stmbl

/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/cm3/scb.h>
#include <libopencm3/stm32/otg_fs.h>
#include <libopencm3/cm3/common.h>

#include "cdc.h"

struct ringbuf rx_buf = { .buf = (char[RX_QUEUE_SIZE]) {0}, .bufsize = RX_QUEUE_SIZE };
struct ringbuf tx_buf = { .buf = (char[TX_QUEUE_SIZE]) {0}, .bufsize = TX_QUEUE_SIZE };

static const struct usb_device_descriptor dev = {
	.bLength = USB_DT_DEVICE_SIZE,
	.bDescriptorType = USB_DT_DEVICE,
	.bcdUSB = 0x0200,
	.bDeviceClass = USB_CLASS_CDC,
	.bDeviceSubClass = 0,
	.bDeviceProtocol = 0,
	.bMaxPacketSize0 = 64,
	.idVendor = 0x0483,
	.idProduct = 0x5740,
	.bcdDevice = 0x0200,
	.iManufacturer = 1,
	.iProduct = 2,
	.iSerialNumber = 3,
	.bNumConfigurations = 1,
};

/*
 * This notification endpoint isn't implemented. According to CDC spec it's
 * optional, but its absence causes a NULL pointer dereference in the
 * Linux cdc_acm driver.
 */
static const struct usb_endpoint_descriptor comm_endp[] = {{
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,
	.bEndpointAddress = 0x83,
	.bmAttributes = USB_ENDPOINT_ATTR_INTERRUPT,
	.wMaxPacketSize = 16,
	.bInterval = 255,
} };

static const struct usb_endpoint_descriptor data_endp[] = {{
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,
	.bEndpointAddress = 0x01,
	.bmAttributes = USB_ENDPOINT_ATTR_BULK,
	.wMaxPacketSize = 64,
	.bInterval = 1,
}, {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,
	.bEndpointAddress = 0x82,
	.bmAttributes = USB_ENDPOINT_ATTR_BULK,
	.wMaxPacketSize = 64,
	.bInterval = 1,
} };

static const struct {
	struct usb_cdc_header_descriptor header;
	struct usb_cdc_call_management_descriptor call_mgmt;
	struct usb_cdc_acm_descriptor acm;
	struct usb_cdc_union_descriptor cdc_union;
} __attribute__((packed)) cdcacm_functional_descriptors = {
	.header = {
		.bFunctionLength = sizeof(struct usb_cdc_header_descriptor),
		.bDescriptorType = CS_INTERFACE,
		.bDescriptorSubtype = USB_CDC_TYPE_HEADER,
		.bcdCDC = 0x0110,
	},
	.call_mgmt = {
		.bFunctionLength =
			sizeof(struct usb_cdc_call_management_descriptor),
		.bDescriptorType = CS_INTERFACE,
		.bDescriptorSubtype = USB_CDC_TYPE_CALL_MANAGEMENT,
		.bmCapabilities = 0,
		.bDataInterface = 1,
	},
	.acm = {
		.bFunctionLength = sizeof(struct usb_cdc_acm_descriptor),
		.bDescriptorType = CS_INTERFACE,
		.bDescriptorSubtype = USB_CDC_TYPE_ACM,
		.bmCapabilities = 0,
	},
	.cdc_union = {
		.bFunctionLength = sizeof(struct usb_cdc_union_descriptor),
		.bDescriptorType = CS_INTERFACE,
		.bDescriptorSubtype = USB_CDC_TYPE_UNION,
		.bControlInterface = 0,
		.bSubordinateInterface0 = 1,
	 }
};

static const struct usb_interface_descriptor comm_iface[] = {{
	.bLength = USB_DT_INTERFACE_SIZE,
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 0,
	.bAlternateSetting = 0,
	.bNumEndpoints = 1,
	.bInterfaceClass = USB_CLASS_CDC,
	.bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
	.bInterfaceProtocol = USB_CDC_PROTOCOL_AT,
	.iInterface = 0,

	.endpoint = comm_endp,

	.extra = &cdcacm_functional_descriptors,
	.extralen = sizeof(cdcacm_functional_descriptors)
} };

static const struct usb_interface_descriptor data_iface[] = {{
	.bLength = USB_DT_INTERFACE_SIZE,
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 1,
	.bAlternateSetting = 0,
	.bNumEndpoints = 2,
	.bInterfaceClass = USB_CLASS_DATA,
	.bInterfaceSubClass = 0,
	.bInterfaceProtocol = 0,
	.iInterface = 0,

	.endpoint = data_endp,
} };

static const struct usb_interface ifaces[] = {{
	.num_altsetting = 1,
	.altsetting = comm_iface,
}, {
	.num_altsetting = 1,
	.altsetting = data_iface,
} };

static const struct usb_config_descriptor config = {
	.bLength = USB_DT_CONFIGURATION_SIZE,
	.bDescriptorType = USB_DT_CONFIGURATION,
	.wTotalLength = 0,
	.bNumInterfaces = 2,
	.bConfigurationValue = 1,
	.iConfiguration = 0,
	.bmAttributes = 0x80,
	.bMaxPower = 0x32,

