NFS: Optimise inode attribute cache updates

[linux-2.6/mini2440.git] / drivers / char / ip2 / i2ellis.c

/*******************************************************************************
*
*   (c) 1998 by Computone Corporation
*
********************************************************************************
*
*
*   PACKAGE:     Linux tty Device Driver for IntelliPort family of multiport
*                serial I/O controllers.
*
*   DESCRIPTION: Low-level interface code for the device driver
*                (This is included source code, not a separate compilation
*                module.)
*
*******************************************************************************/
//---------------------------------------------
// Function declarations private to this module
//---------------------------------------------
// Functions called only indirectly through i2eBordStr entries.

static int iiWriteBuf16(i2eBordStrPtr, unsigned char *, int);
static int iiWriteBuf8(i2eBordStrPtr, unsigned char *, int);
static int iiReadBuf16(i2eBordStrPtr, unsigned char *, int);
static int iiReadBuf8(i2eBordStrPtr, unsigned char *, int);

static unsigned short iiReadWord16(i2eBordStrPtr);
static unsigned short iiReadWord8(i2eBordStrPtr);
static void iiWriteWord16(i2eBordStrPtr, unsigned short);
static void iiWriteWord8(i2eBordStrPtr, unsigned short);

static int iiWaitForTxEmptyII(i2eBordStrPtr, int);
static int iiWaitForTxEmptyIIEX(i2eBordStrPtr, int);
static int iiTxMailEmptyII(i2eBordStrPtr);
static int iiTxMailEmptyIIEX(i2eBordStrPtr);
static int iiTrySendMailII(i2eBordStrPtr, unsigned char);
static int iiTrySendMailIIEX(i2eBordStrPtr, unsigned char);

static unsigned short iiGetMailII(i2eBordStrPtr);
static unsigned short iiGetMailIIEX(i2eBordStrPtr);

static void iiEnableMailIrqII(i2eBordStrPtr);
static void iiEnableMailIrqIIEX(i2eBordStrPtr);
static void iiWriteMaskII(i2eBordStrPtr, unsigned char);
static void iiWriteMaskIIEX(i2eBordStrPtr, unsigned char);

static void ii2DelayTimer(unsigned int);
static void ii2DelayWakeup(unsigned long id);
static void ii2Nop(void);

//***************
//* Static Data *
//***************

static int ii2Safe;         // Safe I/O address for delay routine

static int iiDelayed;   // Set when the iiResetDelay function is
                                                        // called. Cleared when ANY board is reset.
static struct timer_list * pDelayTimer;   // Used by iiDelayTimer
static wait_queue_head_t pDelayWait;    // Used by iiDelayTimer
static rwlock_t Dl_spinlock;

//********
//* Code *
//********

//=======================================================
// Initialization Routines
//
// iiSetAddress
// iiReset
// iiResetDelay
// iiInitialize
//=======================================================

//******************************************************************************
// Function:   iiEllisInit()
// Parameters: None
//
// Returns:    Nothing
//
// Description:
//
// This routine performs any required initialization of the iiEllis subsystem.
//
//******************************************************************************
static void
iiEllisInit(void)
{
        pDelayTimer = kmalloc ( sizeof (struct timer_list), GFP_KERNEL );
        init_timer(pDelayTimer);
        init_waitqueue_head(&pDelayWait);
        LOCK_INIT(&Dl_spinlock);
}

//******************************************************************************
// Function:   iiEllisCleanup()
// Parameters: None
//
// Returns:    Nothing
//
// Description:
//
// This routine performs any required cleanup of the iiEllis subsystem.
//
//******************************************************************************
static void
iiEllisCleanup(void)
{
        if ( pDelayTimer != NULL ) {
                kfree ( pDelayTimer );
        }
}

//******************************************************************************
// Function:   iiSetAddress(pB, address, delay)
// Parameters: pB      - pointer to the board structure
//             address - the purported I/O address of the board
//             delay   - pointer to the 1-ms delay function to use
//                       in this and any future operations to this board
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// This routine (roughly) checks for address validity, sets the i2eValid OK and
// sets the state to II_STATE_COLD which means that we haven't even sent a reset
// yet.
//
//******************************************************************************
static int
iiSetAddress( i2eBordStrPtr pB, int address, delayFunc_t delay )
{
        // Should any failure occur before init is finished...
        pB->i2eValid = I2E_INCOMPLETE;

