teensy-cores/usb_serial/usb.c

/* USB Serial for Teensy USB Development Board
 * http://www.pjrc.com/teensy/
 * Copyright (c) 2008 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:
 * 
 * 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 "usb_common.h"
#include "usb_private.h"


/**************************************************************************
 *
 *  Endpoint Buffer Configuration
 *
 **************************************************************************/


static const uint8_t PROGMEM endpoint_config_table[] = {
	0,
	1, EP_TYPE_INTERRUPT_IN,  EP_SIZE(CDC_ACM_SIZE) | CDC_ACM_BUFFER,
	1, EP_TYPE_BULK_OUT,      EP_SIZE(CDC_RX_SIZE) | CDC_RX_BUFFER,
	1, EP_TYPE_BULK_IN,       EP_SIZE(CDC_TX_SIZE) | CDC_TX_BUFFER
};


/**************************************************************************
 *
 *  Descriptor Data
 *
 **************************************************************************/

// Descriptors are the data that your computer reads when it auto-detects
// this USB device (called "enumeration" in USB lingo).  The most commonly
// changed items are editable at the top of this file.  Changing things
// in here should only be done by those who've read chapter 9 of the USB
// spec and relevant portions of any USB class specifications!

static const uint8_t PROGMEM device_descriptor[] = {
	18,					// bLength
	1,					// bDescriptorType
	0x00, 0x02,				// bcdUSB
	2,					// bDeviceClass
	0,					// bDeviceSubClass
	0,					// bDeviceProtocol
	ENDPOINT0_SIZE,				// bMaxPacketSize0
	LSB(VENDOR_ID), MSB(VENDOR_ID),		// idVendor
	LSB(PRODUCT_ID), MSB(PRODUCT_ID),	// idProduct
#if defined(__AVR_ATmega32U4__)
	0x71, 0x02,
#elif defined(__AVR_AT90USB1286__)
	0x72, 0x02,
#else
	0x00, 0x01,				// bcdDevice
#endif
	1,					// iManufacturer
	2,					// iProduct
	3,					// iSerialNumber
	1					// bNumConfigurations
};

#define CONFIG1_DESC_SIZE (9+9+5+5+4+5+7+9+7+7)
static const uint8_t PROGMEM config1_descriptor[CONFIG1_DESC_SIZE] = {
	// configuration descriptor, USB spec 9.6.3, page 264-266, Table 9-10
	9, 					// bLength;
	2,					// bDescriptorType;
	LSB(CONFIG1_DESC_SIZE),			// wTotalLength
	MSB(CONFIG1_DESC_SIZE),
	2,					// bNumInterfaces
	1,					// bConfigurationValue
	0,					// iConfiguration
	0xC0,					// bmAttributes
	50,					// bMaxPower
	// interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
	9,					// bLength
	4,					// bDescriptorType
	0,					// bInterfaceNumber
	0,					// bAlternateSetting
	1,					// bNumEndpoints
	0x02,					// bInterfaceClass
	0x02,					// bInterfaceSubClass
	0x01,					// bInterfaceProtocol
	0,					// iInterface
	// CDC Header Functional Descriptor, CDC Spec 5.2.3.1, Table 26
	5,					// bFunctionLength
	0x24,					// bDescriptorType
	0x00,					// bDescriptorSubtype
	0x10, 0x01,				// bcdCDC
	// Call Management Functional Descriptor, CDC Spec 5.2.3.2, Table 27
	5,					// bFunctionLength
	0x24,					// bDescriptorType
	0x01,					// bDescriptorSubtype
	0x00,					// bmCapabilities
	1,					// bDataInterface
	// Abstract Control Management Functional Descriptor, CDC Spec 5.2.3.3, Table 28
	4,					// bFunctionLength
	0x24,					// bDescriptorType
	0x02,					// bDescriptorSubtype
	0x06,					// bmCapabilities
	// Union Functional Descriptor, CDC Spec 5.2.3.8, Table 33
	5,					// bFunctionLength
	0x24,					// bDescriptorType
	0x06,					// bDescriptorSubtype
	0,					// bMasterInterface
	1,					// bSlaveInterface0
	// endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
	7,					// bLength
	5,					// bDescriptorType
	CDC_ACM_ENDPOINT | 0x80,		// bEndpointAddress
	0x03,					// bmAttributes (0x03=intr)
	CDC_ACM_SIZE, 0,			// wMaxPacketSize
	64,					// bInterval
	// interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
	9,					// bLength
	4,					// bDescriptorType
	1,					// bInterfaceNumber
	0,					// bAlternateSetting
	2,					// bNumEndpoints
	0x0A,					// bInterfaceClass
	0x00,					// bInterfaceSubClass
	0x00,					// bInterfaceProtocol
	0,					// iInterface
	// endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
	7,					// bLength
	5,					// bDescriptorType
	CDC_RX_ENDPOINT,			// bEndpointAddress
	0x02,					// bmAttributes (0x02=bulk)
	CDC_RX_SIZE, 0,				// wMaxPacketSize
	0,					// bInterval
	// endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
	7,					// bLength
	5,					// bDescriptorType
	CDC_TX_ENDPOINT | 0x80,			// bEndpointAddress
	0x02,					// bmAttributes (0x02=bulk)
	CDC_TX_SIZE, 0,				// wMaxPacketSize
	0					// bInterval
};

