/*
 * at91sam7s USB CDC device implementation
 *
 * Copyright (c) 2012, Roel Verdult
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the
 * names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * based on the "Basic USB Example" from ATMEL (doc6123.pdf)
 *
 * @file usb_cdc.c
 * @brief
 */

#include "usb_cdc.h"
#include "util.h"

#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#define AT91C_EP_IN_SIZE  0x40
#define AT91C_EP_OUT         1
#define AT91C_EP_OUT_SIZE 0x40
#define AT91C_EP_IN          2

const char devDescriptor[] = {
	/* Device descriptor */
	0x12,      // bLength
	0x01,      // bDescriptorType
	0x10,0x01, // Complies with USB Spec. Release (0110h = release 1.10)
	0x02,      // bDeviceClass:    CDC class code
	0x00,      // bDeviceSubclass: CDC class sub code
	0x00,      // bDeviceProtocol: CDC Device protocol
	0x08,      // bMaxPacketSize0
	0x2d,0x2d, // Vendor ID (--)
	0x4d,0x50, // Product ID (PM), transmitted in reverse
	0x01,0x00, // Device release number (0001)
	0x01,      // iManufacturer    // 0x01
	0x00,      // iProduct
	0x00,      // SerialNumber
	0x01       // bNumConfigs
};

const char cfgDescriptor[] = {
	/* ============== CONFIGURATION 1 =========== */
	/* Configuration 1 descriptor */
	0x09,   // CbLength
	0x02,   // CbDescriptorType
	0x43,   // CwTotalLength 2 EP + Control
	0x00,
	0x02,   // CbNumInterfaces
	0x01,   // CbConfigurationValue
	0x00,   // CiConfiguration
	0xC0,   // CbmAttributes 0xA0
	0x00,   // CMaxPower

	/* Communication Class Interface Descriptor Requirement */
	0x09, // bLength
	0x04, // bDescriptorType
	0x00, // bInterfaceNumber
	0x00, // bAlternateSetting
	0x01, // bNumEndpoints
	0x02, // bInterfaceClass
	0x02, // bInterfaceSubclass
	0x00, // bInterfaceProtocol
	0x00, // iInterface

	/* Header Functional Descriptor */
	0x05, // bFunction Length
	0x24, // bDescriptor type: CS_INTERFACE
	0x00, // bDescriptor subtype: Header Func Desc
	0x10, // bcdCDC:1.1
	0x01,

	/* ACM Functional Descriptor */
	0x04, // bFunctionLength
	0x24, // bDescriptor Type: CS_INTERFACE
	0x02, // bDescriptor Subtype: ACM Func Desc
	0x00, // bmCapabilities

	/* Union Functional Descriptor */
	0x05, // bFunctionLength
	0x24, // bDescriptorType: CS_INTERFACE
	0x06, // bDescriptor Subtype: Union Func Desc
	0x00, // bMasterInterface: Communication Class Interface
	0x01, // bSlaveInterface0: Data Class Interface

	/* Call Management Functional Descriptor */
	0x05, // bFunctionLength
	0x24, // bDescriptor Type: CS_INTERFACE
	0x01, // bDescriptor Subtype: Call Management Func Desc
	0x00, // bmCapabilities: D1 + D0
	0x01, // bDataInterface: Data Class Interface 1

	/* Endpoint 1 descriptor */
	0x07,   // bLength
	0x05,   // bDescriptorType
	0x83,   // bEndpointAddress, Endpoint 03 - IN
	0x03,   // bmAttributes      INT
	0x08,   // wMaxPacketSize
	0x00,
	0xFF,   // bInterval

	/* Data Class Interface Descriptor Requirement */
	0x09, // bLength
	0x04, // bDescriptorType
	0x01, // bInterfaceNumber
	0x00, // bAlternateSetting
	0x02, // bNumEndpoints
	0x0A, // bInterfaceClass
	0x00, // bInterfaceSubclass
	0x00, // bInterfaceProtocol
	0x00, // iInterface

