Add USB keyboard for Teensy 4.0

teensy4/WProgram.h

 #include "avr_emulation.h"
 #include "usb_serial.h"
 #include "usb_seremu.h"
-//#include "usb_keyboard.h"
+#include "usb_keyboard.h"
 //#include "usb_mouse.h"
 //#include "usb_joystick.h"
 //#include "usb_midi.h"

teensy4/usb.c

 #define USB_DESC_LIST_DEFINE
 #include "usb_desc.h"
 #include "usb_serial.h"
+#include "usb_seremu.h"
+#include "usb_keyboard.h"
 #include "core_pins.h" // for delay()
 #include "avr/pgmspace.h"
 #include <string.h>
 		#if defined(RAWHID_INTERFACE)
 		usb_rawhid_configure();
 		#endif
+		#if defined(KEYBOARD_INTERFACE)
+		usb_keyboard_configure();
+		#endif
 		endpoint0_receive(NULL, 0, 0);
 		return;
 	  case 0x0880: // GET_CONFIGURATION

teensy4/usb_desc.c

 #endif
 
 #ifdef CDC_DATA_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // CDC_DATA_INTERFACE
 
 #ifdef MIDI_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // Standard MS Interface Descriptor,
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // MIDI_INTERFACE
 
 #ifdef KEYBOARD_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // KEYBOARD_INTERFACE
 
 #ifdef MOUSE_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // MOUSE_INTERFACE
 
 #ifdef RAWHID_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // RAWHID_INTERFACE
 
 #ifdef FLIGHTSIM_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // FLIGHTSIM_INTERFACE
 
 #ifdef SEREMU_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // SEREMU_INTERFACE
 
 #ifdef JOYSTICK_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // JOYSTICK_INTERFACE
 
 #ifdef MTP_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // MTP_INTERFACE
 
 #ifdef KEYMEDIA_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // KEYMEDIA_INTERFACE
 
 #ifdef AUDIO_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface association descriptor, USB ECN, Table 9-Z
         8,                                      // bLength
         11,                                     // bDescriptorType
 #endif
 
 #ifdef MULTITOUCH_INTERFACE
+	// configuration for 480 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif
 
 #ifdef CDC_DATA_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // CDC_DATA_INTERFACE
 
 #ifdef MIDI_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // Standard MS Interface Descriptor,
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // MIDI_INTERFACE
 
 #ifdef KEYBOARD_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // KEYBOARD_INTERFACE
 
 #ifdef MOUSE_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // MOUSE_INTERFACE
 
 #ifdef RAWHID_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // RAWHID_INTERFACE
 
 #ifdef FLIGHTSIM_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // FLIGHTSIM_INTERFACE
 
 #ifdef SEREMU_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // SEREMU_INTERFACE
 
 #ifdef JOYSTICK_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // JOYSTICK_INTERFACE
 
 #ifdef MTP_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // MTP_INTERFACE
 
 #ifdef KEYMEDIA_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType
 #endif // KEYMEDIA_INTERFACE
 
 #ifdef AUDIO_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface association descriptor, USB ECN, Table 9-Z
         8,                                      // bLength
         11,                                     // bDescriptorType
 #endif
 
 #ifdef MULTITOUCH_INTERFACE
+	// configuration for 12 Mbit/sec speed
         // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
         9,                                      // bLength
         4,                                      // bDescriptorType

