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_ALTFN_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 enum rc_keys {
 306         RC_POWER_OFF,
 307         RC_POWER_ON,
 308         RC_HIGH,
 309         RC_MED,
 310         RC_LO,
 311         RC_SLEEP,
 312         RC_DRY,
 313         RC_WARM,
 314         RC_COLD,
 315         RC_T17,
 316         RC_T18,
 317         RC_T19,
 318         RC_T20,
 319         RC_T21,
 320         RC_T22,
 321         RC_T23,
 322         RC_T24,
 323         RC_T25,
 324         RC_T26,
 325         RC_T27,
 326         RC_T28,
 327         RC_T29,
 328         RC_T30,
 329         RC_MAX
 330 };
 331
 332 static const char * const rc_patterns[RC_MAX] = {
 333         [RC_POWER_OFF]  = "*#*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*B*A*A*B*A*A*#*$",
 334         [RC_POWER_ON]   = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*B*A*A*A*A*B*#*$",
 335         [RC_HIGH]       = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*B*A*A*A*B*A*B*A*B*A*A*B*#*$",
 336         [RC_MED]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*B*A*A*A*B*B*A*B*A*B*B*B*B*#*$",
 337         [RC_LO]         = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*B*A*A*A*B*A*B*A*B*A*B*B*A*B*#*$",
 338         [RC_SLEEP]      = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*B*A*A*B*A*A*A*B*A*B*A*B*A*A*B*A*B*#*$",
 339         [RC_DRY]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*B*A*A*B*A*A*B*A*B*A*B*A*B*B*#*$",
 340         [RC_WARM]       = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*B*B*B*A*B*A*B*B*B*A*#*$",
 341         [RC_COLD]       = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*B*A*A*A*A*B*#*$",
 342         [RC_T17]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*A*A*B*A*B*A*A*B*#*$",
 343         [RC_T18]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*A*A*B*B*B*A*A*A*#*$",
 344         [RC_T19]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*A*B*A*A*A*B*B*B*#*$",
 345         [RC_T20]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*A*B*A*B*A*B*B*A*#*$",
 346         [RC_T21]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*A*B*B*A*A*B*A*B*#*$",
 347         [RC_T22]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*A*B*B*B*A*B*A*A*#*$",
 348         [RC_T23]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*A*A*A*A*B*B*#*$",
 349         [RC_T24]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*A*B*A*A*B*A*#*$",
 350         [RC_T25]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*B*A*A*A*A*B*#*$",
 351         [RC_T26]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*A*B*B*A*A*A*A*#*$",
 352         [RC_T27]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*B*A*A*B*B*B*B*#*$",
 353         [RC_T28]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*B*A*B*B*B*B*A*#*$",
 354         [RC_T29]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*B*B*A*B*B*A*B*#*$",
 355         [RC_T30]        = "*#*A*A*A*A*A*A*B*B*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*A*B*A*A*A*A*A*A*A*A*B*B*B*B*B*B*A*A*#*$",
 356 };
 357
 358 static const char rc_keys[] = "Oohmlsdwc7890123456&*()";
 359
 360 static void rc_init(void)
 361 {
 362         // TIM4 runs at 1 MHz and it is used for timing of RC pulses
 363         timer_set_prescaler(TIM4, CPU_CLOCK_MHZ - 1);
 364         timer_set_mode(TIM4, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
 365         timer_update_on_overflow(TIM4);
 366         timer_disable_preload(TIM4);
 367         timer_one_shot_mode(TIM4);
 368         timer_enable_irq(TIM4, TIM_DIER_UIE);
 369         nvic_enable_irq(NVIC_TIM4_IRQ);
 370 }
 371
 372 static volatile const char *rc_pattern_pos;
 373 static volatile char rc_pending;
 374
 375 void tim4_isr(void)
 376 {
 377         if (TIM_SR(TIM4) & TIM_SR_UIF) {
 378                 TIM_SR(TIM4) &= ~TIM_SR_UIF;
 379
 380                 if (!rc_pattern_pos)    // Just to be sure
 381                         return;
 382
 383                 bool val;       // 1=pulse, 0=break
 384                 uint duration;  // in μs
 385
 386                 switch (*rc_pattern_pos++) {
 387                         case '#':
 388                                 val = 0;
 389                                 duration = 3600;
 390                                 break;
 391                         case '*':
 392                                 val = 1;
 393                                 duration = 565;
 394                                 break;
 395                         case 'A':
 396                                 val = 0;
 397                                 duration = 480;
 398                                 break;
