test-sinclair/main.c

   1 /*
   2  *      Testing Communication with Sinclair Air Conditioner
   3  *
   4  *      (c) 2023 Martin Mareš <mj@ucw.cz>
   5  */
   6
   7 #include "util.h"
   8
   9 #include <libopencm3/cm3/cortex.h>
  10 #include <libopencm3/cm3/nvic.h>
  11 #include <libopencm3/cm3/systick.h>
  12 #include <libopencm3/cm3/scb.h>
  13 #include <libopencm3/stm32/rcc.h>
  14 #include <libopencm3/stm32/desig.h>
  15 #include <libopencm3/stm32/gpio.h>
  16 #include <libopencm3/stm32/usart.h>
  17 #include <libopencm3/stm32/spi.h>
  18 #include <libopencm3/stm32/timer.h>
  19 #include <libopencm3/usb/dfu.h>
  20 #include <libopencm3/usb/usbd.h>
  21
  22 #include <string.h>
  23
  24 /*** Hardware init ***/
  25
  26 static void clock_init(void)
  27 {
  28         rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE8_72MHZ]);
  29
  30         rcc_periph_clock_enable(RCC_GPIOA);
  31         rcc_periph_clock_enable(RCC_GPIOB);
  32         rcc_periph_clock_enable(RCC_GPIOC);
  33         rcc_periph_clock_enable(RCC_SPI2);
  34         rcc_periph_clock_enable(RCC_USART1);
  35         rcc_periph_clock_enable(RCC_USB);
  36         rcc_periph_clock_enable(RCC_TIM3);
  37         rcc_periph_clock_enable(RCC_TIM4);
  38
  39         rcc_periph_reset_pulse(RST_GPIOA);
  40         rcc_periph_reset_pulse(RST_GPIOB);
  41         rcc_periph_reset_pulse(RST_GPIOC);
  42         rcc_periph_reset_pulse(RST_SPI2);
  43         rcc_periph_reset_pulse(RST_USART1);
  44         rcc_periph_reset_pulse(RST_USB);
  45         rcc_periph_reset_pulse(RST_TIM3);
  46         rcc_periph_reset_pulse(RST_TIM4);
  47 }
  48
  49 static void gpio_init(void)
  50 {
  51         // PA9 = TXD1 for debugging console
  52         // PA10 = RXD1 for debugging console
  53         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
  54         gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO10);
  55
  56         // PC13 = BluePill LED
  57         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
  58         gpio_clear(GPIOC, GPIO13);
  59
  60         // PB13 = SCK2
  61         // PB15 = MOSI2
  62         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO13);
  63         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO15);
  64
  65         // PA8 = IR remote control
  66         gpio_clear(GPIOA, GPIO8);
  67         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8);
  68 }
  69
  70 static void usart_init(void)
  71 {
  72         usart_set_baudrate(USART1, 115200);
  73         usart_set_databits(USART1, 8);
  74         usart_set_stopbits(USART1, USART_STOPBITS_1);
  75         usart_set_mode(USART1, USART_MODE_TX_RX);
  76         usart_set_parity(USART1, USART_PARITY_NONE);
  77         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
  78
  79         usart_enable(USART1);
  80 }
  81
  82 /*** System ticks ***/
  83
  84 static volatile u32 ms_ticks;
  85
  86 void sys_tick_handler(void)
  87 {
  88         ms_ticks++;
  89 }
  90
  91 static void tick_init(void)
  92 {
  93         systick_set_frequency(1000, CPU_CLOCK_MHZ * 1000000);
  94         systick_counter_enable();
  95         systick_interrupt_enable();
  96 }
  97
  98 static void delay_ms(uint ms)
  99 {
 100         u32 start_ticks = ms_ticks;
 101         while (ms_ticks - start_ticks < ms)
 102                 ;
 103 }
 104
 105 /*** Emulated TM1618 LED Driver ***/
 106
 107 /*
 108  *  Theory of operation:
 109  *
 110  *  TM1618 communicates using a bi-directional SPI-like protocol.
 111  *  The AC unit is sending a stream of commands like this once per ca. 4 ms:
 112  *
 113  *      00 - set mode: 4 grids, 8 segments
 114  *      44 - will write to display memory, no auto-increment
 115  *      Cx - set memory address to x
 116  *      yy - data to write, two most-significant bits are always zero
 117  *      8B - display ON, duty cycle 10/16
 118  *
 119  *  No read commands are issued, so we can simulate TM1618 using a pure SPI slave.
