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/exti.h>
  19 #include <libopencm3/stm32/timer.h>
  20 #include <libopencm3/usb/dfu.h>
  21 #include <libopencm3/usb/usbd.h>
  22
  23 #include <string.h>
  24
  25 /*** Hardware init ***/
  26
  27 static void clock_init(void)
  28 {
  29         rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE8_72MHZ]);
  30
  31         rcc_periph_clock_enable(RCC_GPIOA);
  32         rcc_periph_clock_enable(RCC_GPIOB);
  33         rcc_periph_clock_enable(RCC_GPIOC);
  34         rcc_periph_clock_enable(RCC_SPI2);
  35         rcc_periph_clock_enable(RCC_USART1);
  36         rcc_periph_clock_enable(RCC_USB);
  37         rcc_periph_clock_enable(RCC_AFIO);
  38         rcc_periph_clock_enable(RCC_TIM3);
  39
  40         rcc_periph_reset_pulse(RST_GPIOA);
  41         rcc_periph_reset_pulse(RST_GPIOB);
  42         rcc_periph_reset_pulse(RST_GPIOC);
  43         rcc_periph_reset_pulse(RST_SPI2);
  44         rcc_periph_reset_pulse(RST_USART1);
  45         rcc_periph_reset_pulse(RST_USB);
  46         rcc_periph_reset_pulse(RST_AFIO);
  47         rcc_periph_reset_pulse(RST_TIM3);
  48 }
  49
  50 static void gpio_init(void)
  51 {
  52         // PA9 = TXD1 for debugging console
  53         // PA10 = RXD1 for debugging console
  54         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
  55         gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO10);
  56
  57         // PC13 = BluePill LED
  58         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
  59         gpio_clear(GPIOC, GPIO13);
  60
  61         // PB12 = SS2 (but used as GP input)
  62         // PB13 = SCK2
  63         // PB15 = MOSI2
  64         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO12);
  65         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO13);
  66         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO15);
  67 }
  68
  69 static void usart_init(void)
  70 {
  71         usart_set_baudrate(USART1, 115200);
  72         usart_set_databits(USART1, 8);
  73         usart_set_stopbits(USART1, USART_STOPBITS_1);
  74         usart_set_mode(USART1, USART_MODE_TX);
  75         usart_set_parity(USART1, USART_PARITY_NONE);
  76         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
  77
  78         usart_enable(USART1);
  79 }
  80
  81 /*** System ticks ***/
  82
  83 static volatile u32 ms_ticks;
  84
  85 void sys_tick_handler(void)
  86 {
  87         ms_ticks++;
  88 }
  89
  90 static void tick_init(void)
  91 {
  92         systick_set_frequency(1000, CPU_CLOCK_MHZ * 1000000);
  93         systick_counter_enable();
  94         systick_interrupt_enable();
  95 }
  96
  97 static void delay_ms(uint ms)
  98 {
  99         u32 start_ticks = ms_ticks;
 100         while (ms_ticks - start_ticks < ms)
 101                 ;
 102 }
 103
 104 /*** Emulated TM1618 LED Driver ***/
 105
 106 static void tm_init(void)
 107 {
 108         // Configure SPI2 to receive
 109         spi_set_receive_only_mode(SPI2);
 110         spi_enable_software_slave_management(SPI2);
 111         spi_set_nss_low(SPI2);
 112         spi_send_lsb_first(SPI2);
 113         spi_set_clock_polarity_0(SPI2);
 114         spi_set_clock_phase_1(SPI2);
 115         spi_enable_rx_buffer_not_empty_interrupt(SPI2);
 116         nvic_enable_irq(NVIC_SPI2_IRQ);
 117         spi_enable(SPI2);
 118
 119 #if 0
 120         // Since our optocouplers are negating, we cannot let STM32 to handle slave
 121         // select in hardware. Instead, we let SS trigger an interrupt, which changes
 122         // SPI state accordingly.
