main.c

   1 /*
   2  * Basic firmware to emulate a USB TEMPer device (which uses an FM75 I2C
   3  * sensor internally) using a Digispark + a DS18B20 1-wire sensor.
   4  *
   5  * Copyright 2018 Jonathan McDowell <noodles@earth.li>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20 #include <stdbool.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <avr/eeprom.h>
  24 #include <avr/interrupt.h>
  25 #include <avr/io.h>
  26 #include <avr/wdt.h>
  27 #include <util/delay.h>
  28
  29 #include <avr/pgmspace.h>
  30 #include "usbdrv.h"
  31 #include "libs-device/osccal.h"
  32
  33 #include "w1.h"
  34
  35 typedef struct {
  36         uint8_t modifier;
  37         uint8_t reserved;
  38         uint8_t keycode[6];
  39 } keyboard_report_t;
  40 keyboard_report_t keyboard_report;
  41
  42 uint8_t temp_state = 0;
  43
  44 uint8_t temp_report[8];
  45 bool have_temp_int = false;
  46
  47 #define NUM_LOCK        1
  48 #define CAPS_LOCK       2
  49 #define SCROLL_LOCK     4
  50 volatile static uchar ledstate = 0xff;
  51 static uchar idlerate;
  52
  53 /* We populate this with the 1-wire device ROM ID when we get it */
  54 int serno_str[] = {
  55         USB_STRING_DESCRIPTOR_HEADER(16),
  56         'F', 'F', 'F', 'F', 'F', 'F', 'F', 'F',
  57         'F', 'F', 'F', 'F', 'F', 'F', 'F', 'F',
  58 };
  59
  60 #define USB_INDEX_KEYBOARD      0
  61 #define USB_INDEX_MOUSE         1
  62
  63 PROGMEM const char usbHidKeyboardReportDescriptor[] = {
  64         0x05, 0x01,             // USAGE_PAGE (Generic Desktop)
  65         0x09, 0x06,             // USAGE (Keyboard)
  66         0xa1, 0x01,             // COLLECTION (Application)
  67         0x85, 0x01,             //   REPORT_ID (1)
  68         0x05, 0x07,             //   USAGE_PAGE (Keyboard) (Key Codes)
  69         0x19, 0xe0,             //   USAGE_MINIMUM (Keyboard LeftControl)(224)
  70         0x29, 0xe7,             //   USAGE_MAXIMUM (Keyboard Right GUI)(231)
  71         0x15, 0x00,             //   LOGICAL_MINIMUM (0)
  72         0x25, 0x01,             //   LOGICAL_MAXIMUM (1)
  73         0x75, 0x01,             //   REPORT_SIZE (1)
  74         0x95, 0x08,             //   REPORT_COUNT (8)
  75         0x81, 0x02,             //   INPUT (Data,Var,Abs) ; Modifier byte
  76         0x95, 0x01,             //   REPORT_COUNT (1)
  77         0x75, 0x08,             //   REPORT_SIZE (8)
  78         0x81, 0x01,             //   INPUT (Cnst,Arr,Abs) ; Reserved byte
  79         0x95, 0x03,             //   REPORT_COUNT (3)
  80         0x75, 0x01,             //   REPORT_SIZE (1)
  81         0x05, 0x08,             //   USAGE_PAGE (LEDs)
  82         0x19, 0x01,             //   USAGE_MINIMUM (Num Lock)
  83         0x29, 0x03,             //   USAGE_MAXIMUM (Scroll Lock)
  84         0x91, 0x02,             //   OUTPUT (Data,Var,Abs) ; LED report
  85         0x95, 0x05,             //   REPORT_COUNT (5)
  86         0x75, 0x01,             //   REPORT_SIZE (1)
  87         0x91, 0x01,             //   OUTPUT (Cnst,Arr,Abs)
  88         0x95, 0x05,             //   REPORT_COUNT (5)
  89         0x75, 0x08,             //   REPORT_SIZE (8)
  90         0x15, 0x00,             //   LOGICAL_MINIMUM (0)
  91         0x25, 0xff,             //   LOGICAL_MAXIMUM (255)
  92         0x05, 0x07,             //   USAGE_PAGE (Keyboard)(Key Codes)
  93         0x19, 0x00,             //   USAGE_MINIMUM (Reserved (no event))(0)
  94         0x29, 0xff,             //   USAGE_MAXIMUM (Keyboard Application)(null)
  95         0x81, 0x00,             //   INPUT (Data,Ary,Abs)
  96         0xc0                    // END_COLLECTION
  97 };
  98
  99 PROGMEM const char usbHidMouseReportDescriptor[] = {
 100         0x06, 0x00, 0xff,       // USAGE_PAGE (65280)
 101         0x09, 0x01,             // USAGE (1)