teensy4/usb_desc.h

   #define NUM_USB_BUFFERS	14
   #define NUM_INTERFACE		3
   #define SEREMU_INTERFACE      1	// Serial emulation
-  #define SEREMU_TX_ENDPOINT    1
+  #define SEREMU_TX_ENDPOINT    2
   #define SEREMU_TX_SIZE        64
-  #define SEREMU_TX_INTERVAL    1
+  #define SEREMU_TX_INTERVAL    1	// TODO: is this ok for 480 Mbit speed
   #define SEREMU_RX_ENDPOINT    2
   #define SEREMU_RX_SIZE        32
-  #define SEREMU_RX_INTERVAL    2
+  #define SEREMU_RX_INTERVAL    2	// TODO: is this ok for 480 Mbit speed
   #define KEYBOARD_INTERFACE    0	// Keyboard
   #define KEYBOARD_ENDPOINT     3
   #define KEYBOARD_SIZE         8
-  #define KEYBOARD_INTERVAL     1
+  #define KEYBOARD_INTERVAL     1	// TODO: is this ok for 480 Mbit speed
   #define KEYMEDIA_INTERFACE    2	// Keyboard Media Keys
   #define KEYMEDIA_ENDPOINT     4
   #define KEYMEDIA_SIZE         8
-  #define KEYMEDIA_INTERVAL     4
-  #define ENDPOINT1_CONFIG	ENDPOINT_TRANSMIT_ONLY
-  #define ENDPOINT2_CONFIG	ENDPOINT_RECEIVE_ONLY
-  #define ENDPOINT3_CONFIG	ENDPOINT_TRANSMIT_ONLY
-  #define ENDPOINT4_CONFIG	ENDPOINT_TRANSMIT_ONLY
-  #define ENDPOINT5_CONFIG	ENDPOINT_TRANSMIT_ONLY
-  #define ENDPOINT6_CONFIG	ENDPOINT_TRANSMIT_ONLY
+  #define KEYMEDIA_INTERVAL     4	// TODO: is this ok for 480 Mbit speed
+  #define ENDPOINT2_CONFIG	ENDPOINT_RECEIVE_INTERRUPT + ENDPOINT_TRANSMIT_INTERRUPT
+  #define ENDPOINT3_CONFIG	ENDPOINT_RECEIVE_UNUSED + ENDPOINT_TRANSMIT_INTERRUPT
+  #define ENDPOINT4_CONFIG	ENDPOINT_RECEIVE_UNUSED + ENDPOINT_TRANSMIT_INTERRUPT
 