 120  *
 121  *  Commands are delimited using the STB* (strobe) pin, but since our opto-couplers
 122  *  are negating, we cannot route this pin to SS (slave select) of our SPI.
 123  *  We tried triggering an external interrupt by this pin, but it turned out
 124  *  that the latency is too high.
 125  *
 126  *  Instead, we ignore STB* completely and implement a self-synchronizing receiver:
 127  *
 128  *    - The only byte which can have top 2 bits both set is the Cx command,
 129  *      so we can use this to find memory addresses and data in the stream.
 130  *      We can ignore all other commands.
 131  *
 132  *    - Whenever 1 ms passes since the last byte was received, we reset the SPI.
 133  *      This allows us to recover from misaligned bytes.
 134  */
 135
 136 static void tm_init(void)
 137 {
 138         // Configure SPI2 to receive
 139         spi_set_receive_only_mode(SPI2);
 140         spi_enable_software_slave_management(SPI2);
 141         spi_set_nss_low(SPI2);
 142         spi_send_lsb_first(SPI2);
 143         spi_set_clock_polarity_0(SPI2);
 144         spi_set_clock_phase_1(SPI2);
 145         spi_enable_rx_buffer_not_empty_interrupt(SPI2);
 146         nvic_enable_irq(NVIC_SPI2_IRQ);
 147         spi_enable(SPI2);
 148
 149         // TIM3 will handle receive timeout
 150         timer_set_prescaler(TIM3, CPU_CLOCK_MHZ-1);     // 1 tick = 1 μs
 151         timer_set_mode(TIM3, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_DOWN);
 152         timer_update_on_overflow(TIM3);
 153         timer_disable_preload(TIM3);
 154         timer_one_shot_mode(TIM3);
 155         timer_enable_irq(TIM3, TIM_DIER_UIE);
 156         nvic_enable_irq(NVIC_TIM3_IRQ);
 157 }
 158
 159 /*
 160  *  Data memory of TM1618:
 161  *
 162  *  [0]    .    .    .    -    -    -    -    -
 163  *  [1]    .    .    -    -    HEAT .    .    .
 164  *  [2]    .    .    .    DRY  -    SLP  MED  LOW
 165  *  [3]    .    .    HIGH AUTO COOL .    .    .
 166  *  [4]    .    .    .    B2   -    G2   D2   C2
 167  *  [5]    .    .    E2   F2   A2   .    .    .
 168  *  [6]    .    .    .    B1   -    G1   D1   C1
 169  *  [7]    .    .    E1   F1   A1   .    .    .
 170  *
 171  *  "." is an always-zero bit not defined by TM1618, "-" is defined, but not used by AC.
 172  */
 173 static volatile byte tm_data[8];
 174 static volatile uint tm_overruns;
 175
 176 static volatile byte tm_buffer[256];
 177 static volatile uint tm_len;
 178
 179 /*
 180  *
 181  *  Display segments:
 182  *
 183  *      +--A--+
 184  *      |     |
 185  *      F     B
 186  *      |     |
 187  *      +--G--+
 188  *      |     |
 189  *      E     C
 190  *      |     |
 191  *      +--D--+
 192  */
 193
 194 enum tm_seg {
 195         SEGa = 0x0800,
 196         SEGb = 0x0010,
 197         SEGc = 0x0001,
 198         SEGd = 0x0002,
 199         SEGe = 0x2000,
 200         SEGf = 0x1000,
 201         SEGg = 0x0004,
 202 };
 203
 204 static const u16 tm_digits[10] = {
 205         [0] = SEGa | SEGb | SEGc | SEGd | SEGe | SEGf,
 206         [1] = SEGb | SEGc,
 207         [2] = SEGa | SEGb | SEGd | SEGe | SEGg,
 208         [3] = SEGa | SEGb | SEGc | SEGd | SEGg,
 209         [4] = SEGb | SEGc | SEGf | SEGg,
 210         [5] = SEGa | SEGc | SEGd | SEGf | SEGg,
 211         [6] = SEGa | SEGc | SEGd | SEGe | SEGf | SEGg,
 212         [7] = SEGa | SEGb | SEGc,
 213         [8] = SEGa | SEGb | SEGc | SEGd | SEGe | SEGf | SEGg,
 214         [9] = SEGa | SEGb | SEGc | SEGd | SEGf | SEGg,
 215 };
 216
 217 static volatile uint tm_timeouts;
 218
 219 void spi2_isr(void)
 220 {
 221         if (SPI_SR(SPI2) & SPI_SR_OVR)
 222                 tm_overruns++;
 223         if (SPI_SR(SPI2) & SPI_SR_RXNE) {
 224                 byte x = SPI_DR(SPI2) ^ 0xff;
 225 #if 0
 226                 if (tm_len < ARRAY_SIZE(tm_buffer))
 227                         tm_buffer[tm_len++] = x;
 228 #endif
 229                 static byte tm_address;