	/* First alternate setting */
	/* Endpoint 1 descriptor */
	0x07,   // bLength
	0x05,   // bDescriptorType
	0x01,   // bEndpointAddress, Endpoint 01 - OUT
	0x02,   // bmAttributes      BULK
	AT91C_EP_OUT_SIZE,   // wMaxPacketSize
	0x00,
	0x00,   // bInterval

	/* Endpoint 2 descriptor */
	0x07,   // bLength
	0x05,   // bDescriptorType
	0x82,   // bEndpointAddress, Endpoint 02 - IN
	0x02,   // bmAttributes      BULK
	AT91C_EP_IN_SIZE,   // wMaxPacketSize
	0x00,
	0x00    // bInterval
};

const char strDescriptor[] = {
  26,				// Length
  0x03,			// Type is string
  'p', 0x00,
  'r', 0x00,
  'o', 0x00,
  'x', 0x00,
  'm', 0x00,
  'a', 0x00,
  'r', 0x00,
  'k', 0x00,
  '.', 0x00,
  'o', 0x00,
  'r', 0x00,
  'g', 0x00,
};


/* USB standard request code */
#define STD_GET_STATUS_ZERO           0x0080
#define STD_GET_STATUS_INTERFACE      0x0081
#define STD_GET_STATUS_ENDPOINT       0x0082

#define STD_CLEAR_FEATURE_ZERO        0x0100
#define STD_CLEAR_FEATURE_INTERFACE   0x0101
#define STD_CLEAR_FEATURE_ENDPOINT    0x0102

#define STD_SET_FEATURE_ZERO          0x0300
#define STD_SET_FEATURE_INTERFACE     0x0301
#define STD_SET_FEATURE_ENDPOINT      0x0302

#define STD_SET_ADDRESS               0x0500
#define STD_GET_DESCRIPTOR            0x0680
#define STD_SET_DESCRIPTOR            0x0700
#define STD_GET_CONFIGURATION         0x0880
#define STD_SET_CONFIGURATION         0x0900
#define STD_GET_INTERFACE             0x0A81
#define STD_SET_INTERFACE             0x0B01
#define STD_SYNCH_FRAME               0x0C82

/* CDC Class Specific Request Code */
#define GET_LINE_CODING               0x21A1
#define SET_LINE_CODING               0x2021
#define SET_CONTROL_LINE_STATE        0x2221

typedef struct {
	unsigned int dwDTERRate;
	char bCharFormat;
	char bParityType;
	char bDataBits;
} AT91S_CDC_LINE_CODING, *AT91PS_CDC_LINE_CODING;

AT91S_CDC_LINE_CODING line = {
	115200, // baudrate
	0,      // 1 Stop Bit
	0,      // None Parity
	8};     // 8 Data bits

void AT91F_CDC_Enumerate();

AT91PS_UDP pUdp = AT91C_BASE_UDP;
byte_t btConfiguration = 0;
byte_t btConnection    = 0;
byte_t btReceiveBank   = AT91C_UDP_RX_DATA_BK0;

//*----------------------------------------------------------------------------
//* \fn    AT91F_USB_Disable
//* \brief This function deactivates the USB device
//*----------------------------------------------------------------------------
void usb_disable() {
  // Disconnect and reconnect USB controller for 100ms
  AT91C_BASE_PIOA->PIO_ODR = AT91C_PIO_PA24;
  SpinDelay(100);
  
  // Clear all lingering interrupts
  if(pUdp->UDP_ISR & AT91C_UDP_ENDBUSRES) {
    pUdp->UDP_ICR = AT91C_UDP_ENDBUSRES;
  }
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_USB_Enable
//* \brief This function Activates the USB device
//*----------------------------------------------------------------------------
void usb_enable() {
  // Set the PLL USB Divider
  AT91C_BASE_CKGR->CKGR_PLLR |= AT91C_CKGR_USBDIV_1 ;
  
  // Specific Chip USB Initialisation
  // Enables the 48MHz USB clock UDPCK and System Peripheral USB Clock
  AT91C_BASE_PMC->PMC_SCER = AT91C_PMC_UDP;
  AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_UDP);
  