        // Cannot check upper limit except extremely: Might be microchannel
        // Address must be on an 8-byte boundary

        if ((unsigned int)address <= 0x100
                || (unsigned int)address >= 0xfff8
                || (address & 0x7)
                )
        {
                COMPLETE(pB,I2EE_BADADDR);
        }

        // Initialize accelerators
        pB->i2eBase    = address;
        pB->i2eData    = address + FIFO_DATA;
        pB->i2eStatus  = address + FIFO_STATUS;
        pB->i2ePointer = address + FIFO_PTR;
        pB->i2eXMail   = address + FIFO_MAIL;
        pB->i2eXMask   = address + FIFO_MASK;

        // Initialize i/o address for ii2DelayIO
        ii2Safe = address + FIFO_NOP;

        // Initialize the delay routine
        pB->i2eDelay = ((delay != (delayFunc_t)NULL) ? delay : (delayFunc_t)ii2Nop);

        pB->i2eValid = I2E_MAGIC;
        pB->i2eState = II_STATE_COLD;

        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiReset(pB)
// Parameters: pB - pointer to the board structure
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Attempts to reset the board (see also i2hw.h). Normally, we would use this to
// reset a board immediately after iiSetAddress(), but it is valid to reset a
// board from any state, say, in order to change or re-load loadware. (Under
// such circumstances, no reason to re-run iiSetAddress(), which is why it is a
// separate routine and not included in this routine.
//
//******************************************************************************
static int
iiReset(i2eBordStrPtr pB)
{
        // Magic number should be set, else even the address is suspect
        if (pB->i2eValid != I2E_MAGIC)
        {
                COMPLETE(pB, I2EE_BADMAGIC);
        }

        OUTB(pB->i2eBase + FIFO_RESET, 0);  // Any data will do
        iiDelay(pB, 50);                    // Pause between resets
        OUTB(pB->i2eBase + FIFO_RESET, 0);  // Second reset

        // We must wait before even attempting to read anything from the FIFO: the
        // board's P.O.S.T may actually attempt to read and write its end of the
        // FIFO in order to check flags, loop back (where supported), etc. On
        // completion of this testing it would reset the FIFO, and on completion
        // of all // P.O.S.T., write the message. We must not mistake data which
        // might have been sent for testing as part of the reset message. To
        // better utilize time, say, when resetting several boards, we allow the
        // delay to be performed externally; in this way the caller can reset 
        // several boards, delay a single time, then call the initialization
        // routine for all.

        pB->i2eState = II_STATE_RESET;

        iiDelayed = 0;  // i.e., the delay routine hasn't been called since the most
                                        // recent reset.

        // Ensure anything which would have been of use to standard loadware is
        // blanked out, since board has now forgotten everything!.

        pB->i2eUsingIrq = IRQ_UNDEFINED; // Not set up to use an interrupt yet
        pB->i2eWaitingForEmptyFifo = 0;
        pB->i2eOutMailWaiting = 0;
        pB->i2eChannelPtr = NULL;
        pB->i2eChannelCnt = 0;

        pB->i2eLeadoffWord[0] = 0;
        pB->i2eFifoInInts = 0;
        pB->i2eFifoOutInts = 0;
        pB->i2eFatalTrap = NULL;
        pB->i2eFatal = 0;

        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiResetDelay(pB)
// Parameters: pB - pointer to the board structure
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Using the delay defined in board structure, waits two seconds (for board to
// reset).
//
//******************************************************************************
static int
iiResetDelay(i2eBordStrPtr pB)
{
        if (pB->i2eValid != I2E_MAGIC) {
                COMPLETE(pB, I2EE_BADMAGIC);
        }
        if (pB->i2eState != II_STATE_RESET) {
                COMPLETE(pB, I2EE_BADSTATE);
        }
        iiDelay(pB,2000);       /* Now we wait for two seconds. */
        iiDelayed = 1;          /* Delay has been called: ok to initialize */
        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiInitialize(pB)
// Parameters: pB - pointer to the board structure
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Attempts to read the Power-on reset message. Initializes any remaining fields
// in the pB structure.
//
// This should be called as the third step of a process beginning with
// iiReset(), then iiResetDelay(). This routine checks to see that the structure
// is "valid" and in the reset state, also confirms that the delay routine has
// been called since the latest reset (to any board! overly strong!).
//
//******************************************************************************
static int
iiInitialize(i2eBordStrPtr pB)
{
        int itemp;
        unsigned char c;
        unsigned short utemp;
        unsigned int ilimit;