// If you're desperate for a little extra code memory, these strings
// can be completely removed if iManufacturer, iProduct, iSerialNumber
// in the device desciptor are changed to zeros.
struct usb_string_descriptor_struct {
	uint8_t bLength;
	uint8_t bDescriptorType;
	int16_t wString[];
};
static const struct usb_string_descriptor_struct PROGMEM string0 = {
	4,
	3,
	{0x0409}
};
static const struct usb_string_descriptor_struct PROGMEM string1 = {
	sizeof(STR_MANUFACTURER),
	3,
	STR_MANUFACTURER
};
static const struct usb_string_descriptor_struct PROGMEM string2 = {
	sizeof(STR_PRODUCT),
	3,
	STR_PRODUCT
};
static const struct usb_string_descriptor_struct PROGMEM string3 = {
	sizeof(STR_SERIAL_NUMBER),
	3,
	STR_SERIAL_NUMBER
};

// This table defines which descriptor data is sent for each specific
// request from the host (in wValue and wIndex).
static const struct descriptor_list_struct {
	uint16_t	wValue;
	uint16_t	wIndex;
	const uint8_t	*addr;
	uint8_t		length;
} PROGMEM descriptor_list[] = {
	{0x0100, 0x0000, device_descriptor, sizeof(device_descriptor)},
	{0x0200, 0x0000, config1_descriptor, sizeof(config1_descriptor)},
	{0x0300, 0x0000, (const uint8_t *)&string0, 4},
	{0x0301, 0x0409, (const uint8_t *)&string1, sizeof(STR_MANUFACTURER)},
	{0x0302, 0x0409, (const uint8_t *)&string2, sizeof(STR_PRODUCT)},
	{0x0303, 0x0409, (const uint8_t *)&string3, sizeof(STR_SERIAL_NUMBER)}
};
#define NUM_DESC_LIST (sizeof(descriptor_list)/sizeof(struct descriptor_list_struct))


/**************************************************************************
 *
 *  Variables - these are the only non-stack RAM usage
 *
 **************************************************************************/

// zero when we are not configured, non-zero when enumerated
volatile uint8_t usb_configuration USBSTATE;
volatile uint8_t usb_suspended USBSTATE;

// the time remaining before we transmit any partially full
// packet, or send a zero length packet.
volatile uint8_t transmit_flush_timer=0;
volatile uint8_t reboot_timer=0;
uint8_t transmit_previous_timeout=0;

// serial port settings (baud rate, control signals, etc) set
// by the PC.  These are ignored, but kept in RAM because the
// CDC spec requires a read that returns the current settings.
volatile uint8_t cdc_line_coding[7]={0x00, 0xE1, 0x00, 0x00, 0x00, 0x00, 0x08};
volatile uint8_t cdc_line_rtsdtr USBSTATE;


/**************************************************************************
 *
 *  Public Functions - these are the API intended for the user
 *
 **************************************************************************/


// initialize USB serial
void usb_init(void)
{
	uint8_t u;

	u = USBCON;
	if ((u & (1<<USBE)) && !(u & (1<<FRZCLK))) return;
	HW_CONFIG();
        USB_FREEZE();				// enable USB
        PLL_CONFIG();				// config PLL
        while (!(PLLCSR & (1<<PLOCK))) ;	// wait for PLL lock
        USB_CONFIG();				// start USB clock
        UDCON = 0;				// enable attach resistor
	usb_configuration = 0;
	usb_suspended = 0;
	cdc_line_rtsdtr = 0;
	UDINT = 0;
        UDIEN = (1<<EORSTE)|(1<<SOFE)|(1<<SUSPE);
}


void usb_shutdown(void)
{
	UDIEN = 0;	// disable interrupts
	UDCON = 1;	// disconnect attach resistor
	USBCON = 0;	// shut off USB periperal
	PLLCSR = 0;	// shut off PLL
	usb_configuration = 0;
	usb_suspended = 1;
}


// Public API functions moved to usb_api.cpp

/**************************************************************************
 *
 *  Private Functions - not intended for general user consumption....
 *
 **************************************************************************/


