Implement audiobusio and enhance PIO for it

This adds I2SOut and PDMIn support via PIO.

StateMachines can now:
 * read and read while writing
 * transfer in 1, 2 or 4 byte increments
 * init pins based on expected defaults automatically
 * be stopped and restarted
 * rxfifo can be cleared and rxstalls detected (good for tracking when
   the reading code isn't keeping up)

Fixes #4162

2 files changed, 275 insertions, 140 deletions

diff --git a/ports/raspberrypi/bindings/rp2pio/StateMachine.c b/ports/raspberrypi/bindings/rp2pio/StateMachine.c
index 34633949e..77f61acd0 100644
--- a/ports/raspberrypi/bindings/rp2pio/StateMachine.c
+++ b/ports/raspberrypi/bindings/rp2pio/StateMachine.c
@@ -36,6 +36,7 @@
 #include "lib/utils/buffer_helper.h"
 #include "lib/utils/context_manager_helpers.h"
 #include "lib/utils/interrupt_char.h"
+#include "py/binary.h"
 #include "py/mperrno.h"
 #include "py/objproperty.h"
 #include "py/runtime.h"
@@ -64,16 +65,23 @@
 //|                  init: Optional[ReadableBuffer] = None,
 //|                  first_out_pin: Optional[microcontroller.Pin] = None,
 //|                  out_pin_count: int = 1,
+//|                  initial_out_pin_state: int = 0,
+//|                  initial_out_pin_direction: int = 0xffffffff,
 //|                  first_in_pin: Optional[microcontroller.Pin] = None,
 //|                  in_pin_count: int = 1,
 //|                  first_set_pin: Optional[microcontroller.Pin] = None,
 //|                  set_pin_count: int = 1,
+//|                  initial_set_pin_state: int = 0,
+//|                  initial_set_pin_direction: int = 0x1f,
 //|                  first_sideset_pin: Optional[microcontroller.Pin] = None,
 //|                  sideset_pin_count: int = 1,
+//|                  initial_sideset_pin_state: int = 0,
+//|                  initial_sideset_pin_direction: int = 0x1f,
 //|                  exclusive_pin_use: bool = True,
 //|                  auto_pull: bool = False,
 //|                  pull_threshold : int = 32,
 //|                  out_shift_right : bool = True,
+//|                  wait_for_txstall: bool = True,
 //|                  auto_push: bool = False,
 //|                  push_threshold : int = 32,
 //|                  in_shift_right : bool = True) -> None:
@@ -87,12 +95,18 @@
 //|              is started so instructions may be intermingled
 //|         :param ~microcontroller.Pin first_out_pin: the first pin to use with the OUT instruction
 //|         :param int out_pin_count: the count of consecutive pins to use with OUT starting at first_out_pin
+//|         :param int initial_out_pin_state: the initial output value for out pins starting at first_out_pin
+//|         :param int initial_out_pin_direction: the initial output direction for out pins starting at first_out_pin
 //|         :param ~microcontroller.Pin first_in_pin: the first pin to use with the IN instruction
 //|         :param int in_pin_count: the count of consecutive pins to use with IN starting at first_in_pin
 //|         :param ~microcontroller.Pin first_set_pin: the first pin to use with the SET instruction
 //|         :param int set_pin_count: the count of consecutive pins to use with SET starting at first_set_pin
+//|         :param int initial_set_pin_state: the initial output value for set pins starting at first_set_pin
+//|         :param int initial_set_pin_direction: the initial output direction for set pins starting at first_set_pin
 //|         :param ~microcontroller.Pin first_sideset_pin: the first pin to use with a side set
 //|         :param int sideset_pin_count: the count of consecutive pins to use with a side set starting at first_sideset_pin
+//|         :param int initial_sideset_pin_state: the initial output value for sideset pins starting at first_sideset_pin
+//|         :param int initial_sideset_pin_direction: the initial output direction for sideset pins starting at first_sideset_pin
 //|         :param bool exclusive_pin_use: When True, do not share any pins with other state machines. Pins are never shared with other peripherals
 //|         :param bool auto_pull: When True, automatically load data from the tx FIFO into the
 //|             output shift register (OSR) when an OUT instruction shifts more than pull_threshold bits
@@ -100,6 +114,10 @@
 //|         :param bool out_shift_right: When True, data is shifted out the right side (LSB) of the
 //|             OSR. It is shifted out the left (MSB) otherwise. NOTE! This impacts data alignment
 //|             when the number of bytes is not a power of two (1, 2 or 4 bytes).
+//|         :param bool wait_for_txstall: When True, writing data out will block until the TX FIFO and OSR are empty
+//|             and an instruction is stalled waiting for more data. When False, data writes won't
+//|             wait for the OSR to empty (only the TX FIFO) so make sure you give enough time before
