#include #include "usb_dev.h" #include "usb_mem.h" // buffer descriptor table typedef struct { uint32_t desc; void * addr; } bdt_t; __attribute__ ((section(".usbdescriptortable"), used)) static bdt_t table[64]; #define BDT_OWN 0x80 #define BDT_DATA1 0x40 #define BDT_DATA0 0x00 #define BDT_DTS 0x08 #define BDT_STALL 0x04 #define BDT_PID(n) (((n) >> 2) & 15) #define BDT_DESC(count, data) (BDT_OWN | BDT_DTS \ | ((data) ? BDT_DATA1 : BDT_DATA0) \ | ((count) << 16)) #define TX 1 #define RX 0 #define ODD 1 #define EVEN 0 #define DATA0 0 #define DATA1 1 #define index(endpoint, tx, odd) (((endpoint) << 2) | ((tx) << 1) | (odd)) #define stat2bufferdescriptor(stat) (table + ((stat) >> 2)) static union { struct { union { struct { uint8_t bmRequestType; uint8_t bRequest; }; uint16_t wRequestAndType; }; uint16_t wValue; uint16_t wIndex; uint16_t wLength; }; struct { uint32_t word1; uint32_t word2; }; } setup; #define GET_STATUS 0 #define CLEAR_FEATURE 1 #define SET_FEATURE 3 #define SET_ADDRESS 5 #define GET_DESCRIPTOR 6 #define SET_DESCRIPTOR 7 #define GET_CONFIGURATION 8 #define SET_CONFIGURATION 9 #define GET_INTERFACE 10 #define SET_INTERFACE 11 #define SYNCH_FRAME 12 // SETUP always uses a DATA0 PID for the data field of the SETUP transaction. // transactions in the data phase start with DATA1 and toggle (figure 8-12, USB1.1) // Status stage uses a DATA1 PID. static uint8_t ep0_rx0_buf[EP0_SIZE] __attribute__ ((aligned (4))); static uint8_t ep0_rx1_buf[EP0_SIZE] __attribute__ ((aligned (4))); static const uint8_t *ep0_tx_ptr = NULL; static uint16_t ep0_tx_len; static uint8_t ep0_tx_bdt_bank = 0; static uint8_t ep0_tx_data_toggle = 0; uint8_t usb_rx_memory_needed = 0; volatile uint8_t usb_configuration = 0; volatile uint8_t usb_reboot_timer = 0; static void endpoint0_stall(void) { USB0_ENDPT0 = USB_ENDPT_EPSTALL | USB_ENDPT_EPRXEN | USB_ENDPT_EPTXEN | USB_ENDPT_EPHSHK; } static void endpoint0_transmit(const void *data, uint32_t len) { #if 0 serial_print("tx0:"); serial_phex32((uint32_t)data); serial_print(","); serial_phex16(len); serial_print(ep0_tx_bdt_bank ? ", odd" : ", even"); serial_print(ep0_tx_data_toggle ? ", d1\n" : ", d0\n"); #endif table[index(0, TX, ep0_tx_bdt_bank)].addr = (void *)data; table[index(0, TX, ep0_tx_bdt_bank)].desc = BDT_DESC(len, ep0_tx_data_toggle); ep0_tx_data_toggle ^= 1; ep0_tx_bdt_bank ^= 1; } static uint8_t reply_buffer[8]; static void usbdev_setup(void) { const uint8_t *data = NULL; uint32_t datalen = 0; const usb_descriptor_list_t *list; uint32_t size; volatile uint8_t *reg; uint8_t epconf; const uint8_t *cfg; int i; switch (setup.wRequestAndType) { case 0x0500: // SET_ADDRESS break; case 0x0900: // SET_CONFIGURATION //serial_print("configure\n"); usb_configuration = setup.wValue; reg = &USB0_ENDPT1; cfg = usb_endpoint_config_table; // clear all BDT entries, free any allocated memory... for (i=4; i <= NUM_ENDPOINTS*4; i++) { if (table[i].desc & BDT_OWN) { usb_free((usb_packet_t *)((uint8_t *)(table[i].addr) - 8)); table[i].desc = 0; } } usb_rx_memory_needed = 0; for (i=1; i <= NUM_ENDPOINTS; i++) { epconf = *cfg++; *reg = epconf; reg += 4; if (epconf & USB_ENDPT_EPRXEN) { usb_packet_t *p; p = usb_malloc(); if (p) { table[index(i, RX, EVEN)].addr = p->buf; table[index(i, RX, EVEN)].desc = BDT_DESC(64, 0); } else { table[index(i, RX, EVEN)].desc = 0; usb_rx_memory_needed++; } p = usb_malloc(); if (p) { table[index(i, RX, ODD)].addr = p->buf; table[index(i, RX, ODD)].desc = BDT_DESC(64, 1); } else { table[index(i, RX, ODD)].desc = 0; usb_rx_memory_needed++; } } table[index(i, TX, EVEN)].desc = 0; table[index(i, TX, ODD)].desc = 0; } break; case 0x0880: // GET_CONFIGURATION reply_buffer[0] = usb_configuration; datalen = 1; data = reply_buffer; break; case 0x0080: // GET_STATUS (device) reply_buffer[0] = 0; reply_buffer[1] = 0; datalen = 2; data = reply_buffer; break; case 0x0082: // GET_STATUS (endpoint) if (setup.wIndex > NUM_ENDPOINTS) { // TODO: do we need to handle IN vs OUT here? endpoint0_stall(); return; } reply_buffer[0] = 0; reply_buffer[1] = 0; if (*(uint8_t *)(&USB0_ENDPT0 + setup.wIndex * 4) & 0x02) reply_buffer[0] = 1; data = reply_buffer; datalen = 2; break; case 0x0102: // CLEAR_FEATURE (endpoint) i = setup.wIndex & 0x7F; if (i > NUM_ENDPOINTS || setup.wValue != 0) { // TODO: do we need to handle IN vs OUT here? endpoint0_stall(); return; } (*(uint8_t *)(&USB0_ENDPT0 + setup.wIndex * 4)) &= ~0x02; // TODO: do we need to clear the data toggle here? break; case 0x0302: // SET_FEATURE (endpoint) i = setup.wIndex & 0x7F; if (i > NUM_ENDPOINTS || setup.wValue != 0) { // TODO: do we need to handle IN vs OUT here? endpoint0_stall(); return; } (*(uint8_t *)(&USB0_ENDPT0 + setup.wIndex * 4)) |= 0x02; // TODO: do we need to clear the data toggle here? break; case 0x0680: // GET_DESCRIPTOR case 0x0681: //serial_print("desc:"); //serial_phex16(setup.wValue); //serial_print("\n"); for (list = usb_descriptor_list; 1; list++) { if (list->addr == NULL) break; //if (setup.wValue == list->wValue && //(setup.wIndex == list->wIndex) || ((setup.wValue >> 8) == 3)) { if (setup.wValue == list->wValue && setup.wIndex == list->wIndex) { data = list->addr; datalen = list->length; #if 0 serial_print("Desc found, "); serial_phex32((uint32_t)data); serial_print(","); serial_phex16(datalen); serial_print(","); serial_phex(data[0]); serial_phex(data[1]); serial_phex(data[2]); serial_phex(data[3]); serial_phex(data[4]); serial_phex(data[5]); serial_print("\n"); #endif goto send; } } //serial_print("desc: not found\n"); endpoint0_stall(); return; #if defined(CDC_STATUS_INTERFACE) case 0x2221: // CDC_SET_CONTROL_LINE_STATE usb_cdc_line_rtsdtr = setup.wValue; //serial_print("set control line state\n"); break; case 0x2021: // CDC_SET_LINE_CODING //serial_print("set coding, waiting...\n"); return; #endif // TODO: this does not work... why? #if defined(KEYBOARD_INTERFACE) case 0x0921: // HID SET_REPORT //serial_print(":)\n"); return; case 0x0A21: // HID SET_IDLE break; // case 0xC940: #endif default: endpoint0_stall(); return; } send: //serial_print("setup send "); //serial_phex32(data); //serial_print(","); //serial_phex16(datalen); //serial_print("\n"); if (datalen > setup.wLength) datalen = setup.wLength; size = datalen; if (size > EP0_SIZE) size = EP0_SIZE; endpoint0_transmit(data, size); data += size; datalen -= size; if (datalen == 0 && size < EP0_SIZE) return; size = datalen; if (size > EP0_SIZE) size = EP0_SIZE; endpoint0_transmit(data, size); data += size; datalen -= size; if (datalen == 0 && size < EP0_SIZE) return; ep0_tx_ptr = data; ep0_tx_len = datalen; } //A bulk endpoint's toggle sequence is initialized to DATA0 when the endpoint //experiences any configuration event (configuration events are explained in //Sections 9.1.1.5 and 9.4.5). //Configuring