 230                 if (tm_address) {
 231                         tm_data[tm_address & 7] = x;
 232                         tm_address = 0;
 233                 } else if ((x & 0xc0) == 0xc0) {
 234                         tm_address = x;
 235                 }
 236                 timer_set_period(TIM3, 999);
 237                 timer_generate_event(TIM3, TIM_EGR_UG);
 238                 timer_enable_counter(TIM3);
 239         }
 240 }
 241
 242 void tim3_isr(void)
 243 {
 244         if (TIM_SR(TIM3) & TIM_SR_UIF) {
 245                 TIM_SR(TIM3) &= ~TIM_SR_UIF;
 246                 tm_timeouts++;
 247                 spi_set_nss_high(SPI2);
 248                 spi_set_nss_low(SPI2);
 249         }
 250 }
 251
 252 static void tm_show(void)
 253 {
 254         debug_printf("TM:");
 255         for (uint i=0; i<8; i++)
 256                 debug_printf(" %02x", tm_data[i]);
 257         debug_printf(" o=%d t=%d", tm_overruns, tm_timeouts);
 258
 259         debug_printf(" =>");
 260         if (tm_data[1] & 0x08)
 261                 debug_printf(" HEAT");
 262         if (tm_data[2] & 0x10)
 263                 debug_printf(" DRY");
 264         if (tm_data[2] & 0x04)
 265                 debug_printf(" SLEEP");
 266         if (tm_data[2] & 0x02)
 267                 debug_printf(" MED");
 268         if (tm_data[2] & 0x01)
 269                 debug_printf(" LOW");
 270         if (tm_data[3] & 0x20)
 271                 debug_printf(" HIGH");
 272         if (tm_data[3] & 0x10)
 273                 debug_printf(" AUTO");
 274         if (tm_data[3] & 0x08)
 275                 debug_printf(" COOL");
 276
 277         debug_putc(' ');
 278         for (int i=0; i<2; i++) {
 279                 uint x = (tm_data[7-2*i] << 8) | tm_data[6-2*i];
 280                 uint j = 0;
 281                 while (j < 10 && tm_digits[j] != x)
 282                         j++;
 283                 if (j == 10)
 284                         debug_putc('?');
 285                 else
 286                         debug_putc('0' + j);
 287         }
 288
 289         debug_putc('\n');
 290
 291 #if 0
 292         static byte tm_dumped;
 293         if (!tm_dumped && tm_len == ARRAY_SIZE(tm_buffer)) {
 294                 for (uint i=0; i < tm_len; i++)
 295                         debug_printf("%02x ", tm_buffer[i]);
 296                 debug_putc('\n');
 297                 // tm_dumped = 1;
 298                 tm_len = 0;
 299         }
 300 #endif
 301 }
 302
 303 /*** Infra-red remote control simulator ***/
 304
 305 #define RC_POWER_OFF_HI         0b00000000000000000000
 306 #define RC_POWER_OFF_LO         0b00000000000000010000000010100100
 307
 308 #define RC_DEFAULT_HI           0b00000011000000000000
 309
 310 // Various temperatures
 311 #define RC_17_COOL_AUTO         0b00000000000000010000000000101001
 312 #define RC_18_COOL_AUTO         0b00000000000000010000000000111000
 313 #define RC_19_COOL_AUTO         0b00000000000000010000000001000111
 314 #define RC_20_COOL_AUTO         0b00000000000000010000000001010110
 315 #define RC_21_COOL_AUTO         0b00000000000000010000000001100101
 316 #define RC_22_COOL_AUTO         0b00000000000000010000000001110100
 317 #define RC_23_COOL_AUTO         0b00000000000000010000000010000011
 318 #define RC_24_COOL_AUTO         0b00000000000000010000000010010010
 319 #define RC_25_COOL_AUTO         0b00000000000000010000000010100001
 320 #define RC_26_COOL_AUTO         0b00000000000000010000000010110000
 321 #define RC_27_COOL_AUTO         0b00000000000000010000000011001111
 322 #define RC_28_COOL_AUTO         0b00000000000000010000000011011110
 323 #define RC_29_COOL_AUTO         0b00000000000000010000000011101101
 324 #define RC_30_COOL_AUTO         0b00000000000000010000000011111100
 325
 326 // Various fan settings
 327 #define RC_17_COOL_HI           0b00000000000000010000100000100001
 328 #define RC_17_COOL_MED          0b00000000000000010001000100100111