+//|             deiniting or stopping the state machine.
 //|         :param bool auto_push: When True, automatically save data from input shift register
 //|              (ISR) into the rx FIFO when an IN instruction shifts more than push_threshold bits
 //|         :param int push_threshold: Number of bits to shift before saving the ISR value to the RX FIFO
@@ -113,29 +131,42 @@ STATIC mp_obj_t rp2pio_statemachine_make_new(const mp_obj_type_t *type, size_t n
     rp2pio_statemachine_obj_t *self = m_new_obj(rp2pio_statemachine_obj_t);
     self->base.type = &rp2pio_statemachine_type;
     enum { ARG_program, ARG_frequency, ARG_init,
-           ARG_first_out_pin, ARG_out_pin_count,
+           ARG_first_out_pin, ARG_out_pin_count, ARG_initial_out_pin_state, ARG_initial_out_pin_direction,
            ARG_first_in_pin, ARG_in_pin_count,
-           ARG_first_set_pin, ARG_set_pin_count,
-           ARG_first_sideset_pin, ARG_sideset_pin_count,
+           ARG_first_set_pin, ARG_set_pin_count, ARG_initial_set_pin_state, ARG_initial_set_pin_direction,
+           ARG_first_sideset_pin, ARG_sideset_pin_count, ARG_initial_sideset_pin_state, ARG_initial_sideset_pin_direction,
            ARG_exclusive_pin_use,
            ARG_auto_pull, ARG_pull_threshold, ARG_out_shift_right,
+           ARG_wait_for_txstall,
            ARG_auto_push, ARG_push_threshold, ARG_in_shift_right};
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_program, MP_ARG_REQUIRED | MP_ARG_OBJ },
         { MP_QSTR_frequency, MP_ARG_REQUIRED | MP_ARG_INT },
         { MP_QSTR_init, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+
         { MP_QSTR_first_out_pin, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_out_pin_count, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
+        { MP_QSTR_initial_out_pin_state, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_initial_out_pin_direction, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0xffffffff} },
+
         { MP_QSTR_first_in_pin, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_in_pin_count, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
+
         { MP_QSTR_first_set_pin, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_set_pin_count, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
+        { MP_QSTR_initial_set_pin_state, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_initial_set_pin_direction, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0x1f} },
+
         { MP_QSTR_first_sideset_pin, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_sideset_pin_count, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
+        { MP_QSTR_initial_sideset_pin_state, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_initial_sideset_pin_direction, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0x1f} },
+
         { MP_QSTR_exclusive_pin_use, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
         { MP_QSTR_auto_pull, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
         { MP_QSTR_pull_threshold, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 32} },
         { MP_QSTR_out_shift_right, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
+        { MP_QSTR_wait_for_txstall, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
         { MP_QSTR_auto_push, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
         { MP_QSTR_push_threshold, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 32} },
         { MP_QSTR_in_shift_right, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
@@ -201,12 +232,13 @@ STATIC mp_obj_t rp2pio_statemachine_make_new(const mp_obj_type_t *type, size_t n
         bufinfo.buf, bufinfo.len / 2,
         args[ARG_frequency].u_int,
         init_bufinfo.buf, init_bufinfo.len / 2,
-        first_out_pin, args[ARG_out_pin_count].u_int,
+        first_out_pin, args[ARG_out_pin_count].u_int, args[ARG_initial_out_pin_state].u_int, args[ARG_initial_out_pin_direction].u_int,
         first_in_pin, args[ARG_in_pin_count].u_int,
-        first_set_pin, args[ARG_set_pin_count].u_int,
-        first_sideset_pin, args[ARG_sideset_pin_count].u_int,
+        first_set_pin, args[ARG_set_pin_count].u_int, args[ARG_initial_set_pin_state].u_int, args[ARG_initial_set_pin_direction].u_int,
+        first_sideset_pin, args[ARG_sideset_pin_count].u_int, args[ARG_initial_sideset_pin_state].u_int, args[ARG_initial_sideset_pin_direction].u_int,
         args[ARG_exclusive_pin_use].u_bool,
         args[ARG_auto_pull].u_bool, pull_threshold, args[ARG_out_shift_right].u_bool,
+        args[ARG_wait_for_txstall].u_bool,
         args[ARG_auto_push].u_bool, push_threshold, args[ARG_in_shift_right].u_bool);
     return MP_OBJ_FROM_PTR(self);
 }
@@ -247,11 +279,53 @@ STATIC void check_for_deinit(rp2pio_statemachine_obj_t *self) {
     }
 }
 
