/*
* Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdio.h>
#include "pico/stdlib.h"
#include "pico/usb_device.h"
#include "pico/audio.h"
#include "pico/audio_i2s.h"
#include "pico/multicore.h"
#include "lufa/AudioClassCommon.h"
// todo forget why this is using core 1 for sound: presumably not necessary
// todo noop when muted
CU_REGISTER_DEBUG_PINS(audio_timing)
// ---- select at most one ---
//CU_SELECT_DEBUG_PINS(audio_timing)
// todo make descriptor strings should probably belong to the configs
static char *descriptor_strings[] =
{
"Raspberry Pi",
"Pico Examples Sound Card",
"0123456789AB"
};
// todo fix these
#define VENDOR_ID 0x2e8au
#define PRODUCT_ID 0xfeddu
#define AUDIO_OUT_ENDPOINT 0x01U
#define AUDIO_IN_ENDPOINT 0x82U
#undef AUDIO_SAMPLE_FREQ
#define AUDIO_SAMPLE_FREQ(frq) (uint8_t)(frq), (uint8_t)((frq >> 8)), (uint8_t)((frq >> 16))
#define AUDIO_MAX_PACKET_SIZE(freq) (uint8_t)(((freq + 999) / 1000) * 4)
#define FEATURE_MUTE_CONTROL 1u
#define FEATURE_VOLUME_CONTROL 2u
#define ENDPOINT_FREQ_CONTROL 1u
struct audio_device_config {
struct usb_configuration_descriptor descriptor;
struct usb_interface_descriptor ac_interface;
struct __packed {
USB_Audio_StdDescriptor_Interface_AC_t core;
USB_Audio_StdDescriptor_InputTerminal_t input_terminal;
USB_Audio_StdDescriptor_FeatureUnit_t feature_unit;
USB_Audio_StdDescriptor_OutputTerminal_t output_terminal;
} ac_audio;
struct usb_interface_descriptor as_zero_interface;
struct usb_interface_descriptor as_op_interface;
struct __packed {
USB_Audio_StdDescriptor_Interface_AS_t streaming;
struct __packed {
USB_Audio_StdDescriptor_Format_t core;
USB_Audio_SampleFreq_t freqs[2];
} format;
} as_audio;
struct __packed {
struct usb_endpoint_descriptor_long core;
USB_Audio_StdDescriptor_StreamEndpoint_Spc_t audio;
} ep1;
struct usb_endpoint_descriptor_long ep2;
};
static const struct audio_device_config audio_device_config = {
.descriptor = {
.bLength = sizeof(audio_device_config.descriptor),
.bDescriptorType = DTYPE_Configuration,
.wTotalLength = sizeof(audio_device_config),
.bNumInterfaces = 2,
.bConfigurationValue = 0x01,
.iConfiguration = 0x00,
.bmAttributes = 0x80,
.bMaxPower = 0x32,
},
.ac_interface = {
.bLength = sizeof(audio_device_config.ac_interface),
.bDescriptorType = DTYPE_Interface,
.bInterfaceNumber = 0x00,
.bAlternateSetting = 0x00,
.bNumEndpoints = 0x00,
.bInterfaceClass = AUDIO_CSCP_AudioClass,
.bInterfaceSubClass = AUDIO_CSCP_ControlSubclass,
.bInterfaceProtocol = AUDIO_CSCP_ControlProtocol,
.iInterface = 0x00,
},
.ac_audio = {
.core = {
.bLength = sizeof(audio_device_config.ac_audio.core),
.bDescriptorType = AUDIO_DTYPE_CSInterface,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSInterface_Header,
.bcdADC = VERSION_BCD(1, 0, 0),
.wTotalLength = sizeof(audio_device_config.ac_audio),
.bInCollection = 1,
.bInterfaceNumbers = 1,
},
.input_terminal = {
.bLength = sizeof(audio_device_config.ac_audio.input_terminal),
.bDescriptorType = AUDIO_DTYPE_CSInterface,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSInterface_InputTerminal,
