--- /dev/null
+/* vim: set sts=4:sw=4:ts=4:noexpandtab
+ *
+ * USB Serial Example for Teensy USB Development Board
+ * http://www.pjrc.com/teensy/usb_serial.html
+ * Copyright (c) 2008,2010,2011 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.
+ */
+
+// Version 1.0: Initial Release
+// Version 1.1: support Teensy++
+// Version 1.2: fixed usb_serial_available
+// Version 1.3: added transmit bandwidth test
+// Version 1.4: added usb_serial_write
+// Version 1.5: add support for Teensy 2.0
+// Version 1.6: fix zero length packet bug
+// Version 1.7: fix usb_serial_set_control
+
+#define USB_SERIAL_PRIVATE_INCLUDE
+#include "at90usb162_cdc_loopback.h"
+
+/**************************************************************************
+ *
+ * Configurable Options
+ *
+ **************************************************************************/
+
+// You can change these to give your code its own name. On Windows,
+// these are only used before an INF file (driver install) is loaded.
+#define STR_MANUFACTURER L"Your Name"
+#define STR_PRODUCT L"USB Serial"
+
+// All USB serial devices are supposed to have a serial number
+// (according to Microsoft). On windows, a new COM port is created
+// for every unique serial/vendor/product number combination. If
+// you program 2 identical boards with 2 different serial numbers
+// and they are assigned COM7 and COM8, each will always get the
+// same COM port number because Windows remembers serial numbers.
+//
+// On Mac OS-X, a device file is created automatically which
+// incorperates the serial number, eg, /dev/cu-usbmodem12341
+//
+// Linux by default ignores the serial number, and creates device
+// files named /dev/ttyACM0, /dev/ttyACM1... in the order connected.
+// Udev rules (in /etc/udev/rules.d) can define persistent device
+// names linked to this serial number, as well as permissions, owner
+// and group settings.
+#define STR_SERIAL_NUMBER L"12345"
+
+// Mac OS-X and Linux automatically load the correct drivers. On
+// Windows, even though the driver is supplied by Microsoft, an
+// INF file is needed to load the driver. These numbers need to
+// match the INF file.
+#define VENDOR_ID 0x16C0
+#define PRODUCT_ID 0x047A
+
+// When you write data, it goes into a USB endpoint buffer, which
+// is transmitted to the PC when it becomes full, or after a timeout
+// with no more writes. Even if you write in exactly packet-size
+// increments, this timeout is used to send a "zero length packet"
+// that tells the PC no more data is expected and it should pass
+// any buffered data to the application that may be waiting. If
+// you want data sent immediately, call usb_serial_flush_output().
+#define TRANSMIT_FLUSH_TIMEOUT 5 /* in milliseconds */
+
+// If the PC is connected but not "listening", this is the length
+// of time before usb_serial_getchar() returns with an error. This
+// is roughly equivilant to a real UART simply transmitting the
+// bits on a wire where nobody is listening, except you get an error
+// code which you can ignore for serial-like discard of data, or
+// use to know your data wasn't sent.
+#define TRANSMIT_TIMEOUT 25 /* in milliseconds */
+
+// USB devices are supposed to implment a halt feature, which is
+// rarely (if ever) used. If you comment this line out, the halt
+// code will be removed, saving 116 bytes of space (gcc 4.3.0).
+// This is not strictly USB compliant, but works with all major
+// operating systems.
+#define SUPPORT_ENDPOINT_HALT
+
+
+
+/**************************************************************************
+ *
+ * Endpoint Buffer Configuration
+ *
+ **************************************************************************/
+
+// These buffer sizes are best for most applications, but perhaps if you
+// want more buffering on some endpoint at the expense of others, this
+// is where you can make such changes. The AT90USB162 has only 176 bytes
+// of DPRAM (USB buffers) and only endpoints 3 & 4 can double buffer.