	.interface = ifaces,
};

//TODO: serial number
//https://github.com/rene-dev/stmbl/blob/master/lib/STM32_USB_Device_VCP-1.2.0/src/usbd_desc.c#L302-L314
//https://github.com/paparazzi/paparazzi/blob/master/sw/airborne/arch/stm32/usb_ser_hw.c#L516
static const char * usb_strings[] = {
	"Black Sphere Technologies",
	"STMBL Virtual ComPort",
	"DEMO",//serial
};

/* Buffer to be used for control requests. */
uint8_t usbd_control_buffer[128];

static int cdcacm_control_request(usbd_device *usbd_dev,
	struct usb_setup_data *req, uint8_t **buf, uint16_t *len,
	void (**complete)(usbd_device *usbd_dev, struct usb_setup_data *req))
{
	(void)complete;
	(void)buf;
	(void)usbd_dev;

	switch (req->bRequest) {
	case USB_CDC_REQ_SET_CONTROL_LINE_STATE: {
		/*
		 * This Linux cdc_acm driver requires this to be implemented
		 * even though it's optional in the CDC spec, and we don't
		 * advertise it in the ACM functional descriptor.
		 */
      char local_buf[10];
      struct usb_cdc_notification *notif = (void *)local_buf;
      /* We echo signals back to host as notification. */
      notif->bmRequestType = 0xA1;
      notif->bNotification = USB_CDC_NOTIFY_SERIAL_STATE;
      notif->wValue = 0;
      notif->wIndex = 0;
      notif->wLength = 2;
      local_buf[8] = req->wValue & 3;
      local_buf[9] = 0;
      usbd_ep_write_packet(usbd_dev, 0x83, local_buf, 10);
      return 1;
		}
	case USB_CDC_REQ_SET_LINE_CODING:
		if (*len < sizeof(struct usb_cdc_line_coding)) {
			return 0;
		}

		return 1;
	}
	return 0;
}

static void cdcacm_data_rx_cb(usbd_device *usbd_dev, uint8_t ep)
{
	(void)ep;

	char buf[64];
	int len = usbd_ep_read_packet(usbd_dev, 0x01, buf, 64);
   int ret = rb_write(&rx_buf, buf, len);
}

int cdcacm_tx(void* data, uint32_t len){
   if(usb_connected == 0){
      return 0;
   }
   int ret, len2, len3;
   char buf[64];
   ret = rb_write(&tx_buf, data, len);
	
	if(tx_buf.len > 0){
		len2 = rb_read(&tx_buf,buf,64);
		len3 = usbd_ep_write_packet(usbd_dev, 0x82, buf, len2);
		rb_undo(&tx_buf, len2 - len3);
	}
   return ret;
}

static void cdcacm_data_tx_cb(usbd_device *usbd_dev, uint8_t ep)
{
   if(usb_connected == 0){
      return;
   }
   char buf[64];
   int len2, len3;
	if(tx_buf.len > 0){
		len2 = rb_read(&tx_buf,buf,64);
		len3 = usbd_ep_write_packet(usbd_dev, 0x82, buf, len2);
		rb_undo(&tx_buf, len2 - len3);
	}
}

int cdcacm_is_connected(){
   return usb_connected;
}

int cdcacm_getline(char *ptr, int len){
   int ret = 0;
   char c;
   if (rx_buf.len == 0){ 
		return 0;
	}

   while(rb_getc(&rx_buf, &c) && ret < len){
      ret++;
      *ptr++ = c;
      if(c == '\r'){
         *--ptr = '\0';
         return ret;
      }
   }
	rb_undo(&rx_buf, ret);
	return 0;
}

// use suspend callback to detect disconnect
static void suspend_cb(void)
{
   usb_connected = 0;
}

static void cdcacm_set_config(usbd_device *usbd_dev, uint16_t wValue)
{
	(void)wValue;

	usbd_ep_setup(usbd_dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, cdcacm_data_rx_cb);
	usbd_ep_setup(usbd_dev, 0x82, USB_ENDPOINT_ATTR_BULK, 64, cdcacm_data_tx_cb);
	usbd_ep_setup(usbd_dev, 0x83, USB_ENDPOINT_ATTR_INTERRUPT, 16, NULL);

	usbd_register_control_callback(
				usbd_dev,
				USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
				USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
				cdcacm_control_request);
   usb_connected = 1;
   tx_buf.len = 0;
   rx_buf.len = 0;
   usbd_register_suspend_callback(usbd_dev, suspend_cb);
}

void cdc_init(void)
{
	rcc_periph_clock_enable(RCC_GPIOA);
	rcc_periph_clock_enable(RCC_OTGFS);

	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO11 | GPIO12);
	gpio_set_af(GPIOA, GPIO_AF10, GPIO11 | GPIO12);

	OTG_FS_GCCFG |= OTG_GCCFG_NOVBUSSENS;
	usbd_dev = usbd_init(&otgfs_usb_driver, &dev, &config, usb_strings, 3, usbd_control_buffer, sizeof(usbd_control_buffer));	
	
	usbd_register_set_config_callback(usbd_dev, cdcacm_set_config);
   usb_connected = 0;
}