 #elif defined(USB_HID)
   #define VENDOR_ID		0x16C0

teensy4/usb_keyboard.c

+/* Teensyduino Core Library
+ * http://www.pjrc.com/teensy/
+ * Copyright (c) 2017 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 "usb_dev.h"
+#include "usb_keyboard.h"
+#include "core_pins.h" // for yield()
+#include "keylayouts.h"
+#include <string.h> // for memcpy()
+#include "avr/pgmspace.h" // for PROGMEM, DMAMEM, FASTRUN
+#include "debug/printf.h"
+#include "core_pins.h"
+
+#ifdef KEYBOARD_INTERFACE // defined by usb_dev.h -> usb_desc.h
+
+// which modifier keys are currently pressed
+// 1=left ctrl,	   2=left shift,   4=left alt,	  8=left gui
+// 16=right ctrl, 32=right shift, 64=right alt, 128=right gui
+uint8_t keyboard_modifier_keys=0;
+
+// which keys are currently pressed, up to 6 keys may be down at once
+uint8_t keyboard_keys[6]={0,0,0,0,0,0};
+
+#ifdef KEYMEDIA_INTERFACE
+uint16_t keymedia_consumer_keys[4];
+uint8_t keymedia_system_keys[3];
+#endif
+
+// protocol setting from the host.  We use exactly the same report
+// either way, so this variable only stores the setting since we
+// are required to be able to report which setting is in use.
+uint8_t keyboard_protocol=1;
+
+// the idle configuration, how often we send the report to the
+// host (ms * 4) even when it hasn't changed
+uint8_t keyboard_idle_config=125;
+
+// count until idle timeout
+uint8_t keyboard_idle_count=0;
+
+// 1=num lock, 2=caps lock, 4=scroll lock, 8=compose, 16=kana
+volatile uint8_t keyboard_leds=0;
+
+
+
+static KEYCODE_TYPE unicode_to_keycode(uint16_t cpoint);
+static void write_key(KEYCODE_TYPE keycode);
+static uint8_t keycode_to_modifier(KEYCODE_TYPE keycode);
+static uint8_t keycode_to_key(KEYCODE_TYPE keycode);
+static void usb_keyboard_press_key(uint8_t key, uint8_t modifier);
+static void usb_keyboard_release_key(uint8_t key, uint8_t modifier);
+#ifdef DEADKEYS_MASK
+static KEYCODE_TYPE deadkey_to_keycode(KEYCODE_TYPE keycode);
+#endif
+#ifdef KEYMEDIA_INTERFACE
+static void usb_keymedia_press_consumer_key(uint16_t key);
+static void usb_keymedia_release_consumer_key(uint16_t key);
+static void usb_keymedia_press_system_key(uint8_t key);
+static void usb_keymedia_release_system_key(uint8_t key);
+static int usb_keymedia_send(void);
+#endif
+
+
+#define TX_NUM     12
+#define TX_BUFSIZE 32
+static transfer_t tx_transfer[TX_NUM] __attribute__ ((used, aligned(32)));
+DMAMEM static uint8_t txbuffer[TX_NUM * TX_BUFSIZE] __attribute__ ((aligned(32)));
+static uint8_t tx_head=0;
+#if KEYBOARD_SIZE > TX_BUFSIZE
+#error "Internal error, transmit buffer size is too small for keyboard endpoint"
+#endif
+#if defined(KEYMEDIA_INTERFACE) && KEYMEDIA_SIZE > TX_BUFSIZE
+#error "Internal error, transmit buffer size is too small for media keys endpoint"
+#endif
+
+
+void usb_keyboard_configure(void)
+{
+	memset(tx_transfer, 0, sizeof(tx_transfer));
+	tx_head = 0;
+	usb_config_tx(KEYBOARD_ENDPOINT, KEYBOARD_SIZE, 0, NULL);  // normal keys use 8 byte packet
+#ifdef KEYMEDIA_INTERFACE
+	usb_config_tx(KEYMEDIA_ENDPOINT, KEYMEDIA_SIZE, 0, NULL);  // media keys use 8 byte packet
+#endif
+}
+
+
+// Step #1, decode UTF8 to Unicode code points
+//
+void usb_keyboard_write(uint8_t c)
+{
+	static int utf8_state=0;
+	static uint16_t unicode_wchar=0;
+
+	if (c < 0x80) {
+		// single byte encoded, 0x00 to 0x7F
+		utf8_state = 0;
+		usb_keyboard_write_unicode(c);
+	} else if (c < 0xC0) {
+		// 2nd, 3rd or 4th byte, 0x80 to 0xBF
+		c &= 0x3F;
+		if (utf8_state == 1) {
+			utf8_state = 0;
