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/*

        LPCUSB, an USB device driver for LPC microcontrollers

        Copyright (C) 2006 Bertrik Sikken (bertrik@sikken.nl)

        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. The name of the author may not be used to endorse or promote products

           derived from this software without specific prior written permission.

        THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

*/

/** @file

        USB hardware layer

 */

#include "usbdebug.h"

#include "usbhw_lpc.h"

#include "usbapi.h"

#ifdef DEBUG

// comment out the following line if you don't want to use debug LEDs

//#define DEBUG_LED

#endif

/** Installed device interrupt handler */

static TFnDevIntHandler *_pfnDevIntHandler = NULL;

/** Installed endpoint interrupt handlers */

static TFnEPIntHandler  *_apfnEPIntHandlers[16];

/** Installed frame interrupt handlers */

static TFnFrameHandler  *_pfnFrameHandler = NULL;

/** convert from endpoint address to endpoint index */

#define EP2IDX(bEP)     ((((bEP)&0xF)<<1)|(((bEP)&0x80)>>7))

/** convert from endpoint index to endpoint address */

#define IDX2EP(idx)     ((((idx)<<7)&0x80)|(((idx)>>1)&0xF))

/**

        Local function to wait for a device interrupt (and clear it)

        @param [in]     dwIntr          Bitmask of interrupts to wait for

 */

static void Wait4DevInt(unsigned long dwIntr)

{

        // wait for specific interrupt

        while ((LPC_USB->USBDevIntSt & dwIntr) != dwIntr);

        // clear the interrupt bits

        LPC_USB->USBDevIntClr = dwIntr;

}

/**

        Local function to send a command to the USB protocol engine

        @param [in]     bCmd            Command to send

 */

static void USBHwCmd(unsigned char bCmd)

{

        // clear CDFULL/CCEMTY

        LPC_USB->USBDevIntClr = CDFULL | CCEMTY;

        // write command code

        LPC_USB->USBCmdCode = 0x00000500 | (bCmd << 16);

        Wait4DevInt(CCEMTY);

}

/**

        Local function to send a command + data to the USB protocol engine

        @param [in]     bCmd            Command to send

        @param [in]     bData           Data to send

 */

static void USBHwCmdWrite(unsigned char bCmd, unsigned short bData)

{

        // write command code

        USBHwCmd(bCmd);

        // write command data

        LPC_USB->USBCmdCode = 0x00000100 | (bData << 16);

        Wait4DevInt(CCEMTY);

}

/**

        Local function to send a command to the USB protocol engine and read data

        @param [in]     bCmd            Command to send

        @return the data

 */

static unsigned char USBHwCmdRead(unsigned char bCmd)

{

        // write command code

        USBHwCmd(bCmd);

        // get data

        LPC_USB->USBCmdCode = 0x00000200 | (bCmd << 16);

        Wait4DevInt(CDFULL);

        return LPC_USB->USBCmdData;

}

/**

        'Realizes' an endpoint, meaning that buffer space is reserved for

        it. An endpoint needs to be realised before it can be used.

        From experiments, it appears that a USB reset causes USBReEP to

        re-initialise to 3 (= just the control endpoints).

        However, a USB bus reset does not disturb the USBMaxPSize settings.

        @param [in]     idx                     Endpoint index

        @param [in] wMaxPSize   Maximum packet size for this endpoint

 */

static void USBHwEPRealize(int idx, unsigned short wMaxPSize)

{

        LPC_USB->USBReEP |= (1 << idx);

        LPC_USB->USBEpInd = idx;

        LPC_USB->USBMaxPSize = wMaxPSize;

        Wait4DevInt(EP_RLZED);

}

/**

        Enables or disables an endpoint

        @param [in]     idx             Endpoint index

        @param [in]     fEnable TRUE to enable, FALSE to disable

 */

static void USBHwEPEnable(int idx, BOOL fEnable)