  // Enable UDP PullUp (USB_DP_PUP) : enable & Clear of the corresponding PIO
  // Set in PIO mode and Configure in Output
  AT91C_BASE_PIOA->PIO_PER = AT91C_PIO_PA16; // Set in PIO mode
	AT91C_BASE_PIOA->PIO_OER = AT91C_PIO_PA16; // Configure as Output
  
  // Clear for set the Pul up resistor
	AT91C_BASE_PIOA->PIO_CODR = AT91C_PIO_PA16;
  
  // Disconnect and USB device
  usb_disable();
  
  // Wait for a short while
  SpinDelay(100);

  // Reconnect USB reconnect
  AT91C_BASE_PIOA->PIO_SODR = AT91C_PIO_PA24;
  AT91C_BASE_PIOA->PIO_OER = AT91C_PIO_PA24;
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_UDP_IsConfigured
//* \brief Test if the device is configured and handle enumeration
//*----------------------------------------------------------------------------
bool usb_check() {
	AT91_REG isr = pUdp->UDP_ISR;

	if (isr & AT91C_UDP_ENDBUSRES) {
		pUdp->UDP_ICR = AT91C_UDP_ENDBUSRES;
		// reset all endpoints
		pUdp->UDP_RSTEP  = (unsigned int)-1;
		pUdp->UDP_RSTEP  = 0;
		// Enable the function
		pUdp->UDP_FADDR = AT91C_UDP_FEN;
		// Configure endpoint 0
		pUdp->UDP_CSR[0] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_CTRL);
	}
	else if (isr & AT91C_UDP_EPINT0) {
		pUdp->UDP_ICR = AT91C_UDP_EPINT0;
		AT91F_CDC_Enumerate();
	}
	return (btConfiguration) ? true : false;
}


bool usb_poll()
{
  if (!usb_check()) return false;
  return (pUdp->UDP_CSR[AT91C_EP_OUT] & btReceiveBank);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_UDP_Read
//* \brief Read available data from Endpoint OUT
//*----------------------------------------------------------------------------
uint32_t usb_read(byte_t* data, size_t len) {
  byte_t bank = btReceiveBank;
	uint32_t packetSize, nbBytesRcv = 0;
  uint32_t time_out = 0;
  
	while (len)
  {
		if (!usb_check()) break;

		if ( pUdp->UDP_CSR[AT91C_EP_OUT] & bank ) {
			packetSize = MIN(pUdp->UDP_CSR[AT91C_EP_OUT] >> 16, len);
      len -= packetSize;
			while(packetSize--)
				data[nbBytesRcv++] = pUdp->UDP_FDR[AT91C_EP_OUT];
			pUdp->UDP_CSR[AT91C_EP_OUT] &= ~(bank);
			if (bank == AT91C_UDP_RX_DATA_BK0)
      {
				bank = AT91C_UDP_RX_DATA_BK1;
      } else {
				bank = AT91C_UDP_RX_DATA_BK0;
      }
		}
    if (time_out++ == 0x1fff) break;
	}

	btReceiveBank = bank;
	return nbBytesRcv;
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_CDC_Write
//* \brief Send through endpoint 2
//*----------------------------------------------------------------------------
uint32_t usb_write(const byte_t* data, const size_t len) {
  size_t length = len;
	uint32_t cpt = 0;

  if (!length) return 0;
  if (!usb_check()) return 0;
  
	// Send the first packet
	cpt = MIN(length, AT91C_EP_IN_SIZE-1);
	length -= cpt;
	while (cpt--) pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
	pUdp->UDP_CSR[AT91C_EP_IN] |= AT91C_UDP_TXPKTRDY;

	while (length) {
		// Fill the second bank
		cpt = MIN(length, AT91C_EP_IN_SIZE-1);
		length -= cpt;
		while (cpt--) pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
		// Wait for the the first bank to be sent
		while (!(pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP)) {
			if (!usb_check()) return length;
    }
		pUdp->UDP_CSR[AT91C_EP_IN] &= ~(AT91C_UDP_TXCOMP);
		while (pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP);
		pUdp->UDP_CSR[AT91C_EP_IN] |= AT91C_UDP_TXPKTRDY;
	}
  
