/* * SPDX-FileCopyrightText: Copyright (c) 2026 Saulo Verissimo * SPDX-License-Identifier: MIT * * This file is part of the TinyUSB stack. */ #include "tusb_option.h" #if (CFG_TUH_ENABLED && CFG_TUH_MIDI2) #include "host/usbh.h" #include "host/usbh_pvt.h" #include "midi2_host.h" #define TU_LOG_DRV(...) TU_LOG(CFG_TUH_MIDI2_LOG_LEVEL, __VA_ARGS__) //--------------------------------------------------------------------+ // Weak stubs for application callbacks //--------------------------------------------------------------------+ TU_ATTR_WEAK void tuh_midi2_descriptor_cb(uint8_t idx, const tuh_midi2_descriptor_cb_t *desc_cb_data) { (void) idx; (void) desc_cb_data; } TU_ATTR_WEAK void tuh_midi2_mount_cb(uint8_t idx, const tuh_midi2_mount_cb_t *mount_cb_data) { (void) idx; (void) mount_cb_data; } TU_ATTR_WEAK void tuh_midi2_rx_cb(uint8_t idx, uint32_t xferred_bytes) { (void) idx; (void) xferred_bytes; } TU_ATTR_WEAK void tuh_midi2_tx_cb(uint8_t idx, uint32_t xferred_bytes) { (void) idx; (void) xferred_bytes; } TU_ATTR_WEAK void tuh_midi2_umount_cb(uint8_t idx) { (void) idx; } //--------------------------------------------------------------------+ // Internal structure and state //--------------------------------------------------------------------+ typedef struct { uint8_t ep_addr; uint16_t mps; tu_fifo_t ff; uint8_t* ep_buf; } midih2_tx_t; typedef struct { uint8_t daddr; uint8_t bInterfaceNumber; uint8_t alt_setting_current; uint8_t protocol_version; uint8_t bcdMSC_hi, bcdMSC_lo; uint8_t rx_cable_count_alt0; uint8_t tx_cable_count_alt0; uint8_t rx_cable_count_alt1; uint8_t tx_cable_count_alt1; struct { midih2_tx_t tx; tu_edpt_stream_t rx; uint8_t rx_ff_buf[CFG_TUH_MIDI2_RX_BUFSIZE]; uint8_t tx_ff_buf[CFG_TUH_MIDI2_TX_BUFSIZE]; } ep_stream; bool mounted; } midih2_interface_t; static midih2_interface_t _midi2_host[CFG_TUH_MIDI2]; typedef struct { TUH_EPBUF_DEF(tx, TUH_EPSIZE_BULK_MAX); TUH_EPBUF_DEF(rx, TUH_EPSIZE_BULK_MAX); } midih2_epbuf_t; CFG_TUH_MEM_SECTION static midih2_epbuf_t _midi2_epbuf[CFG_TUH_MIDI2]; //--------------------------------------------------------------------+ // Helper functions //--------------------------------------------------------------------+ static inline uint8_t find_new_midi2_index(void) { for (uint8_t idx = 0; idx < CFG_TUH_MIDI2; idx++) { if (_midi2_host[idx].daddr == 0) { return idx; } } return TUSB_INDEX_INVALID_8; } static inline uint8_t get_idx_by_ep_addr(uint8_t daddr, uint8_t ep_addr) { for (uint8_t idx = 0; idx < CFG_TUH_MIDI2; idx++) { const midih2_interface_t *p_midi = &_midi2_host[idx]; if ((p_midi->daddr == daddr) && (ep_addr == p_midi->ep_stream.rx.ep_addr || ep_addr == p_midi->ep_stream.tx.ep_addr)) { return idx; } } return TUSB_INDEX_INVALID_8; } static inline bool _tuh_tx_opened(const midih2_interface_t* p_midi) { return p_midi->ep_stream.tx.ep_addr != 0; } static uint8_t _tuh_tx_byte_at(const tu_fifo_buffer_info_t* info, uint16_t offset) { if (offset < info->linear.len) { return info->linear.ptr[offset]; } offset = (uint16_t)(offset - info->linear.len); if (offset < info->wrapped.len) { return