 102         0xa1, 0x01,             // COLLECTION (Application)
 103         0x09, 0x01,             // USAGE (1)
 104         0x15, 0x00,             //   LOGICAL_MINIMUM (0)
 105         0x26, 0xff, 0x00,       //   LOGICAL_MAXIMUM (255)
 106         0x75, 0x08,             //   REPORT_SIZE (8)
 107         0x95, 0x08,             //   REPORT_COUNT (8)
 108         0x81, 0x02,             //   INPUT (Data,Var,Abs) ; Modifier byte
 109         0x09, 0x01,             // USAGE (Pointer)
 110         0x95, 0x08,             //   REPORT_COUNT (8)
 111         0x91, 0x02,             //   OUTPUT (Data,Var,Abs) ; Modifier byte
 112         0x05, 0x0c,             // USAGE_PAGE (Consumer)
 113         0x09, 0x00,             //   USAGE (0)
 114         0x15, 0x80,             //   LOGICAL_MINIMUM (128)
 115         0x25, 0x7f,             //   LOGICAL_MAXIMUM (127)
 116         0x75, 0x08,             //   REPORT_SIZE (8)
 117         0x95, 0x08,             //   REPORT_COUNT (8)
 118         0xb1, 0x02,             //   FEATURE (Data,Var,Abs)
 119         0xc0                    // END_COLLECTION
 120 };
 121
 122 /* USB configuration descriptor */
 123 PROGMEM const char usbDescriptorConfiguration[] = {
 124         9,                              /* sizeof(usbDescriptorConfiguration) */
 125         USBDESCR_CONFIG,                /* descriptor type */
 126         /* total length of data returned (including inlined descriptors) */
 127         18 + 9 + 9 + 7 + 9 + 7, 0,
 128         2,                              /* number of interfaces in this cfg */
 129         1,                              /* index of this configuration */
 130         0,                              /* configuration name string index */
 131         (1 << 7) | USBATTR_REMOTEWAKE,  /* attributes */
 132         USB_CFG_MAX_BUS_POWER/2,        /* max USB current in 2mA units */
 133
 134         /* Keyboard interface descriptor follows inline: */
 135
 136         /* sizeof(usbDescrInterface): length of descriptor in bytes */
 137         9,
 138         USBDESCR_INTERFACE,     /* descriptor type */
 139         0,                      /* index of this interface */
 140         0,                      /* alternate setting for this interface */
 141         /* endpoints excl 0: number of endpoint descriptors to follow */
 142         1,
 143         3,                      /* Interface class: HID */
 144         1,                      /* SubClass: Boot Interface */
 145         1,                      /* Interface protocol: Keyboard */
 146         0,                      /* string index for interface */
 147         9,                      /* sizeof(usbDescrHID) */
 148         USBDESCR_HID,           /* descriptor type: HID */
 149         0x10, 0x01,             /* BCD representation of HID version */
 150         0x00,                   /* target country code */
 151         /* number of HID Report (or other HID class) Descriptors to follow */
 152         0x01,
 153         0x22,                   /* descriptor type: report */
 154         sizeof(usbHidKeyboardReportDescriptor),
 155         0,              /* total length of report descriptor */
 156
 157         /* endpoint descriptor for endpoint 1 */
 158         7,                              /* sizeof(usbDescrEndpoint) */
 159         USBDESCR_ENDPOINT,              /* descriptor type = endpoint */
 160         (char)0x81,                     /* IN endpoint number 1 */
 161         0x03,                           /* attrib: Interrupt endpoint */
 162         8, 0,                           /* maximum packet size */
 163         USB_CFG_INTR_POLL_INTERVAL,     /* in ms */
 164
 165         /* Mouse interface descriptor follows inline: */
 166
 167         /* sizeof(usbDescrInterface): length of descriptor in bytes */
 168         9,