.bTerminalID = 1,
.wTerminalType = AUDIO_TERMINAL_STREAMING,
.bAssocTerminal = 0,
.bNrChannels = 2,
.wChannelConfig = AUDIO_CHANNEL_LEFT_FRONT | AUDIO_CHANNEL_RIGHT_FRONT,
.iChannelNames = 0,
.iTerminal = 0,
},
.feature_unit = {
.bLength = sizeof(audio_device_config.ac_audio.feature_unit),
.bDescriptorType = AUDIO_DTYPE_CSInterface,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSInterface_Feature,
.bUnitID = 2,
.bSourceID = 1,
.bControlSize = 1,
.bmaControls = {AUDIO_FEATURE_MUTE | AUDIO_FEATURE_VOLUME, 0, 0},
.iFeature = 0,
},
.output_terminal = {
.bLength = sizeof(audio_device_config.ac_audio.output_terminal),
.bDescriptorType = AUDIO_DTYPE_CSInterface,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSInterface_OutputTerminal,
.bTerminalID = 3,
.wTerminalType = AUDIO_TERMINAL_OUT_SPEAKER,
.bAssocTerminal = 0,
.bSourceID = 2,
.iTerminal = 0,
},
},
.as_zero_interface = {
.bLength = sizeof(audio_device_config.as_zero_interface),
.bDescriptorType = DTYPE_Interface,
.bInterfaceNumber = 0x01,
.bAlternateSetting = 0x00,
.bNumEndpoints = 0x00,
.bInterfaceClass = AUDIO_CSCP_AudioClass,
.bInterfaceSubClass = AUDIO_CSCP_AudioStreamingSubclass,
.bInterfaceProtocol = AUDIO_CSCP_ControlProtocol,
.iInterface = 0x00,
},
.as_op_interface = {
.bLength = sizeof(audio_device_config.as_op_interface),
.bDescriptorType = DTYPE_Interface,
.bInterfaceNumber = 0x01,
.bAlternateSetting = 0x01,
.bNumEndpoints = 0x02,
.bInterfaceClass = AUDIO_CSCP_AudioClass,
.bInterfaceSubClass = AUDIO_CSCP_AudioStreamingSubclass,
.bInterfaceProtocol = AUDIO_CSCP_ControlProtocol,
.iInterface = 0x00,
},
.as_audio = {
.streaming = {
.bLength = sizeof(audio_device_config.as_audio.streaming),
.bDescriptorType = AUDIO_DTYPE_CSInterface,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSInterface_General,
.bTerminalLink = 1,
.bDelay = 1,
.wFormatTag = 1, // PCM
},
.format = {
.core = {
.bLength = sizeof(audio_device_config.as_audio.format),
.bDescriptorType = AUDIO_DTYPE_CSInterface,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSInterface_FormatType,
.bFormatType = 1,
.bNrChannels = 2,
.bSubFrameSize = 2,
.bBitResolution = 16,
.bSampleFrequencyType = count_of(audio_device_config.as_audio.format.freqs),
},
.freqs = {
AUDIO_SAMPLE_FREQ(44100),
AUDIO_SAMPLE_FREQ(48000)
},
},
},
.ep1 = {
.core = {
.bLength = sizeof(audio_device_config.ep1.core),
.bDescriptorType = DTYPE_Endpoint,
.bEndpointAddress = AUDIO_OUT_ENDPOINT,
.bmAttributes = 5,
.wMaxPacketSize = AUDIO_MAX_PACKET_SIZE(AUDIO_FREQ_MAX),
.bInterval = 1,
.bRefresh = 0,
.bSyncAddr = AUDIO_IN_ENDPOINT,
},
.audio = {
.bLength = sizeof(audio_device_config.ep1.audio),
.bDescriptorType = AUDIO_DTYPE_CSEndpoint,
.bDescriptorSubtype = AUDIO_DSUBTYPE_CSEndpoint_General,
.bmAttributes = 1,
.bLockDelayUnits = 0,
.wLockDelay = 0,
}
},
.ep2 = {
.bLength = sizeof(audio_device_config.ep2),
.bDescriptorType = 0x05,
.bEndpointAddress = AUDIO_IN_ENDPOINT,
.bmAttributes = 0x11,
.wMaxPacketSize = 3,
.bInterval = 0x01,
.bRefresh = 2,
