/*
* Fadecandy firmware
* Copyright (c) 2013 Micah Elizabeth Scott
*
* Teensyduino Core Library
* http://www.pjrc.com/teensy/
* Copyright (c) 2013 PJRC.COM, LLC.
*
* 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:
*
* 1. The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* 2. If the Software is incorporated into a build system that allows
* selection among a list of target devices, then similar target
* devices manufactured by PJRC.COM must be included in the list of
* target devices and selectable in the same manner.
*
* 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 "mk20dx128.h"
#include "usb_dev.h"
#include "usb_mem.h"
#include "usb_desc.h"
// buffer descriptor table
typedef struct {
uint32_t desc;
void * addr;
} bdt_t;
__attribute__ ((section(".usbdescriptortable"), used))
static bdt_t table[(NUM_ENDPOINTS+1)*4];
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];
uint16_t usb_rx_byte_count_data[NUM_ENDPOINTS];
static uint8_t reply_buffer[8];
// Performance counters
volatile uint32_t perf_frameCounter;
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_EVEN_FIRST 4
#define TX_STATE_NONE_FREE_ODD_FIRST 5
#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 uint8_t ep0_tx0_buf[EP0_SIZE] __attribute__ ((aligned (4)));
static uint8_t ep0_tx1_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_dfu_state = DFU_appIDLE;
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)
{
// Use a local transmit buffer pair in RAM, and copy in the source data (usually decriptors).
// We can't reliably serve USB data from flash apparently, and this is a little more RAM
// efficient than keeping all descriptors in RAM.
uint8_t *buffer = ep0_tx_bdt_bank ? ep0_tx1_buf : ep0_tx0_buf;
uint32_t count = len;
while (count--) {
*buffer = *(const uint8_t*)data;
data++;
buffer++;
}
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 void usb_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
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));
}
}
// free all queued packets
for (i=0; i < NUM_ENDPOINTS; i++) {
usb_packet_t *p, *n;
p = rx_first[i];
while (p) {
n = p->next;
usb_free(p);
p = n;
}
rx_first[i] = NULL;
rx_last[i] = NULL;
p = tx_first[i];
while (p) {
n = p->next;
usb_free(p);
p = n;
}
tx_first[i] = NULL;
tx_last[i] = NULL;
usb_rx_byte_count_data[i] = 0;
switch (tx_state[i]) {
case TX_STATE_EVEN_FREE:
case TX_STATE_NONE_FREE_EVEN_FIRST:
tx_state[i] = TX_STATE_BOTH_FREE_EVEN_FIRST;
break;
case TX_STATE_ODD_FREE:
case TX_STATE_NONE_FREE_ODD_FIRST:
tx_state[i] = TX_STATE_BOTH_FREE_ODD_FIRST;
break;
default:
break;
}
}
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) {
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) {
endpoint0_stall();
return;
}
(*(uint8_t *)(&USB0_ENDPT0 + setup.wIndex * 4)) &= ~0x02;
break;
case 0x0302: // SET_FEATURE (endpoint)
i = setup.wIndex & 0x7F;
if (i > NUM_ENDPOINTS || setup.wValue != 0) {
endpoint0_stall();
return;
}
(*(uint8_t *)(&USB0_ENDPT0 + setup.wIndex * 4)) |= 0x02;
break;
case 0x0680: // GET_DESCRIPTOR
case 0x0681:
for (list = usb_descriptor_list; 1; list++) {
if (list->addr == NULL) break;
if (setup.wValue == list->wValue) {
data = list->addr;
if ((setup.wValue >> 8) == 3) {
// for string descriptors, use the descriptor's
// length field, allowing runtime configured
// length.