+			usb_keyboard_write_unicode(unicode_wchar | c);
+		} else if (utf8_state == 2) {
+			unicode_wchar |= ((uint16_t)c << 6);
+			utf8_state = 1;
+		}
+	} else if (c < 0xE0) {
+		// begin 2 byte sequence, 0xC2 to 0xDF
+		// or illegal 2 byte sequence, 0xC0 to 0xC1
+		unicode_wchar = (uint16_t)(c & 0x1F) << 6;
+		utf8_state = 1;
+	} else if (c < 0xF0) {
+		// begin 3 byte sequence, 0xE0 to 0xEF
+		unicode_wchar = (uint16_t)(c & 0x0F) << 12;
+		utf8_state = 2;
+	} else {
+		// begin 4 byte sequence (not supported), 0xF0 to 0xF4
+		// or illegal, 0xF5 to 0xFF
+		utf8_state = 255;
+	}
+}
+
+
+// Step #2: translate Unicode code point to keystroke sequence
+//
+static KEYCODE_TYPE unicode_to_keycode(uint16_t cpoint)
+{
+	// Unicode code points beyond U+FFFF are not supported
+	// technically this input should probably be called UCS-2
+	if (cpoint < 32) {
+		if (cpoint == 10) return KEY_ENTER & KEYCODE_MASK;
+		if (cpoint == 11) return KEY_TAB & KEYCODE_MASK;
+		return 0;
+	}
+	if (cpoint < 128) {
+		return keycodes_ascii[cpoint - 0x20];
+	}
+	#ifdef ISO_8859_1_A0
+	if (cpoint >= 0xA0 && cpoint < 0x100) {
+		return keycodes_iso_8859_1[cpoint - 0xA0];
+	}
+	#endif
+	//#ifdef UNICODE_20AC
+	//if (cpoint == 0x20AC) return UNICODE_20AC & 0x3FFF;
+	//#endif
+	#ifdef KEYCODE_EXTRA00
+	if (cpoint == UNICODE_EXTRA00) return (KEYCODE_EXTRA00) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA01
+	if (cpoint == UNICODE_EXTRA01) return (KEYCODE_EXTRA01) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA02
+	if (cpoint == UNICODE_EXTRA02) return (KEYCODE_EXTRA02) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA03
+	if (cpoint == UNICODE_EXTRA03) return (KEYCODE_EXTRA03) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA04
+	if (cpoint == UNICODE_EXTRA04) return (KEYCODE_EXTRA04) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA05
+	if (cpoint == UNICODE_EXTRA05) return (KEYCODE_EXTRA05) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA06
+	if (cpoint == UNICODE_EXTRA06) return (KEYCODE_EXTRA06) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA07
+	if (cpoint == UNICODE_EXTRA07) return (KEYCODE_EXTRA07) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA08
+	if (cpoint == UNICODE_EXTRA08) return (KEYCODE_EXTRA08) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA09
+	if (cpoint == UNICODE_EXTRA09) return (KEYCODE_EXTRA09) & 0x3FFF;
+	#endif
+	#ifdef KEYCODE_EXTRA0A
+	if (cpoint == UNICODE_EXTRA0A) return (KEYCODE_EXTRA0A) & 0x3FFF;
+	#endif
+	return 0;
+}
+
+// Step #3: execute keystroke sequence
+//
+#ifdef DEADKEYS_MASK
+static KEYCODE_TYPE deadkey_to_keycode(KEYCODE_TYPE keycode)
+{
+	keycode &= DEADKEYS_MASK;
+	if (keycode == 0) return 0;
+	#ifdef ACUTE_ACCENT_BITS
+	if (keycode == ACUTE_ACCENT_BITS) return DEADKEY_ACUTE_ACCENT;
+	#endif
+	#ifdef CEDILLA_BITS
+	if (keycode == CEDILLA_BITS) return DEADKEY_CEDILLA;
+	#endif
+	#ifdef CIRCUMFLEX_BITS
+	if (keycode == CIRCUMFLEX_BITS) return DEADKEY_CIRCUMFLEX;
+	#endif
+	#ifdef DIAERESIS_BITS
+	if (keycode == DIAERESIS_BITS) return DEADKEY_DIAERESIS;
+	#endif
+	#ifdef GRAVE_ACCENT_BITS
+	if (keycode == GRAVE_ACCENT_BITS) return DEADKEY_GRAVE_ACCENT;
+	#endif
+	#ifdef TILDE_BITS
+	if (keycode == TILDE_BITS) return DEADKEY_TILDE;
+	#endif
+	#ifdef RING_ABOVE_BITS
+	if (keycode == RING_ABOVE_BITS) return DEADKEY_RING_ABOVE;
+	#endif
+	#ifdef DEGREE_SIGN_BITS
+	if (keycode == DEGREE_SIGN_BITS) return DEADKEY_DEGREE_SIGN;
+	#endif
+	#ifdef CARON_BITS
+	if (keycode == CARON_BITS) return DEADKEY_CARON;