.bSyncAddr = 0,
},
};
static struct usb_interface ac_interface;
static struct usb_interface as_op_interface;
static struct usb_endpoint ep_op_out, ep_op_sync;
static const struct usb_device_descriptor boot_device_descriptor = {
.bLength = 18,
.bDescriptorType = 0x01,
.bcdUSB = 0x0110,
.bDeviceClass = 0x00,
.bDeviceSubClass = 0x00,
.bDeviceProtocol = 0x00,
.bMaxPacketSize0 = 0x40,
.idVendor = VENDOR_ID,
.idProduct = PRODUCT_ID,
.bcdDevice = 0x0200,
.iManufacturer = 0x01,
.iProduct = 0x02,
.iSerialNumber = 0x03,
.bNumConfigurations = 0x01,
};
const char *_get_descriptor_string(uint index) {
if (index <= count_of(descriptor_strings)) {
return descriptor_strings[index - 1];
} else {
return "";
}
}
static struct {
uint32_t freq;
int16_t volume;
int16_t vol_mul;
bool mute;
} audio_state = {
.freq = 44100,
};
static struct audio_buffer_pool *producer_pool;
static void _as_audio_packet(struct usb_endpoint *ep) {
assert(ep->current_transfer);
struct usb_buffer *usb_buffer = usb_current_out_packet_buffer(ep);
DEBUG_PINS_SET(audio_timing, 1);
// todo deal with blocking correctly
struct audio_buffer *audio_buffer = take_audio_buffer(producer_pool, true);
DEBUG_PINS_CLR(audio_timing, 1);
assert(!(usb_buffer->data_len & 3u));
audio_buffer->sample_count = usb_buffer->data_len / 4;
assert(audio_buffer->sample_count);
assert(audio_buffer->max_sample_count >= audio_buffer->sample_count);
uint16_t vol_mul = audio_state.vol_mul;
int16_t *out = (int16_t *) audio_buffer->buffer->bytes;
int16_t *in = (int16_t *) usb_buffer->data;
for (int i = 0; i < audio_buffer->sample_count * 2; i++) {
out[i] = (int16_t) ((in[i] * vol_mul) >> 15u);
}
give_audio_buffer(producer_pool, audio_buffer);
// keep on truckin'
usb_grow_transfer(ep->current_transfer, 1);
usb_packet_done(ep);
}
static void _as_sync_packet(struct usb_endpoint *ep) {
assert(ep->current_transfer);
DEBUG_PINS_SET(audio_timing, 2);
DEBUG_PINS_CLR(audio_timing, 2);
struct usb_buffer *buffer = usb_current_in_packet_buffer(ep);
assert(buffer->data_max >= 3);
buffer->data_len = 3;
// todo lie thru our teeth for now
uint feedback = (audio_state.freq << 14u) / 1000u;
buffer->data[0] = feedback;
buffer->data[1] = feedback >> 8u;
buffer->data[2] = feedback >> 16u;
// keep on truckin'
usb_grow_transfer(ep->current_transfer, 1);
usb_packet_done(ep);
}
static const struct usb_transfer_type as_transfer_type = {
.on_packet = _as_audio_packet,
.initial_packet_count = 1,
};
static const struct usb_transfer_type as_sync_transfer_type = {
.on_packet = _as_sync_packet,
.initial_packet_count = 1,
};
static struct usb_transfer as_transfer;
static struct usb_transfer as_sync_transfer;
static bool do_get_current(struct usb_setup_packet *setup) {
usb_debug("AUDIO_REQ_GET_CUR\n");
if ((setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK) == USB_REQ_TYPE_RECIPIENT_INTERFACE) {
switch (setup->wValue >> 8u) {
case FEATURE_MUTE_CONTROL: {
usb_start_tiny_control_in_transfer(audio_state.mute, 1);
return true;
}
case FEATURE_VOLUME_CONTROL: {