-// // |     def restart(self, *other_state_machines) -> None:
-// // |         """Restarts this state machine and any others given. They must share
-// // |            an underlying PIO. An exception will be raised otherwise."""
-// // |         ...
-// // |
+//|     def restart(self) -> None:
+//|         """Resets this state machine, runs any init and enables the clock."""
+// TODO: "and any others given. They must share an underlying PIO. An exception will be raised otherwise.""
+//|         ...
+//|
+STATIC mp_obj_t rp2pio_statemachine_restart(mp_obj_t self_obj) {
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(self_obj);
+    check_for_deinit(self);
+
+    common_hal_rp2pio_statemachine_restart(self);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(rp2pio_statemachine_restart_obj, rp2pio_statemachine_restart);
+
+
+//|     def run(self, instructions: ReadableBuffer) -> None:
+//|         """Runs all given instructions. They will likely be interleaved with
+//|            in-memory instructions. Make sure this doesn't wait for input!
+//|
+//|            This can be used to output internal state to the RX FIFO and then
+//|            read with `readinto`."""
+//|         ...
+//|
+STATIC mp_obj_t rp2pio_statemachine_run(mp_obj_t self_obj, mp_obj_t instruction_obj) {
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(self_obj);
+    check_for_deinit(self);
+
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(instruction_obj, &bufinfo, MP_BUFFER_READ);
+
+    common_hal_rp2pio_statemachine_run(self, bufinfo.buf, bufinfo.len);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(rp2pio_statemachine_run_obj, rp2pio_statemachine_run);
+
+//|     def stop(self) -> None:
+//|         """Stops the state machine clock. Use `restart` to enable it."""
+//|         ...
+//|
+STATIC mp_obj_t rp2pio_statemachine_stop(mp_obj_t self_obj) {
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(self_obj);
+    check_for_deinit(self);
+
+    common_hal_rp2pio_statemachine_stop(self);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(rp2pio_statemachine_stop_obj, rp2pio_statemachine_stop);
 