	// Wait for the end of transfer
	while (!(pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP)) {
		if (!usb_check()) return length;
  }
  
	pUdp->UDP_CSR[AT91C_EP_IN] &= ~(AT91C_UDP_TXCOMP);
	while (pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP);

	return length;
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_USB_SendData
//* \brief Send Data through the control endpoint
//*----------------------------------------------------------------------------
unsigned int csrTab[100];
unsigned char csrIdx = 0;

static void AT91F_USB_SendData(AT91PS_UDP pUdp, const char *pData, uint32_t length) {
	uint32_t cpt = 0;
	AT91_REG csr;

	do {
		cpt = MIN(length, 8);
		length -= cpt;

		while (cpt--)
			pUdp->UDP_FDR[0] = *pData++;

		if (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) {
			pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
			while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
		}

		pUdp->UDP_CSR[0] |= AT91C_UDP_TXPKTRDY;
		do {
			csr = pUdp->UDP_CSR[0];

			// Data IN stage has been stopped by a status OUT
			if (csr & AT91C_UDP_RX_DATA_BK0) {
				pUdp->UDP_CSR[0] &= ~(AT91C_UDP_RX_DATA_BK0);
				return;
			}
		} while ( !(csr & AT91C_UDP_TXCOMP) );

	} while (length);

	if (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) {
		pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
		while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
	}
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_USB_SendZlp
//* \brief Send zero length packet through the control endpoint
//*----------------------------------------------------------------------------
void AT91F_USB_SendZlp(AT91PS_UDP pUdp) {
	pUdp->UDP_CSR[0] |= AT91C_UDP_TXPKTRDY;
	while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) );
	pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
	while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_USB_SendStall
//* \brief Stall the control endpoint
//*----------------------------------------------------------------------------
void AT91F_USB_SendStall(AT91PS_UDP pUdp) {
	pUdp->UDP_CSR[0] |= AT91C_UDP_FORCESTALL;
	while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_ISOERROR) );
	pUdp->UDP_CSR[0] &= ~(AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR);
	while (pUdp->UDP_CSR[0] & (AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR));
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_CDC_Enumerate
//* \brief This function is a callback invoked when a SETUP packet is received
//*----------------------------------------------------------------------------
void AT91F_CDC_Enumerate() {
	byte_t bmRequestType, bRequest;
	uint16_t wValue, wIndex, wLength, wStatus;

	if ( !(pUdp->UDP_CSR[0] & AT91C_UDP_RXSETUP) )
		return;

	bmRequestType = pUdp->UDP_FDR[0];
	bRequest      = pUdp->UDP_FDR[0];
	wValue        = (pUdp->UDP_FDR[0] & 0xFF);
	wValue       |= (pUdp->UDP_FDR[0] << 8);
	wIndex        = (pUdp->UDP_FDR[0] & 0xFF);
	wIndex       |= (pUdp->UDP_FDR[0] << 8);
	wLength       = (pUdp->UDP_FDR[0] & 0xFF);
	wLength      |= (pUdp->UDP_FDR[0] << 8);

	if (bmRequestType & 0x80) {
		pUdp->UDP_CSR[0] |= AT91C_UDP_DIR;
		while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_DIR) );
	}
	pUdp->UDP_CSR[0] &= ~AT91C_UDP_RXSETUP;
	while ( (pUdp->UDP_CSR[0]  & AT91C_UDP_RXSETUP)  );

