test-display/main.c

   1 /*
   2  *      Test Gadget
   3  *
   4  *      (c) 2020 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/i2c.h>
  18 #include <libopencm3/usb/dfu.h>
  19 #include <libopencm3/usb/usbd.h>
  20
  21 #include <string.h>
  22
  23 /*** Hardware init ***/
  24
  25 static void clock_init(void)
  26 {
  27         rcc_clock_setup_in_hse_8mhz_out_72mhz();
  28
  29         rcc_periph_clock_enable(RCC_GPIOA);
  30         rcc_periph_clock_enable(RCC_GPIOB);
  31         rcc_periph_clock_enable(RCC_GPIOC);
  32         rcc_periph_clock_enable(RCC_I2C1);
  33         rcc_periph_clock_enable(RCC_USART1);
  34         rcc_periph_clock_enable(RCC_USB);
  35
  36         rcc_periph_reset_pulse(RST_GPIOA);
  37         rcc_periph_reset_pulse(RST_GPIOB);
  38         rcc_periph_reset_pulse(RST_GPIOC);
  39         rcc_periph_reset_pulse(RST_I2C1);
  40         rcc_periph_reset_pulse(RST_USART1);
  41         rcc_periph_reset_pulse(RST_USB);
  42 }
  43
  44 static void gpio_init(void)
  45 {
  46         // PA9 = TXD1 for debugging console
  47         // PA10 = RXD1 for debugging console
  48         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
  49         gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO10);
  50
  51         // PC13 = BluePill LED
  52         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
  53         gpio_clear(GPIOC, GPIO13);
  54
  55         // PB7 = SDA for display controller
  56         // PB6 = SCL for display controller
  57         gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, GPIO6 | GPIO7);
  58 }
  59
  60 static void usart_init(void)
  61 {
  62         usart_set_baudrate(USART1, 115200);
  63         usart_set_databits(USART1, 8);
  64         usart_set_stopbits(USART1, USART_STOPBITS_1);
  65         usart_set_mode(USART1, USART_MODE_TX);
  66         usart_set_parity(USART1, USART_PARITY_NONE);
  67         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
  68
  69         usart_enable(USART1);
  70 }
  71
  72 /*** System ticks ***/
  73
  74 static volatile u32 ms_ticks;
  75
  76 void sys_tick_handler(void)
  77 {
  78         ms_ticks++;
  79 }
  80
  81 static void tick_init(void)
  82 {
  83         systick_set_frequency(1000, CPU_CLOCK_MHZ * 1000000);
  84         systick_counter_enable();
  85         systick_interrupt_enable();
  86 }
  87
  88 static void delay_ms(uint ms)
  89 {
  90         u32 start_ticks = ms_ticks;
  91         while (ms_ticks - start_ticks < ms)
  92                 ;
  93 }
  94
  95 /*** Display ***/
  96
  97 /*
  98  *      Display digits:
  99  *
 100  *                 ---- 20 ----
 101  *               |              |
 102  *               |              |
 103  *              40              10
 104  *               |              |
 105  *               |              |
 106  *                 ---- 80 ----
 107  *               |              |
 108  *               |              |
 109  *              08              02
 110  *               |              |
 111  *               |              |
 112  *                 ---- 04 ----
 113  *                                      (01)
 114  */
 115
 116 static byte disp[4];
 117 static byte ctrl = 0x77;
 118
 119 static void display_update(void)
 120 {
 121         byte cmds[6];
 122         cmds[0] = 0;
 123         cmds[1] = ctrl;
 124         cmds[2] = (disp[0] & 0xf0) | (disp[2] >> 4);
 125         cmds[3] = (disp[1] & 0xf0) | (disp[3] >> 4);
 126         cmds[4] = (disp[2] & 0x0f) | (disp[0] << 4);
 127         cmds[5] = (disp[3] & 0x0f) | (disp[1] << 4);
 128
 129         debug_puts("I2C transfer\n");
 130         i2c_transfer7(I2C1, 0x70/2, (byte *) cmds, sizeof(cmds), NULL, 0);
 131         debug_puts("I2C done\n");
 132 }
 133
 134 static void display_init(void)
 135 {
 136         debug_puts("I2C init\n");
 137         i2c_peripheral_disable(I2C1);
 138         i2c_set_speed(I2C1, i2c_speed_sm_100k, rcc_apb1_frequency / 1000000);
 139         i2c_peripheral_enable(I2C1);
 140
 141         disp[0] = 0x7f;
 142         disp[1] = 0x12;
 143         disp[2] = 0xbc;
 144         disp[3] = 0xb6;
 145         display_update();
 146 }
 147
 148 static void display_test(void)
 149 {
 150         static byte mode;
 151
 152         disp[0] ^= 0x01;
 153         display_update();
 154
 155 #if 0
 156         byte cmds[] = { 0x00, mode ? 0x77 : 0x77 };
 157         i2c_transfer7(I2C1, 0x70/2, (byte *) cmds, sizeof(cmds), NULL, 0);