 123         nvic_set_priority(NVIC_EXTI15_10_IRQ, 0);
 124         nvic_enable_irq(NVIC_EXTI15_10_IRQ);
 125         exti_set_trigger(EXTI12, EXTI_TRIGGER_BOTH);
 126         exti_select_source(EXTI12, GPIOB);
 127         exti_enable_request(EXTI12);
 128 #endif
 129
 130 #if 1
 131         timer_set_prescaler(TIM3, CPU_CLOCK_MHZ-1);     // 1 tick = 1 μs
 132         timer_set_mode(TIM3, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_DOWN);
 133         timer_update_on_overflow(TIM3);
 134         timer_disable_preload(TIM3);
 135         timer_one_shot_mode(TIM3);
 136         timer_enable_irq(TIM3, TIM_DIER_UIE);
 137         nvic_enable_irq(NVIC_TIM3_IRQ);
 138         //timer_set_period(TIM3, 9999);
 139         //timer_generate_event(TIM3, TIM_EGR_UG);
 140         //timer_enable_counter(TIM3);
 141 #endif
 142 }
 143
 144 void exti15_10_isr(void)
 145 {
 146         // We require low latency here, so interaction with peripherals is open-coded.
 147 #if 0
 148         if (GPIO_IDR(GPIOB) & (1 << 12))
 149                 SPI_CR1(SPI2) |= SPI_CR1_SSI;
 150         else
 151                 SPI_CR1(SPI2) &= ~SPI_CR1_SSI;
 152 #else
 153         SPI_CR1(SPI2) &= ~SPI_CR1_SSI;
 154 #endif
 155         EXTI_PR = EXTI12;
 156 }
 157
 158 static volatile byte tm_data[8];
 159 static volatile byte tm_overrun;
 160
 161 static volatile byte tm_buffer[256];
 162 static volatile uint tm_len;
 163
 164 static volatile uint tm_timeouts;
 165
 166 void spi2_isr(void)
 167 {
 168         /*
 169          *  The AC unit is sending a stream of commands like this:
 170          *
 171          *  00 - set mode: 4 grids, 8 segments
 172          *  44 - will write to display memory, no auto-increment
 173          *  Cx - set memory address to x
 174          *  yy - data to write, two most-significant bits are always zero
 175          *  8B - display ON, duty cycle 10/16
 176          *
 177          *  So the only byte which can have top 2 bits both set is the Cx command.
 178          *  We make use of this to synchronize the stream.
 179          */
 180         if (SPI_SR(SPI2) & SPI_SR_OVR)
 181                 tm_overrun = 1;
 182         if (SPI_SR(SPI2) & SPI_SR_RXNE) {
 183                 byte x = SPI_DR(SPI2) ^ 0xff;
 184 #if 0
 185                 if (tm_len < ARRAY_SIZE(tm_buffer))
 186                         tm_buffer[tm_len++] = x;
 187 #endif
 188                 static byte tm_address;
 189                 if (tm_address) {
 190                         tm_data[tm_address & 7] = x;
 191                         tm_address = 0;
 192                 } else if ((x & 0xc0) == 0xc0) {
 193                         tm_address = x;
 194                 }
 195                 timer_set_period(TIM3, 999);
 196                 timer_generate_event(TIM3, TIM_EGR_UG);
 197                 timer_enable_counter(TIM3);
 198         }
 199 }
 200
 201 void tim3_isr(void)
 202 {
 203         if (TIM_SR(TIM3) & TIM_SR_UIF) {
 204                 TIM_SR(TIM3) &= ~TIM_SR_UIF;
 205                 tm_timeouts++;
 206                 spi_set_nss_high(SPI2);
 207                 spi_set_nss_low(SPI2);
 208         }
 209 }
 210
 211 #if 0
 212 static void tm_test(void)
 213 {
 214         u32 start_ticks = ms_ticks;
 215         static byte tmbuf[256];
 216         uint len = 0;
 217
 218         while (ms_ticks - start_ticks < 1000 && len < ARRAY_SIZE(tmbuf)) {
 219                 if (SPI_SR(SPI2) & SPI_SR_RXNE) {
 220                         tmbuf[len++] = SPI_DR(SPI2) ^ 0xff;
 221                 }
 222         }
 223
 224         for (uint i=0; i<len; i++) {
 225                 debug_printf("%02x ", tmbuf[i]);
 226                 if ((i % 5) == 4)
 227                         debug_putc('\n');
 228         }
 229         debug_putc('\n');
 230 }
 231 #endif
 232
 233 static void tm_show(void)
 234 {
 235         debug_printf("TM:");
 236         for (uint i=0; i<8; i++)
 237                 debug_printf(" %02x", tm_data[i]);
 238         debug_printf(" o=%d t=%d", tm_overrun, tm_timeouts);