 169         USBDESCR_INTERFACE,     /* descriptor type */
 170         1,                      /* index of this interface */
 171         0,                      /* alternate setting for this interface */
 172         /* endpoints excl 0: number of endpoint descriptors to follow */
 173         1,
 174         3,                      /* Interface class: HID */
 175         1,                      /* SubClass: Boot Interface */
 176         2,                      /* Interface protocol: Mouse */
 177         0,                      /* string index for interface */
 178         9,                      /* sizeof(usbDescrHID) */
 179         USBDESCR_HID,           /* descriptor type: HID */
 180         0x10, 0x01,             /* BCD representation of HID version */
 181         0x00,                   /* target country code */
 182         /* number of HID Report (or other HID class) Descriptors to follow */
 183         0x01,
 184         0x22,                   /* descriptor type: report */
 185         /* total length of report descriptor */
 186         sizeof(usbHidMouseReportDescriptor), 0,
 187
 188         /* endpoint descriptor for endpoint 2 */
 189         7,                              /* sizeof(usbDescrEndpoint) */
 190         USBDESCR_ENDPOINT,              /* descriptor type = endpoint */
 191         (char)0x82,                     /* IN endpoint number 2 */
 192         0x03,                           /* attrib: Interrupt endpoint */
 193         8, 0,                           /* maximum packet size */
 194         USB_CFG_INTR_POLL_INTERVAL,     /* in ms */
 195 };
 196
 197 inline char hexdigit(unsigned int i)
 198 {
 199         return (i < 10) ? ('0' + i) : ('A' - 10 + i);
 200 }
 201
 202 /* Look for a 1-Wire device and use its ROMID to set the serial ID */
 203 void set_serial(void)
 204 {
 205         uint8_t buf[8];
 206         uint8_t i;
 207
 208         if (!w1_reset()) {
 209                 return;
 210         }
 211
 212         w1_write(0x33);         /* READ ROM */
 213         w1_read(buf, 8);
 214
 215         for (i = 0; i < 8; i++) {
 216                 serno_str[i * 2 + 1] = hexdigit(buf[i] >> 4);
 217                 serno_str[i * 2 + 2] = hexdigit(buf[i] & 0xF);
 218         }
 219 }
 220
 221 uint16_t read_temp(void)
 222 {
 223         uint8_t buf[9];
 224
 225         cli();
 226         if (!w1_reset()) {
 227                 return 0xFFFF;
 228                 sei();
 229         }
 230
 231         w1_write(0xCC);         /* SKIP ROM */
 232         w1_write(0x44);         /* Convert T */
 233
 234         do {
 235                 w1_read(buf, 1);
 236         } while (buf[0] != 0xFF);
 237
 238         if (!w1_reset()) {
 239                 return 0xFFFF;
 240                 sei();
 241         }
 242
 243         w1_write(0xCC);         /* SKIP ROM */
 244         w1_write(0xBE);         /* Read Scratchpad */
 245         w1_read(buf, 9);
 246         sei();
 247
 248         return buf[2] << 8 | buf[1];
 249 }
 250
 251 usbMsgLen_t usbFunctionDescriptor(usbRequest_t *rq)
 252 {
 253         if (rq->wValue.bytes[1] == USBDESCR_STRING &&
 254                         rq->wValue.bytes[0] == 3) {
 255                 usbMsgPtr = (usbMsgPtr_t) serno_str;
 256                 return sizeof(serno_str);
 257         } else if (rq->wValue.bytes[1] == USBDESCR_HID) {
 258                 if (rq->wIndex.word == USB_INDEX_MOUSE) {
 259                         /* "Mouse" */
 260                         usbMsgPtr = (usbMsgPtr_t)
 261                                 &usbDescriptorConfiguration[43];
 262                 } else {
 263                         /* "Keyboard" */
 264                         usbMsgPtr = (usbMsgPtr_t)
 265                                 &usbDescriptorConfiguration[18];
 266                 }
 267         } else if (rq->wValue.bytes[1] == USBDESCR_HID_REPORT) {