{

        USBHwCmdWrite(CMD_EP_SET_STATUS | idx, fEnable ? 0 : EP_DA);

}

/**

        Configures an endpoint and enables it

        @param [in]     bEP                             Endpoint number

        @param [in]     wMaxPacketSize  Maximum packet size for this EP

 */

void USBHwEPConfig(unsigned char bEP, unsigned short wMaxPacketSize)

{

        int idx;

        idx = EP2IDX(bEP);

        // realise EP

        USBHwEPRealize(idx, wMaxPacketSize);

        // enable EP

        USBHwEPEnable(idx, TRUE);

}

/**

        Registers an endpoint event callback

        @param [in]     bEP                             Endpoint number

        @param [in]     pfnHandler              Callback function

 */

void USBHwRegisterEPIntHandler(unsigned char bEP, TFnEPIntHandler *pfnHandler)

{

        int idx;

        idx = EP2IDX(bEP);

        ASSERT(idx<32);

        /* add handler to list of EP handlers */

        _apfnEPIntHandlers[idx / 2] = pfnHandler;

        /* enable EP interrupt */

        LPC_USB->USBEpIntEn |= (1 << idx);

        LPC_USB->USBDevIntEn |= EP_SLOW;

        DBG("Registered handler for EP 0x%x\n", bEP);

}

/**

        Registers an device status callback

        @param [in]     pfnHandler      Callback function

 */

void USBHwRegisterDevIntHandler(TFnDevIntHandler *pfnHandler)

{

        _pfnDevIntHandler = pfnHandler;

        // enable device interrupt

        LPC_USB->USBDevIntEn |= DEV_STAT;

        DBG("Registered handler for device status\n");

}

/**

        Registers the frame callback

        @param [in]     pfnHandler      Callback function

 */

void USBHwRegisterFrameHandler(TFnFrameHandler *pfnHandler)

{

        _pfnFrameHandler = pfnHandler;

        // enable device interrupt

        LPC_USB->USBDevIntEn |= FRAME;

        DBG("Registered handler for frame\n");

}

/**

        Sets the USB address.

        @param [in]     bAddr           Device address to set

 */

void USBHwSetAddress(unsigned char bAddr)

{

        USBHwCmdWrite(CMD_DEV_SET_ADDRESS, DEV_EN | bAddr);

}

/**

        Connects or disconnects from the USB bus

        @param [in]     fConnect        If TRUE, connect, otherwise disconnect

 */

void USBHwConnect(BOOL fConnect)

{

        USBHwCmdWrite(CMD_DEV_STATUS, fConnect ? CON : 0);

}

/**

        Enables interrupt on NAK condition

        For IN endpoints a NAK is generated when the host wants to read data

        from the device, but none is available in the endpoint buffer.

        For OUT endpoints a NAK is generated when the host wants to write data

        to the device, but the endpoint buffer is still full.

        The endpoint interrupt handlers can distinguish regular (ACK) interrupts

        from NAK interrupt by checking the bits in their bEPStatus argument.

        @param [in]     bIntBits        Bitmap indicating which NAK interrupts to enable

 */

void USBHwNakIntEnable(unsigned char bIntBits)

{

        USBHwCmdWrite(CMD_DEV_SET_MODE, bIntBits);

}

/**

        Gets the status from a specific endpoint.

        @param [in]     bEP             Endpoint number

        @return Endpoint status byte (containing EP_STATUS_xxx bits)

 */

unsigned char   USBHwEPGetStatus(unsigned char bEP)

{

        int idx = EP2IDX(bEP);

        return USBHwCmdRead(CMD_EP_SELECT | idx);

}

/**

        Sets the stalled property of an endpoint

        @param [in]     bEP             Endpoint number

        @param [in]     fStall  TRUE to stall, FALSE to unstall

 */

void USBHwEPStall(unsigned char bEP, BOOL fStall)

{

        int idx = EP2IDX(bEP);

        USBHwCmdWrite(CMD_EP_SET_STATUS | idx, fStall ? EP_ST : 0);

}

/**

        Writes data to an endpoint buffer

        @param [in]     bEP             Endpoint number

        @param [in]     pbBuf   Endpoint data

        @param [in]     iLen    Number of bytes to write

        @return TRUE if the data was successfully written or <0 in case of error.

