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Add floppyio
Initially enabled for samd51, this enables reading raw flux data as well as DOS/MFM formatted media. This is only the low-level code for reading & decoding flux pulses from a floppy drive. high level details will live in a Python library. adafruit-circuitpython-floppy will take care of details like stepping from track to track, etc.
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‎.gitmodules‎

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url = https://github.com/raspberrypi/rpi-firmware.git
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branch = master
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shallow = true
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[submodule "lib/adafruit_floppy"]
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path = lib/adafruit_floppy
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url = https://github.com/adafruit/Adafruit_Floppy

‎lib/adafruit_floppy‎

Submodule adafruit_floppy added at d5d3412

‎ports/atmel-samd/common-hal/floppyio/__init__.h‎

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/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2022 Jeff Epler for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#pragma once
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// empirical-ish from Arduino @ 120MHz
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#define FLOPPYIO_SAMPLERATE (14666667)

‎ports/atmel-samd/mpconfigport.mk‎

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@@ -87,6 +87,7 @@ CIRCUITPY_TOUCHIO_USE_NATIVE = 0
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CIRCUITPY_ALARM ?= 1
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CIRCUITPY_PS2IO ?= 1
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CIRCUITPY_SAMD ?= 1
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CIRCUITPY_FLOPPYIO ?= 1
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CIRCUITPY_FRAMEBUFFERIO ?= $(CIRCUITPY_FULL_BUILD)
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CIRCUITPY_RGBMATRIX ?= $(CIRCUITPY_FRAMEBUFFERIO)
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CIRCUITPY_WATCHDOG ?= 1
@@ -107,6 +108,7 @@ CIRCUITPY_TOUCHIO_USE_NATIVE = 0
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CIRCUITPY_ALARM ?= 1
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CIRCUITPY_PS2IO ?= 1
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CIRCUITPY_SAMD ?= 1
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CIRCUITPY_FLOPPYIO ?= 1
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CIRCUITPY_FRAMEBUFFERIO ?= $(CIRCUITPY_FULL_BUILD)
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CIRCUITPY_RGBMATRIX ?= $(CIRCUITPY_FRAMEBUFFERIO)
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‎py/circuitpy_defns.mk‎

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ifeq ($(CIRCUITPY_VECTORIO),1)
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SRC_PATTERNS += vectorio/%
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endif
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ifeq ($(CIRCUITPY_FLOPPYIO),1)
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SRC_PATTERNS += floppyio/%
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endif
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ifeq ($(CIRCUITPY_FRAMEBUFFERIO),1)
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SRC_PATTERNS += framebufferio/%
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endif
@@ -526,6 +529,7 @@ SRC_SHARED_MODULE_ALL = \
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displayio/TileGrid.c \
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displayio/area.c \
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displayio/__init__.c \
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floppyio/__init__.c \
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fontio/BuiltinFont.c \
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fontio/__init__.c \
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framebufferio/FramebufferDisplay.c \

‎py/circuitpy_mpconfig.mk‎

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CIRCUITPY__EVE ?= 0
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CFLAGS += -DCIRCUITPY__EVE=$(CIRCUITPY__EVE)
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CIRCUITPY_FLOPPYIO ?= 0
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CFLAGS += -DCIRCUITPY_FLOPPYIO=$(CIRCUITPY_FLOPPYIO)
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CIRCUITPY_FREQUENCYIO ?= $(CIRCUITPY_FULL_BUILD)
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CFLAGS += -DCIRCUITPY_FREQUENCYIO=$(CIRCUITPY_FREQUENCYIO)
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‎shared-bindings/floppyio/__init__.c‎