 158 #endif
 159
 160 #if 0
 161         byte disp[] = { 0xff, 0xff, mode ? 0xff : 0x00, mode ? 0xff : 0xff };
 162         byte cmds[] = { 0x00, 0x77, 0, 0, 0, 0 };
 163         cmds[2] = (disp[0] & 0xf0) | (disp[2] >> 4);
 164         cmds[3] = (disp[1] & 0xf0) | (disp[3] >> 4);
 165         cmds[4] = (disp[2] & 0x0f) | (disp[0] << 4);
 166         cmds[5] = (disp[3] & 0x0f) | (disp[1] << 4);
 167         i2c_transfer7(I2C1, 0x70/2, (byte *) cmds, sizeof(cmds), NULL, 0);
 168 #endif
 169
 170         mode = !mode;
 171 }
 172
 173 static const byte lcd_font[] = {
 174         [0] = 0x7e,
 175         [1] = 0x12,
 176         [2] = 0xbc,
 177         [3] = 0xb6,
 178         [4] = 0xd2,
 179         [5] = 0xe6,
 180         [6] = 0xee,
 181         [7] = 0x32,
 182         [8] = 0xfe,
 183         [9] = 0xf6,
 184         [10] = 0xfa,
 185         [11] = 0xce,
 186         [12] = 0x6c,
 187         [13] = 0x9e,
 188         [14] = 0xec,
 189         [15] = 0xe8,
 190 };
 191
 192 /*** USB ***/
 193
 194 static usbd_device *usbd_dev;
 195
 196 enum usb_string {
 197         STR_MANUFACTURER = 1,
 198         STR_PRODUCT,
 199         STR_SERIAL,
 200 };
 201
 202 static char usb_serial_number[13];
 203
 204 static const char *usb_strings[] = {
 205         "United Computer Wizards",
 206         "Test Gadget",
 207         usb_serial_number,
 208 };
 209
 210 static const struct usb_device_descriptor device = {
 211         .bLength = USB_DT_DEVICE_SIZE,
 212         .bDescriptorType = USB_DT_DEVICE,
 213         .bcdUSB = 0x0200,
 214         .bDeviceClass = 0xFF,
 215         .bDeviceSubClass = 0,
 216         .bDeviceProtocol = 0,
 217         .bMaxPacketSize0 = 64,
 218         .idVendor = 0x4242,
 219         .idProduct = 0x0007,
 220         .bcdDevice = 0x0000,
 221         .iManufacturer = STR_MANUFACTURER,
 222         .iProduct = STR_PRODUCT,
 223         .iSerialNumber = STR_SERIAL,
 224         .bNumConfigurations = 1,
 225 };
 226
 227 static const struct usb_endpoint_descriptor endpoints[] = {{
 228         // Bulk end-point for sending values to DMX
 229         .bLength = USB_DT_ENDPOINT_SIZE,
 230         .bDescriptorType = USB_DT_ENDPOINT,
 231         .bEndpointAddress = 0x01,
 232         .bmAttributes = USB_ENDPOINT_ATTR_BULK,
 233         .wMaxPacketSize = 64,
 234         .bInterval = 1,
 235 }};
 236
 237 static const struct usb_interface_descriptor iface = {
 238         .bLength = USB_DT_INTERFACE_SIZE,
 239         .bDescriptorType = USB_DT_INTERFACE,
 240         .bInterfaceNumber = 0,
 241         .bAlternateSetting = 0,
 242         .bNumEndpoints = 1,
 243         .bInterfaceClass = 0xFF,
 244         .bInterfaceSubClass = 0,
 245         .bInterfaceProtocol = 0,
 246         .iInterface = 0,
 247         .endpoint = endpoints,
 248 };
 249
 250 static const struct usb_dfu_descriptor dfu_function = {
 251         .bLength = sizeof(struct usb_dfu_descriptor),
 252         .bDescriptorType = DFU_FUNCTIONAL,
 253         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
 254         .wDetachTimeout = 255,
 255         .wTransferSize = 1024,
 256         .bcdDFUVersion = 0x0100,
 257 };
 258
 259 static const struct usb_interface_descriptor dfu_iface = {
 260         .bLength = USB_DT_INTERFACE_SIZE,
 261         .bDescriptorType = USB_DT_INTERFACE,
 262         .bInterfaceNumber = 1,
 263         .bAlternateSetting = 0,
 264         .bNumEndpoints = 0,
 265         .bInterfaceClass = 0xFE,
 266         .bInterfaceSubClass = 1,
 267         .bInterfaceProtocol = 1,
 268         .iInterface = 0,
 269
 270         .extra = &dfu_function,
 271         .extralen = sizeof(dfu_function),
 272 };
 273
 274 static const struct usb_interface ifaces[] = {{
 275         .num_altsetting = 1,
 276         .altsetting = &iface,
 277 }, {
 278         .num_altsetting = 1,
 279         .altsetting = &dfu_iface,
 280 }};
 281
 282 static const struct usb_config_descriptor config = {
 283         .bLength = USB_DT_CONFIGURATION_SIZE,
 284         .bDescriptorType = USB_DT_CONFIGURATION,
 285         .wTotalLength = 0,
 286         .bNumInterfaces = 2,
 287         .bConfigurationValue = 1,
 288         .iConfiguration = 0,
 289         .bmAttributes = 0x80,
 290         .bMaxPower = 50,        // multiplied by 2 mA
 291         .interface = ifaces,
 292 };
 293
 294 static byte usb_configured;
 295 static uint8_t usbd_control_buffer[64];
 296
 297 static void dfu_detach_complete(usbd_device *dev UNUSED, struct usb_setup_data *req UNUSED)