// USB Device Interrupt - handle all device-level events
// the transmit buffer flushing is triggered by the start of frame
//
ISR(USB_GEN_vect)
{
	uint8_t intbits, t;

        intbits = UDINT;
        UDINT = 0;
        if (intbits & (1<<EORSTI)) {
		// USB Reset
		UENUM = 0;
		UECONX = 1;
		UECFG0X = EP_TYPE_CONTROL;
		UECFG1X = EP_SIZE(ENDPOINT0_SIZE) | EP_SINGLE_BUFFER;
		UEIENX = (1<<RXSTPE);
		usb_configuration = 0;
		cdc_line_rtsdtr = 0;
	}
	if (intbits & (1<<SOFI)) {
		// Start Of Frame
		if (usb_configuration) {
			t = transmit_flush_timer;
			if (t) {
				transmit_flush_timer = --t;
				if (!t) {
					UENUM = CDC_TX_ENDPOINT;
					UEINTX = 0x3A;
				}
			}
			t = reboot_timer;
			if (t) {
				reboot_timer = --t;
				if (!t) _reboot_Teensyduino_();
			}
		}
	}
	// in active state
	if (intbits & (1<<SUSPI)) {
		// USB Suspend (inactivity for 3ms)
		UDIEN = (1<<WAKEUPE);
		usb_configuration = 0;
		usb_suspended = 1;
		#if (F_CPU >= 8000000L)
		// WAKEUPI does not work with USB clock freeze 
		// when CPU is running less than 8 MHz.
		// Is this a hardware bug?
		USB_FREEZE();			// shut off USB
		PLLCSR = 0;			// shut off PLL
		#endif
		// to properly meet the USB spec, current must
		// reduce to less than 2.5 mA, which means using
		// powerdown mode, but that breaks the Arduino
		// user's paradigm....
	}
	if (usb_suspended && (intbits & (1<<WAKEUPI))) {
		// USB Resume (pretty much any activity)
		#if (F_CPU >= 8000000L)
		PLL_CONFIG();
		while (!(PLLCSR & (1<<PLOCK))) ;
		USB_CONFIG();
		#endif
		UDIEN = (1<<EORSTE)|(1<<SOFE)|(1<<SUSPE);
		usb_suspended = 0;
		return;
	}
}


// Misc functions to wait for ready and send/receive packets
static inline void usb_wait_in_ready(void)
{
	while (!(UEINTX & (1<<TXINI))) ;
}
static inline void usb_send_in(void)
{
	UEINTX = ~(1<<TXINI);
}
static inline void usb_wait_receive_out(void)
{
	while (!(UEINTX & (1<<RXOUTI))) ;
}
static inline void usb_ack_out(void)
{
	UEINTX = ~(1<<RXOUTI);
}



// USB Endpoint Interrupt - endpoint 0 is handled here.  The
// other endpoints are manipulated by the user-callable
// functions, and the start-of-frame interrupt.
//
ISR(USB_COM_vect)
{
        uint8_t intbits;
	const uint8_t *list;
        const uint8_t *cfg;
	uint8_t i, n, len, en;
	volatile uint8_t *p;
	uint8_t bmRequestType;
	uint8_t bRequest;
	uint16_t wValue;
	uint16_t wIndex;
	uint16_t wLength;
	uint16_t desc_val;
	uint32_t baud;
	const uint8_t *desc_addr;
	uint8_t	desc_length;