+
+#define ENDPOINT0_SIZE 16
+#define CDC_ACM_ENDPOINT 2
+#define CDC_RX_ENDPOINT 3
+#define CDC_TX_ENDPOINT 4
+#if defined(__AVR_AT90USB162__)
+#define CDC_ACM_SIZE 16
+#define CDC_ACM_BUFFER EP_SINGLE_BUFFER
+#define CDC_RX_SIZE 32
+#define CDC_RX_BUFFER EP_DOUBLE_BUFFER
+#define CDC_TX_SIZE 32
+#define CDC_TX_BUFFER EP_DOUBLE_BUFFER
+#else
+#define CDC_ACM_SIZE 16
+#define CDC_ACM_BUFFER EP_SINGLE_BUFFER
+#define CDC_RX_SIZE 64
+#define CDC_RX_BUFFER EP_DOUBLE_BUFFER
+#define CDC_TX_SIZE 64
+#define CDC_TX_BUFFER EP_DOUBLE_BUFFER
+#endif
+
+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 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
+ 0x00, 0x01, // bcdDevice
+ 1, // iManufacturer
+ 2, // iProduct
+ 3, // iSerialNumber
+ 1 // bNumConfigurations
+};
+
+#define CONFIG1_DESC_SIZE (9+9+5+5+4+5+7+9+7+7)
+static 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
+ 0x01, // 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 struct usb_string_descriptor_struct PROGMEM string0 = {
+ 4,
+ 3,
+ {0x0409}
+};
+static struct usb_string_descriptor_struct PROGMEM string1 = {
+ sizeof(STR_MANUFACTURER),
+ 3,
+ STR_MANUFACTURER
+};
+static struct usb_string_descriptor_struct PROGMEM string2 = {
+ sizeof(STR_PRODUCT),
+ 3,
+ STR_PRODUCT
+};
+static 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 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
+static volatile uint8_t usb_configuration=0;
+
+// the time remaining before we transmit any partially full
+// packet, or send a zero length packet.
+static volatile uint8_t transmit_flush_timer=0;
+static 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.
+static uint8_t cdc_line_coding[7]={0x00, 0xE1, 0x00, 0x00, 0x00, 0x00, 0x08};
+static uint8_t cdc_line_rtsdtr=0;
+
+
+/**************************************************************************
+ *
+ * Public Functions - these are the API intended for the user
+ *
+ **************************************************************************/
+
+// initialize USB serial
+void usb_init(void)
+{
+ sei();
+ HW_CONFIG();
+ USB_FREEZE(); // enable USB
+ PLL_CONFIG(); // config PLL, 16 MHz xtal
+ while (!(PLLCSR & (1<<PLOCK))) ; // wait for PLL lock
+ USB_CONFIG(); // start USB clock
+ UDCON = 0; // enable attach resistor
+ usb_configuration = 0;
+ cdc_line_rtsdtr = 0;
+ UDIEN = (1<<EORSTE)|(1<<SOFE);
+}
+
+// return 0 if the USB is not configured, or the configuration
+// number selected by the HOST
+uint8_t usb_configured(void)
+{
+ return usb_configuration;
+}
+
+// get the next character, or -1 if nothing received
+int16_t usb_serial_getchar(void)
+{
+ uint8_t c, intr_state;
+
+ // interrupts are disabled so these functions can be
+ // used from the main program or interrupt context,
+ // even both in the same program!