*/

int USBHwEPWrite(unsigned char bEP, unsigned char *pbBuf, int iLen)

{

        int idx;

        idx = EP2IDX(bEP);

        // set write enable for specific endpoint

        LPC_USB->USBCtrl = WR_EN | ((bEP & 0xF) << 2);

        // set packet length

        LPC_USB->USBTxPLen = iLen;

        // write data

        while (LPC_USB->USBCtrl & WR_EN) {

                LPC_USB->USBTxData = (pbBuf[3] << 24) | (pbBuf[2] << 16) | (pbBuf[1] << 8) | pbBuf[0];

                pbBuf += 4;

        }

        // select endpoint and validate buffer

        USBHwCmd(CMD_EP_SELECT | idx);

        USBHwCmd(CMD_EP_VALIDATE_BUFFER);

        return iLen;

}

/**

        Reads data from an endpoint buffer

        @param [in]     bEP             Endpoint number

        @param [in]     pbBuf   Endpoint data

        @param [in]     iMaxLen Maximum number of bytes to read

        @return the number of bytes available in the EP (possibly more than iMaxLen),

        or <0 in case of error.

 */

int USBHwEPRead(unsigned char bEP, unsigned char *pbBuf, int iMaxLen)

{

        int i, idx;

        unsigned long   dwData, dwLen;

        idx = EP2IDX(bEP);

        // set read enable bit for specific endpoint

        LPC_USB->USBCtrl = RD_EN | ((bEP & 0xF) << 2);

        // wait for PKT_RDY

        do {

                dwLen = LPC_USB->USBRxPLen;

        } while ((dwLen & PKT_RDY) == 0);

        // packet valid?

        if ((dwLen & DV) == 0) {

                return -1;

        }

        // get length

        dwLen &= PKT_LNGTH_MASK;

        // get data

        dwData = 0;

        for (i = 0; i < dwLen; i++) {

                if ((i % 4) == 0) {

                        dwData = LPC_USB->USBRxData;

                }

                if ((pbBuf != NULL) && (i < iMaxLen)) {

                        pbBuf[i] = dwData & 0xFF;

                }

                dwData >>= 8;

        }

        // make sure RD_EN is clear

        LPC_USB->USBCtrl = 0;

        // select endpoint and clear buffer

        USBHwCmd(CMD_EP_SELECT | idx);

        USBHwCmd(CMD_EP_CLEAR_BUFFER);

        return dwLen;

}

/**

        Sets the 'configured' state.

        All registered endpoints are 'realised' and enabled, and the

        'configured' bit is set in the device status register.

        @param [in]     fConfigured     If TRUE, configure device, else unconfigure

 */

void USBHwConfigDevice(BOOL fConfigured)

{

        // set configured bit

        USBHwCmdWrite(CMD_DEV_CONFIG, fConfigured ? CONF_DEVICE : 0);

}

/**

        USB interrupt handler

        @todo Get all 11 bits of frame number instead of just 8

        Endpoint interrupts are mapped to the slow interrupt

 */

void USBHwISR(void)

{

        unsigned long   dwStatus;

        unsigned long dwIntBit;

        unsigned char   bEPStat, bDevStat, bStat;

        int i;

        unsigned short  wFrame;

        // handle device interrupts

        dwStatus = LPC_USB->USBDevIntSt;

        // frame interrupt

        if (dwStatus & FRAME) {

                // clear int

                LPC_USB->USBDevIntClr = FRAME;

                // call handler

                if (_pfnFrameHandler != NULL) {

                        wFrame = USBHwCmdRead(CMD_DEV_READ_CUR_FRAME_NR);

                        _pfnFrameHandler(wFrame);

                }

        }

        // device status interrupt

        if (dwStatus & DEV_STAT) {

                /*      Clear DEV_STAT interrupt before reading DEV_STAT register.