 //|     def write(self, buffer: ReadableBuffer, *, start: int = 0, end: Optional[int] = None) -> None:
 //|         """Write the data contained in ``buffer`` to the state machine. If the buffer is empty, nothing happens.
@@ -261,7 +335,6 @@ STATIC void check_for_deinit(rp2pio_statemachine_obj_t *self) {
 //|         :param int end: End of the slice; this index is not included. Defaults to ``len(buffer)``"""
 //|         ...
 //|
-
 STATIC mp_obj_t rp2pio_statemachine_write(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_buffer, ARG_start, ARG_end };
     static const mp_arg_t allowed_args[] = {
@@ -279,12 +352,17 @@ STATIC mp_obj_t rp2pio_statemachine_write(size_t n_args, const mp_obj_t *pos_arg
     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;
     }
 
-    bool ok = common_hal_rp2pio_statemachine_write(self, ((uint8_t*)bufinfo.buf) + start, length);
+    uint8_t* original_pointer = bufinfo.buf;
+    int stride_in_bytes = mp_binary_get_size('@', bufinfo.typecode, NULL);
+    if (stride_in_bytes > 4) {
+        mp_raise_ValueError(translate("Buffer elements must be 4 bytes long or less"));
+    }
+
+    bool ok = common_hal_rp2pio_statemachine_write(self, ((uint8_t*)bufinfo.buf) + start, length, stride_in_bytes);
     if (mp_hal_is_interrupted()) {
         return mp_const_none;
     }
@@ -296,110 +374,132 @@ STATIC mp_obj_t rp2pio_statemachine_write(size_t n_args, const mp_obj_t *pos_arg
 MP_DEFINE_CONST_FUN_OBJ_KW(rp2pio_statemachine_write_obj, 2, rp2pio_statemachine_write);
 