+ intr_state = SREG;
+ cli();
+ if (!usb_configuration) {
+ SREG = intr_state;
+ return -1;
+ }
+ UENUM = CDC_RX_ENDPOINT;
+ retry:
+ c = UEINTX;
+ if (!(c & (1<<RWAL))) {
+ // no data in buffer
+ if (c & (1<<RXOUTI)) {
+ UEINTX = 0x6B;
+ goto retry;
+ }
+ SREG = intr_state;
+ return -1;
+ }
+ // take one byte out of the buffer
+ c = UEDATX;
+ // if buffer completely used, release it
+ if (!(UEINTX & (1<<RWAL))) UEINTX = 0x6B;
+ SREG = intr_state;
+ return c;
+}
+
+// number of bytes available in the receive buffer
+uint8_t usb_serial_available(void)
+{
+ uint8_t n=0, i, intr_state;
+
+ intr_state = SREG;
+ cli();
+ if (usb_configuration) {
+ UENUM = CDC_RX_ENDPOINT;
+ n = UEBCLX;
+ if (!n) {
+ i = UEINTX;
+ if (i & (1<<RXOUTI) && !(i & (1<<RWAL))) UEINTX = 0x6B;
+ }
+ }
+ SREG = intr_state;
+ return n;
+}
+
+// discard any buffered input
+void usb_serial_flush_input(void)
+{
+ uint8_t intr_state;
+
+ if (usb_configuration) {
+ intr_state = SREG;
+ cli();
+ UENUM = CDC_RX_ENDPOINT;
+ while ((UEINTX & (1<<RWAL))) {
+ UEINTX = 0x6B;
+ }
+ SREG = intr_state;
+ }
+}
+
+// transmit a character. 0 returned on success, -1 on error
+int8_t usb_serial_putchar(uint8_t c)
+{
+ uint8_t timeout, intr_state;
+
+ // if we're not online (enumerated and configured), error
+ if (!usb_configuration) return -1;
+ // interrupts are disabled so these functions can be
+ // used from the main program or interrupt context,
+ // even both in the same program!
+ intr_state = SREG;
+ cli();
+ UENUM = CDC_TX_ENDPOINT;
+ // if we gave up due to timeout before, don't wait again
+ if (transmit_previous_timeout) {
+ if (!(UEINTX & (1<<RWAL))) {
+ SREG = intr_state;
+ return -1;
+ }
+ transmit_previous_timeout = 0;
+ }
+ // wait for the FIFO to be ready to accept data
+ timeout = UDFNUML + TRANSMIT_TIMEOUT;
+ while (1) {
+ // are we ready to transmit?
+ if (UEINTX & (1<<RWAL)) break;
+ SREG = intr_state;
+ // have we waited too long? This happens if the user
+ // is not running an application that is listening
+ if (UDFNUML == timeout) {
+ transmit_previous_timeout = 1;
+ return -1;
+ }
+ // has the USB gone offline?
+ if (!usb_configuration) return -1;
+ // get ready to try checking again
+ intr_state = SREG;
+ cli();
+ UENUM = CDC_TX_ENDPOINT;
+ }
+ // actually write the byte into the FIFO
+ UEDATX = c;
+ // if this completed a packet, transmit it now!
+ if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
+ transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
+ SREG = intr_state;
+ return 0;
+}
+
+
+// transmit a character, but do not wait if the buffer is full,
+// 0 returned on success, -1 on buffer full or error
+int8_t usb_serial_putchar_nowait(uint8_t c)
+{
+ uint8_t intr_state;
+
+ if (!usb_configuration) return -1;
+ intr_state = SREG;
+ cli();
+ UENUM = CDC_TX_ENDPOINT;
+ if (!(UEINTX & (1<<RWAL))) {
+ // buffer is full
+ SREG = intr_state;
+ return -1;
+ }
+ // actually write the byte into the FIFO
+ UEDATX = c;
+ // if this completed a packet, transmit it now!
+ if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
+ transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
+ SREG = intr_state;
+ return 0;
+}
+
+// transmit a buffer.
+// 0 returned on success, -1 on error
+// This function is optimized for speed! Each call takes approx 6.1 us overhead
+// plus 0.25 us per byte. 12 Mbit/sec USB has 8.67 us per-packet overhead and
+// takes 0.67 us per byte. If called with 64 byte packet-size blocks, this function
+// can transmit at full USB speed using 43% CPU time. The maximum theoretical speed
+// is 19 packets per USB frame, or 1216 kbytes/sec. However, bulk endpoints have the
+// lowest priority, so any other USB devices will likely reduce the speed. Speed
+// can also be limited by how quickly the PC-based software reads data, as the host
+// controller in the PC will not allocate bandwitdh without a pending read request.