 329 #define RC_17_COOL_LO           0b00000000000000010010001000100101
 330
 331 // Stand-alone, no temperature nor fan setting
 332 #define RC_DEHUMIDIFY           0b00000000000000010010010000100011
 333
 334 // Combines with a temperature setting, but no fan setting
 335 #define RC_17_WARM              0b00000000000000010000001100100110
 336
 337 // All modes have a sleep variant, which we do not use yet
 338 #define RC_17_COOL_AUTO_SLEEP   0b00000000000010010000000000100001
 339
 340 static const u32 rc_fan_settings[4] = {
 341         0,
 342         RC_17_COOL_LO ^ RC_17_COOL_AUTO,
 343         RC_17_COOL_MED ^ RC_17_COOL_AUTO,
 344         RC_17_COOL_HI ^ RC_17_COOL_AUTO,
 345 };
 346
 347 static const u32 rc_temp_settings[14] = {
 348 #define X(t) RC_##t##_COOL_AUTO ^ RC_17_COOL_AUTO
 349         X(17),
 350         X(18),
 351         X(19),
 352         X(20),
 353         X(21),
 354         X(22),
 355         X(23),
 356         X(24),
 357         X(25),
 358         X(26),
 359         X(27),
 360         X(28),
 361         X(29),
 362         X(30),
 363 #undef X
 364 };
 365
 366 enum rc_mode {
 367         MODE_OFF,
 368         MODE_COOL,
 369         MODE_WARM,
 370         MODE_DEHUMIDIFY,
 371 };
 372
 373 static byte rc_mode;            // MODE_xxx
 374 static byte rc_fan;             // 0-3
 375 static byte rc_temp;            // 17-30
 376
 377 static void rc_init(void)
 378 {
 379         // TIM4 runs at 1 MHz and it is used for timing of RC pulses
 380         timer_set_prescaler(TIM4, CPU_CLOCK_MHZ - 1);
 381         timer_set_mode(TIM4, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
 382         timer_update_on_overflow(TIM4);
 383         timer_disable_preload(TIM4);
 384         timer_one_shot_mode(TIM4);
 385         timer_enable_irq(TIM4, TIM_DIER_UIE);
 386         nvic_enable_irq(NVIC_TIM4_IRQ);
 387 }
 388
 389 static u32 rc_pattern[2];
 390 static uint rc_tick;
 391
 392 static void rc_encode(void)
 393 {
 394         if (rc_mode == MODE_OFF) {
 395                 rc_pattern[0] = RC_POWER_OFF_HI;
 396                 rc_pattern[1] = RC_POWER_OFF_LO;
 397                 return;
 398         }
 399
 400         rc_pattern[0] = RC_DEFAULT_HI;
 401         uint t = rc_temp, f = rc_fan;
 402
 403         if (rc_mode == MODE_COOL) {
 404                 rc_pattern[1] = RC_17_COOL_AUTO;
 405         } else if (rc_mode == MODE_WARM) {
 406                 rc_pattern[1] = RC_17_WARM;
 407                 f = 0;
 408         } else {
 409                 rc_pattern[1] = RC_DEHUMIDIFY;
 410                 f = t = 0;
 411         }
 412
 413         rc_pattern[1] ^= rc_fan_settings[f];
 414
 415         if (t >= 17 && t < 17 + ARRAY_SIZE(rc_temp_settings))
 416                 rc_pattern[1] ^= rc_temp_settings[t - 17];
 417 }
 418
 419 void tim4_isr(void)
 420 {
 421         if (TIM_SR(TIM4) & TIM_SR_UIF) {
 422                 TIM_SR(TIM4) &= ~TIM_SR_UIF;
 423
 424                 bool val;       // 1=pulse, 0=break
 425                 uint duration;  // in μs
 426
 427                 switch (rc_tick++) {
 428                         case 0:
 429                                 // Better be safe
 430                                 return;
 431                         case 2:
 432                         case 108:
 433                                 // Initial / final marker
 434                                 val = 0;
 435                                 duration = 3600;
 436                                 break;
 437                         case 110:
 438                                 // Inter-packet gap
 439                                 val = 0;
 440                                 duration = 10000;
 441                                 break;
 442                         case 111:
 443                                 // End of message
 444                                 rc_tick = 0;
 445                                 return;