	UENUM = 0;
	intbits = UEINTX;
	if (intbits & (1<<RXSTPI)) {
		bmRequestType = UEDATX;
		bRequest = UEDATX;
		//wValue = UEDATX;
		//wValue |= (UEDATX << 8);
		read_word_lsbfirst(wValue, UEDATX);
		//wIndex = UEDATX;
		//wIndex |= (UEDATX << 8);
		read_word_lsbfirst(wIndex, UEDATX);
		//wLength = UEDATX;
		//wLength |= (UEDATX << 8);
		read_word_lsbfirst(wLength, UEDATX);
                UEINTX = ~((1<<RXSTPI) | (1<<RXOUTI) | (1<<TXINI));
                if (bRequest == GET_DESCRIPTOR) {
			list = (const uint8_t *)descriptor_list;
			for (i=0; ; i++) {
				if (i >= NUM_DESC_LIST) {
					UECONX = (1<<STALLRQ)|(1<<EPEN);  //stall
					return;
				}
				//desc_val = pgm_read_word(list);
				//list += 2;
				pgm_read_word_postinc(desc_val, list);
				if (desc_val != wValue) {
					list += sizeof(struct descriptor_list_struct)-2;
					continue;
				}
				//desc_val = pgm_read_word(list);
				//list += 2;
				pgm_read_word_postinc(desc_val, list);
				if (desc_val != wIndex) {
					list += sizeof(struct descriptor_list_struct)-4;
					continue;
				}
				//desc_addr = (const uint8_t *)pgm_read_word(list);
				//list += 2;
				pgm_read_word_postinc(desc_addr, list);
				desc_length = pgm_read_byte(list);
				break;
			}
			len = (wLength < 256) ? wLength : 255;
			if (len > desc_length) len = desc_length;
			list = desc_addr;
			do {
				// wait for host ready for IN packet
				do {
					i = UEINTX;
				} while (!(i & ((1<<TXINI)|(1<<RXOUTI))));
				if (i & (1<<RXOUTI)) return;	// abort
				// send IN packet
				n = len < ENDPOINT0_SIZE ? len : ENDPOINT0_SIZE;
				for (i = n; i; i--) {
					//UEDATX = pgm_read_byte(desc_addr++);
					//pgm_read_byte_postinc(UEDATX, desc_addr);
					pgm_read_byte_postinc(UEDATX, list);
				}
				len -= n;
				usb_send_in();
			} while (len || n == ENDPOINT0_SIZE);
			return;
                }
		if (bRequest == SET_ADDRESS) {
			usb_send_in();
			usb_wait_in_ready();
			UDADDR = wValue | (1<<ADDEN);
			return;
		}
		if (bRequest == SET_CONFIGURATION && bmRequestType == 0) {
			usb_configuration = wValue;
			cdc_line_rtsdtr = 0;
			transmit_flush_timer = 0;
			usb_send_in();
			cfg = endpoint_config_table;
			for (i=1; i<5; i++) {
				UENUM = i;
				//en = pgm_read_byte(cfg++);
				pgm_read_byte_postinc(en, cfg);
				UECONX = en;
				if (en) {
					//UECFG0X = pgm_read_byte(cfg++);
					//UECFG1X = pgm_read_byte(cfg++);
					pgm_read_byte_postinc(UECFG0X, cfg);
					pgm_read_byte_postinc(UECFG1X, cfg);
				}
			}
        		UERST = 0x1E;
        		UERST = 0;
			return;
		}
		if (bRequest == GET_CONFIGURATION && bmRequestType == 0x80) {
			usb_wait_in_ready();
			UEDATX = usb_configuration;
			usb_send_in();
			return;
		}
		if (bRequest == CDC_GET_LINE_CODING /* 0x21 */ && bmRequestType == 0xA1) {
			usb_wait_in_ready();
			p = cdc_line_coding;
			for (i=0; i<7; i++) {
				UEDATX = *p++;
			}
			usb_send_in();
			return;
		}
		if (bRequest == CDC_SET_LINE_CODING /* 0x20 */ && bmRequestType == 0x21) {
			usb_wait_receive_out();
			p = cdc_line_coding;
			for (i=0; i<7; i++) {
				*p++ = UEDATX;
			}
			usb_ack_out();
			usb_send_in();
			baud = (uint32_t)cdc_line_coding[0]
				| ((uint32_t)cdc_line_coding[1] << 8)
				| ((uint32_t)cdc_line_coding[2] << 16)
				| ((uint32_t)cdc_line_coding[3] << 24);
			if (baud == 134UL) reboot_timer = 15;
			if (baud == 150UL) {
				UENUM = CDC_TX_ENDPOINT;
				while (UESTA0X & 0x03) {
					UEINTX = 0xFF;
					while (UEINTX & 0x04) /* TODO: timeout? */ ;
				}
				_restart_Teensyduino_();
			}
			return;
		}
		if (bRequest == CDC_SET_CONTROL_LINE_STATE /* 0x22 */ && bmRequestType == 0x21) {
			cdc_line_rtsdtr = wValue;
			usb_wait_in_ready();
			usb_send_in();
			return;
		}
		if (bRequest == CDC_SEND_BREAK /* 0x23 */ && bmRequestType == 0x21) {
			usb_wait_in_ready();
			usb_send_in();
			return;
		}
		if (bRequest == GET_STATUS) {
			usb_wait_in_ready();
			i = 0;
			if (bmRequestType == 0x82) {
				UENUM = wIndex;
				if (UECONX & (1<<STALLRQ)) i = 1;
				UENUM = 0;
			}
			UEDATX = i;
			UEDATX = 0;
			usb_send_in();
			return;
		}
		if ((bRequest == CLEAR_FEATURE || bRequest == SET_FEATURE)
		  && bmRequestType == 0x02 && wValue == 0) {
			i = wIndex & 0x7F;
			if (i >= 1 && i <= MAX_ENDPOINT) {
				usb_send_in();
				UENUM = i;
				if (bRequest == SET_FEATURE) {
					UECONX = (1<<STALLRQ)|(1<<EPEN);
				} else {
					UECONX = (1<<STALLRQC)|(1<<RSTDT)|(1<<EPEN);
					UERST = (1 << i);
					UERST = 0;
				}
				return;
			}
		}
        }
	UECONX = (1<<STALLRQ) | (1<<EPEN);	// stall
}