info->wrapped.ptr[offset]; } return 0; } // Largest byte count containing only whole UMP packets and fitting one xfer. static uint16_t _tuh_tx_nonseg_len_to_mps(midih2_tx_t* tx) { tu_fifo_buffer_info_t info; tu_fifo_get_read_info(&tx->ff, &info); const uint16_t available = (uint16_t)(info.linear.len + info.wrapped.len); uint16_t bytes = 0; while (bytes < tx->mps) { if ((uint16_t)(available - bytes) < 4) break; uint8_t mt = (uint8_t)((_tuh_tx_byte_at(&info, (uint16_t)(bytes + 3)) >> 4) & 0x0F); uint8_t pkt_words = midi2_ump_word_count(mt); uint16_t pkt_bytes = (uint16_t)(pkt_words * 4); if (pkt_bytes == 0) break; if ((uint16_t)(available - bytes) < pkt_bytes) break; if ((uint16_t)(bytes + pkt_bytes) > tx->mps) break; bytes = (uint16_t)(bytes + pkt_bytes); } return bytes; } // Start one OUT transfer capped at mps. Returns bytes queued, or 0 if nothing. static uint16_t _tuh_tx_start_xfer(midih2_interface_t* p_midi) { midih2_tx_t* tx = &p_midi->ep_stream.tx; uint16_t ff_count = tu_fifo_count(&tx->ff); if (ff_count == 0) return 0; if (!usbh_edpt_claim(p_midi->daddr, tx->ep_addr)) return 0; uint16_t bytes; if (p_midi->alt_setting_current == 1) { bytes = _tuh_tx_nonseg_len_to_mps(tx); } else { bytes = tu_min16(tu_fifo_count(&tx->ff), tx->mps); } if (bytes == 0) { usbh_edpt_release(p_midi->daddr, tx->ep_addr); return 0; } tu_fifo_read_n(&tx->ff, tx->ep_buf, bytes); TU_ASSERT(usbh_edpt_xfer(p_midi->daddr, tx->ep_addr, tx->ep_buf, bytes), 0); return bytes; } static uint32_t _tuh_tx_ump_write(midih2_interface_t* p_midi, const uint32_t* words, uint32_t count) { uint32_t written = 0; while (written < count) { uint8_t mt = (uint8_t)((words[written] >> 28) & 0x0F); uint8_t pkt_words = midi2_ump_word_count(mt); uint16_t pkt_bytes = (uint16_t)(pkt_words * 4); if (written + pkt_words > count) break; if (tu_fifo_remaining(&p_midi->ep_stream.tx.ff) < pkt_bytes) break; if (tu_fifo_write_n(&p_midi->ep_stream.tx.ff, &words[written], pkt_bytes) != pkt_bytes) break; written += pkt_words; } (void) _tuh_tx_start_xfer(p_midi); return written; } //--------------------------------------------------------------------+ // Descriptor parsing //--------------------------------------------------------------------+ // Parse Alt Setting 0 (MIDI 1.0) descriptors. Returns pointer past last consumed descriptor. static const uint8_t* midih2_parse_descriptors_alt0(midih2_interface_t *p_midi, const tusb_desc_interface_t *desc_itf, const uint8_t *desc_end) { TU_VERIFY(AUDIO_SUBCLASS_MIDI_STREAMING == desc_itf->bInterfaceSubClass, NULL); p_midi->bInterfaceNumber = desc_itf->bInterfaceNumber; const uint8_t *p_desc = (const uint8_t *) desc_itf; p_desc = tu_desc_next(p_desc); uint8_t rx_cable_count = 0; uint8_t tx_cable_count = 0; bool found_new_interface = false; while (tu_desc_in_bounds(p_desc, desc_end) && !found_new_interface) { switch (tu_desc_type(p_desc)) { case TUSB_DESC_INTERFACE: found_new_interface = true; break; case TUSB_DESC_ENDPOINT: { const tusb_desc_endpoint_t *p_ep = (const tusb_desc_endpoint_t *) p_desc; TU_ASSERT(tuh_edpt_open(p_midi->daddr, p_ep), NULL); if (tu_edpt_dir(p_ep->bEndpointAddress) == TUSB_DIR_IN) { tu_edpt_stream_open(&p_midi->ep_stream.rx, p_midi->daddr, p_ep, tu_edpt_packet_size(p_ep)); tu_edpt_stream_clear(&p_midi->ep_stream.rx); } else { p_midi->ep_stream.tx.ep_addr = p_ep->bEndpointAddress; p_midi->ep_stream.tx.mps = tu_edpt_packet_size(p_ep); tu_fifo_clear(&p_midi->ep_stream.tx.ff); } p_desc = tu_desc_next(p_desc); if (tu_desc_in_bounds(p_desc, desc_end) && tu_desc_type(p_desc) == TUSB_DESC_CS_ENDPOINT) { const midi_desc_cs_endpoint_t *p_csep = (const midi_desc_cs_endpoint_t *) p_desc; if (tu_edpt_dir(p_ep->bEndpointAddress) == TUSB_DIR_OUT) { tx_cable_count = p_csep->bNumEmbMIDIJack; } else { rx_cable_count = p_csep->bNumEmbMIDIJack; } } break; } default: break; } if (!found_new_interface) { p_desc = tu_desc_next(p_desc); } } p_midi->rx_cable_count_alt0 = rx_cable_count; p_midi->tx_cable_count_alt0 = tx_cable_count; return p_desc; } // Parse Alt Setting 1 (MIDI 2.0 UMP) descriptors. Returns pointer past last consumed descriptor. static const uint8_t* midih2_parse_descriptors_alt1(midih2_interface_t *p_midi, const tusb_desc_interface_t *desc_itf, const uint8_t *desc_end) { TU_VERIFY(AUDIO_SUBCLASS_MIDI_STREAMING == desc_itf->bInterfaceSubClass, NULL); TU_VERIFY(desc_itf->bAlternateSetting == 1, NULL); const uint8_t *p_desc = (const uint8_t *) desc_itf; p_desc = tu_desc_next(p_desc); uint8_t rx_cable_count = 0; uint8_t tx_cable_count = 0; bool found_new_interface = false; while (tu_desc_in_bounds(p_desc, desc_end) && !found_new_interface) { switch (tu_desc_type(p_desc)) { case TUSB_DESC_INTERFACE: found_new_interface = true; break; case TUSB_DESC_CS_INTERFACE: if (tu_desc_subtype(p_desc) == MIDI_CS_INTERFACE_HEADER) { // bcdMSC at offset 3-4 in CS Interface Header const uint8_t *bcd_ptr = p_desc + 3; p_midi->bcdMSC_lo = bcd_ptr[0]; p_midi->bcdMSC_hi = bcd_ptr[1]; if (p_midi->bcdMSC_hi == 0x02) { // bcdMSC 0x0200 = USB-MIDI 2.0 p_midi->protocol_version = 1; } } break; case TUSB_DESC_ENDPOINT: { const tusb_desc_endpoint_t *p_ep = (const tusb_desc_endpoint_t *) p_desc; p_desc = tu_desc_next(p_desc); if (tu_desc_in_bounds(p_desc, desc_end) && tu_desc_type(p_desc) == TUSB_DESC_CS_ENDPOINT) { // MIDI 2.0 CS Endpoint General 2.0: bNumGrpTrmBlk at offset 3 if (p_desc[0] >= 4 && p_desc[2] == MIDI_CS_ENDPOINT_GENERAL_2_0) { uint8_t num_grp_trm_blk = p_desc[3]; if (tu_edpt_dir(p_ep->bEndpointAddress) == TUSB_DIR_OUT) { tx_cable_count = num_grp_trm_blk; } else { rx_cable_count = num_grp_trm_blk; } } } break; } default: break; } if (!found_new_interface) { p_desc = tu_desc_next(p_desc); } } p_midi->rx_cable_count_alt1 = rx_cable_count; p_midi->tx_cable_count_alt1 = tx_cable_count; return p_desc; } //--------------------------------------------------------------------+ // Auto-selection logic //--------------------------------------------------------------------+ static void midih2_auto_select_alt_setting(midih2_interface_t *p_midi) { p_midi->alt_setting_current = 0; if (p_midi->protocol_version == 1) { p_midi->alt_setting_current = 1; } } //--------------------------------------------------------------------+ // Init/Deinit //--------------------------------------------------------------------+ bool midih2_init(void) { tu_memclr(&_midi2_host, sizeof(_midi2_host)); for (int inst = 0; inst < CFG_TUH_MIDI2; inst++) { midih2_interface_t *p_midi = &_midi2_host[inst]; tu_edpt_stream_init(&p_midi->ep_stream.rx, true, false, false, p_midi->ep_stream.rx_ff_buf, CFG_TUH_MIDI2_RX_BUFSIZE, _midi2_epbuf[inst].rx); // TX uses raw tu_fifo + direct usbh_edpt_xfer (no FIFO wrapper) to preserve // UMP packet boundaries across USB transfers. midih2_tx_t* tx = &p_midi->ep_stream.tx; (void) tu_fifo_config(&tx->ff, p_midi->ep_stream.tx_ff_buf, CFG_TUH_MIDI2_TX_BUFSIZE, false); tx->ep_buf = _midi2_epbuf[inst].tx; } return true; } bool midih2_deinit(void) { for (size_t i = 0; i < CFG_TUH_MIDI2; i++) { midih2_interface_t* p_midi = &_midi2_host[i]; tu_edpt_stream_deinit(&p_midi->ep_stream.rx); } return true; } //--------------------------------------------------------------------+ // Class driver callbacks //--------------------------------------------------------------------+ uint16_t midih2_open(uint8_t rhport, uint8_t dev_addr, const tusb_desc_interface_t *desc_itf, uint16_t max_len) { (void) rhport; TU_VERIFY(TUSB_CLASS_AUDIO == desc_itf->bInterfaceClass, 0); // For Alt Setting 1, reuse existing slot for same device+interface uint8_t idx = TUSB_INDEX_INVALID_8; if (desc_itf->bAlternateSetting > 0) { for (uint8_t i = 0; i < CFG_TUH_MIDI2; i++) { if (_midi2_host[i].daddr == dev_addr && _midi2_host[i].bInterfaceNumber == desc_itf->bInterfaceNumber) { idx = i; break; } } } if (idx == TUSB_INDEX_INVALID_8) { idx = find_new_midi2_index(); } TU_VERIFY(idx < CFG_TUH_MIDI2, 0); midih2_interface_t *p_midi = &_midi2_host[idx]; p_midi->daddr = dev_addr; const uint8_t *desc_start = (const uint8_t *) desc_itf; const uint8_t *desc_end = desc_start + max_len; // Skip Audio Control interface and any non-MIDI-Streaming descriptors // (following midi_host.c pattern from Ha Thach) if (AUDIO_SUBCLASS_CONTROL == desc_itf->bInterfaceSubClass) { const uint8_t *p_desc = tu_desc_next((const uint8_t *)desc_itf); // Skip CS_INTERFACE header TU_VERIFY(tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE, 0); p_desc = tu_desc_next(p_desc); desc_itf = (const tusb_desc_interface_t *) p_desc; // Skip until we find MIDI Streaming interface while (tu_desc_in_bounds(p_desc, desc_end) && (desc_itf->bDescriptorType != TUSB_DESC_INTERFACE || (desc_itf->bInterfaceClass == TUSB_CLASS_AUDIO && desc_itf->bInterfaceSubClass != AUDIO_SUBCLASS_MIDI_STREAMING))) { p_desc = tu_desc_next(p_desc); desc_itf = (const tusb_desc_interface_t *) p_desc; } TU_VERIFY(tu_desc_in_bounds(p_desc, desc_end), 0); TU_VERIFY(TUSB_CLASS_AUDIO == desc_itf->bInterfaceClass, 0); } TU_VERIFY(AUDIO_SUBCLASS_MIDI_STREAMING == desc_itf->bInterfaceSubClass, 0); TU_LOG_DRV("MIDI2 opening Interface %u Alt %u (addr = %u)\r\n", desc_itf->bInterfaceNumber, desc_itf->bAlternateSetting, dev_addr); // Dispatch to appropriate parser based on Alt Setting const uint8_t *p_end = NULL; if (desc_itf->bAlternateSetting == 0) { p_end = midih2_parse_descriptors_alt0(p_midi, desc_itf, desc_end); } else if (desc_itf->bAlternateSetting == 1) { p_end = midih2_parse_descriptors_alt1(p_midi, desc_itf, desc_end); } // Return number of bytes consumed (following midi_host.c pattern) uint16_t const parsed_len = (p_end != NULL) ? (uint16_t)(p_end - desc_start) : 0; return parsed_len; } static void midih2_set_config_complete(midih2_interface_t *p_midi, uint8_t idx) { uint8_t dev_addr = p_midi->daddr; // Invoke descriptor_cb tuh_midi2_descriptor_cb_t desc_cb = { .protocol_version = p_midi->protocol_version, .bcdMSC_hi = p_midi->bcdMSC_hi, .bcdMSC_lo = p_midi->bcdMSC_lo, .rx_cable_count = (p_midi->alt_setting_current == 0) ? p_midi->rx_cable_count_alt0 : p_midi->rx_cable_count_alt1, .tx_cable_count = (p_midi->alt_setting_current == 0) ? p_midi->tx_cable_count_alt0 : p_midi->tx_cable_count_alt1, }; tuh_midi2_descriptor_cb(idx, &desc_cb); // Mark as mounted TU_LOG_DRV("MIDI2 mounted addr = %u, alt = %u, protocol = %u\r\n", dev_addr, p_midi->alt_setting_current, p_midi->protocol_version); p_midi->mounted = true; // Invoke mount_cb tuh_midi2_mount_cb_t mount_cb = { .daddr = dev_addr, .bInterfaceNumber = p_midi->bInterfaceNumber, .protocol_version = p_midi->protocol_version, .alt_setting_active = p_midi->alt_setting_current, .rx_cable_count = desc_cb.rx_cable_count, .tx_cable_count = desc_cb.tx_cable_count, }; tuh_midi2_mount_cb(idx, &mount_cb); // Prepare RX transfer tu_edpt_stream_read_xfer(&p_midi->ep_stream.rx); // Signal USBH that configuration is complete usbh_driver_set_config_complete(dev_addr, p_midi->bInterfaceNumber); } static void midih2_set_interface_cb(tuh_xfer_t *xfer) { uint8_t const dev_addr = xfer->daddr; uint8_t const itf_num = (uint8_t) tu_le16toh(xfer->setup->wIndex); // Find our interface for (uint8_t idx = 0; idx < CFG_TUH_MIDI2; idx++) { if (_midi2_host[idx].daddr == dev_addr && _midi2_host[idx].bInterfaceNumber == itf_num) { if (xfer->result == XFER_RESULT_SUCCESS) { midih2_set_config_complete(&_midi2_host[idx], idx); } else { // SET_INTERFACE failed, fall back to alt 0 TU_LOG_DRV("MIDI2 SET_INTERFACE failed, falling back to alt 0\r\n"); _midi2_host[idx].alt_setting_current = 0; midih2_set_config_complete(&_midi2_host[idx], idx); } return; } } } bool midih2_set_config(uint8_t dev_addr, uint8_t itf_num) { uint8_t idx = 0; for (idx = 0; idx < CFG_TUH_MIDI2; idx++) { if (_midi2_host[idx].daddr == dev_addr && _midi2_host[idx].bInterfaceNumber == itf_num) { break; } } if (idx >= CFG_TUH_MIDI2) { // Not our interface (e.g. Audio Control) - pass through to next usbh_driver_set_config_complete(dev_addr, itf_num); return true; } midih2_interface_t *p_midi = &_midi2_host[idx]; // Auto-select alt setting midih2_auto_select_alt_setting(p_midi); // If MIDI 2.0 detected, issue SET_INTERFACE to activate Alt Setting 1 if (p_midi->alt_setting_current == 1) { TU_LOG_DRV("MIDI2 requesting SET_INTERFACE alt 1 for itf %u\r\n", itf_num); TU_ASSERT(tuh_interface_set(dev_addr, itf_num, 1, midih2_set_interface_cb, 0)); } else { // MIDI 1.0 only, complete immediately