 446                         default:
 447                                 if (rc_tick % 2) {
 448                                         val = 1;
 449                                         duration = 565;
 450                                 } else {
 451                                         // Even ticks 4 to 106 transmit 52 bits of data
 452                                         uint i = 12 + (rc_tick - 4) / 2;
 453                                         val = 0;
 454                                         if (rc_pattern[i>>5] & (1 << (i & 31)))
 455                                                 duration = 1471;
 456                                         else
 457                                                 duration = 480;
 458                                 }
 459                 }
 460
 461                 if (val)
 462                         gpio_set(GPIOA, GPIO8);
 463                 else
 464                         gpio_clear(GPIOA, GPIO8);
 465
 466                 timer_set_period(TIM4, duration - 1);
 467                 timer_generate_event(TIM4, TIM_EGR_UG);
 468                 timer_enable_counter(TIM4);
 469         }
 470 }
 471
 472 static void rc_send(void)
 473 {
 474         if (rc_tick)
 475                 return;
 476
 477         rc_encode();
 478         debug_printf("RC sending: %05x %08x\n", (uint) rc_pattern[0], (uint) rc_pattern[1]);
 479         rc_tick = 1;
 480
 481         timer_set_period(TIM4, 1);
 482         timer_generate_event(TIM4, TIM_EGR_UG);
 483         timer_enable_counter(TIM4);
 484 }
 485
 486 static bool rc_key(char key)
 487 {
 488         if (key == 'o') {
 489                 rc_mode = MODE_OFF;
 490                 rc_send();
 491                 return true;
 492         } else if (key == 'c') {
 493                 rc_mode = MODE_COOL;
 494                 rc_send();
 495                 return true;
 496         } else if (key == 'w') {
 497                 rc_mode = MODE_WARM;
 498                 rc_send();
 499                 return true;
 500         } else if (key == 'd') {
 501                 rc_mode = MODE_DEHUMIDIFY;
 502                 rc_send();
 503                 return true;
 504         } else if (key == 'a') {
 505                 rc_fan = 0;
 506                 rc_send();
 507                 return true;
 508         } else if (key == 'l') {
 509                 rc_fan = 1;
 510                 rc_send();
 511                 return true;
 512         } else if (key == 'm') {
 513                 rc_fan = 2;
 514                 rc_send();
 515                 return true;
 516         } else if (key == 'h') {
 517                 rc_fan = 3;
 518                 rc_send();
 519                 return true;
 520         } else if (key >= '7' && key <= '9') {
 521                 rc_temp = key - '0' + 10;
 522                 rc_send();
 523                 return true;
 524         } else if (key >= '0' && key <= '6') {
 525                 rc_temp = key - '0' + 20;
 526                 rc_send();
 527                 return true;
 528         } else if (key == '&') {
 529                 rc_temp = 27;
 530                 rc_send();
 531                 return true;
 532         } else if (key == '*') {
 533                 rc_temp = 28;
 534                 rc_send();
 535                 return true;
 536         } else if (key == '(') {
 537                 rc_temp = 29;
 538                 rc_send();
 539                 return true;
 540         } else if (key == ')') {
 541                 rc_temp = 30;
 542                 rc_send();
 543                 return true;
 544         }
 545         return false;
 546 }
 547
 548 /*** USB ***/
 549
 550 static usbd_device *usbd_dev;
 551
 552 enum usb_string {
 553         STR_MANUFACTURER = 1,
 554         STR_PRODUCT,
 555         STR_SERIAL,
 556 };
 557
 558 static char usb_serial_number[13];
 559
 560 static const char *usb_strings[] = {