/* Current volume. See UAC Spec 1.0 p.77 */
usb_start_tiny_control_in_transfer(audio_state.volume, 2);
return true;
}
}
} else if ((setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK) == USB_REQ_TYPE_RECIPIENT_ENDPOINT) {
if ((setup->wValue >> 8u) == ENDPOINT_FREQ_CONTROL) {
/* Current frequency */
usb_start_tiny_control_in_transfer(audio_state.freq, 3);
return true;
}
}
return false;
}
// todo this seemed like aood guess, but is not correct
uint16_t db_to_vol[91] = {
0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0002, 0x0002,
0x0002, 0x0002, 0x0003, 0x0003, 0x0004, 0x0004, 0x0005, 0x0005,
0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000d, 0x000e,
0x0010, 0x0012, 0x0014, 0x0017, 0x001a, 0x001d, 0x0020, 0x0024,
0x0029, 0x002e, 0x0033, 0x003a, 0x0041, 0x0049, 0x0052, 0x005c,
0x0067, 0x0074, 0x0082, 0x0092, 0x00a4, 0x00b8, 0x00ce, 0x00e7,
0x0104, 0x0124, 0x0147, 0x016f, 0x019c, 0x01ce, 0x0207, 0x0246,
0x028d, 0x02dd, 0x0337, 0x039b, 0x040c, 0x048a, 0x0518, 0x05b7,
0x066a, 0x0732, 0x0813, 0x090f, 0x0a2a, 0x0b68, 0x0ccc, 0x0e5c,
0x101d, 0x1214, 0x1449, 0x16c3, 0x198a, 0x1ca7, 0x2026, 0x2413,
0x287a, 0x2d6a, 0x32f5, 0x392c, 0x4026, 0x47fa, 0x50c3, 0x5a9d,
0x65ac, 0x7214, 0x7fff
};
// actually windows doesn't seem to like this in the middle, so set top range to 0db
#define CENTER_VOLUME_INDEX 91
#define ENCODE_DB(x) ((uint16_t)(int16_t)((x)*256))
#define MIN_VOLUME ENCODE_DB(-CENTER_VOLUME_INDEX)
#define DEFAULT_VOLUME ENCODE_DB(0)
#define MAX_VOLUME ENCODE_DB(count_of(db_to_vol)-CENTER_VOLUME_INDEX)
#define VOLUME_RESOLUTION ENCODE_DB(1)
static bool do_get_minimum(struct usb_setup_packet *setup) {
usb_debug("AUDIO_REQ_GET_MIN\n");
if ((setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK) == USB_REQ_TYPE_RECIPIENT_INTERFACE) {
switch (setup->wValue >> 8u) {
case FEATURE_VOLUME_CONTROL: {
usb_start_tiny_control_in_transfer(MIN_VOLUME, 2);
return true;
}
}
}
return false;
}
static bool do_get_maximum(struct usb_setup_packet *setup) {
usb_debug("AUDIO_REQ_GET_MAX\n");
if ((setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK) == USB_REQ_TYPE_RECIPIENT_INTERFACE) {
switch (setup->wValue >> 8u) {
case FEATURE_VOLUME_CONTROL: {
usb_start_tiny_control_in_transfer(MAX_VOLUME, 2);
return true;
}
}
}
return false;
}
static bool do_get_resolution(struct usb_setup_packet *setup) {
usb_debug("AUDIO_REQ_GET_RES\n");
if ((setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK) == USB_REQ_TYPE_RECIPIENT_INTERFACE) {
switch (setup->wValue >> 8u) {
case FEATURE_VOLUME_CONTROL: {
usb_start_tiny_control_in_transfer(VOLUME_RESOLUTION, 2);
return true;
}
}
}
return false;
}
static struct audio_control_cmd {
uint8_t cmd;
uint8_t type;
uint8_t cs;
uint8_t cn;
uint8_t unit;
uint8_t len;
} audio_control_cmd_t;
static void _audio_reconfigure() {
switch (audio_state.freq) {
case 44100:
case 48000:
break;
default:
audio_state.freq = 44100;
}
// todo hack overwriting const
((struct audio_format *) producer_pool->format)->sample_freq = audio_state.freq;
}
static void audio_set_volume(int16_t volume) {