        if (pB->i2eValid != I2E_MAGIC)
        {
                COMPLETE(pB, I2EE_BADMAGIC);
        }

        if (pB->i2eState != II_STATE_RESET || !iiDelayed)
        {
                COMPLETE(pB, I2EE_BADSTATE);
        }

        // In case there is a failure short of our completely reading the power-up
        // message.
        pB->i2eValid = I2E_INCOMPLETE;


        // Now attempt to read the message.

        for (itemp = 0; itemp < sizeof(porStr); itemp++)
        {
                // We expect the entire message is ready.
                if (HAS_NO_INPUT(pB))
                {
                        pB->i2ePomSize = itemp;
                        COMPLETE(pB, I2EE_PORM_SHORT);
                }

                pB->i2ePom.c[itemp] = c = BYTE_FROM(pB);

                // We check the magic numbers as soon as they are supposed to be read
                // (rather than after) to minimize effect of reading something we
                // already suspect can't be "us".
                if (  (itemp == POR_1_INDEX && c != POR_MAGIC_1) ||
                                (itemp == POR_2_INDEX && c != POR_MAGIC_2))
                {
                        pB->i2ePomSize = itemp+1;
                        COMPLETE(pB, I2EE_BADMAGIC);
                }
        }

        pB->i2ePomSize = itemp;

        // Ensure that this was all the data...
        if (HAS_INPUT(pB))
                COMPLETE(pB, I2EE_PORM_LONG);

        // For now, we'll fail to initialize if P.O.S.T reports bad chip mapper:
        // Implying we will not be able to download any code either:  That's ok: the
        // condition is pretty explicit.
        if (pB->i2ePom.e.porDiag1 & POR_BAD_MAPPER)
        {
                COMPLETE(pB, I2EE_POSTERR);
        }

        // Determine anything which must be done differently depending on the family
        // of boards!
        switch (pB->i2ePom.e.porID & POR_ID_FAMILY)
        {
        case POR_ID_FII:  // IntelliPort-II

                pB->i2eFifoStyle   = FIFO_II;
                pB->i2eFifoSize    = 512;     // 512 bytes, always
                pB->i2eDataWidth16 = NO;

                pB->i2eMaxIrq = 15;     // Because board cannot tell us it is in an 8-bit
                                                        // slot, we do allow it to be done (documentation!)

                pB->i2eGoodMap[1] =
                pB->i2eGoodMap[2] =
                pB->i2eGoodMap[3] =
                pB->i2eChannelMap[1] =
                pB->i2eChannelMap[2] =
                pB->i2eChannelMap[3] = 0;

                switch (pB->i2ePom.e.porID & POR_ID_SIZE)
                {
                case POR_ID_II_4:
                        pB->i2eGoodMap[0] =
                        pB->i2eChannelMap[0] = 0x0f;  // four-port

                        // Since porPorts1 is based on the Hardware ID register, the numbers
                        // should always be consistent for IntelliPort-II.  Ditto below...
                        if (pB->i2ePom.e.porPorts1 != 4)
                        {
                                COMPLETE(pB, I2EE_INCONSIST);
                        }
                        break;

                case POR_ID_II_8:
                case POR_ID_II_8R:
                        pB->i2eGoodMap[0] =
                        pB->i2eChannelMap[0] = 0xff;  // Eight port
                        if (pB->i2ePom.e.porPorts1 != 8)
                        {
                                COMPLETE(pB, I2EE_INCONSIST);
                        }
                        break;

                case POR_ID_II_6:
                        pB->i2eGoodMap[0] =
                        pB->i2eChannelMap[0] = 0x3f;  // Six Port
                        if (pB->i2ePom.e.porPorts1 != 6)
                        {
                                COMPLETE(pB, I2EE_INCONSIST);
                        }
                        break;
                }