                        This prevents corrupted device status reads, see

                        LPC2148 User manual revision 2, 25 july 2006.

                */

                LPC_USB->USBDevIntClr = DEV_STAT;

                bDevStat = USBHwCmdRead(CMD_DEV_STATUS);

                if (bDevStat & (CON_CH | SUS_CH | RST)) {

                        // convert device status into something HW independent

                        bStat = ((bDevStat & CON) ? DEV_STATUS_CONNECT : 0) |

                                        ((bDevStat & SUS) ? DEV_STATUS_SUSPEND : 0) |

                                        ((bDevStat & RST) ? DEV_STATUS_RESET : 0);

                        // call handler

                        if (_pfnDevIntHandler != NULL) {

                                _pfnDevIntHandler(bStat);

                        }

                }

        }

        // endpoint interrupt

        if (dwStatus & EP_SLOW) {

                // clear EP_SLOW

                LPC_USB->USBDevIntClr = EP_SLOW;

                // check all endpoints

                for (i = 0; i < 32; i++) {

                        dwIntBit = (1 << i);

                        if (LPC_USB->USBEpIntSt & dwIntBit) {

                                // clear int (and retrieve status)

                                LPC_USB->USBEpIntClr = dwIntBit;

                                Wait4DevInt(CDFULL);

                                bEPStat = LPC_USB->USBCmdData;

                                // convert EP pipe stat into something HW independent

                                bStat = ((bEPStat & EPSTAT_FE) ? EP_STATUS_DATA : 0) |

                                                ((bEPStat & EPSTAT_ST) ? EP_STATUS_STALLED : 0) |

                                                ((bEPStat & EPSTAT_STP) ? EP_STATUS_SETUP : 0) |

                                                ((bEPStat & EPSTAT_EPN) ? EP_STATUS_NACKED : 0) |

                                                ((bEPStat & EPSTAT_PO) ? EP_STATUS_ERROR : 0);

                                // call handler

                                if (_apfnEPIntHandlers[i / 2] != NULL) {

                                        _apfnEPIntHandlers[i / 2](IDX2EP(i), bStat);

                                }

                        }

                }

        }

}

/**

        Initialises the USB hardware

        @return TRUE if the hardware was successfully initialised

 */

BOOL USBHwInit(void)

{

        // P2.9 -> USB_CONNECT

        LPC_PINCON->PINSEL4 &= ~0x000C0000;

        LPC_PINCON->PINSEL4 |= 0x00040000;

        // P1.18 -> USB_UP_LED

        // P1.30 -> VBUS

        LPC_PINCON->PINSEL3 &= ~0x30000030;

        LPC_PINCON->PINSEL3 |= 0x20000010;

        // P0.29 -> USB_D+

        // P0.30 -> USB_D-

        LPC_PINCON->PINSEL1 &= ~0x3C000000;

        LPC_PINCON->PINSEL1 |= 0x14000000;

        // enable PUSB

        LPC_SC->PCONP |= (1 << 31);

        LPC_USB->OTGClkCtrl = 0x12;                       /* Dev clock, AHB clock enable  */

        while ((LPC_USB->OTGClkSt & 0x12) != 0x12);

        // disable/clear all interrupts for now

        LPC_USB->USBDevIntEn = 0;

        LPC_USB->USBDevIntClr = 0xFFFFFFFF;

        LPC_USB->USBDevIntPri = 0;

        LPC_USB->USBEpIntEn = 0;

        LPC_USB->USBEpIntClr = 0xFFFFFFFF;

        LPC_USB->USBEpIntPri = 0;

        // by default, only ACKs generate interrupts

        USBHwNakIntEnable(0);

        return TRUE;

}