 561         "United Computer Wizards",
 562         "Sinclair Air Conditioner",
 563         usb_serial_number,
 564 };
 565
 566 static const struct usb_device_descriptor device = {
 567         .bLength = USB_DT_DEVICE_SIZE,
 568         .bDescriptorType = USB_DT_DEVICE,
 569         .bcdUSB = 0x0200,
 570         .bDeviceClass = 0xFF,
 571         .bDeviceSubClass = 0,
 572         .bDeviceProtocol = 0,
 573         .bMaxPacketSize0 = 64,
 574         .idVendor = 0x4242,
 575         .idProduct = 0x0007,
 576         .bcdDevice = 0x0000,
 577         .iManufacturer = STR_MANUFACTURER,
 578         .iProduct = STR_PRODUCT,
 579         .iSerialNumber = STR_SERIAL,
 580         .bNumConfigurations = 1,
 581 };
 582
 583 static const struct usb_endpoint_descriptor endpoints[] = {{
 584         // Bulk end-point for sending values to the display
 585         .bLength = USB_DT_ENDPOINT_SIZE,
 586         .bDescriptorType = USB_DT_ENDPOINT,
 587         .bEndpointAddress = 0x01,
 588         .bmAttributes = USB_ENDPOINT_ATTR_BULK,
 589         .wMaxPacketSize = 64,
 590         .bInterval = 1,
 591 }};
 592
 593 static const struct usb_interface_descriptor iface = {
 594         .bLength = USB_DT_INTERFACE_SIZE,
 595         .bDescriptorType = USB_DT_INTERFACE,
 596         .bInterfaceNumber = 0,
 597         .bAlternateSetting = 0,
 598         .bNumEndpoints = 1,
 599         .bInterfaceClass = 0xFF,
 600         .bInterfaceSubClass = 0,
 601         .bInterfaceProtocol = 0,
 602         .iInterface = 0,
 603         .endpoint = endpoints,
 604 };
 605
 606 static const struct usb_dfu_descriptor dfu_function = {
 607         .bLength = sizeof(struct usb_dfu_descriptor),
 608         .bDescriptorType = DFU_FUNCTIONAL,
 609         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
 610         .wDetachTimeout = 255,
 611         .wTransferSize = 1024,
 612         .bcdDFUVersion = 0x0100,
 613 };
 614
 615 static const struct usb_interface_descriptor dfu_iface = {
 616         .bLength = USB_DT_INTERFACE_SIZE,
 617         .bDescriptorType = USB_DT_INTERFACE,
 618         .bInterfaceNumber = 1,
 619         .bAlternateSetting = 0,
 620         .bNumEndpoints = 0,
 621         .bInterfaceClass = 0xFE,
 622         .bInterfaceSubClass = 1,
 623         .bInterfaceProtocol = 1,
 624         .iInterface = 0,
 625
 626         .extra = &dfu_function,
 627         .extralen = sizeof(dfu_function),
 628 };
 629
 630 static const struct usb_interface ifaces[] = {{
 631         .num_altsetting = 1,
 632         .altsetting = &iface,
 633 }, {
 634         .num_altsetting = 1,
 635         .altsetting = &dfu_iface,
 636 }};
 637
 638 static const struct usb_config_descriptor config = {
 639         .bLength = USB_DT_CONFIGURATION_SIZE,
 640         .bDescriptorType = USB_DT_CONFIGURATION,
 641         .wTotalLength = 0,
 642         .bNumInterfaces = 2,
 643         .bConfigurationValue = 1,
 644         .iConfiguration = 0,
 645         .bmAttributes = 0x80,
 646         .bMaxPower = 50,        // multiplied by 2 mA
 647         .interface = ifaces,
 648 };
 649
 650 static byte usb_configured;
 651 static uint8_t usbd_control_buffer[64];
 652
 653 static void dfu_detach_complete(usbd_device *dev UNUSED, struct usb_setup_data *req UNUSED)
 654 {
 655         // Reset to bootloader, which implements the rest of DFU
 656         debug_printf("Switching to DFU\n");
 657         debug_flush();
 658         scb_reset_core();
 659 }
 660
 661 static enum usbd_request_return_codes dfu_control_cb(usbd_device *dev UNUSED,
 662         struct usb_setup_data *req,
 663         uint8_t **buf UNUSED,
 664         uint16_t *len UNUSED,
 665         void (**complete)(usbd_device *dev, struct usb_setup_data *req))
 666 {
 667         if (req->bmRequestType != 0x21 || req->bRequest != DFU_DETACH)
 668                 return USBD_REQ_NOTSUPP;
 669
 670         *complete = dfu_detach_complete;
 671         return USBD_REQ_HANDLED;