 399                         case 'B':
 400                                 val = 0;
 401                                 duration = 1471;
 402                                 break;
 403                         case '$':
 404                                 val = 0;
 405                                 duration = 10000;
 406                                 break;
 407                         default:
 408                                 // End of transmission
 409                                 rc_pattern_pos = NULL;
 410                                 rc_pending = 0;
 411                                 return;
 412                 }
 413
 414                 if (val)
 415                         gpio_set(GPIOA, GPIO8);
 416                 else
 417                         gpio_clear(GPIOA, GPIO8);
 418
 419                 timer_set_period(TIM4, duration - 1);
 420                 timer_generate_event(TIM4, TIM_EGR_UG);
 421                 timer_enable_counter(TIM4);
 422         }
 423 }
 424
 425 static bool rc_send(char key)
 426 {
 427         if (rc_pending)
 428                 return false;
 429         if (!key)
 430                 return false;
 431
 432         const char *s = strchr(rc_keys, key);
 433         if (!s)
 434                 return false;
 435         rc_pending = key;
 436         rc_pattern_pos = rc_patterns[s - rc_keys];
 437         debug_printf("RC sending: %c\n", key);
 438
 439         timer_set_period(TIM4, 1);
 440         timer_generate_event(TIM4, TIM_EGR_UG);
 441         timer_enable_counter(TIM4);
 442         return true;
 443 }
 444
 445 /*** USB ***/
 446
 447 static usbd_device *usbd_dev;
 448
 449 enum usb_string {
 450         STR_MANUFACTURER = 1,
 451         STR_PRODUCT,
 452         STR_SERIAL,
 453 };
 454
 455 static char usb_serial_number[13];
 456
 457 static const char *usb_strings[] = {
 458         "United Computer Wizards",
 459         "Sinclair Air Conditioner",
 460         usb_serial_number,
 461 };
 462
 463 static const struct usb_device_descriptor device = {
 464         .bLength = USB_DT_DEVICE_SIZE,
 465         .bDescriptorType = USB_DT_DEVICE,
 466         .bcdUSB = 0x0200,
 467         .bDeviceClass = 0xFF,
 468         .bDeviceSubClass = 0,
 469         .bDeviceProtocol = 0,
 470         .bMaxPacketSize0 = 64,
 471         .idVendor = 0x4242,
 472         .idProduct = 0x0007,
 473         .bcdDevice = 0x0000,
 474         .iManufacturer = STR_MANUFACTURER,
 475         .iProduct = STR_PRODUCT,
 476         .iSerialNumber = STR_SERIAL,
 477         .bNumConfigurations = 1,
 478 };
 479
 480 static const struct usb_endpoint_descriptor endpoints[] = {{
 481         // Bulk end-point for sending values to the display
 482         .bLength = USB_DT_ENDPOINT_SIZE,
 483         .bDescriptorType = USB_DT_ENDPOINT,
 484         .bEndpointAddress = 0x01,
 485         .bmAttributes = USB_ENDPOINT_ATTR_BULK,
 486         .wMaxPacketSize = 64,
 487         .bInterval = 1,
 488 }};
 489
 490 static const struct usb_interface_descriptor iface = {
 491         .bLength = USB_DT_INTERFACE_SIZE,
 492         .bDescriptorType = USB_DT_INTERFACE,
 493         .bInterfaceNumber = 0,
 494         .bAlternateSetting = 0,
 495         .bNumEndpoints = 1,
 496         .bInterfaceClass = 0xFF,
 497         .bInterfaceSubClass = 0,
 498         .bInterfaceProtocol = 0,
 499         .iInterface = 0,
 500         .endpoint = endpoints,
 501 };
 502
 503 static const struct usb_dfu_descriptor dfu_function = {
 504         .bLength = sizeof(struct usb_dfu_descriptor),
 505         .bDescriptorType = DFU_FUNCTIONAL,
 506         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
 507         .wDetachTimeout = 255,
 508         .wTransferSize = 1024,
 509         .bcdDFUVersion = 0x0100,
 510 };
 511
 512 static const struct usb_interface_descriptor dfu_iface = {
 513         .bLength = USB_DT_INTERFACE_SIZE,
 514         .bDescriptorType = USB_DT_INTERFACE,
 515         .bInterfaceNumber = 1,
 516         .bAlternateSetting = 0,
 517         .bNumEndpoints = 0,
 518         .bInterfaceClass = 0xFE,
 519         .bInterfaceSubClass = 1,
 520         .bInterfaceProtocol = 1,
 521         .iInterface = 0,
 522
 523         .extra = &dfu_function,
 524         .extralen = sizeof(dfu_function),
 525 };
 526
 527 static const struct usb_interface ifaces[] = {{
 528         .num_altsetting = 1,
 529         .altsetting = &iface,
 530 }, {
 531         .num_altsetting = 1,
 532         .altsetting = &dfu_iface,
 533 }};
 534
 535 static const struct usb_config_descriptor config = {
 536         .bLength = USB_DT_CONFIGURATION_SIZE,
 537         .bDescriptorType = USB_DT_CONFIGURATION,