                // Fix up the "good channel list based on any errors reported.
                if (pB->i2ePom.e.porDiag1 & POR_BAD_UART1)
                {
                        pB->i2eGoodMap[0] &= ~0x0f;
                }

                if (pB->i2ePom.e.porDiag1 & POR_BAD_UART2)
                {
                        pB->i2eGoodMap[0] &= ~0xf0;
                }

                break;   // POR_ID_FII case

        case POR_ID_FIIEX:   // IntelliPort-IIEX

                pB->i2eFifoStyle = FIFO_IIEX;

                itemp = pB->i2ePom.e.porFifoSize;

                // Implicit assumption that fifo would not grow beyond 32k, 
                // nor would ever be less than 256.

                if (itemp < 8 || itemp > 15)
                {
                        COMPLETE(pB, I2EE_INCONSIST);
                }
                pB->i2eFifoSize = (1 << itemp);

                // These are based on what P.O.S.T thinks should be there, based on
                // box ID registers
                ilimit = pB->i2ePom.e.porNumBoxes;
                if (ilimit > ABS_MAX_BOXES)
                {
                        ilimit = ABS_MAX_BOXES;
                }

                // For as many boxes as EXIST, gives the type of box.
                // Added 8/6/93: check for the ISA-4 (asic) which looks like an
                // expandable but for whom "8 or 16?" is not the right question.

                utemp = pB->i2ePom.e.porFlags;
                if (utemp & POR_CEX4)
                {
                        pB->i2eChannelMap[0] = 0x000f;
                } else {
                        utemp &= POR_BOXES;
                        for (itemp = 0; itemp < ilimit; itemp++)
                        {
                                pB->i2eChannelMap[itemp] = 
                                        ((utemp & POR_BOX_16) ? 0xffff : 0x00ff);
                                utemp >>= 1;
                        }
                }

                // These are based on what P.O.S.T actually found.

                utemp = (pB->i2ePom.e.porPorts2 << 8) + pB->i2ePom.e.porPorts1;

                for (itemp = 0; itemp < ilimit; itemp++)
                {
                        pB->i2eGoodMap[itemp] = 0;
                        if (utemp & 1) pB->i2eGoodMap[itemp] |= 0x000f;
                        if (utemp & 2) pB->i2eGoodMap[itemp] |= 0x00f0;
                        if (utemp & 4) pB->i2eGoodMap[itemp] |= 0x0f00;
                        if (utemp & 8) pB->i2eGoodMap[itemp] |= 0xf000;
                        utemp >>= 4;
                }

                // Now determine whether we should transfer in 8 or 16-bit mode.
                switch (pB->i2ePom.e.porBus & (POR_BUS_SLOT16 | POR_BUS_DIP16) )
                {
                case POR_BUS_SLOT16 | POR_BUS_DIP16:
                        pB->i2eDataWidth16 = YES;
                        pB->i2eMaxIrq = 15;
                        break;

                case POR_BUS_SLOT16:
                        pB->i2eDataWidth16 = NO;
                        pB->i2eMaxIrq = 15;
                        break;

                case 0:
                case POR_BUS_DIP16:     // In an 8-bit slot, DIP switch don't care.
                default:
                        pB->i2eDataWidth16 = NO;
                        pB->i2eMaxIrq = 7;
                        break;
                }
                break;   // POR_ID_FIIEX case

        default:    // Unknown type of board
                COMPLETE(pB, I2EE_BAD_FAMILY);
                break;
        }  // End the switch based on family

        // Temporarily, claim there is no room in the outbound fifo. 
        // We will maintain this whenever we check for an empty outbound FIFO.
        pB->i2eFifoRemains = 0;

        // Now, based on the bus type, should we expect to be able to re-configure
        // interrupts (say, for testing purposes).
        switch (pB->i2ePom.e.porBus & POR_BUS_TYPE)
        {
        case POR_BUS_T_ISA:
        case POR_BUS_T_UNK:  // If the type of bus is undeclared, assume ok.
                pB->i2eChangeIrq = YES;
                break;
        case POR_BUS_T_MCA:
        case POR_BUS_T_EISA:
                pB->i2eChangeIrq = NO;
                break;
        default:
                COMPLETE(pB, I2EE_BADBUS);
        }