 672 }
 673
 674 static void ep01_cb(usbd_device *dev, uint8_t ep UNUSED)
 675 {
 676         // We received a frame from the USB host
 677         byte buf[8];
 678         uint len = usbd_ep_read_packet(dev, 0x01, buf, 8);
 679         debug_printf("USB: Host sent %u bytes\n", len);
 680 }
 681
 682 static void set_config_cb(usbd_device *dev, uint16_t wValue UNUSED)
 683 {
 684         usbd_register_control_callback(
 685                 dev,
 686                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 687                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 688                 dfu_control_cb);
 689         usbd_ep_setup(dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, ep01_cb);
 690         usb_configured = 1;
 691 }
 692
 693 static void reset_cb(void)
 694 {
 695         debug_printf("USB: Reset\n");
 696         usb_configured = 0;
 697 }
 698
 699 static volatile bool usb_event_pending;
 700
 701 void usb_lp_can_rx0_isr(void)
 702 {
 703         /*
 704          *  We handle USB in the main loop to avoid race conditions between
 705          *  USB interrupts and other code. However, we need an interrupt to
 706          *  up the main loop from sleep.
 707          *
 708          *  We set up only the low-priority ISR, because high-priority ISR handles
 709          *  only double-buffered bulk transfers and isochronous transfers.
 710          */
 711         nvic_disable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 712         usb_event_pending = 1;
 713 }
 714
 715 static void usb_init(void)
 716 {
 717         // Simulate USB disconnect
 718         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 719         gpio_clear(GPIOA, GPIO11 | GPIO12);
 720         delay_ms(100);
 721
 722         usbd_dev = usbd_init(
 723                 &st_usbfs_v1_usb_driver,
 724                 &device,
 725                 &config,
 726                 usb_strings,
 727                 ARRAY_SIZE(usb_strings),
 728                 usbd_control_buffer,
 729                 sizeof(usbd_control_buffer)
 730         );
 731         usbd_register_reset_callback(usbd_dev, reset_cb);
 732         usbd_register_set_config_callback(usbd_dev, set_config_cb);
 733         usb_event_pending = 1;
 734 }
 735
 736 /*** Main ***/
 737
 738 int main(void)
 739 {
 740         clock_init();
 741         gpio_init();
 742         usart_init();
 743
 744         tick_init();
 745         desig_get_unique_id_as_dfu(usb_serial_number);
 746
 747         debug_printf("Hello, world!\n");
 748
 749         tm_init();
 750         rc_init();
 751         usb_init();
 752
 753         u32 last_blink = 0;
 754
 755         for (;;) {
 756                 if (ms_ticks - last_blink >= 1000) {
 757                         debug_led_toggle();
 758                         last_blink = ms_ticks;
 759                         tm_show();
 760                 }
 761
 762                 if (usart_get_flag(USART1, USART_SR_RXNE)) {
 763                         uint ch = usart_recv(USART1);
 764 #if 0
 765                         if (ch == '1')
 766                                 gpio_set(GPIOA, GPIO8);
 767                         else if (ch == '0')
 768                                 gpio_clear(GPIOA, GPIO8);
 769 #else
 770                         if (rc_key(ch))
 771                                 ;
 772 #endif
 773                         else
 774                                 debug_putc(ch);
 775                 }
 776
 777                 if (usb_event_pending) {
 778                         usbd_poll(usbd_dev);
 779                         usb_event_pending = 0;
 780                         nvic_clear_pending_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 781                         nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 782                 }
 783
 784                 wait_for_interrupt();
 785         }
 786
 787         return 0;
 788 }