audio_state.volume = volume;
// todo interpolate
volume += CENTER_VOLUME_INDEX * 256;
if (volume < 0) volume = 0;
if (volume >= count_of(db_to_vol) * 256) volume = count_of(db_to_vol) * 256 - 1;
audio_state.vol_mul = db_to_vol[((uint16_t)volume) >> 8u];
// printf("VOL MUL %04x\n", audio_state.vol_mul);
}
static void audio_cmd_packet(struct usb_endpoint *ep) {
assert(audio_control_cmd_t.cmd == AUDIO_REQ_SetCurrent);
struct usb_buffer *buffer = usb_current_out_packet_buffer(ep);
audio_control_cmd_t.cmd = 0;
if (buffer->data_len >= audio_control_cmd_t.len) {
if (audio_control_cmd_t.type == USB_REQ_TYPE_RECIPIENT_INTERFACE) {
switch (audio_control_cmd_t.cs) {
case FEATURE_MUTE_CONTROL: {
audio_state.mute = buffer->data[0];
usb_warn("Set Mute %d\n", buffer->data[0]);
break;
}
case FEATURE_VOLUME_CONTROL: {
audio_set_volume(*(int16_t *) buffer->data);
break;
}
}
} else if (audio_control_cmd_t.type == USB_REQ_TYPE_RECIPIENT_ENDPOINT) {
if (audio_control_cmd_t.cs == ENDPOINT_FREQ_CONTROL) {
uint32_t new_freq = (*(uint32_t *) buffer->data) & 0x00ffffffu;
usb_warn("Set freq %d\n", new_freq == 0xffffffu ? -1 : (int) new_freq);
if (audio_state.freq != new_freq) {
audio_state.freq = new_freq;
_audio_reconfigure();
}
}
}
}
usb_start_empty_control_in_transfer_null_completion();
// todo is there error handling?
}
static const struct usb_transfer_type _audio_cmd_transfer_type = {
.on_packet = audio_cmd_packet,
.initial_packet_count = 1,
};
static bool as_set_alternate(struct usb_interface *interface, uint alt) {
assert(interface == &as_op_interface);
usb_warn("SET ALTERNATE %d\n", alt);
return alt < 2;
}
static bool do_set_current(struct usb_setup_packet *setup) {
#ifndef NDEBUG
usb_warn("AUDIO_REQ_SET_CUR\n");
#endif
if (setup->wLength && setup->wLength < 64) {
audio_control_cmd_t.cmd = AUDIO_REQ_SetCurrent;
audio_control_cmd_t.type = setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK;
audio_control_cmd_t.len = (uint8_t) setup->wLength;
audio_control_cmd_t.unit = setup->wIndex >> 8u;
audio_control_cmd_t.cs = setup->wValue >> 8u;
audio_control_cmd_t.cn = (uint8_t) setup->wValue;
usb_start_control_out_transfer(&_audio_cmd_transfer_type);
return true;
}
return false;
}
static bool ac_setup_request_handler(__unused struct usb_interface *interface, struct usb_setup_packet *setup) {
setup = __builtin_assume_aligned(setup, 4);
if (USB_REQ_TYPE_TYPE_CLASS == (setup->bmRequestType & USB_REQ_TYPE_TYPE_MASK)) {
switch (setup->bRequest) {
case AUDIO_REQ_SetCurrent:
return do_set_current(setup);
case AUDIO_REQ_GetCurrent:
return do_get_current(setup);
case AUDIO_REQ_GetMinimum:
return do_get_minimum(setup);
case AUDIO_REQ_GetMaximum:
return do_get_maximum(setup);
case AUDIO_REQ_GetResolution:
return do_get_resolution(setup);
default:
break;
}
}
return false;
}
bool _as_setup_request_handler(__unused struct usb_endpoint *ep, struct usb_setup_packet *setup) {
setup = __builtin_assume_aligned(setup, 4);
if (USB_REQ_TYPE_TYPE_CLASS == (setup->bmRequestType & USB_REQ_TYPE_TYPE_MASK)) {