        if (pB->i2eDataWidth16 == YES)
        {
                pB->i2eWriteBuf  = iiWriteBuf16;
                pB->i2eReadBuf   = iiReadBuf16;
                pB->i2eWriteWord = iiWriteWord16;
                pB->i2eReadWord  = iiReadWord16;
        } else {
                pB->i2eWriteBuf  = iiWriteBuf8;
                pB->i2eReadBuf   = iiReadBuf8;
                pB->i2eWriteWord = iiWriteWord8;
                pB->i2eReadWord  = iiReadWord8;
        }

        switch(pB->i2eFifoStyle)
        {
        case FIFO_II:
                pB->i2eWaitForTxEmpty = iiWaitForTxEmptyII;
                pB->i2eTxMailEmpty    = iiTxMailEmptyII;
                pB->i2eTrySendMail    = iiTrySendMailII;
                pB->i2eGetMail        = iiGetMailII;
                pB->i2eEnableMailIrq  = iiEnableMailIrqII;
                pB->i2eWriteMask      = iiWriteMaskII;

                break;

        case FIFO_IIEX:
                pB->i2eWaitForTxEmpty = iiWaitForTxEmptyIIEX;
                pB->i2eTxMailEmpty    = iiTxMailEmptyIIEX;
                pB->i2eTrySendMail    = iiTrySendMailIIEX;
                pB->i2eGetMail        = iiGetMailIIEX;
                pB->i2eEnableMailIrq  = iiEnableMailIrqIIEX;
                pB->i2eWriteMask      = iiWriteMaskIIEX;

                break;

        default:
                COMPLETE(pB, I2EE_INCONSIST);
        }

        // Initialize state information.
        pB->i2eState = II_STATE_READY;   // Ready to load loadware.

        // Some Final cleanup:
        // For some boards, the bootstrap firmware may perform some sort of test
        // resulting in a stray character pending in the incoming mailbox. If one is
        // there, it should be read and discarded, especially since for the standard
        // firmware, it's the mailbox that interrupts the host.

        pB->i2eStartMail = iiGetMail(pB);

        // Throw it away and clear the mailbox structure element
        pB->i2eStartMail = NO_MAIL_HERE;

        // Everything is ok now, return with good status/

        pB->i2eValid = I2E_MAGIC;
        COMPLETE(pB, I2EE_GOOD);
}

//=======================================================
// Delay Routines
//
// iiDelayIO
// iiNop
//=======================================================

static void
ii2DelayWakeup(unsigned long id)
{
        wake_up_interruptible ( &pDelayWait );
}

//******************************************************************************
// Function:   ii2DelayTimer(mseconds)
// Parameters: mseconds - number of milliseconds to delay
//
// Returns:    Nothing
//
// Description:
//
// This routine delays for approximately mseconds milliseconds and is intended
// to be called indirectly through i2Delay field in i2eBordStr. It uses the
// Linux timer_list mechanism.
//
// The Linux timers use a unit called "jiffies" which are 10mS in the Intel
// architecture. This function rounds the delay period up to the next "jiffy".
// In the Alpha architecture the "jiffy" is 1mS, but this driver is not intended
// for Alpha platforms at this time.
//
//******************************************************************************
static void
ii2DelayTimer(unsigned int mseconds)
{
        wait_queue_t wait;

        init_waitqueue_entry(&wait, current);

        init_timer ( pDelayTimer );

        add_wait_queue(&pDelayWait, &wait);

        set_current_state( TASK_INTERRUPTIBLE );

        pDelayTimer->expires  = jiffies + ( mseconds + 9 ) / 10;
        pDelayTimer->function = ii2DelayWakeup;
        pDelayTimer->data     = 0;

        add_timer ( pDelayTimer );

        schedule();

        set_current_state( TASK_RUNNING );
        remove_wait_queue(&pDelayWait, &wait);

