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.
This commit is contained in:
Jeff Epler 2022-01-04 17:26:25 -06:00
parent db5f99c63e
commit d816a4f19d
No known key found for this signature in database
GPG Key ID: D5BF15AB975AB4DE
9 changed files with 311 additions and 0 deletions

3
.gitmodules vendored
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@ -199,3 +199,6 @@
url = https://github.com/raspberrypi/rpi-firmware.git
branch = master
shallow = true
[submodule "lib/adafruit_floppy"]
path = lib/adafruit_floppy
url = https://github.com/adafruit/Adafruit_Floppy

1
lib/adafruit_floppy Submodule

@ -0,0 +1 @@
Subproject commit d5d34127db8167b7a6aca8045d27f6b9e3930c6d

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

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

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@ -164,6 +164,9 @@ endif
ifeq ($(CIRCUITPY_VECTORIO),1)
SRC_PATTERNS += vectorio/%
endif
ifeq ($(CIRCUITPY_FLOPPYIO),1)
SRC_PATTERNS += floppyio/%
endif
ifeq ($(CIRCUITPY_FRAMEBUFFERIO),1)
SRC_PATTERNS += framebufferio/%
endif
@ -526,6 +529,7 @@ SRC_SHARED_MODULE_ALL = \
displayio/TileGrid.c \
displayio/area.c \
displayio/__init__.c \
floppyio/__init__.c \
fontio/BuiltinFont.c \
fontio/__init__.c \
framebufferio/FramebufferDisplay.c \

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@ -219,6 +219,9 @@ CFLAGS += -DCIRCUITPY_ESPIDF=$(CIRCUITPY_ESPIDF)
CIRCUITPY__EVE ?= 0
CFLAGS += -DCIRCUITPY__EVE=$(CIRCUITPY__EVE)
CIRCUITPY_FLOPPYIO ?= 0
CFLAGS += -DCIRCUITPY_FLOPPYIO=$(CIRCUITPY_FLOPPYIO)
CIRCUITPY_FREQUENCYIO ?= $(CIRCUITPY_FULL_BUILD)
CFLAGS += -DCIRCUITPY_FREQUENCYIO=$(CIRCUITPY_FREQUENCYIO)

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

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

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@ -0,0 +1,108 @@
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2022 Jeff Epler for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "hal_gpio.h"
#include "py/runtime.h"
#include "shared-bindings/time/__init__.h"
#include "shared-bindings/floppyio/__init__.h"
#include "common-hal/floppyio/__init__.h"
#include "shared-bindings/digitalio/DigitalInOut.h"
#define T2_5 (FLOPPYIO_SAMPLERATE * 5 / 2 / 1000000)
#define T3_5 (FLOPPYIO_SAMPLERATE * 7 / 2 / 1000000)
#define MFM_IO_MMIO (1)
#include "lib/adafruit_floppy/mfm_impl.h"
__attribute__((optimize("O3")))
int common_hal_floppyio_flux_readinto(void *buf, size_t len, digitalio_digitalinout_obj_t *data, digitalio_digitalinout_obj_t *index) {
uint32_t index_mask;
volatile uint32_t *index_port = common_hal_digitalio_digitalinout_get_reg(index, DIGITALINOUT_REG_READ, &index_mask);
uint32_t data_mask;
volatile uint32_t *data_port = common_hal_digitalio_digitalinout_get_reg(data, DIGITALINOUT_REG_READ, &data_mask);
#undef READ_INDEX
#undef READ_DATA
#define READ_INDEX() (!!(*index_port & index_mask))
#define READ_DATA() (!!(*data_port & data_mask))
memset(buf, 0, len);
uint8_t *pulses = buf, *pulses_ptr = pulses, *pulses_end = pulses + len;
common_hal_mcu_disable_interrupts();
// wait for index pulse low
while (READ_INDEX()) { /* NOTHING */
}
// if data line is low, wait till it rises
while (!READ_DATA()) { /* NOTHING */
}
// and then till it drops down
while (READ_DATA()) { /* NOTHING */
}
uint32_t index_state = 0;
while (pulses_ptr < pulses_end) {
index_state = (index_state << 1) | READ_INDEX();
if ((index_state & 3) == 2) { // a zero-to-one transition
break;
}
unsigned pulse_count = 3;
while (!READ_DATA()) {
pulse_count++;
}
while (READ_DATA()) {
pulse_count++;
}
*pulses_ptr++ = MIN(255, pulse_count);
}
common_hal_mcu_enable_interrupts();
return pulses_ptr - pulses;
}
int common_hal_floppyio_mfm_readinto(void *buf, size_t n_sectors, digitalio_digitalinout_obj_t *data, digitalio_digitalinout_obj_t *index) {
mfm_io_t io;
io.index_port = common_hal_digitalio_digitalinout_get_reg(index, DIGITALINOUT_REG_READ, &io.index_mask);
io.data_port = common_hal_digitalio_digitalinout_get_reg(data, DIGITALINOUT_REG_READ, &io.data_mask);
common_hal_mcu_disable_interrupts();
uint8_t validity[n_sectors];
int result = read_track(io, n_sectors, buf, validity);
common_hal_mcu_enable_interrupts();
return result;
}