 
-// // |     def readinto(self, buffer: WriteableBuffer, *, start: int = 0, end: Optional[int] = None) -> None:
-// // |         """Read into ``buffer``. If the number of bytes to read is 0, nothing happens.
-// // |
-// // |         :param ~_typing.WriteableBuffer 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. (Usually ignored.)"""
-// // |         ...
-// // |
-
-// STATIC mp_obj_t rp2pio_statemachine_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} },
-//     };
-//     rp2pio_statemachine_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[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;
-//     }
-
-//     bool ok = common_hal_rp2pio_statemachine_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_KW(rp2pio_statemachine_readinto_obj, 2, rp2pio_statemachine_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:
-// //|         """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 ~_typing.ReadableBuffer buffer_out: Write out the data in this buffer
-// //|         :param ~_typing.WriteableBuffer 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. Defaults to ``len(buffer_out)``
-// //|         :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. Defaults to ``len(buffer_in)``"""
-// //|         ...
-// //|
-
-// STATIC mp_obj_t rp2pio_statemachine_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} },
-//     };
-//     rp2pio_statemachine_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 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;
-//     size_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;
-//     size_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(translate("buffer slices must be of equal length"));
-//     }
-
-//     if (out_length == 0) {
-//         return mp_const_none;
-//     }
-
-//     bool ok = common_hal_rp2pio_statemachine_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(rp2pio_statemachine_write_readinto_obj, 2, rp2pio_statemachine_write_readinto);
+//|     def readinto(self, buffer: WriteableBuffer, *, start: int = 0, end: Optional[int] = None) -> None:
+//|         """Read into ``buffer``. If the number of bytes to read is 0, nothing happens. The buffer
+//|            include any data added to the fifo even if it was added before this was called.
+//|
+//|         :param ~_typing.WriteableBuffer 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)``"""
+//|         ...
+//|
+
+STATIC mp_obj_t rp2pio_statemachine_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_buffer, ARG_start, ARG_end };
+    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} },
+    };
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    check_for_deinit(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[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;
+    }
+
+    uint8_t* original_pointer = bufinfo.buf;
+    int stride_in_bytes = mp_binary_get_size('@', bufinfo.typecode, NULL);
+    if (stride_in_bytes > 4) {
+        mp_raise_ValueError(translate("Buffer elements must be 4 bytes long or less"));
+    }
+
+    bool ok = common_hal_rp2pio_statemachine_readinto(self, ((uint8_t*)bufinfo.buf) + start, length, stride_in_bytes);
+    if (!ok) {
+        mp_raise_OSError(MP_EIO);
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(rp2pio_statemachine_readinto_obj, 2, rp2pio_statemachine_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:
+//|         """Write out the data in ``buffer_out`` while simultaneously reading data into ``buffer_in``.
+//|         The lengths of the slices defined by ``buffer_out[out_start:out_end]`` and ``buffer_in[in_start:in_end]``
+//|         may be different. The function will return once both are filled.
+//|         If buffer slice lengths are both 0, nothing happens.
+//|
+//|         :param ~_typing.ReadableBuffer buffer_out: Write out the data in this buffer
+//|         :param ~_typing.WriteableBuffer 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. Defaults to ``len(buffer_out)``
+//|         :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. Defaults to ``len(buffer_in)``"""
+//|         ...
+//|
+
+STATIC mp_obj_t rp2pio_statemachine_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} },
+    };
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    check_for_deinit(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;
+    size_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;
+    size_t in_length = buf_in_info.len;
+    normalize_buffer_bounds(&in_start, args[ARG_in_end].u_int, &in_length);
+
+    if (out_length == 0 && in_length == 0) {
+        return mp_const_none;
+    }
+
+    int in_stride_in_bytes = mp_binary_get_size('@', buf_in_info.typecode, NULL);
+    if (in_stride_in_bytes > 4) {
+        mp_raise_ValueError(translate("In buffer elements must be 4 bytes long or less"));
+    }
+
+    int out_stride_in_bytes = mp_binary_get_size('@', buf_out_info.typecode, NULL);
+    if (out_stride_in_bytes > 4) {
+        mp_raise_ValueError(translate("Out buffer elements must be 4 bytes long or less"));
+    }
+
+    bool ok = common_hal_rp2pio_statemachine_write_readinto(self,
+                                            ((uint8_t*)buf_out_info.buf) + out_start,
+                                            out_length,
+                                            out_stride_in_bytes,
+                                            ((uint8_t*)buf_in_info.buf) + in_start,
+                                            in_length,
+                                            in_stride_in_bytes);
+    if (!ok) {
+        mp_raise_OSError(MP_EIO);
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(rp2pio_statemachine_write_readinto_obj, 2, rp2pio_statemachine_write_readinto);
+
+//|     def clear_rxfifo(self) -> None:
+//|         """Clears any unread bytes in the rxfifo."""
+//|         ...
+//|
+STATIC mp_obj_t rp2pio_statemachine_obj_clear_rxfifo(mp_obj_t self_in) {
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_rp2pio_statemachine_clear_rxfifo(self);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(rp2pio_statemachine_clear_rxfifo_obj, rp2pio_statemachine_obj_clear_rxfifo);
 
 //|     frequency: int
 //|     """The actual state machine frequency. This may not match the frequency requested
@@ -413,9 +513,37 @@ STATIC mp_obj_t rp2pio_statemachine_obj_get_frequency(mp_obj_t self_in) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(rp2pio_statemachine_get_frequency_obj, rp2pio_statemachine_obj_get_frequency);
 