datalen = *(list->addr);
} else {
datalen = list->length;
}
goto send;
}
}
endpoint0_stall();
return;
case 0x01C0: // Read frame counter
case 0x01C1:
data = (uint8_t*) &perf_frameCounter;
datalen = sizeof perf_frameCounter;
break;
case (MSFT_VENDOR_CODE << 8) | 0xC0: // Get Microsoft descriptor
case (MSFT_VENDOR_CODE << 8) | 0xC1:
if (setup.wIndex == 0x0004) {
// Return WCID descriptor
data = usb_microsoft_wcid;
datalen = usb_microsoft_wcid[0];
break;
} else if (setup.wIndex == 0x0005) {
// Return Extended Properties descriptor
data = usb_microsoft_extprop;
datalen = usb_microsoft_extprop[0];
break;
}
endpoint0_stall();
return;
case 0x03a1: // DFU_GETSTATUS
if (setup.wIndex != DFU_INTERFACE) {
endpoint0_stall();
return;
}
reply_buffer[0] = 0; // bStatus = OK
reply_buffer[1] = 1; // bwPollTimeout LSB = 1
reply_buffer[2] = 0; // bwPollTimeout
reply_buffer[3] = 0; // bwPollTimeout
reply_buffer[4] = usb_dfu_state;
reply_buffer[5] = 0; // iString = 0
data = reply_buffer;
datalen = 6;
break;
case 0x05a1: // DFU_GETSTATE
if (setup.wIndex != DFU_INTERFACE) {
endpoint0_stall();
return;
}
reply_buffer[0] = usb_dfu_state;
data = reply_buffer;
datalen = 1;
break;
case 0x0021: // DFU_DETACH
if (setup.wIndex != DFU_INTERFACE) {
endpoint0_stall();
return;
}
usb_dfu_state = DFU_appDETACH;
break;
default:
endpoint0_stall();
return;
}
send:
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);
buf = b->addr;
switch (pid) {
case 0x0D: // Setup received from host
// 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);
// clear any leftover pending IN transactions
ep0_tx_ptr = NULL;
// first IN after Setup is always DATA1
ep0_tx_data_toggle = 1;
// actually "do" the setup request
usb_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
// give the buffer back
b->desc = BDT_DESC(EP0_SIZE, DATA1);
break;
case 0x09: // IN transaction completed to host
// 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;
USB0_ADDR = setup.wValue;
}
break;
}
USB0_CTL = USB_CTL_USBENSOFEN; // clear TXSUSPENDTOKENBUSY bit
}
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;
usb_rx_byte_count_data[endpoint] -= ret->len;
__enable_irq();
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;
}
// TODO: make this an inline function...
/*
uint32_t usb_rx_byte_count(uint32_t endpoint)
{
endpoint--;
if (endpoint >= NUM_ENDPOINTS) return 0;
return usb_rx_byte_count_data[endpoint];
//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;
__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();
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();
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();
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_ODD_FIRST;
break;
case TX_STATE_ODD_FREE:
b++;
next = TX_STATE_NONE_FREE_EVEN_FIRST;
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_isr(void)
{
uint8_t status, stat;
restart:
status = USB0_ISTAT;
if ((status & USB_INTEN_SOFTOKEN /* 04 */ )) {
USB0_ISTAT = USB_INTEN_SOFTOKEN;
}
if ((status & USB_ISTAT_TOKDNE /* 08 */ )) {
uint8_t endpoint;
stat = USB0_STAT;
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);
endpoint--; // endpoint is index to zero-based arrays
if (stat & 0x08) { // transmit
usb_free(packet);
packet = tx_first[endpoint];
if (packet) {
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:
tx_state[endpoint] = TX_STATE_NONE_FREE_ODD_FIRST;
break;
case TX_STATE_ODD_FREE:
tx_state[endpoint] = TX_STATE_NONE_FREE_EVEN_FIRST;
break;
default:
break;
}
b->desc = BDT_DESC(packet->len, ((uint32_t)b & 8) ? DATA1 : DATA0);
} else {
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;
if (packet->len > 0) {
packet->next = NULL;
if (rx_first[endpoint] == NULL) {
rx_first[endpoint] = packet;
} else {
rx_last[endpoint]->next = packet;
}
rx_last[endpoint] = packet;
usb_rx_byte_count_data[endpoint] += packet->len;
// 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 {
b->desc = 0;
usb_rx_memory_needed++;
}
} else {
b->desc = BDT_DESC(64, ((uint32_t)b & 8) ? DATA1 : DATA0);
}
}
}
USB0_ISTAT = USB_ISTAT_TOKDNE;
goto restart;
}
if (status & USB_ISTAT_USBRST /* 01 */ ) {
// 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, EVEN)].addr = ep0_tx0_buf;
table[index(0, TX, ODD)].desc = 0;
table[index(0, TX, ODD)].addr = ep0_tx1_buf;
// 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 */ )) {
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;
USB0_ISTAT = USB_ISTAT_ERROR;
}
if ((status & USB_ISTAT_SLEEP /* 10 */ )) {
USB0_ISTAT = USB_ISTAT_SLEEP;
}
}
void usb_init(void)
{
int i;
usb_init_serialnumber();
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;
}