a device or changing an alternate setting causes all of the status //and configuration values associated with endpoints in the affected interfaces //to be set to their default values. This includes setting the data toggle of //any endpoint using data toggles to the value DATA0. //For endpoints using data toggle, regardless of whether an endpoint has the //Halt feature set, a ClearFeature(ENDPOINT_HALT) request always results in the //data toggle being reinitialized to DATA0. // #define stat2bufferdescriptor(stat) (table + ((stat) >> 2)) static void usb_control(uint32_t stat) { bdt_t *b; uint32_t pid, size; uint8_t *buf; const uint8_t *data; b = stat2bufferdescriptor(stat); pid = BDT_PID(b->desc); //count = b->desc >> 16; buf = b->addr; //serial_print("pid:"); //serial_phex(pid); //serial_print(", count:"); //serial_phex(count); //serial_print("\n"); switch (pid) { case 0x0D: // Setup received from host //serial_print("PID=Setup\n"); //if (count != 8) ; // panic? // grab the 8 byte setup info setup.word1 = *(uint32_t *)(buf); setup.word2 = *(uint32_t *)(buf + 4); // give the buffer back b->desc = BDT_DESC(EP0_SIZE, DATA1); //table[index(0, RX, EVEN)].desc = BDT_DESC(EP0_SIZE, 1); //table[index(0, RX, ODD)].desc = BDT_DESC(EP0_SIZE, 1); // clear any leftover pending IN transactions ep0_tx_ptr = NULL; if (ep0_tx_data_toggle) { } //if (table[index(0, TX, EVEN)].desc & 0x80) { //serial_print("leftover tx even\n"); //} //if (table[index(0, TX, ODD)].desc & 0x80) { //serial_print("leftover tx odd\n"); //} table[index(0, TX, EVEN)].desc = 0; table[index(0, TX, ODD)].desc = 0; // first IN after Setup is always DATA1 ep0_tx_data_toggle = 1; #if 0 serial_print("bmRequestType:"); serial_phex(setup.bmRequestType); serial_print(", bRequest:"); serial_phex(setup.bRequest); serial_print(", wValue:"); serial_phex16(setup.wValue); serial_print(", wIndex:"); serial_phex16(setup.wIndex); serial_print(", len:"); serial_phex16(setup.wLength); serial_print("\n"); #endif // actually "do" the setup request usbdev_setup(); // unfreeze the USB, now that we're ready USB0_CTL = USB_CTL_USBENSOFEN; // clear TXSUSPENDTOKENBUSY bit break; case 0x01: // OUT transaction received from host case 0x02: //serial_print("PID=OUT\n"); #ifdef CDC_STATUS_INTERFACE if (setup.wRequestAndType == 0x2021 /*CDC_SET_LINE_CODING*/) { int i; uint8_t *dst = usb_cdc_line_coding; //serial_print("set line coding "); for (i=0; i<7; i++) { //serial_phex(*buf); *dst++ = *buf++; } //serial_phex32(*(uint32_t *)usb_cdc_line_coding); //serial_print("\n"); // XXX - Not sure why this was casted to uint32_t... -HaaTa //if (*(uint32_t *)usb_cdc_line_coding == 134) usb_reboot_timer = 15; if (*usb_cdc_line_coding == 134) usb_reboot_timer = 15; endpoint0_transmit(NULL, 0); } #endif #ifdef KEYBOARD_INTERFACE if (setup.word1 == 0x02000921 && setup.word2 == ((1<<16)|KEYBOARD_INTERFACE)) { USBKeys_LEDs = buf[0]; endpoint0_transmit(NULL, 0); } #endif // give the buffer back b->desc = BDT_DESC(EP0_SIZE, DATA1); break; case 0x09: // IN transaction completed to host //serial_print("PID=IN:"); //serial_phex(stat); //serial_print("\n"); // send remaining data, if any... data = ep0_tx_ptr; if (data) { size = ep0_tx_len; if (size > EP0_SIZE) size = EP0_SIZE; endpoint0_transmit(data, size); data += size; ep0_tx_len -= size; ep0_tx_ptr = (ep0_tx_len > 0 || size == EP0_SIZE) ? data : NULL; } if (setup.bRequest == 5 && setup.bmRequestType == 0) { setup.bRequest = 0; //serial_print("set address: "); //serial_phex16(setup.wValue); //serial_print("\n"); USB0_ADDR = setup.wValue; } break; //default: //serial_print("PID=unknown:"); //serial_phex(pid); //serial_print("\n"); } USB0_CTL = USB_CTL_USBENSOFEN; // clear TXSUSPENDTOKENBUSY bit } static usb_packet_t *rx_first[NUM_ENDPOINTS]; static usb_packet_t *rx_last[NUM_ENDPOINTS]; static usb_packet_t *tx_first[NUM_ENDPOINTS]; static usb_packet_t *tx_last[NUM_ENDPOINTS]; static uint8_t tx_state[NUM_ENDPOINTS]; #define TX_STATE_BOTH_FREE_EVEN_FIRST 0 #define TX_STATE_BOTH_FREE_ODD_FIRST 1 #define TX_STATE_EVEN_FREE 2 #define TX_STATE_ODD_FREE 3 #define TX_STATE_NONE_FREE 4 usb_packet_t *usb_rx(uint32_t endpoint) { usb_packet_t *ret; endpoint--; if (endpoint >= NUM_ENDPOINTS) return NULL; __disable_irq(); ret = rx_first[endpoint]; if (ret) rx_first[endpoint] = ret->next; __enable_irq(); //serial_print("rx, epidx="); //serial_phex(endpoint); //serial_print(", packet="); //serial_phex32(ret); //serial_print("\n"); return ret; } static uint32_t usb_queue_byte_count(const usb_packet_t *p) { uint32_t count=0; __disable_irq(); for ( ; p; p = p->next) { count += p->len; } __enable_irq(); return count; } uint32_t usb_rx_byte_count(uint32_t endpoint) { endpoint--; if (endpoint >= NUM_ENDPOINTS) return 0; return usb_queue_byte_count(rx_first[endpoint]); } uint32_t usb_tx_byte_count(uint32_t endpoint) { endpoint--; if (endpoint >= NUM_ENDPOINTS) return 0; return usb_queue_byte_count(tx_first[endpoint]); } uint32_t usb_tx_packet_count(uint32_t endpoint) { const usb_packet_t *p; uint32_t count=0; endpoint--; if (endpoint >= NUM_ENDPOINTS) return 0; p = tx_first[endpoint]; __disable_irq(); for ( ; p; p = p->next) count++; __enable_irq(); return count; } // Called from usb_free, but only when usb_rx_memory_needed > 0, indicating // receive endpoints are starving for memory. The intention is to give // endpoints needing receive memory priority over the user's code, which is // likely calling usb_malloc to obtain memory for transmitting. When the // user is creating data very quickly, their consumption could starve reception // without this prioritization. The packet buffer (input) is assigned to the // first endpoint needing memory. // void usb_rx_memory(usb_packet_t *packet) { unsigned int i; const uint8_t *cfg; cfg = usb_endpoint_config_table; //serial_print("rx_mem:"); __disable_irq(); for (i=1; i <= NUM_ENDPOINTS; i++) { if (*cfg++ & USB_ENDPT_EPRXEN) { if (table[index(i, RX, EVEN)].desc == 0) { table[index(i, RX, EVEN)].addr = packet->buf; table[index(i, RX, EVEN)].desc = BDT_DESC(64, 0); usb_rx_memory_needed--; __enable_irq(); //serial_phex(i); //serial_print(",even\n"); return; } if (table[index(i, RX, ODD)].desc == 0) { table[index(i, RX, ODD)].addr = packet->buf; table[index(i, RX, ODD)].desc = BDT_DESC(64, 1); usb_rx_memory_needed--; __enable_irq(); //serial_phex(i); //serial_print(",odd\n"); return; } } } __enable_irq(); // we should never reach this point. If we get here, it means // usb_rx_memory_needed was set greater than zero, but no memory // was actually needed. usb_rx_memory_needed = 0; usb_free(packet); return; } //#define index(endpoint, tx, odd) (((endpoint) << 2) | ((tx) << 1) | (odd)) //#define stat2bufferdescriptor(stat) (table + ((stat) >> 2)) void usb_tx(uint32_t endpoint, usb_packet_t *packet) { bdt_t *b = &table[index(endpoint, TX, EVEN)]; uint8_t next; endpoint--; if (endpoint >= NUM_ENDPOINTS) return; __disable_irq(); //serial_print("txstate="); //serial_phex(tx_state[endpoint]); //serial_print("\n"); switch (tx_state[endpoint]) { case TX_STATE_BOTH_FREE_EVEN_FIRST: next = TX_STATE_ODD_FREE; break; case TX_STATE_BOTH_FREE_ODD_FIRST: b++; next = TX_STATE_EVEN_FREE; break; case TX_STATE_EVEN_FREE: next = TX_STATE_NONE_FREE; break; case TX_STATE_ODD_FREE: b++; next = TX_STATE_NONE_FREE; break; default: if (tx_first[endpoint] == NULL) { tx_first[endpoint] = packet; } else { tx_last[endpoint]->next = packet; } tx_last[endpoint] = packet; __enable_irq(); return; } tx_state[endpoint] = next; b->addr = packet->buf; b->desc = BDT_DESC(packet->len, ((uint32_t)b & 8) ? DATA1 : DATA0); __enable_irq(); } void usb_device_reload() { asm volatile("bkpt"); } void _reboot_Teensyduino_(void) { // TODO: initialize R0 with a code.... asm volatile("bkpt"); } void usb_isr(void) { uint8_t status, stat, t; //serial_print("isr"); //status = USB0_ISTAT; //serial_phex(status); //serial_print("\n"); restart: status = USB0_ISTAT; if ((status & USB_INTEN_SOFTOKEN /* 04 */ )) { if (usb_configuration) { t = usb_reboot_timer; if (t) { usb_reboot_timer = --t; if (!t) _reboot_Teensyduino_(); } #ifdef CDC_DATA_INTERFACE t = usb_cdc_transmit_flush_timer; if (t) { usb_cdc_transmit_flush_timer = --t; if (t == 0) usb_serial_flush_callback(); } #endif } USB0_ISTAT = USB_INTEN_SOFTOKEN; } if ((status & USB_ISTAT_TOKDNE /* 08 */ )) { uint8_t endpoint; stat = USB0_STAT; //serial_print("token: ep="); //serial_phex(stat >> 4); //serial_print(stat & 0x08 ? ",tx" : ",rx"); //serial_print(stat & 0x04 ? ",odd\n" : ",even\n"); endpoint = stat >> 4; if (endpoint == 0) { usb_control(stat); } else { bdt_t *b = stat2bufferdescriptor(stat); usb_packet_t *packet = (usb_packet_t *)((uint8_t *)(b->addr) - 8); #if 0 serial_print("ep:"); serial_phex(endpoint); serial_print(", pid:"); serial_phex(BDT_PID(b->desc)); serial_print(((uint32_t)b & 8) ? ", odd" : ", even"); serial_print(", count:"); serial_phex(b->desc >> 16); serial_print("\n"); #endif endpoint--; // endpoint is index to zero-based arrays if (stat & 0x08) { // transmit usb_free(packet); packet = tx_first[endpoint]; if (packet) { //serial_print("tx packet\n"); tx_first[endpoint] = packet->next; b->addr = packet->buf; switch (tx_state[endpoint]) { case TX_STATE_BOTH_FREE_EVEN_FIRST: tx_state[endpoint] = TX_STATE_ODD_FREE; break; case TX_STATE_BOTH_FREE_ODD_FIRST: tx_state[endpoint] = TX_STATE_EVEN_FREE; break; case TX_STATE_EVEN_FREE: case TX_STATE_ODD_FREE: default: tx_state[endpoint] = TX_STATE_NONE_FREE; break; } b->desc = BDT_DESC(packet->len, ((uint32_t)b & 8) ? DATA1 : DATA0); } else { //serial_print("tx no packet\n"); switch (tx_state[endpoint]) { case TX_STATE_BOTH_FREE_EVEN_FIRST: case TX_STATE_BOTH_FREE_ODD_FIRST: break; case TX_STATE_EVEN_FREE: tx_state[endpoint] = TX_STATE_BOTH_FREE_EVEN_FIRST; break; case TX_STATE_ODD_FREE: tx_state[endpoint] = TX_STATE_BOTH_FREE_ODD_FIRST; break; default: tx_state[endpoint] = ((uint32_t)b & 8) ? TX_STATE_ODD_FREE : TX_STATE_EVEN_FREE; break; } } } else { // receive packet->len = b->desc >> 16; packet->index = 0; packet->next = NULL; if (rx_first[endpoint] == NULL) { //serial_print("rx 1st, epidx="); //serial_phex(endpoint); //serial_print(", packet="); //serial_phex32((uint32_t)packet); //serial_print("\n"); rx_first[endpoint] = packet; } else { //serial_print("rx Nth, epidx="); //serial_phex(endpoint); //serial_print(", packet="); //serial_phex32((uint32_t)packet); //serial_print("\n"); rx_last[endpoint]->next = packet; } rx_last[endpoint] = packet; // TODO: implement a per-endpoint maximum # of allocated packets // so a flood of incoming data on 1 endpoint doesn't starve // the others if the user isn't reading it regularly packet = usb_malloc(); if (packet) { b->addr = packet->buf; b->desc = BDT_DESC(64, ((uint32_t)b & 8) ? DATA1 : DATA0); } else { //serial_print("starving "); //serial_phex(endpoint + 1); //serial_print(((uint32_t)b & 8) ? ",odd\n" : ",even\n"); b->desc = 0; usb_rx_memory_needed++; } } } USB0_ISTAT = USB_ISTAT_TOKDNE; goto restart; } if (status & USB_ISTAT_USBRST /* 01 */ ) { //serial_print("reset\n"); // initialize BDT toggle bits USB0_CTL = USB_CTL_ODDRST; ep0_tx_bdt_bank = 0; // set up buffers to receive Setup and OUT packets table[index(0, RX, EVEN)].desc = BDT_DESC(EP0_SIZE, 0); table[index(0, RX, EVEN)].addr = ep0_rx0_buf; table[index(0, RX, ODD)].desc = BDT_DESC(EP0_SIZE, 0); table[index(0, RX, ODD)].addr = ep0_rx1_buf; table[index(0, TX, EVEN)].desc = 0; table[index(0, TX, ODD)].desc = 0; // activate endpoint 0 USB0_ENDPT0 = USB_ENDPT_EPRXEN | USB_ENDPT_EPTXEN | USB_ENDPT_EPHSHK; // clear all ending interrupts USB0_ERRSTAT = 0xFF; USB0_ISTAT = 0xFF; // set the address to zero during enumeration USB0_ADDR = 0; // enable other interrupts USB0_ERREN = 0xFF; USB0_INTEN = USB_INTEN_TOKDNEEN | USB_INTEN_SOFTOKEN | USB_INTEN_STALLEN | USB_INTEN_ERROREN | USB_INTEN_USBRSTEN | USB_INTEN_SLEEPEN; // is this necessary? USB0_CTL = USB_CTL_USBENSOFEN; return; } if ((status & USB_ISTAT_STALL /* 80 */ )) { //serial_print("stall:\n"); USB0_ENDPT0 = USB_ENDPT_EPRXEN | USB_ENDPT_EPTXEN | USB_ENDPT_EPHSHK; USB0_ISTAT = USB_ISTAT_STALL; } if ((status & USB_ISTAT_ERROR /* 02 */ )) { uint8_t err = USB0_ERRSTAT; USB0_ERRSTAT = err; //serial_print("err:"); //serial_phex(err); //serial_print("\n"); USB0_ISTAT = USB_ISTAT_ERROR; } if ((status & USB_ISTAT_SLEEP /* 10 */ )) { //serial_print("sleep\n"); USB0_ISTAT = USB_ISTAT_SLEEP; } } void usb_init(void) { int i; //serial_begin(BAUD2DIV(115200)); //serial_print("usb_init\n"); for (i=0; i <= NUM_ENDPOINTS*4; i++) { table[i].desc = 0; table[i].addr = 0; } // this basically follows the flowchart in the Kinetis // Quick Reference User Guide, Rev. 1, 03/2012, page 141 // assume 48 MHz clock already running // SIM - enable clock SIM_SCGC4 |= SIM_SCGC4_USBOTG; // reset USB module USB0_USBTRC0 = USB_USBTRC_USBRESET; while ((USB0_USBTRC0 & USB_USBTRC_USBRESET) != 0) ; // wait for reset to end // set desc table base addr USB0_BDTPAGE1 = ((uint32_t)table) >> 8; USB0_BDTPAGE2 = ((uint32_t)table) >> 16; USB0_BDTPAGE3 = ((uint32_t)table) >> 24; // clear all ISR flags USB0_ISTAT = 0xFF; USB0_ERRSTAT = 0xFF; USB0_OTGISTAT = 0xFF; USB0_USBTRC0 |= 0x40; // undocumented bit // enable USB USB0_CTL = USB_CTL_USBENSOFEN; USB0_USBCTRL = 0; // enable reset interrupt USB0_INTEN = USB_INTEN_USBRSTEN; // enable interrupt in NVIC... NVIC_ENABLE_IRQ(IRQ_USBOTG); // enable d+ pullup USB0_CONTROL = USB_CONTROL_DPPULLUPNONOTG; } // return 0 if the USB is not configured, or the configuration // number selected by the HOST uint8_t usb_configured(void) { return usb_configuration; }