	// Handle supported standard device request Cf Table 9-3 in USB specification Rev 1.1
	switch ((bRequest << 8) | bmRequestType) {
	case STD_GET_DESCRIPTOR:
		if (wValue == 0x100)       // Return Device Descriptor
			AT91F_USB_SendData(pUdp, devDescriptor, MIN(sizeof(devDescriptor), wLength));
		else if (wValue == 0x200)  // Return Configuration Descriptor
			AT91F_USB_SendData(pUdp, cfgDescriptor, MIN(sizeof(cfgDescriptor), wLength));
		else if ((wValue & 0x300) == 0x300)  // Return String Descriptor
			AT91F_USB_SendData(pUdp, strDescriptor, MIN(sizeof(strDescriptor), wLength));
		else
			AT91F_USB_SendStall(pUdp);
		break;
	case STD_SET_ADDRESS:
		AT91F_USB_SendZlp(pUdp);
		pUdp->UDP_FADDR = (AT91C_UDP_FEN | wValue);
		pUdp->UDP_GLBSTATE  = (wValue) ? AT91C_UDP_FADDEN : 0;
		break;
	case STD_SET_CONFIGURATION:
		btConfiguration = wValue;
		AT91F_USB_SendZlp(pUdp);
		pUdp->UDP_GLBSTATE  = (wValue) ? AT91C_UDP_CONFG : AT91C_UDP_FADDEN;
		pUdp->UDP_CSR[1] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT) : 0;
		pUdp->UDP_CSR[2] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN)  : 0;
		pUdp->UDP_CSR[3] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_INT_IN)   : 0;
		break;
	case STD_GET_CONFIGURATION:
		AT91F_USB_SendData(pUdp, (char *) &(btConfiguration), sizeof(btConfiguration));
		break;
	case STD_GET_STATUS_ZERO:
		wStatus = 0;
		AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
		break;
	case STD_GET_STATUS_INTERFACE:
		wStatus = 0;
		AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
		break;
	case STD_GET_STATUS_ENDPOINT:
		wStatus = 0;
		wIndex &= 0x0F;
		if ((pUdp->UDP_GLBSTATE & AT91C_UDP_CONFG) && (wIndex <= 3)) {
			wStatus = (pUdp->UDP_CSR[wIndex] & AT91C_UDP_EPEDS) ? 0 : 1;
			AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
		}
		else if ((pUdp->UDP_GLBSTATE & AT91C_UDP_FADDEN) && (wIndex == 0)) {
			wStatus = (pUdp->UDP_CSR[wIndex] & AT91C_UDP_EPEDS) ? 0 : 1;
			AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
		}
		else
			AT91F_USB_SendStall(pUdp);
		break;
	case STD_SET_FEATURE_ZERO:
		AT91F_USB_SendStall(pUdp);
	    break;
	case STD_SET_FEATURE_INTERFACE:
		AT91F_USB_SendZlp(pUdp);
		break;
	case STD_SET_FEATURE_ENDPOINT:
		wIndex &= 0x0F;
		if ((wValue == 0) && wIndex && (wIndex <= 3)) {
			pUdp->UDP_CSR[wIndex] = 0;
			AT91F_USB_SendZlp(pUdp);
		}
		else
			AT91F_USB_SendStall(pUdp);
		break;
	case STD_CLEAR_FEATURE_ZERO:
		AT91F_USB_SendStall(pUdp);
	    break;
	case STD_CLEAR_FEATURE_INTERFACE:
		AT91F_USB_SendZlp(pUdp);
		break;
	case STD_CLEAR_FEATURE_ENDPOINT:
		wIndex &= 0x0F;
		if ((wValue == 0) && wIndex && (wIndex <= 3)) {
			if (wIndex == 1)
				pUdp->UDP_CSR[1] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT);
			else if (wIndex == 2)
				pUdp->UDP_CSR[2] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN);
			else if (wIndex == 3)
				pUdp->UDP_CSR[3] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_ISO_IN);
			AT91F_USB_SendZlp(pUdp);
		}
		else
			AT91F_USB_SendStall(pUdp);
		break;

	// handle CDC class requests
	case SET_LINE_CODING:
		while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_RX_DATA_BK0) );
		pUdp->UDP_CSR[0] &= ~(AT91C_UDP_RX_DATA_BK0);
		AT91F_USB_SendZlp(pUdp);
		break;
	case GET_LINE_CODING:
		AT91F_USB_SendData(pUdp, (char *) &line, MIN(sizeof(line), wLength));
		break;
	case SET_CONTROL_LINE_STATE:
		btConnection = wValue;
		AT91F_USB_SendZlp(pUdp);
		break;
	default:
		AT91F_USB_SendStall(pUdp);
	    break;
	}
}