+	#endif
+	#ifdef BREVE_BITS
+	if (keycode == BREVE_BITS) return DEADKEY_BREVE;
+	#endif
+	#ifdef OGONEK_BITS
+	if (keycode == OGONEK_BITS) return DEADKEY_OGONEK;
+	#endif
+	#ifdef DOT_ABOVE_BITS
+	if (keycode == DOT_ABOVE_BITS) return DEADKEY_DOT_ABOVE;
+	#endif
+	#ifdef DOUBLE_ACUTE_BITS
+	if (keycode == DOUBLE_ACUTE_BITS) return DEADKEY_DOUBLE_ACUTE;
+	#endif
+	return 0;
+}
+#endif
+
+void usb_keyboard_write_unicode(uint16_t cpoint)
+{
+	KEYCODE_TYPE keycode;
+
+	keycode = unicode_to_keycode(cpoint);
+	if (keycode) {
+		#ifdef DEADKEYS_MASK
+		KEYCODE_TYPE deadkeycode = deadkey_to_keycode(keycode);
+		if (deadkeycode) write_key(deadkeycode);
+		#endif
+		write_key(keycode);
+	}
+}
+
+
+// Step #4: do each keystroke
+//
+static void write_key(KEYCODE_TYPE keycode)
+{
+/*
+	uint8_t key, modifier=0;
+
+	#ifdef SHIFT_MASK
+	if (keycode & SHIFT_MASK) modifier |= MODIFIERKEY_SHIFT;
+	#endif
+	#ifdef ALTGR_MASK
+	if (keycode & ALTGR_MASK) modifier |= MODIFIERKEY_RIGHT_ALT;
+	#endif
+	#ifdef RCTRL_MASK
+	if (keycode & RCTRL_MASK) modifier |= MODIFIERKEY_RIGHT_CTRL;
+	#endif
+	key = keycode & 0x3F;
+	#ifdef KEY_NON_US_100
+	if (key == KEY_NON_US_100) key = 100;
+	#endif
+	usb_keyboard_press(key, modifier);
+*/
+	usb_keyboard_press(keycode_to_key(keycode), keycode_to_modifier(keycode));
+}
+
+static uint8_t keycode_to_modifier(KEYCODE_TYPE keycode)
+{
+	uint8_t modifier=0;
+
+	#ifdef SHIFT_MASK
+	if (keycode & SHIFT_MASK) modifier |= MODIFIERKEY_SHIFT;
+	#endif
+	#ifdef ALTGR_MASK
+	if (keycode & ALTGR_MASK) modifier |= MODIFIERKEY_RIGHT_ALT;
+	#endif
+	#ifdef RCTRL_MASK
+	if (keycode & RCTRL_MASK) modifier |= MODIFIERKEY_RIGHT_CTRL;
+	#endif
+	return modifier;
+}
+
+static uint8_t keycode_to_key(KEYCODE_TYPE keycode)
+{
+	uint8_t key = keycode & 0x3F;
+	#ifdef KEY_NON_US_100
+	if (key == KEY_NON_US_100) key = 100;
+	#endif
+	return key;
+}
+
+
+// Input can be:
+//     32 - 127     ASCII direct (U+0020 to U+007F) <-- uses layout
+//    128 - 0xC1FF  Unicode direct (U+0080 to U+C1FF) <-- uses layout
+// 0xC200 - 0xDFFF  Unicode UTF8 packed (U+0080 to U+07FF) <-- uses layout
+// 0xE000 - 0xE0FF  Modifier key (bitmap, 8 keys, shift/ctrl/alt/gui)
+// 0xE200 - 0xE2FF  System key (HID usage code, within usage page 1)
+// 0xE400 - 0xE7FF  Media/Consumer key (HID usage code, within usage page 12)
+// 0xF000 - 0xFFFF  Normal key (HID usage code, within usage page 7)
+
+void usb_keyboard_press_keycode(uint16_t n)
+{
+	uint8_t key, mod, msb, modrestore=0;
+	KEYCODE_TYPE keycode;
+	#ifdef DEADKEYS_MASK
+	KEYCODE_TYPE deadkeycode;
+	#endif
+
+	msb = n >> 8;
+
+	if (msb >= 0xC2) {
+		if (msb <= 0xDF) {
+			n = (n & 0x3F) | ((uint16_t)(msb & 0x1F) << 6);
+		} else if (msb == 0xF0) {
+			usb_keyboard_press_key(n, 0);
+			return;
+		} else if (msb == 0xE0) {
+			usb_keyboard_press_key(0, n);
+			return;
+#ifdef KEYMEDIA_INTERFACE
+		} else if (msb == 0xE2) {
+			usb_keymedia_press_system_key(n);
+			return;
+		} else if (msb >= 0xE4 && msb <= 0xE7) {
+			usb_keymedia_press_consumer_key(n & 0x3FF);
+			return;
+#endif
+		} else {
+			return;
+		}
+	}
+	keycode = unicode_to_keycode(n);
+	if (!keycode) return;
+#ifdef DEADKEYS_MASK
+	deadkeycode = deadkey_to_keycode(keycode);
+	if (deadkeycode) {
+		modrestore = keyboard_modifier_keys;
+		if (modrestore) {
+			keyboard_modifier_keys = 0;
+			usb_keyboard_send();
+		}
+		// TODO: test if operating systems recognize
+		// deadkey sequences when other keys are held
+		mod = keycode_to_modifier(deadkeycode);
