: End of the slice; this index is not included
+//|
+STATIC mp_obj_t busio_spi_write_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_buffer_out, ARG_buffer_in, ARG_out_start, ARG_out_end, ARG_in_start, ARG_in_end };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_buffer_out,    MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_buffer_in,     MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_out_start,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_out_end,       MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
+        { MP_QSTR_in_start,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_in_end,        MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
+    };
+    busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    raise_error_if_deinited(common_hal_busio_spi_deinited(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 buf_out_info;
+    mp_get_buffer_raise(args[ARG_buffer_out].u_obj, &buf_out_info, MP_BUFFER_READ);
+    int32_t out_start = args[ARG_out_start].u_int;
+    uint32_t out_length = buf_out_info.len;
+    normalize_buffer_bounds(&out_start, args[ARG_out_end].u_int, &out_length);
+
+    mp_buffer_info_t buf_in_info;
+    mp_get_buffer_raise(args[ARG_buffer_in].u_obj, &buf_in_info, MP_BUFFER_WRITE);
+    int32_t in_start = args[ARG_in_start].u_int;
+    uint32_t in_length = buf_in_info.len;
+    normalize_buffer_bounds(&in_start, args[ARG_in_end].u_int, &in_length);
+
+    if (out_length != in_length) {
+        mp_raise_ValueError("buffer slices must be of equal length");
+    }
+
+    if (out_length == 0) {
+        return mp_const_none;
+    }
+
+    bool ok = common_hal_busio_spi_transfer(self,
+                                            ((uint8_t*)buf_out_info.buf) + out_start,
+                                            ((uint8_t*)buf_in_info.buf) + in_start,
+                                            out_length);
+    if (!ok) {
+        mp_raise_OSError(MP_EIO);
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_write_readinto_obj, 2, busio_spi_write_readinto);
+
 STATIC const mp_rom_map_elem_t busio_spi_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_spi_deinit_obj) },
     { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
@@ -288,6 +361,7 @@ STATIC const mp_rom_map_elem_t busio_spi_locals_dict_table[] = {
 
     { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&busio_spi_readinto_obj) },
     { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&busio_spi_write_obj) },
+    { MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&busio_spi_write_readinto_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(busio_spi_locals_dict, busio_spi_locals_dict_table);
 
diff --git a/shared-bindings/busio/SPI.h b/shared-bindings/busio/SPI.h
index ac31d5060..b6e5c9b1b 100644
--- a/shared-bindings/busio/SPI.h
+++ b/shared-bindings/busio/SPI.h
@@ -55,4 +55,7 @@ extern bool common_hal_busio_spi_write(busio_spi_obj_t *self, const uint8_t *dat
 // Reads in len bytes while outputting zeroes.
 extern bool common_hal_busio_spi_read(busio_spi_obj_t *self, uint8_t *data, size_t len, uint8_t write_value);
 
+// Reads and write len bytes simultaneously.
+extern bool common_hal_busio_spi_transfer(busio_spi_obj_t *self, uint8_t *data_out, uint8_t *data_in, size_t len);
+
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_BUSIO_SPI_H