 268                 if (rq->wIndex.word == USB_INDEX_MOUSE) {
 269                         usbMsgPtr = (usbMsgPtr_t)
 270                                 &usbHidMouseReportDescriptor[0];
 271                         return sizeof(usbHidMouseReportDescriptor);
 272                 } else {
 273                         usbMsgPtr = (usbMsgPtr_t)
 274                                 &usbHidKeyboardReportDescriptor[0];
 275                         return sizeof(usbHidKeyboardReportDescriptor);
 276                 }
 277         }
 278
 279         return 0;
 280 }
 281
 282 usbMsgLen_t usbFunctionSetup(uchar data[8])
 283 {
 284         usbRequest_t *rq = (void *) data;
 285
 286         if ((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS) {
 287                 if (rq->bRequest == USBRQ_HID_GET_REPORT) {
 288                         /* No keys pressed, no mouse event */
 289                         usbMsgPtr = (void *) &keyboard_report;
 290                         keyboard_report.modifier = 0;
 291                         keyboard_report.reserved = 0;
 292                         keyboard_report.keycode[0] = 0;
 293                         return sizeof(keyboard_report);
 294                 } else if (rq->bRequest == USBRQ_HID_SET_REPORT) {
 295                         if (rq->wIndex.word == USB_INDEX_MOUSE) {
 296                                 return (rq->wLength.word == 8) ?
 297                                                 USB_NO_MSG : 0;
 298                         } else {
 299                                 /* Keyboard */
 300                                 return (rq->wLength.word == 1) ?
 301                                                 USB_NO_MSG : 0;
 302                         }
 303                 } else if (rq->bRequest == USBRQ_HID_GET_IDLE) {
 304                         usbMsgPtr = &idlerate;
 305                         return 1;
 306                 } else if (rq->bRequest == USBRQ_HID_SET_IDLE) {
 307                         idlerate = rq->wValue.bytes[1];
 308                 }
 309         }
 310
 311         return 0;
 312 }
 313
 314 usbMsgLen_t usbFunctionWrite(uint8_t * data, uchar len)
 315 {
 316         if (len == 1) {
 317                 PORTB |= 1 << PB1; // LED on
 318                 if (data[0] != ledstate) {
 319                         ledstate = data[0];
 320
 321                         if (ledstate & CAPS_LOCK) {
 322                                 PORTB |= 1 << PB1; // LED on
 323                         } else {
 324                                 PORTB &= ~(1 << PB1); // LED off
 325                         }
 326                 }
 327                 return 1;
 328         } else if (len == 8) {
 329                 /* Silently consume if unexpected*/
 330                 if (data[0] != 1)
 331                         return 8;
 332                 if ((data[4] | data[5] | data[6] | data[7]) != 0)
 333                         return 8;
 334
 335                 if (data[1] == 0x80 && data[2] == 0x33 && data[3] == 1) {
 336                         /* Temperature query */
 337                         memset(temp_report, 0, 8);
 338                         temp_state = 1;
 339                         temp_report[0] = 0x80;
 340                         temp_report[1] = 2;
 341                 } else if (data[1] == 0x82 && data[2] == 0x77 &&
 342                                 data[3] == 1) {
 343                         /* Initialisation Query #1 */
 344                         have_temp_int = true;
 345                         temp_report[0] = 0x82;
 346                         temp_report[1] = 1;
 347                         temp_report[2] = 0;
 348                 } else if (data[1] == 0x86 && data[2] == 0xff &&
 349                                 data[3] == 1) {
 350                         /* Initialisation Query #2 */