+STATIC mp_obj_t rp2pio_statemachine_obj_set_frequency(mp_obj_t self_in, mp_obj_t frequency) {
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    check_for_deinit(self);
+
+    common_hal_rp2pio_statemachine_set_frequency(self, mp_obj_get_int(frequency));
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(rp2pio_statemachine_set_frequency_obj, rp2pio_statemachine_obj_set_frequency);
+
 const mp_obj_property_t rp2pio_statemachine_frequency_obj = {
     .base.type = &mp_type_property,
     .proxy = {(mp_obj_t)&rp2pio_statemachine_get_frequency_obj,
+              (mp_obj_t)&rp2pio_statemachine_set_frequency_obj,
+              (mp_obj_t)&mp_const_none_obj},
+};
+
+//|     rxstall: bool
+//|     """True when the state machine has stalled due to a full RX FIFO since the last
+//|        `clear_rxfifo` call."""
+//|
+
+STATIC mp_obj_t rp2pio_statemachine_obj_get_rxstall(mp_obj_t self_in) {
+    rp2pio_statemachine_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    check_for_deinit(self);
+    return MP_OBJ_NEW_SMALL_INT(common_hal_rp2pio_statemachine_get_rxstall(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(rp2pio_statemachine_get_rxstall_obj, rp2pio_statemachine_obj_get_rxstall);
+
+const mp_obj_property_t rp2pio_statemachine_rxstall_obj = {
+    .base.type = &mp_type_property,
+    .proxy = {(mp_obj_t)&rp2pio_statemachine_get_rxstall_obj,
               (mp_obj_t)&mp_const_none_obj,
               (mp_obj_t)&mp_const_none_obj},
 };
@@ -425,12 +553,17 @@ STATIC const mp_rom_map_elem_t rp2pio_statemachine_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
     { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&rp2pio_statemachine_obj___exit___obj) },
 
-//    { MP_ROM_QSTR(MP_QSTR_restart), MP_ROM_PTR(&rp2pio_statemachine_configure_obj) },
+    { MP_ROM_QSTR(MP_QSTR_stop), MP_ROM_PTR(&rp2pio_statemachine_stop_obj) },
+    { MP_ROM_QSTR(MP_QSTR_restart), MP_ROM_PTR(&rp2pio_statemachine_restart_obj) },
+    { MP_ROM_QSTR(MP_QSTR_run), MP_ROM_PTR(&rp2pio_statemachine_run_obj) },
+    { MP_ROM_QSTR(MP_QSTR_clear_rxfifo), MP_ROM_PTR(&rp2pio_statemachine_clear_rxfifo_obj) },
 
-//    { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&rp2pio_statemachine_readinto_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&rp2pio_statemachine_readinto_obj) },
     { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&rp2pio_statemachine_write_obj) },
-//     { MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&rp2pio_statemachine_write_readinto_obj) },
-    { MP_ROM_QSTR(MP_QSTR_frequency), MP_ROM_PTR(&rp2pio_statemachine_frequency_obj) }
+    { MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&rp2pio_statemachine_write_readinto_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_frequency), MP_ROM_PTR(&rp2pio_statemachine_frequency_obj) },
+    { MP_ROM_QSTR(MP_QSTR_rxstall), MP_ROM_PTR(&rp2pio_statemachine_rxstall_obj) }
 };
 STATIC MP_DEFINE_CONST_DICT(rp2pio_statemachine_locals_dict, rp2pio_statemachine_locals_dict_table);
 
diff --git a/ports/raspberrypi/bindings/rp2pio/StateMachine.h b/ports/raspberrypi/bindings/rp2pio/StateMachine.h
index 5ff20a75b..36e44f191 100644
--- a/ports/raspberrypi/bindings/rp2pio/StateMachine.h
+++ b/ports/raspberrypi/bindings/rp2pio/StateMachine.h
@@ -36,36 +36,38 @@
 extern const mp_obj_type_t rp2pio_statemachine_type;
 