+// (thanks to Victor Suarez for testing and feedback and initial code)
+
+int8_t usb_serial_write(const uint8_t *buffer, uint16_t size)
+{
+ uint8_t timeout, intr_state, write_size;
+
+ // if we're not online (enumerated and configured), error
+ if (!usb_configuration) return -1;
+ // interrupts are disabled so these functions can be
+ // used from the main program or interrupt context,
+ // even both in the same program!
+ intr_state = SREG;
+ cli();
+ UENUM = CDC_TX_ENDPOINT;
+ // if we gave up due to timeout before, don't wait again
+ if (transmit_previous_timeout) {
+ if (!(UEINTX & (1<<RWAL))) {
+ SREG = intr_state;
+ return -1;
+ }
+ transmit_previous_timeout = 0;
+ }
+ // each iteration of this loop transmits a packet
+ while (size) {
+ // wait for the FIFO to be ready to accept data
+ timeout = UDFNUML + TRANSMIT_TIMEOUT;
+ while (1) {
+ // are we ready to transmit?
+ if (UEINTX & (1<<RWAL)) break;
+ SREG = intr_state;
+ // have we waited too long? This happens if the user
+ // is not running an application that is listening
+ if (UDFNUML == timeout) {
+ transmit_previous_timeout = 1;
+ return -1;
+ }
+ // has the USB gone offline?
+ if (!usb_configuration) return -1;
+ // get ready to try checking again
+ intr_state = SREG;
+ cli();
+ UENUM = CDC_TX_ENDPOINT;
+ }
+
+ // compute how many bytes will fit into the next packet
+ write_size = CDC_TX_SIZE - UEBCLX;
+ if (write_size > size) write_size = size;
+ size -= write_size;
+
+ // write the packet
+ switch (write_size) {
+ #if (CDC_TX_SIZE == 64)
+ case 64: UEDATX = *buffer++;
+ case 63: UEDATX = *buffer++;
+ case 62: UEDATX = *buffer++;
+ case 61: UEDATX = *buffer++;
+ case 60: UEDATX = *buffer++;
+ case 59: UEDATX = *buffer++;
+ case 58: UEDATX = *buffer++;
+ case 57: UEDATX = *buffer++;
+ case 56: UEDATX = *buffer++;
+ case 55: UEDATX = *buffer++;
+ case 54: UEDATX = *buffer++;
+ case 53: UEDATX = *buffer++;
+ case 52: UEDATX = *buffer++;
+ case 51: UEDATX = *buffer++;
+ case 50: UEDATX = *buffer++;
+ case 49: UEDATX = *buffer++;
+ case 48: UEDATX = *buffer++;
+ case 47: UEDATX = *buffer++;
+ case 46: UEDATX = *buffer++;
+ case 45: UEDATX = *buffer++;
+ case 44: UEDATX = *buffer++;
+ case 43: UEDATX = *buffer++;
+ case 42: UEDATX = *buffer++;
+ case 41: UEDATX = *buffer++;
+ case 40: UEDATX = *buffer++;
+ case 39: UEDATX = *buffer++;
+ case 38: UEDATX = *buffer++;
+ case 37: UEDATX = *buffer++;
+ case 36: UEDATX = *buffer++;
+ case 35: UEDATX = *buffer++;
+ case 34: UEDATX = *buffer++;
+ case 33: UEDATX = *buffer++;
+ #endif
+ #if (CDC_TX_SIZE >= 32)
+ case 32: UEDATX = *buffer++;
+ case 31: UEDATX = *buffer++;
+ case 30: UEDATX = *buffer++;
+ case 29: UEDATX = *buffer++;
+ case 28: UEDATX = *buffer++;
+ case 27: UEDATX = *buffer++;
+ case 26: UEDATX = *buffer++;
+ case 25: UEDATX = *buffer++;
+ case 24: UEDATX = *buffer++;
+ case 23: UEDATX = *buffer++;
+ case 22: UEDATX = *buffer++;
+ case 21: UEDATX = *buffer++;