+		key = keycode_to_key(deadkeycode);
+		usb_keyboard_press_key(key, mod);
+		usb_keyboard_release_key(key, mod);
+	}
+#endif
+	mod = keycode_to_modifier(keycode);
+	key = keycode_to_key(keycode);
+	usb_keyboard_press_key(key, mod | modrestore);
+}
+
+
+void usb_keyboard_release_keycode(uint16_t n)
+{
+	uint8_t key, mod, msb;
+
+	msb = n >> 8;
+	if (msb >= 0xC2) {
+		if (msb <= 0xDF) {
+			n = (n & 0x3F) | ((uint16_t)(msb & 0x1F) << 6);
+		} else if (msb == 0xF0) {
+			usb_keyboard_release_key(n, 0);
+			return;
+		} else if (msb == 0xE0) {
+			usb_keyboard_release_key(0, n);
+			return;
+#ifdef KEYMEDIA_INTERFACE
+		} else if (msb == 0xE2) {
+			usb_keymedia_release_system_key(n);
+			return;
+		} else if (msb >= 0xE4 && msb <= 0xE7) {
+			usb_keymedia_release_consumer_key(n & 0x3FF);
+			return;
+#endif
+		} else {
+			return;
+		}
+	}
+	KEYCODE_TYPE keycode = unicode_to_keycode(n);
+	if (!keycode) return;
+	mod = keycode_to_modifier(keycode);
+	key = keycode_to_key(keycode);
+	usb_keyboard_release_key(key, mod);
+}
+
+
+static void usb_keyboard_press_key(uint8_t key, uint8_t modifier)
+{
+	int i, send_required = 0;
+
+	if (modifier) {
+		if ((keyboard_modifier_keys & modifier) != modifier) {
+			keyboard_modifier_keys |= modifier;
+			send_required = 1;
+		}
+	}
+	if (key) {
+		for (i=0; i < 6; i++) {
+			if (keyboard_keys[i] == key) goto end;
+		}
+		for (i=0; i < 6; i++) {
+			if (keyboard_keys[i] == 0) {
+				keyboard_keys[i] = key;
+				send_required = 1;
+				goto end;
+			}
+		}
+	}
+	end:
+	if (send_required) usb_keyboard_send();
+}
+
+
+static void usb_keyboard_release_key(uint8_t key, uint8_t modifier)
+{
+	int i, send_required = 0;
+
+	if (modifier) {
+		if ((keyboard_modifier_keys & modifier) != 0) {
+			keyboard_modifier_keys &= ~modifier;
+			send_required = 1;
+		}
+	}
+	if (key) {
+		for (i=0; i < 6; i++) {
+			if (keyboard_keys[i] == key) {
+				keyboard_keys[i] = 0;
+				send_required = 1;
+			}
+		}
+	}
+	if (send_required) usb_keyboard_send();
+}
+
+void usb_keyboard_release_all(void)
+{
+	uint8_t i, anybits;
+
+	anybits = keyboard_modifier_keys;
+	keyboard_modifier_keys = 0;
+	for (i=0; i < 6; i++) {
+		anybits |= keyboard_keys[i];
+		keyboard_keys[i] = 0;
+	}
+	if (anybits) usb_keyboard_send();
+#ifdef KEYMEDIA_INTERFACE
+	anybits = 0;
+	for (i=0; i < 4; i++) {
+		if (keymedia_consumer_keys[i] != 0) anybits = 1;
+		keymedia_consumer_keys[i] = 0;
+	}
+	for (i=0; i < 3; i++) {
+		if (keymedia_system_keys[i] != 0) anybits = 1;
+		keymedia_system_keys[i] = 0;
+	}
+	if (anybits) usb_keymedia_send();
+#endif
+}
+
+
+int usb_keyboard_press(uint8_t key, uint8_t modifier)
+{
+	int r;
+	keyboard_modifier_keys = modifier;
+	keyboard_keys[0] = key;
+	keyboard_keys[1] = 0;
+	keyboard_keys[2] = 0;
+	keyboard_keys[3] = 0;
+	keyboard_keys[4] = 0;
+	keyboard_keys[5] = 0;
+	r = usb_keyboard_send();
+	if (r) return r;
+	keyboard_modifier_keys = 0;
+	keyboard_keys[0] = 0;
+	return usb_keyboard_send();
+}
+
+
+static uint8_t transmit_previous_timeout=0;
+
+// When the PC isn't listening, how long do we wait before discarding data?
+#define TX_TIMEOUT_MSEC 50
+
+int usb_keyboard_transmit(int endpoint, const uint8_t *data, uint32_t len)
+{
+	if (!usb_configuration) return -1;
+	uint32_t head = tx_head;
+	transfer_t *xfer = tx_transfer + head;
+	uint32_t wait_begin_at = systick_millis_count;
+	while (1) {
+		uint32_t status = usb_transfer_status(xfer);
+		if (!(status & 0x80)) {
+			if (status & 0x68) {
+				// TODO: what if status has errors???