 // Construct an underlying SPI object.
-extern void common_hal_rp2pio_statemachine_construct(rp2pio_statemachine_obj_t *self,
+void common_hal_rp2pio_statemachine_construct(rp2pio_statemachine_obj_t *self,
     const uint16_t* program, size_t program_len,
     size_t frequency,
     const uint16_t* init, size_t init_len,
-    const mcu_pin_obj_t * first_out_pin, uint8_t out_pin_count,
+    const mcu_pin_obj_t * first_out_pin, uint8_t out_pin_count, uint32_t initial_out_pin_state, uint32_t initial_out_pin_direction,
     const mcu_pin_obj_t * first_in_pin, uint8_t in_pin_count,
-    const mcu_pin_obj_t * first_set_pin, uint8_t set_pin_count,
-    const mcu_pin_obj_t * first_sideset_pin, uint8_t sideset_pin_count,
+    const mcu_pin_obj_t * first_set_pin, uint8_t set_pin_count, uint32_t initial_set_pin_state, uint32_t initial_set_pin_direction,
+    const mcu_pin_obj_t * first_sideset_pin, uint8_t sideset_pin_count, uint32_t initial_sideset_pin_state, uint32_t initial_sideset_pin_direction,
     bool exclusive_pin_use,
     bool auto_pull, uint8_t pull_threshold, bool out_shift_right,
+    bool wait_for_txstall,
     bool auto_push, uint8_t push_threshold, bool in_shift_right);
 
-extern void common_hal_rp2pio_statemachine_deinit(rp2pio_statemachine_obj_t *self);
-extern bool common_hal_rp2pio_statemachine_deinited(rp2pio_statemachine_obj_t *self);
+void common_hal_rp2pio_statemachine_deinit(rp2pio_statemachine_obj_t *self);
+bool common_hal_rp2pio_statemachine_deinited(rp2pio_statemachine_obj_t *self);
 
-// Writes out the given data.
-extern bool common_hal_rp2pio_statemachine_write(rp2pio_statemachine_obj_t *self, const uint8_t *data, size_t len);
-
-// // Reads in len bytes while outputting zeroes.
-// extern bool common_hal_rp2pio_statemachine_read(rp2pio_statemachine_obj_t *self, uint8_t *data, size_t len, uint8_t write_value);
+void common_hal_rp2pio_statemachine_restart(rp2pio_statemachine_obj_t *self);
+void common_hal_rp2pio_statemachine_stop(rp2pio_statemachine_obj_t *self);
+void common_hal_rp2pio_statemachine_run(rp2pio_statemachine_obj_t *self, const uint16_t *instructions, size_t len);
 
-// // Reads and write len bytes simultaneously.
-// extern bool common_hal_rp2pio_statemachine_transfer(rp2pio_statemachine_obj_t *self,
-//                                           const uint8_t *data_out, size_t out_len,
-//                                           uint8_t *data_in, size_t in_len);
+// Writes out the given data.
+bool common_hal_rp2pio_statemachine_write(rp2pio_statemachine_obj_t *self, const uint8_t *data, size_t len, uint8_t stride_in_bytes);
+bool common_hal_rp2pio_statemachine_readinto(rp2pio_statemachine_obj_t *self, uint8_t *data, size_t len, uint8_t stride_in_bytes);
+bool common_hal_rp2pio_statemachine_write_readinto(rp2pio_statemachine_obj_t *self,
+                                                   const uint8_t *data_out, size_t out_len, uint8_t out_stride_in_bytes,
+                                                   uint8_t *data_in, size_t in_len, uint8_t in_stride_in_bytes);
 
-// Return actual SPI bus frequency.
+// Return actual state machine frequency.
 uint32_t common_hal_rp2pio_statemachine_get_frequency(rp2pio_statemachine_obj_t* self);
+void common_hal_rp2pio_statemachine_set_frequency(rp2pio_statemachine_obj_t* self, uint32_t frequency);
 
-// This is used by the supervisor to claim SPI devices indefinitely.
-// extern void common_hal_rp2pio_statemachine_never_reset(rp2pio_statemachine_obj_t *self);
+bool common_hal_rp2pio_statemachine_get_rxstall(rp2pio_statemachine_obj_t* self);
+void common_hal_rp2pio_statemachine_clear_rxfifo(rp2pio_statemachine_obj_t *self);
 
 #endif // MICROPY_INCLUDED_RASPBERRYPI_BINDINGS_RP2PIO_STATEMACHINE_H