+ case 20: UEDATX = *buffer++;
+ case 19: UEDATX = *buffer++;
+ case 18: UEDATX = *buffer++;
+ case 17: UEDATX = *buffer++;
+ #endif
+ #if (CDC_TX_SIZE >= 16)
+ case 16: UEDATX = *buffer++;
+ case 15: UEDATX = *buffer++;
+ case 14: UEDATX = *buffer++;
+ case 13: UEDATX = *buffer++;
+ case 12: UEDATX = *buffer++;
+ case 11: UEDATX = *buffer++;
+ case 10: UEDATX = *buffer++;
+ case 9: UEDATX = *buffer++;
+ #endif
+ case 8: UEDATX = *buffer++;
+ case 7: UEDATX = *buffer++;
+ case 6: UEDATX = *buffer++;
+ case 5: UEDATX = *buffer++;
+ case 4: UEDATX = *buffer++;
+ case 3: UEDATX = *buffer++;
+ case 2: UEDATX = *buffer++;
+ default:
+ case 1: UEDATX = *buffer++;
+ case 0: break;
+ }
+ // if this completed a packet, transmit it now!
+ if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
+ transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
+ SREG = intr_state;
+ }
+ return 0;
+}
+
+
+// immediately transmit any buffered output.
+// This doesn't actually transmit the data - that is impossible!
+// USB devices only transmit when the host allows, so the best
+// we can do is release the FIFO buffer for when the host wants it
+void usb_serial_flush_output(void)
+{
+ uint8_t intr_state;
+
+ intr_state = SREG;
+ cli();
+ if (transmit_flush_timer) {
+ UENUM = CDC_TX_ENDPOINT;
+ UEINTX = 0x3A;
+ transmit_flush_timer = 0;
+ }
+ SREG = intr_state;
+}
+
+// functions to read the various async serial settings. These
+// aren't actually used by USB at all (communication is always
+// at full USB speed), but they are set by the host so we can
+// set them properly if we're converting the USB to a real serial
+// communication
+// uint32_t usb_serial_get_baud(void)
+// {
+// return *(uint32_t *)cdc_line_coding;
+// }
+uint8_t usb_serial_get_stopbits(void)
+{
+ return cdc_line_coding[4];
+}
+uint8_t usb_serial_get_paritytype(void)
+{
+ return cdc_line_coding[5];
+}
+uint8_t usb_serial_get_numbits(void)
+{
+ return cdc_line_coding[6];
+}
+uint8_t usb_serial_get_control(void)
+{
+ return cdc_line_rtsdtr;
+}
+// write the control signals, DCD, DSR, RI, etc
+// There is no CTS signal. If software on the host has transmitted
+// data to you but you haven't been calling the getchar function,
+// it remains buffered (either here or on the host) and can not be
+// lost because you weren't listening at the right time, like it
+// would in real serial communication.
+int8_t usb_serial_set_control(uint8_t signals)
+{
+ uint8_t intr_state;
+
+ intr_state = SREG;
+ cli();
+ if (!usb_configuration) {
+ // we're not enumerated/configured
+ SREG = intr_state;
+ return -1;
+ }
+
+ UENUM = CDC_ACM_ENDPOINT;
+ if (!(UEINTX & (1<<RWAL))) {
+ // unable to write
+ // TODO; should this try to abort the previously
+ // buffered message??
+ SREG = intr_state;
+ return -1;
+ }
+ UEDATX = 0xA1;
+ UEDATX = 0x20;
+ UEDATX = 0;
+ UEDATX = 0;
+ UEDATX = 0; // 0 seems to work nicely. what if this is 1??