+				printf("ERROR status = %x, i=%d, ms=%u\n",
+					status, tx_head, systick_millis_count);
+			}
+			transmit_previous_timeout = 0;
+			break;
+		}
+		if (transmit_previous_timeout) return -1;
+		if (systick_millis_count - wait_begin_at > TX_TIMEOUT_MSEC) {
+			// waited too long, assume the USB host isn't listening
+			transmit_previous_timeout = 1;
+			return -1;
+		}
+		if (!usb_configuration) return -1;
+		yield();
+	}
+	uint8_t *buffer = txbuffer + head * TX_BUFSIZE;
+	memcpy(buffer, data, len);
+	usb_prepare_transfer(xfer, buffer, len, 0);
+	arm_dcache_flush_delete(buffer, TX_BUFSIZE);
+	usb_transmit(endpoint, xfer);
+	if (++head >= TX_NUM) head = 0;
+	tx_head = head;
+	return 0;
+}
+
+
+// send the contents of keyboard_keys and keyboard_modifier_keys
+int usb_keyboard_send(void)
+{
+	uint8_t buffer[KEYBOARD_SIZE];
+	buffer[0] = keyboard_modifier_keys;
+	buffer[1] = 0;
+	buffer[2] = keyboard_keys[0];
+	buffer[3] = keyboard_keys[1];
+	buffer[4] = keyboard_keys[2];
+	buffer[5] = keyboard_keys[3];
+	buffer[6] = keyboard_keys[4];
+	buffer[7] = keyboard_keys[5];
+	return usb_keyboard_transmit(KEYBOARD_ENDPOINT, buffer, KEYBOARD_SIZE);
+}
+
+
+#ifdef KEYMEDIA_INTERFACE
+
+static void usb_keymedia_press_consumer_key(uint16_t key)
+{
+	int i;
+
+	if (key == 0) return;
+	for (i=0; i < 4; i++) {
+		if (keymedia_consumer_keys[i] == key) return;
+	}
+	for (i=0; i < 4; i++) {
+		if (keymedia_consumer_keys[i] == 0) {
+			keymedia_consumer_keys[i] = key;
+			usb_keymedia_send();
+			return;
+		}
+	}
+}
+
+static void usb_keymedia_release_consumer_key(uint16_t key)
+{
+	int i;
+
+	if (key == 0) return;
+	for (i=0; i < 4; i++) {
+		if (keymedia_consumer_keys[i] == key) {
+			keymedia_consumer_keys[i] = 0;
+			usb_keymedia_send();
+			return;
+		}
+	}
+}
+
+static void usb_keymedia_press_system_key(uint8_t key)
+{
+	int i;
+
+	if (key == 0) return;
+	for (i=0; i < 3; i++) {
+		if (keymedia_system_keys[i] == key) return;
+	}
+	for (i=0; i < 3; i++) {
+		if (keymedia_system_keys[i] == 0) {
+			keymedia_system_keys[i] = key;
+			usb_keymedia_send();
+			return;
+		}
+	}
+}
+
+static void usb_keymedia_release_system_key(uint8_t key)
+{
+	int i;
+
+	if (key == 0) return;
+	for (i=0; i < 3; i++) {
+		if (keymedia_system_keys[i] == key) {
+			keymedia_system_keys[i] = 0;
+			usb_keymedia_send();
+			return;
+		}
+	}
+}
+
+void usb_keymedia_release_all(void)
+{
+	uint8_t i, anybits;
+
+	anybits = 0;
+	for (i=0; i < 4; i++) {
+		if (keymedia_consumer_keys[i] != 0) anybits = 1;
+		keymedia_consumer_keys[i] = 0;
+	}
+	for (i=0; i < 3; i++) {
+		if (keymedia_system_keys[i] != 0) anybits = 1;
+		keymedia_system_keys[i] = 0;
+	}
+	if (anybits) usb_keymedia_send();
+}
+
+// send the contents of keyboard_keys and keyboard_modifier_keys
+static int usb_keymedia_send(void)
+{
+	uint8_t buffer[8];
+	const uint16_t *consumer = keymedia_consumer_keys;
+	// 44444444 44333333 33332222 22222211 11111111
+	// 98765432 10987654 32109876 54321098 76543210
+	buffer[0] = consumer[0];
+	buffer[1] = (consumer[1] << 2) | ((consumer[0] >> 8) & 0x03);
+	buffer[2] = (consumer[2] << 4) | ((consumer[1] >> 6) & 0x0F);
+	buffer[3] = (consumer[3] << 6) | ((consumer[2] >> 4) & 0x3F);
+	buffer[4] = consumer[3] >> 2;
+	buffer[5] = keymedia_system_keys[0];
+	buffer[6] = keymedia_system_keys[1];
+	buffer[7] = keymedia_system_keys[2];
+	return usb_keyboard_transmit(KEYMEDIA_ENDPOINT, buffer, KEYMEDIA_SIZE);
+}
+
+#endif // KEYMEDIA_INTERFACE
+
+#endif // KEYBOARD_INTERFACE