midih2_set_config_complete(p_midi, idx); } return true; } void midih2_close(uint8_t dev_addr) { for (uint8_t idx = 0; idx < CFG_TUH_MIDI2; idx++) { midih2_interface_t *p_midi = &_midi2_host[idx]; if (p_midi->daddr == dev_addr) { TU_LOG_DRV(" MIDI2 close addr = %u index = %u\r\n", dev_addr, idx); tu_edpt_stream_close(&p_midi->ep_stream.rx); tu_fifo_clear(&p_midi->ep_stream.tx.ff); p_midi->ep_stream.tx.ep_addr = 0; tuh_midi2_umount_cb(idx); tu_memclr(p_midi, sizeof(midih2_interface_t)); } } } bool midih2_xfer_cb(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) { uint8_t idx = get_idx_by_ep_addr(dev_addr, ep_addr); TU_VERIFY(idx < CFG_TUH_MIDI2); midih2_interface_t *p_midi = &_midi2_host[idx]; midih2_tx_t* ep_tx = &p_midi->ep_stream.tx; if (ep_addr == p_midi->ep_stream.rx.ep_addr) { if (result == XFER_RESULT_SUCCESS && xferred_bytes > 0) { tu_edpt_stream_read_xfer_complete(&p_midi->ep_stream.rx, xferred_bytes); tuh_midi2_rx_cb(idx, xferred_bytes); } tu_edpt_stream_read_xfer(&p_midi->ep_stream.rx); } else if (ep_addr == ep_tx->ep_addr) { tuh_midi2_tx_cb(idx, xferred_bytes); if (result == XFER_RESULT_SUCCESS) { uint16_t queued = _tuh_tx_start_xfer(p_midi); // Send ZLP if no more data is queued but the last transfer was exactly mps if (queued == 0 && tu_fifo_count(&ep_tx->ff) == 0 && xferred_bytes > 0 && (0 == (xferred_bytes & (ep_tx->mps - 1)))) { if (usbh_edpt_claim(dev_addr, ep_tx->ep_addr)) { usbh_edpt_xfer(dev_addr, ep_tx->ep_addr, NULL, 0); } } } } return true; } //--------------------------------------------------------------------+ // Public API //--------------------------------------------------------------------+ bool tuh_midi2_mounted(uint8_t idx) { TU_VERIFY(idx < CFG_TUH_MIDI2); return _midi2_host[idx].mounted; } uint8_t tuh_midi2_get_protocol_version(uint8_t idx) { TU_VERIFY(idx < CFG_TUH_MIDI2); return _midi2_host[idx].protocol_version; } uint8_t tuh_midi2_get_alt_setting_active(uint8_t idx) { TU_VERIFY(idx < CFG_TUH_MIDI2); return _midi2_host[idx].alt_setting_current; } uint8_t tuh_midi2_get_cable_count(uint8_t idx) { TU_VERIFY(idx < CFG_TUH_MIDI2); return (_midi2_host[idx].alt_setting_current == 0) ? _midi2_host[idx].rx_cable_count_alt0 : _midi2_host[idx].rx_cable_count_alt1; } uint32_t tuh_midi2_ump_read(uint8_t idx, uint32_t* words, uint32_t max_words) { TU_VERIFY(idx < CFG_TUH_MIDI2 && words && max_words); midih2_interface_t *p_midi = &_midi2_host[idx]; tu_edpt_stream_t *ep_rx = &p_midi->ep_stream.rx; uint32_t n_words = 0; for (uint32_t i = 0; i < max_words; i++) { if (tu_edpt_stream_read_available(ep_rx) >= 4) { tu_edpt_stream_read(ep_rx, (uint8_t *) &words[i], 4); n_words++; } else { break; } } return n_words; } uint32_t tuh_midi2_ump_write(uint8_t idx, const uint32_t* words, uint32_t count) { TU_VERIFY(idx < CFG_TUH_MIDI2 && words && count); midih2_interface_t *p_midi = &_midi2_host[idx]; TU_VERIFY(_tuh_tx_opened(p_midi), 0); return _tuh_tx_ump_write(p_midi, words, count); } uint32_t tuh_midi2_write_flush(uint8_t idx) { TU_VERIFY(idx < CFG_TUH_MIDI2); return _tuh_tx_start_xfer(&_midi2_host[idx]); } #endif // CFG_TUH_ENABLED && CFG_TUH_MIDI2