 298 {
 299         // Reset to bootloader, which implements the rest of DFU
 300         debug_printf("Switching to DFU\n");
 301         debug_flush();
 302         scb_reset_core();
 303 }
 304
 305 static enum usbd_request_return_codes dfu_control_cb(usbd_device *dev UNUSED,
 306         struct usb_setup_data *req,
 307         uint8_t **buf UNUSED,
 308         uint16_t *len UNUSED,
 309         void (**complete)(usbd_device *dev, struct usb_setup_data *req))
 310 {
 311         if (req->bmRequestType != 0x21 || req->bRequest != DFU_DETACH)
 312                 return USBD_REQ_NOTSUPP;
 313
 314         *complete = dfu_detach_complete;
 315         return USBD_REQ_HANDLED;
 316 }
 317
 318 static void ep01_cb(usbd_device *dev, uint8_t ep UNUSED)
 319 {
 320         // We received a frame from the USB host
 321         byte buf[8];
 322         uint len = usbd_ep_read_packet(dev, 0x01, buf, 8);
 323         debug_printf("USB: Host sent %u bytes\n", len);
 324         if (len >= 5) {
 325                 for (uint i=0; i<4; i++) {
 326                         if (buf[i] < 16)
 327                                 disp[i] = lcd_font[buf[i]];
 328                         else
 329                                 disp[i] = 0;
 330                 }
 331                 if (buf[4])
 332                         disp[1] |= 1;
 333                 display_update();
 334         }
 335 }
 336
 337 static void set_config_cb(usbd_device *dev, uint16_t wValue UNUSED)
 338 {
 339         usbd_register_control_callback(
 340                 dev,
 341                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 342                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 343                 dfu_control_cb);
 344         usbd_ep_setup(dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, ep01_cb);
 345         usb_configured = 1;
 346 }
 347
 348 static void reset_cb(void)
 349 {
 350         debug_printf("USB: Reset\n");
 351         usb_configured = 0;
 352 }
 353
 354 static volatile bool usb_event_pending;
 355
 356 void usb_lp_can_rx0_isr(void)
 357 {
 358         /*
 359          *  We handle USB in the main loop to avoid race conditions between
 360          *  USB interrupts and other code. However, we need an interrupt to
 361          *  up the main loop from sleep.
 362          *
 363          *  We set up only the low-priority ISR, because high-priority ISR handles
 364          *  only double-buffered bulk transfers and isochronous transfers.
 365          */
 366         nvic_disable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 367         usb_event_pending = 1;
 368 }
 369
 370 static void usb_init(void)
 371 {
 372         // Simulate USB disconnect
 373         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 374         gpio_clear(GPIOA, GPIO11 | GPIO12);
 375         delay_ms(100);
 376
 377         usbd_dev = usbd_init(
 378                 &st_usbfs_v1_usb_driver,
 379                 &device,
 380                 &config,
 381                 usb_strings,
 382                 ARRAY_SIZE(usb_strings),
 383                 usbd_control_buffer,
 384                 sizeof(usbd_control_buffer)
 385         );
 386         usbd_register_reset_callback(usbd_dev, reset_cb);
 387         usbd_register_set_config_callback(usbd_dev, set_config_cb);
 388         usb_event_pending = 1;
 389 }
 390
 391 /*** Main ***/
 392
 393 int main(void)
 394 {
 395         clock_init();
 396         gpio_init();
 397         tick_init();
 398         usart_init();
 399         desig_get_unique_id_as_dfu(usb_serial_number);
 400
 401         debug_printf("Hello, world!\n");
 402
 403         usb_init();
 404         display_init();
 405
 406         u32 last_blink = 0;
 407
 408         for (;;) {
 409                 if (ms_ticks - last_blink >= 500) {
 410                         debug_led_toggle();
 411                         last_blink = ms_ticks;
 412                         display_test();
 413                 }
 414
 415                 if (usb_event_pending) {
 416                         usbd_poll(usbd_dev);
 417                         usb_event_pending = 0;
 418                         nvic_clear_pending_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 419                         nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 420                 }
 421
 422                 wait_for_interrupt();
 423         }
 424
 425         return 0;
 426 }