 351                         have_temp_int = true;
 352                         memcpy(temp_report, "TEMPerF1", 8);
 353                 }
 354
 355                 return 8;
 356         }
 357
 358         return 0;
 359 }
 360
 361 int main(void)
 362 {
 363         unsigned char i;
 364         uint8_t buf[9];
 365
 366         wdt_enable(WDTO_1S);
 367
 368         w1_setup();
 369         set_serial();
 370
 371         usbInit();
 372         usbDeviceDisconnect();
 373
 374         i = 0;
 375         while (--i) {
 376                 wdt_reset();
 377                 _delay_ms(1);
 378         }
 379
 380         usbDeviceConnect();
 381
 382         /* PB1 as output for LED */
 383         DDRB |= 1 << PB1;
 384
 385         sei(); /* We're ready to go; enable interrupts */
 386
 387         keyboard_report.modifier = 0;
 388         keyboard_report.reserved = 0;
 389         keyboard_report.keycode[0] = 0;
 390
 391         while (1) {
 392                 wdt_reset();
 393                 usbPoll();
 394
 395                 if (have_temp_int && usbInterruptIsReady3()) {
 396                         usbSetInterrupt3((void *) temp_report,
 397                                         sizeof(temp_report));
 398                         if (temp_report[0] == 'T') {
 399                                 /* Hack up second response for 0x86 query */
 400                                 memcpy(temp_report, ".2", 2);
 401                         } else {
 402                                 have_temp_int = false;
 403                         }
 404                 }
 405
 406                 if (temp_state == 1) {
 407                         if (w1_reset()) {
 408                                 temp_state = 2;
 409                         } else {
 410                                 temp_report[2] = 0xFF;
 411                                 temp_report[3] = 0xFF;
 412                                 have_temp_int = true;
 413                                 temp_state = 0;
 414                         }
 415                 } else if (temp_state == 2) {
 416                         w1_write(0xCC);         /* SKIP ROM */
 417                         temp_state = 3;
 418                 } else if (temp_state == 3) {
 419                         w1_write(0x44);         /* Convert T */
 420                         temp_state = 4;
 421                 } else if (temp_state == 4) {
 422                         if (w1_read_byte() == 0xFF)
 423                                 temp_state = 5;
 424                 } else if (temp_state == 5) {
 425                         if (w1_reset()) {
 426                                 temp_state = 6;
 427                         } else {
 428                                 temp_report[2] = 0xFF;
 429                                 temp_report[3] = 0xFE;
 430                                 have_temp_int = true;
 431                                 temp_state = 0;
 432                         }
 433                 } else if (temp_state == 6) {
 434                         w1_write(0xCC);         /* SKIP ROM */
 435                         temp_state = 7;
 436                 } else if (temp_state == 7) {
 437                         w1_write(0xBE);         /* Read Scratchpad */
 438                         temp_state = 8;
 439                 } else if (temp_state > 7 && temp_state < 17) {
 440                         buf[temp_state - 8] = w1_read_byte();
 441                         temp_state++;
 442                 } else if (temp_state == 17) {
 443                         temp_report[2] = buf[1] << 4 | buf[0] >> 4;
 444                         temp_report[3] = buf[0] << 4;
 445                         have_temp_int = true;
 446                         temp_state = 0;
 447                 }
 448         }
 449 }