 239         tm_overrun = 0;
 240         debug_putc('\n');
 241
 242 #if 0
 243         static byte tm_dumped;
 244         if (!tm_dumped && tm_len == ARRAY_SIZE(tm_buffer)) {
 245                 for (uint i=0; i < tm_len; i++)
 246                         debug_printf("%02x ", tm_buffer[i]);
 247                 debug_putc('\n');
 248                 // tm_dumped = 1;
 249                 tm_len = 0;
 250         }
 251 #endif
 252 }
 253
 254 /*** USB ***/
 255
 256 static usbd_device *usbd_dev;
 257
 258 enum usb_string {
 259         STR_MANUFACTURER = 1,
 260         STR_PRODUCT,
 261         STR_SERIAL,
 262 };
 263
 264 static char usb_serial_number[13];
 265
 266 static const char *usb_strings[] = {
 267         "United Computer Wizards",
 268         "Sinclair Air Conditioner",
 269         usb_serial_number,
 270 };
 271
 272 static const struct usb_device_descriptor device = {
 273         .bLength = USB_DT_DEVICE_SIZE,
 274         .bDescriptorType = USB_DT_DEVICE,
 275         .bcdUSB = 0x0200,
 276         .bDeviceClass = 0xFF,
 277         .bDeviceSubClass = 0,
 278         .bDeviceProtocol = 0,
 279         .bMaxPacketSize0 = 64,
 280         .idVendor = 0x4242,
 281         .idProduct = 0x0007,
 282         .bcdDevice = 0x0000,
 283         .iManufacturer = STR_MANUFACTURER,
 284         .iProduct = STR_PRODUCT,
 285         .iSerialNumber = STR_SERIAL,
 286         .bNumConfigurations = 1,
 287 };
 288
 289 static const struct usb_endpoint_descriptor endpoints[] = {{
 290         // Bulk end-point for sending values to the display
 291         .bLength = USB_DT_ENDPOINT_SIZE,
 292         .bDescriptorType = USB_DT_ENDPOINT,
 293         .bEndpointAddress = 0x01,
 294         .bmAttributes = USB_ENDPOINT_ATTR_BULK,
 295         .wMaxPacketSize = 64,
 296         .bInterval = 1,
 297 }};
 298
 299 static const struct usb_interface_descriptor iface = {
 300         .bLength = USB_DT_INTERFACE_SIZE,
 301         .bDescriptorType = USB_DT_INTERFACE,
 302         .bInterfaceNumber = 0,
 303         .bAlternateSetting = 0,
 304         .bNumEndpoints = 1,
 305         .bInterfaceClass = 0xFF,
 306         .bInterfaceSubClass = 0,
 307         .bInterfaceProtocol = 0,
 308         .iInterface = 0,
 309         .endpoint = endpoints,
 310 };
 311
 312 static const struct usb_dfu_descriptor dfu_function = {
 313         .bLength = sizeof(struct usb_dfu_descriptor),
 314         .bDescriptorType = DFU_FUNCTIONAL,
 315         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
 316         .wDetachTimeout = 255,
 317         .wTransferSize = 1024,
 318         .bcdDFUVersion = 0x0100,
 319 };
 320
 321 static const struct usb_interface_descriptor dfu_iface = {
 322         .bLength = USB_DT_INTERFACE_SIZE,
 323         .bDescriptorType = USB_DT_INTERFACE,
 324         .bInterfaceNumber = 1,
 325         .bAlternateSetting = 0,
 326         .bNumEndpoints = 0,
 327         .bInterfaceClass = 0xFE,
 328         .bInterfaceSubClass = 1,
 329         .bInterfaceProtocol = 1,
 330         .iInterface = 0,
 331
 332         .extra = &dfu_function,
 333         .extralen = sizeof(dfu_function),
 334 };
 335
 336 static const struct usb_interface ifaces[] = {{
 337         .num_altsetting = 1,
 338         .altsetting = &iface,
 339 }, {
 340         .num_altsetting = 1,
 341         .altsetting = &dfu_iface,
 342 }};
 343
 344 static const struct usb_config_descriptor config = {
 345         .bLength = USB_DT_CONFIGURATION_SIZE,
 346         .bDescriptorType = USB_DT_CONFIGURATION,
 347         .wTotalLength = 0,
 348         .bNumInterfaces = 2,
 349         .bConfigurationValue = 1,
 350         .iConfiguration = 0,
 351         .bmAttributes = 0x80,
 352         .bMaxPower = 50,        // multiplied by 2 mA
 353         .interface = ifaces,
 354 };
 355
 356 static byte usb_configured;
 357 static uint8_t usbd_control_buffer[64];
 358
 359 static void dfu_detach_complete(usbd_device *dev UNUSED, struct usb_setup_data *req UNUSED)