        del_timer ( pDelayTimer );
}

#if 0
//static void ii2DelayIO(unsigned int);
//******************************************************************************
// !!! Not Used, this is DOS crap, some of you young folks may be interested in
//     in how things were done in the stone age of caculating machines       !!!
// Function:   ii2DelayIO(mseconds)
// Parameters: mseconds - number of milliseconds to delay
//
// Returns:    Nothing
//
// Description:
//
// This routine delays for approximately mseconds milliseconds and is intended
// to be called indirectly through i2Delay field in i2eBordStr. It is intended
// for use where a clock-based function is impossible: for example, DOS drivers.
//
// This function uses the IN instruction to place bounds on the timing and
// assumes that ii2Safe has been set. This is because I/O instructions are not
// subject to caching and will therefore take a certain minimum time. To ensure
// the delay is at least long enough on fast machines, it is based on some
// fastest-case calculations.  On slower machines this may cause VERY long
// delays. (3 x fastest case). In the fastest case, everything is cached except
// the I/O instruction itself.
//
// Timing calculations:
// The fastest bus speed for I/O operations is likely to be 10 MHz. The I/O
// operation in question is a byte operation to an odd address. For 8-bit
// operations, the architecture generally enforces two wait states. At 10 MHz, a
// single cycle time is 100nS. A read operation at two wait states takes 6
// cycles for a total time of 600nS. Therefore approximately 1666 iterations
// would be required to generate a single millisecond delay. The worst
// (reasonable) case would be an 8MHz system with no cacheing. In this case, the
// I/O instruction would take 125nS x 6 cyles = 750 nS. More importantly, code
// fetch of other instructions in the loop would take time (zero wait states,
// however) and would be hard to estimate. This is minimized by using in-line
// assembler for the in inner loop of IN instructions. This consists of just a
// few bytes. So we'll guess about four code fetches per loop. Each code fetch
// should take four cycles, so we have 125nS * 8 = 1000nS. Worst case then is
// that what should have taken 1 mS takes instead 1666 * (1750) = 2.9 mS.
//
// So much for theoretical timings: results using 1666 value on some actual
// machines:
// IBM      286      6MHz     3.15 mS
// Zenith   386      33MHz    2.45 mS
// (brandX) 386      33MHz    1.90 mS  (has cache)
// (brandY) 486      33MHz    2.35 mS
// NCR      486      ??       1.65 mS (microchannel)
//
// For most machines, it is probably safe to scale this number back (remember,
// for robust operation use an actual timed delay if possible), so we are using
// a value of 1190. This yields 1.17 mS for the fastest machine in our sample,
// 1.75 mS for typical 386 machines, and 2.25 mS the absolute slowest machine.
//
// 1/29/93:
// The above timings are too slow. Actual cycle times might be faster. ISA cycle
// times could approach 500 nS, and ...
// The IBM model 77 being microchannel has no wait states for 8-bit reads and
// seems to be accessing the I/O at 440 nS per access (from start of one to
// start of next). This would imply we need 1000/.440 = 2272 iterations to
// guarantee we are fast enough. In actual testing, we see that 2 * 1190 are in
// fact enough. For diagnostics, we keep the level at 1190, but developers note
// this needs tuning.
//
// Safe assumption:  2270 i/o reads = 1 millisecond
//
//******************************************************************************


static int ii2DelValue = 1190;  // See timing calculations below
                                                // 1666 for fastest theoretical machine
                                                // 1190 safe for most fast 386 machines
                                                // 1000 for fastest machine tested here
                                                //  540 (sic) for AT286/6Mhz
static void
ii2DelayIO(unsigned int mseconds)
{
        if (!ii2Safe) 
                return;   /* Do nothing if this variable uninitialized */

        while(mseconds--) {
                int i = ii2DelValue;
                while ( i-- ) {
                        INB ( ii2Safe );
                }
        }
}
#endif 

//******************************************************************************
// Function:   ii2Nop()
// Parameters: None
//
// Returns:    Nothing
//
// Description:
//
// iiInitialize will set i2eDelay to this if the delay parameter is NULL. This
// saves checking for a NULL pointer at every call.
//******************************************************************************
static void
ii2Nop(void)
{
        return; // no mystery here
}

//=======================================================
// Routines which are available in 8/16-bit versions, or
// in different fifo styles. These are ALL called
// indirectly through the board structure.
//=======================================================

//******************************************************************************
// Function:   iiWriteBuf16(pB, address, count)
// Parameters: pB      - pointer to board structure
//             address - address of data to write
//             count   - number of data bytes to write
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Writes 'count' bytes from 'address' to the data fifo specified by the board
// structure pointer pB. Should count happen to be odd, an extra pad byte is
// sent (identity unknown...). Uses 16-bit (word) operations. Is called
// indirectly through pB->i2eWriteBuf.
//
//******************************************************************************
static int
iiWriteBuf16(i2eBordStrPtr pB, unsigned char *address, int count)
{
        // Rudimentary sanity checking here.
        if (pB->i2eValid != I2E_MAGIC)
                COMPLETE(pB, I2EE_INVALID);