switch (setup->bRequest) {
case AUDIO_REQ_SetCurrent:
return do_set_current(setup);
case AUDIO_REQ_GetCurrent:
return do_get_current(setup);
case AUDIO_REQ_GetMinimum:
return do_get_minimum(setup);
case AUDIO_REQ_GetMaximum:
return do_get_maximum(setup);
case AUDIO_REQ_GetResolution:
return do_get_resolution(setup);
default:
break;
}
}
return false;
}
void usb_sound_card_init() {
//msd_interface.setup_request_handler = msd_setup_request_handler;
usb_interface_init(&ac_interface, &audio_device_config.ac_interface, NULL, 0, true);
ac_interface.setup_request_handler = ac_setup_request_handler;
static struct usb_endpoint *const op_endpoints[] = {
&ep_op_out, &ep_op_sync
};
usb_interface_init(&as_op_interface, &audio_device_config.as_op_interface, op_endpoints, count_of(op_endpoints),
true);
as_op_interface.set_alternate_handler = as_set_alternate;
ep_op_out.setup_request_handler = _as_setup_request_handler;
as_transfer.type = &as_transfer_type;
usb_set_default_transfer(&ep_op_out, &as_transfer);
as_sync_transfer.type = &as_sync_transfer_type;
usb_set_default_transfer(&ep_op_sync, &as_sync_transfer);
static struct usb_interface *const boot_device_interfaces[] = {
&ac_interface,
&as_op_interface,
};
__unused struct usb_device *device = usb_device_init(&boot_device_descriptor, &audio_device_config.descriptor,
boot_device_interfaces, count_of(boot_device_interfaces),
_get_descriptor_string);
assert(device);
audio_set_volume(DEFAULT_VOLUME);
_audio_reconfigure();
// device->on_configure = _on_configure;
usb_device_start();
}
static void core1_worker() {
audio_i2s_set_enabled(true);
}
int main(void) {
set_sys_clock_48mhz();
stdout_uart_init();
//gpio_debug_pins_init();
puts("USB SOUND CARD");
#ifndef NDEBUG
for(uint i=0;i<count_of(audio_device_config.as_audio.format.freqs);i++) {
uint freq = audio_device_config.as_audio.format.freqs[i].Byte1 |
(audio_device_config.as_audio.format.freqs[i].Byte2 << 8u) |
(audio_device_config.as_audio.format.freqs[i].Byte3 << 16u);
assert(freq <= AUDIO_FREQ_MAX);
}
#endif
// initialize for 48k we allow changing later
struct audio_format audio_format_48k = {
.format = AUDIO_BUFFER_FORMAT_PCM_S16,
.sample_freq = 48000,
.channel_count = 2,
};
struct audio_buffer_format producer_format = {
.format = &audio_format_48k,
.sample_stride = 4
};
producer_pool = audio_new_producer_pool(&producer_format, 8, 48); // todo correct size
bool __unused ok;
struct audio_i2s_config config = {
.data_pin = PICO_AUDIO_I2S_DATA_PIN,
.clock_pin_base = PICO_AUDIO_I2S_CLOCK_PIN_BASE,
.dma_channel = 0,
.pio_sm = 0,
};
const struct audio_format *output_format;
output_format = audio_i2s_setup(&audio_format_48k, &config);
if (!output_format) {
panic("PicoAudio: Unable to open audio device.\n");
}
ok = audio_i2s_connect_extra(producer_pool, false, 2, 96, NULL);
assert(ok);
usb_sound_card_init();
multicore_launch_core1(core1_worker);
printf("HAHA %04x %04x %04x %04x\n", MIN_VOLUME, DEFAULT_VOLUME, MAX_VOLUME, VOLUME_RESOLUTION);
// MSD is irq driven
while (1) __wfi();
}