 360 {
 361         // Reset to bootloader, which implements the rest of DFU
 362         debug_printf("Switching to DFU\n");
 363         debug_flush();
 364         scb_reset_core();
 365 }
 366
 367 static enum usbd_request_return_codes dfu_control_cb(usbd_device *dev UNUSED,
 368         struct usb_setup_data *req,
 369         uint8_t **buf UNUSED,
 370         uint16_t *len UNUSED,
 371         void (**complete)(usbd_device *dev, struct usb_setup_data *req))
 372 {
 373         if (req->bmRequestType != 0x21 || req->bRequest != DFU_DETACH)
 374                 return USBD_REQ_NOTSUPP;
 375
 376         *complete = dfu_detach_complete;
 377         return USBD_REQ_HANDLED;
 378 }
 379
 380 static void ep01_cb(usbd_device *dev, uint8_t ep UNUSED)
 381 {
 382         // We received a frame from the USB host
 383         byte buf[8];
 384         uint len = usbd_ep_read_packet(dev, 0x01, buf, 8);
 385         debug_printf("USB: Host sent %u bytes\n", len);
 386 }
 387
 388 static void set_config_cb(usbd_device *dev, uint16_t wValue UNUSED)
 389 {
 390         usbd_register_control_callback(
 391                 dev,
 392                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 393                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 394                 dfu_control_cb);
 395         usbd_ep_setup(dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, ep01_cb);
 396         usb_configured = 1;
 397 }
 398
 399 static void reset_cb(void)
 400 {
 401         debug_printf("USB: Reset\n");
 402         usb_configured = 0;
 403 }
 404
 405 static volatile bool usb_event_pending;
 406
 407 void usb_lp_can_rx0_isr(void)
 408 {
 409         /*
 410          *  We handle USB in the main loop to avoid race conditions between
 411          *  USB interrupts and other code. However, we need an interrupt to
 412          *  up the main loop from sleep.
 413          *
 414          *  We set up only the low-priority ISR, because high-priority ISR handles
 415          *  only double-buffered bulk transfers and isochronous transfers.
 416          */
 417         nvic_disable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 418         usb_event_pending = 1;
 419 }
 420
 421 static void usb_init(void)
 422 {
 423         // Simulate USB disconnect
 424         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 425         gpio_clear(GPIOA, GPIO11 | GPIO12);
 426         delay_ms(100);
 427
 428         usbd_dev = usbd_init(
 429                 &st_usbfs_v1_usb_driver,
 430                 &device,
 431                 &config,
 432                 usb_strings,
 433                 ARRAY_SIZE(usb_strings),
 434                 usbd_control_buffer,
 435                 sizeof(usbd_control_buffer)
 436         );
 437         usbd_register_reset_callback(usbd_dev, reset_cb);
 438         usbd_register_set_config_callback(usbd_dev, set_config_cb);
 439         usb_event_pending = 1;
 440 }
 441
 442 /*** Main ***/
 443
 444 int main(void)
 445 {
 446         clock_init();
 447         gpio_init();
 448         usart_init();
 449
 450         tick_init();
 451         desig_get_unique_id_as_dfu(usb_serial_number);
 452
 453         debug_printf("Hello, world!\n");
 454
 455         tm_init();
 456         usb_init();
 457
 458         u32 last_blink = 0;
 459
 460         for (;;) {
 461                 if (ms_ticks - last_blink >= 1000) {
 462                         debug_led_toggle();
 463                         last_blink = ms_ticks;
 464                         tm_show();
 465                 }
 466
 467                 if (usb_event_pending) {
 468                         usbd_poll(usbd_dev);
 469                         usb_event_pending = 0;
 470                         nvic_clear_pending_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 471                         nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 472                 }
 473
 474                 wait_for_interrupt();
 475         }
 476
 477         return 0;
 478 }