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/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2022 Jeff Epler for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "shared-bindings/floppyio/__init__.h"
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#include "shared-bindings/digitalio/DigitalInOut.h"
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#include "common-hal/floppyio/__init__.h"
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#include <stdint.h>
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#include "py/binary.h"
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#include "py/enum.h"
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#include "py/obj.h"
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#include "py/runtime.h"
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//| def flux_readinto(buffer: WriteableBuffer, data: DigitalInOut, index: DigitalInOut) -> int:
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//| """Read flux transition information into the buffer.
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//|
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//| The function returns when the buffer has filled, or when the index input
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//| indicates that one full revolution of data has been recorded. Due to
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//| technical limitations, this process may not be interruptible by
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//| KeyboardInterrupt.
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//|
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//| :param buffer: Read data into this buffer. Each element represents the time between successive zero-to-one transitions.
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//| :param data: Pin on which the flux data appears
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//| :param index: Pin on which the index pulse appears
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//| :return: The actual number of bytes of read
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//| """
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//| ...
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//|
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STATIC mp_obj_t floppyio_flux_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_buffer, ARG_data, ARG_index };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_index, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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};
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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mp_buffer_info_t bufinfo;
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mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE);
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digitalio_digitalinout_obj_t *data = assert_digitalinout(args[ARG_data].u_obj);
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digitalio_digitalinout_obj_t *index = assert_digitalinout(args[ARG_index].u_obj);
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return MP_OBJ_NEW_SMALL_INT(common_hal_floppyio_flux_readinto(bufinfo.buf, bufinfo.len, data, index));
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}
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MP_DEFINE_CONST_FUN_OBJ_KW(floppyio_flux_readinto_obj, 0, floppyio_flux_readinto);
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//| def mfm_readinto(buffer: WriteableBuffer, data: DigitalInOut, index: DigitalInOut) -> int:
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//| """Read mfm blocks into the buffer.
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//|
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//| The track is assumed to consist of 512-byte sectors.
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//|
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//| The function returns when all sectors have been successfully read, or
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//| a number of index pulses have occurred. Due to technical limitations, this
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//| process may not be interruptible by KeyboardInterrupt.
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//|
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//| :param buffer: Read data into this buffer. Must be a multiple of 512.
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//| :param data: Pin on which the mfm data appears
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//| :param index: Pin on which the index pulse appears
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//| :return: The actual number of sectors read
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//| """
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//| ...
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//|
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STATIC mp_obj_t floppyio_mfm_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_buffer, ARG_data, ARG_index };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_index, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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};
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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mp_buffer_info_t bufinfo;
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mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE);
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digitalio_digitalinout_obj_t *data = assert_digitalinout(args[ARG_data].u_obj);
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digitalio_digitalinout_obj_t *index = assert_digitalinout(args[ARG_index].u_obj);
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if (bufinfo.len % 512 != 0) {
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mp_raise_ValueError(translate("Buffer must be a multiple of 512 bytes"));
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}
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size_t n_sectors = bufinfo.len / 512;
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return MP_OBJ_NEW_SMALL_INT(common_hal_floppyio_mfm_readinto(bufinfo.buf, n_sectors, data, index));
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}
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MP_DEFINE_CONST_FUN_OBJ_KW(floppyio_mfm_readinto_obj, 0, floppyio_mfm_readinto);
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//| samplerate: int
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//| """The approximate sample rate in Hz used by flux_readinto."""
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//|
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STATIC const mp_rom_map_elem_t floppyio_module_globals_table[] = {
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{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_floppyio) },
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{ MP_ROM_QSTR(MP_QSTR_flux_readinto), MP_ROM_PTR(&floppyio_flux_readinto_obj) },
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{ MP_ROM_QSTR(MP_QSTR_mfm_readinto), MP_ROM_PTR(&floppyio_mfm_readinto_obj) },
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{ MP_ROM_QSTR(MP_QSTR_samplerate), MP_ROM_INT(FLOPPYIO_SAMPLERATE) },
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};
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STATIC MP_DEFINE_CONST_DICT(floppyio_module_globals, floppyio_module_globals_table);
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const mp_obj_module_t floppyio_module = {
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.base = {&mp_type_module },
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.globals = (mp_obj_dict_t *)&floppyio_module_globals,
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};
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MP_REGISTER_MODULE(MP_QSTR_floppyio, floppyio_module, CIRCUITPY_FLOPPYIO);