teensy4/usb_keyboard.h

+/* Teensyduino Core Library
+ * http://www.pjrc.com/teensy/
+ * Copyright (c) 2017 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.
+ */
+
+#pragma once
+
+#include "usb_desc.h"
+
+#include "keylayouts.h"
+
+#if defined(KEYBOARD_INTERFACE)
+
+#include <inttypes.h>
+
+// C language implementation
+#ifdef __cplusplus
+extern "C" {
+#endif
+void usb_keyboard_configure(void);
+void usb_keyboard_write(uint8_t c);
+void usb_keyboard_write_unicode(uint16_t cpoint);
+void usb_keyboard_press_keycode(uint16_t n);
+void usb_keyboard_release_keycode(uint16_t n);
+void usb_keyboard_release_all(void);
+int usb_keyboard_press(uint8_t key, uint8_t modifier);
+int usb_keyboard_send(void);
+#ifdef KEYMEDIA_INTERFACE
+void usb_keymedia_release_all(void);
+#endif
+extern uint8_t keyboard_modifier_keys;
+extern uint8_t keyboard_keys[6];
+extern uint8_t keyboard_protocol;
+extern uint8_t keyboard_idle_config;
+extern uint8_t keyboard_idle_count;
+extern volatile uint8_t keyboard_leds;
+extern volatile uint8_t usb_configuration;
+#ifdef __cplusplus
+}
+#endif
+
+
+
+// C++ interface
+#ifdef __cplusplus
+#include "Stream.h"
+class usb_keyboard_class : public Print
+{
+public:
+	void begin(void) { }
+	void end(void) { }
+	virtual size_t write(uint8_t c) { usb_keyboard_write(c); return 1; }
+        size_t write(unsigned long n) { return write((uint8_t)n); }
+        size_t write(long n) { return write((uint8_t)n); }
+        size_t write(unsigned int n) { return write((uint8_t)n); }
+        size_t write(int n) { return write((uint8_t)n); }
+	using Print::write;
+	void write_unicode(uint16_t n) { usb_keyboard_write_unicode(n); }
+	void set_modifier(uint16_t c) { keyboard_modifier_keys = (uint8_t)c; }
+	void set_key1(uint8_t c) { keyboard_keys[0] = c; }
+	void set_key2(uint8_t c) { keyboard_keys[1] = c; }
+	void set_key3(uint8_t c) { keyboard_keys[2] = c; }
+	void set_key4(uint8_t c) { keyboard_keys[3] = c; }
+	void set_key5(uint8_t c) { keyboard_keys[4] = c; }
+	void set_key6(uint8_t c) { keyboard_keys[5] = c; }
+#ifdef KEYMEDIA_INTERFACE
+	void set_media(uint16_t c) {
+		if (c == 0) {
+			usb_keymedia_release_all();
+		} else if (c >= 0xE400 && c <= 0xE7FF) {
+			press(c);
+		}
+	}
+#endif
+	void send_now(void) { usb_keyboard_send(); }
+	void press(uint16_t n) { usb_keyboard_press_keycode(n); }
+	void release(uint16_t n) { usb_keyboard_release_keycode(n); }
+	void releaseAll(void) { usb_keyboard_release_all(); }
+};
+
+extern usb_keyboard_class Keyboard;
+
+#endif // __cplusplus
+
+#endif // KEYBOARD_INTERFACE
+

teensy4/usb_seremu.c

 
 // TODO: should be 2 different timeouts, high speed (480) vs full speed (12)
 #define TRANSMIT_FLUSH_TIMEOUT  75   /* in microseconds */
-volatile uint8_t usb_seremu_transmit_flush_timer=0;
 static void timer_config(void (*callback)(void), uint32_t microseconds);
 static void timer_start_oneshot();
 static void timer_stop();

teensy4/usb_seremu.h

 int usb_seremu_write(const void *buffer, uint32_t size);
 int usb_seremu_write_buffer_free(void);
 void usb_seremu_flush_output(void);
-extern volatile uint8_t usb_seremu_transmit_flush_timer;
 extern volatile uint8_t usb_configuration;
 #ifdef __cplusplus
 }