+ UEDATX = 0;
+ UEDATX = 1;
+ UEDATX = 0;
+ UEDATX = signals;
+ UEINTX = 0x3A;
+ SREG = intr_state;
+ return 0;
+}
+
+
+
+/**************************************************************************
+ *
+ * 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, ISR_BLOCK)
+{
+ uint8_t intbits, t;
+ intbits = UDINT;
+ UDINT = 0;
+ if (intbits & (1<<EORSTI)) {
+ 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)) {
+ if (usb_configuration) {
+ t = transmit_flush_timer;
+ if (t) {
+ transmit_flush_timer = --t;
+ if (!t) {
+ UENUM = CDC_TX_ENDPOINT;
+ UEINTX = 0x3A;
+ }
+ }
+ }
+ }
+}
+
+
+// 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, ISR_BLOCK)
+{
+ uint8_t intbits;
+ const uint8_t *list;
+ const uint8_t *cfg;
+ uint8_t i, n, len, en;
+ uint8_t *p;
+ uint8_t bmRequestType;
+ uint8_t bRequest;
+ uint16_t wValue;
+ uint16_t wIndex;
+ uint16_t wLength;
+ uint16_t desc_val;
+ 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);
+ wIndex = UEDATX;
+ wIndex |= (UEDATX << 8);
+ wLength = UEDATX;
+ wLength |= (UEDATX << 8);
+ 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);
+ if (desc_val != wValue) {
+ list += sizeof(struct descriptor_list_struct);
+ continue;
+ }
+ list += 2;
+ desc_val = pgm_read_word(list);
+ if (desc_val != wIndex) {
+ list += sizeof(struct descriptor_list_struct)-2;
+ continue;
+ }
+ list += 2;
+ desc_addr = (const uint8_t *)pgm_read_word(list);
+ list += 2;
+ desc_length = pgm_read_byte(list);
+ break;
+ }
+ len = (wLength < 256) ? wLength : 255;
+ if (len > desc_length) len = desc_length;
+ 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++);
+ }
+ 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++);
+ UECONX = en;
+ if (en) {
+ UECFG0X = pgm_read_byte(cfg++);
+ UECFG1X = pgm_read_byte(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 && 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 && bmRequestType == 0x21) {
+ usb_wait_receive_out();
+ p = cdc_line_coding;
+ for (i=0; i<7; i++) {
+ *p++ = UEDATX;
+ }
+ usb_ack_out();
+ usb_send_in();
+ return;
+ }
+ if (bRequest == CDC_SET_CONTROL_LINE_STATE && bmRequestType == 0x21) {
+ cdc_line_rtsdtr = wValue;
+ usb_wait_in_ready();
+ usb_send_in();
+ return;
+ }
+ if (bRequest == GET_STATUS) {
+ usb_wait_in_ready();
+ i = 0;
+ #ifdef SUPPORT_ENDPOINT_HALT
+ if (bmRequestType == 0x82) {
+ UENUM = wIndex;
+ if (UECONX & (1<<STALLRQ)) i = 1;
+ UENUM = 0;
+ }
+ #endif
+ UEDATX = i;
+ UEDATX = 0;
+ usb_send_in();
+ return;
+ }
+ #ifdef SUPPORT_ENDPOINT_HALT
+ 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;
+ }
+ }
+ #endif
+ }
+ UECONX = (1<<STALLRQ) | (1<<EPEN); // stall
+}
+
+
+#define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
+
+#if 0
+#include <stdio.h>
+static int dw_putchar(char __c, FILE *__stream) { DWDR = __c;(void)__stream; return __c;}
+FILE dwout = FDEV_SETUP_STREAM(dw_putchar, NULL, _FDEV_SETUP_WRITE);
+stdout=&dwout;
+#endif
+
+// Very simple character echo test
+int main(void)
+{
+ CPU_PRESCALE(0);
+ usb_init();
+ while(usb_configured()==0);
+ while (1) {
+ int n = usb_serial_getchar();
+ if (n >= 0) usb_serial_putchar(n);
+ }
+}