‎shared-bindings/floppyio/__init__.h‎

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/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2022 Jeff Epler for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
13+
* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#pragma once
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#include "common-hal/digitalio/DigitalInOut.h"
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int common_hal_floppyio_flux_readinto(void *buf, size_t len, digitalio_digitalinout_obj_t *data, digitalio_digitalinout_obj_t *index);
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int common_hal_floppyio_mfm_readinto(void *buf, size_t n_sector, digitalio_digitalinout_obj_t *data, digitalio_digitalinout_obj_t *index);

‎shared-module/floppyio/__init__.c‎

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/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2022 Jeff Epler for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "hal_gpio.h"
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#include "py/runtime.h"
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#include "shared-bindings/time/__init__.h"
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#include "shared-bindings/floppyio/__init__.h"
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#include "common-hal/floppyio/__init__.h"
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#include "shared-bindings/digitalio/DigitalInOut.h"
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#define T2_5 (FLOPPYIO_SAMPLERATE * 5 / 2 / 1000000)
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#define T3_5 (FLOPPYIO_SAMPLERATE * 7 / 2 / 1000000)
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#define MFM_IO_MMIO (1)
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#include "lib/adafruit_floppy/mfm_impl.h"
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__attribute__((optimize("O3")))
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int common_hal_floppyio_flux_readinto(void *buf, size_t len, digitalio_digitalinout_obj_t *data, digitalio_digitalinout_obj_t *index) {
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uint32_t index_mask;
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volatile uint32_t *index_port = common_hal_digitalio_digitalinout_get_reg(index, DIGITALINOUT_REG_READ, &index_mask);
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uint32_t data_mask;
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volatile uint32_t *data_port = common_hal_digitalio_digitalinout_get_reg(data, DIGITALINOUT_REG_READ, &data_mask);
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#undef READ_INDEX
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#undef READ_DATA
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#define READ_INDEX() (!!(*index_port & index_mask))
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#define READ_DATA() (!!(*data_port & data_mask))
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memset(buf, 0, len);
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uint8_t *pulses = buf, *pulses_ptr = pulses, *pulses_end = pulses + len;
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common_hal_mcu_disable_interrupts();
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// wait for index pulse low
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while (READ_INDEX()) { /* NOTHING */
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}
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// if data line is low, wait till it rises
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while (!READ_DATA()) { /* NOTHING */
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}
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// and then till it drops down
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while (READ_DATA()) { /* NOTHING */
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}
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uint32_t index_state = 0;
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while (pulses_ptr < pulses_end) {
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index_state = (index_state << 1) | READ_INDEX();
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if ((index_state & 3) == 2) { // a zero-to-one transition
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break;
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}
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unsigned pulse_count = 3;
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while (!READ_DATA()) {
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pulse_count++;
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}
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while (READ_DATA()) {
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pulse_count++;
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}
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*pulses_ptr++ = MIN(255, pulse_count);
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}
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common_hal_mcu_enable_interrupts();
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return pulses_ptr - pulses;
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}
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int common_hal_floppyio_mfm_readinto(void *buf, size_t n_sectors, digitalio_digitalinout_obj_t *data, digitalio_digitalinout_obj_t *index) {
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mfm_io_t io;
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io.index_port = common_hal_digitalio_digitalinout_get_reg(index, DIGITALINOUT_REG_READ, &io.index_mask);
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io.data_port = common_hal_digitalio_digitalinout_get_reg(data, DIGITALINOUT_REG_READ, &io.data_mask);
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common_hal_mcu_disable_interrupts();
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uint8_t validity[n_sectors];
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int result = read_track(io, n_sectors, buf, validity);
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common_hal_mcu_enable_interrupts();
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return result;
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}

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