 538         .wTotalLength = 0,
 539         .bNumInterfaces = 2,
 540         .bConfigurationValue = 1,
 541         .iConfiguration = 0,
 542         .bmAttributes = 0x80,
 543         .bMaxPower = 50,        // multiplied by 2 mA
 544         .interface = ifaces,
 545 };
 546
 547 static byte usb_configured;
 548 static uint8_t usbd_control_buffer[64];
 549
 550 static void dfu_detach_complete(usbd_device *dev UNUSED, struct usb_setup_data *req UNUSED)
 551 {
 552         // Reset to bootloader, which implements the rest of DFU
 553         debug_printf("Switching to DFU\n");
 554         debug_flush();
 555         scb_reset_core();
 556 }
 557
 558 static enum usbd_request_return_codes dfu_control_cb(usbd_device *dev UNUSED,
 559         struct usb_setup_data *req,
 560         uint8_t **buf UNUSED,
 561         uint16_t *len UNUSED,
 562         void (**complete)(usbd_device *dev, struct usb_setup_data *req))
 563 {
 564         if (req->bmRequestType != 0x21 || req->bRequest != DFU_DETACH)
 565                 return USBD_REQ_NOTSUPP;
 566
 567         *complete = dfu_detach_complete;
 568         return USBD_REQ_HANDLED;
 569 }
 570
 571 static void ep01_cb(usbd_device *dev, uint8_t ep UNUSED)
 572 {
 573         // We received a frame from the USB host
 574         byte buf[8];
 575         uint len = usbd_ep_read_packet(dev, 0x01, buf, 8);
 576         debug_printf("USB: Host sent %u bytes\n", len);
 577 }
 578
 579 static void set_config_cb(usbd_device *dev, uint16_t wValue UNUSED)
 580 {
 581         usbd_register_control_callback(
 582                 dev,
 583                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 584                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 585                 dfu_control_cb);
 586         usbd_ep_setup(dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, ep01_cb);
 587         usb_configured = 1;
 588 }
 589
 590 static void reset_cb(void)
 591 {
 592         debug_printf("USB: Reset\n");
 593         usb_configured = 0;
 594 }
 595
 596 static volatile bool usb_event_pending;
 597
 598 void usb_lp_can_rx0_isr(void)
 599 {
 600         /*
 601          *  We handle USB in the main loop to avoid race conditions between
 602          *  USB interrupts and other code. However, we need an interrupt to
 603          *  up the main loop from sleep.
 604          *
 605          *  We set up only the low-priority ISR, because high-priority ISR handles
 606          *  only double-buffered bulk transfers and isochronous transfers.
 607          */
 608         nvic_disable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 609         usb_event_pending = 1;
 610 }
 611
 612 static void usb_init(void)
 613 {
 614         // Simulate USB disconnect
 615         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 616         gpio_clear(GPIOA, GPIO11 | GPIO12);
 617         delay_ms(100);
 618
 619         usbd_dev = usbd_init(
 620                 &st_usbfs_v1_usb_driver,
 621                 &device,
 622                 &config,
 623                 usb_strings,
 624                 ARRAY_SIZE(usb_strings),
 625                 usbd_control_buffer,
 626                 sizeof(usbd_control_buffer)
 627         );
 628         usbd_register_reset_callback(usbd_dev, reset_cb);
 629         usbd_register_set_config_callback(usbd_dev, set_config_cb);
 630         usb_event_pending = 1;
 631 }
 632
 633 /*** Main ***/
 634
 635 int main(void)
 636 {
 637         clock_init();
 638         gpio_init();
 639         usart_init();
 640
 641         tick_init();
 642         desig_get_unique_id_as_dfu(usb_serial_number);
 643
 644         debug_printf("Hello, world!\n");
 645
 646         tm_init();
 647         rc_init();
 648         usb_init();
 649
 650         u32 last_blink = 0;
 651
 652         for (;;) {
 653                 if (ms_ticks - last_blink >= 1000) {
 654                         debug_led_toggle();
 655                         last_blink = ms_ticks;
 656                         tm_show();
 657                 }
 658
 659                 if (usart_get_flag(USART1, USART_SR_RXNE)) {
 660                         uint ch = usart_recv(USART1);
 661                         debug_putc(ch);
 662                 }
 663
 664                 if (usb_event_pending) {
 665                         usbd_poll(usbd_dev);
 666                         usb_event_pending = 0;
 667                         nvic_clear_pending_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 668                         nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 669                 }
 670
 671                 wait_for_interrupt();
 672         }
 673
 674         return 0;
 675 }