cdc-acm.c

#include "cdc-acm.h"
#include "cdc.h"
#include "usb-api.h"
#include "usb-core.h"

#include <stdio.h>

#ifdef DEBUG
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif

static uint8_t usb_ctrl_data_buffer[32];

static struct usb_cdc_line_coding usb_line_coding = { 9600, 0x00, 0x00, 0x08 }; // 9600 baud, 8N1
static uint8_t line_state;
static uint8_t events;
static struct process *cdc_event_process = NULL;

static void
notify_user(uint8_t e)
{
  events |= e;
  if(cdc_event_process) {
    process_poll(cdc_event_process);
  }
}

static void
encapsulated_command(uint8_t *data, unsigned int length)
{
  PRINTF("Got CDC command: length %d\n", length);
  usb_send_ctrl_status();
}
static void
set_line_encoding(uint8_t *data, unsigned int length)
{
  if(length == 7) {
#ifdef DEBUG
    static const char parity_char[] = { 'N', 'O', 'E', 'M', 'S' };
    static const char *stop_bits_str[] = { "1", "1.5", "2" };
    const struct usb_cdc_line_coding *coding =
      (const struct usb_cdc_line_coding *)usb_ctrl_data_buffer;
    char parity = ((coding->bParityType > 4)
                   ? '?' : parity_char[coding->bParityType]);

    const char *stop_bits = ((coding->bCharFormat > 2)
                             ? "?" : stop_bits_str[coding->bCharFormat]);

    PRINTF("Got CDC line coding: %ld/%d/%c/%s\n",
           coding->dwDTERate, coding->bDataBits, parity, stop_bits);
#endif
    memcpy(&usb_line_coding, data, sizeof(usb_line_coding));
    notify_user(USB_CDC_ACM_LINE_CODING);
    usb_send_ctrl_status();
  } else {
    usb_error_stall();
  }
}

static unsigned int
handle_cdc_acm_requests()
{
  PRINTF("CDC request %02x %02x\n", usb_setup_buffer.bmRequestType,
         usb_setup_buffer.bRequest);
  switch (usb_setup_buffer.bmRequestType) {
  case 0x21: /* CDC interface OUT requests */
    /* Check if it's the right interface */
    if(usb_setup_buffer.wIndex != 0)
      return 0;
    switch (usb_setup_buffer.bRequest) {
    case SET_CONTROL_LINE_STATE:
      line_state = usb_setup_buffer.wValue;
      notify_user(USB_CDC_ACM_LINE_STATE);
      usb_send_ctrl_status();
      return 1;

    case SEND_ENCAPSULATED_COMMAND:
      {
        unsigned int len = usb_setup_buffer.wLength;
        if(len > sizeof(usb_ctrl_data_buffer))
          len = sizeof(usb_ctrl_data_buffer);
        usb_get_ctrl_data(usb_ctrl_data_buffer, len, encapsulated_command);
      }

      return 1;


    case SET_LINE_CODING:
      {
        unsigned int len = usb_setup_buffer.wLength;
        if(len > sizeof(usb_ctrl_data_buffer))
          len = sizeof(usb_ctrl_data_buffer);
        usb_get_ctrl_data(usb_ctrl_data_buffer, len, set_line_encoding);
      }
      return 1;
    }
    break;
  case 0xa1:                   /* CDC interface IN requests */
    if(usb_setup_buffer.wIndex != 0)
      return 0;
    switch (usb_setup_buffer.bRequest) {
    case GET_ENCAPSULATED_RESPONSE:
      PRINTF("CDC response");
      usb_send_ctrl_status();
      return 1;
    case GET_LINE_CODING:
      usb_send_ctrl_response((uint8_t *) & usb_line_coding, 7);
      return 1;
    }
  }
  return 0;
}

static const struct USBRequestHandler cdc_acm_request_handler = {
  0x21, 0x7f,
  0x00, 0x00,
  handle_cdc_acm_requests
};

static struct USBRequestHandlerHook cdc_acm_request_hook = {
  NULL,
  &cdc_acm_request_handler
};

void
usb_cdc_acm_setup()
{
  usb_register_request_handler(&cdc_acm_request_hook);
}

uint8_t
usb_cdc_acm_get_events(void)
{
  uint8_t r = events;
  events = 0;
  return r;
}

uint8_t
usb_cdc_acm_get_line_state(void)
{
  return line_state;
}

const struct usb_cdc_line_coding *
usb_cdc_acm_get_line_coding(void)
{
  return &usb_line_coding;
}

void
usb_cdc_acm_set_event_process(struct process *p)
{
  cdc_event_process = p;
}