        OUTSW ( pB->i2eData, address, count);

        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiWriteBuf8(pB, address, count)
// Parameters: pB      - pointer to board structure
//             address - address of data to write
//             count   - number of data bytes to write
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Writes 'count' bytes from 'address' to the data fifo specified by the board
// structure pointer pB. Should count happen to be odd, an extra pad byte is
// sent (identity unknown...). This is to be consistent with the 16-bit version.
// Uses 8-bit (byte) operations. Is called indirectly through pB->i2eWriteBuf.
//
//******************************************************************************
static int
iiWriteBuf8(i2eBordStrPtr pB, unsigned char *address, int count)
{
        /* Rudimentary sanity checking here */
        if (pB->i2eValid != I2E_MAGIC)
                COMPLETE(pB, I2EE_INVALID);

        OUTSB ( pB->i2eData, address, count );

        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiReadBuf16(pB, address, count)
// Parameters: pB      - pointer to board structure
//             address - address to put data read
//             count   - number of data bytes to read
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Reads 'count' bytes into 'address' from the data fifo specified by the board
// structure pointer pB. Should count happen to be odd, an extra pad byte is
// received (identity unknown...). Uses 16-bit (word) operations. Is called
// indirectly through pB->i2eReadBuf.
//
//******************************************************************************
static int
iiReadBuf16(i2eBordStrPtr pB, unsigned char *address, int count)
{
        // Rudimentary sanity checking here.
        if (pB->i2eValid != I2E_MAGIC)
                COMPLETE(pB, I2EE_INVALID);

        INSW ( pB->i2eData, address, count);

        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiReadBuf8(pB, address, count)
// Parameters: pB      - pointer to board structure
//             address - address to put data read
//             count   - number of data bytes to read
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Reads 'count' bytes into 'address' from the data fifo specified by the board
// structure pointer pB. Should count happen to be odd, an extra pad byte is
// received (identity unknown...). This to match the 16-bit behaviour. Uses
// 8-bit (byte) operations. Is called indirectly through pB->i2eReadBuf.
//
//******************************************************************************
static int
iiReadBuf8(i2eBordStrPtr pB, unsigned char *address, int count)
{
        // Rudimentary sanity checking here.
        if (pB->i2eValid != I2E_MAGIC)
                COMPLETE(pB, I2EE_INVALID);

        INSB ( pB->i2eData, address, count);

        COMPLETE(pB, I2EE_GOOD);
}

//******************************************************************************
// Function:   iiReadWord16(pB)
// Parameters: pB      - pointer to board structure
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Returns the word read from the data fifo specified by the board-structure
// pointer pB. Uses a 16-bit operation. Is called indirectly through
// pB->i2eReadWord.
//
//******************************************************************************
static unsigned short
iiReadWord16(i2eBordStrPtr pB)
{
        return (unsigned short)( INW(pB->i2eData) );
}

//******************************************************************************
// Function:   iiReadWord8(pB)
// Parameters: pB      - pointer to board structure
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Returns the word read from the data fifo specified by the board-structure
// pointer pB. Uses two 8-bit operations. Bytes are assumed to be LSB first. Is
// called indirectly through pB->i2eReadWord.
//
//******************************************************************************
static unsigned short
iiReadWord8(i2eBordStrPtr pB)
{
        unsigned short urs;

        urs = INB ( pB->i2eData );

        return ( ( INB ( pB->i2eData ) << 8 ) | urs );
}

//******************************************************************************
// Function:   iiWriteWord16(pB, value)
// Parameters: pB    - pointer to board structure
//             value - data to write
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Writes the word 'value' to the data fifo specified by the board-structure
// pointer pB. Uses 16-bit operation. Is called indirectly through
// pB->i2eWriteWord.
//
//******************************************************************************
static void
iiWriteWord16(i2eBordStrPtr pB, unsigned short value)
{
        WORD_TO(pB, (int)value);
}

//******************************************************************************
// Function:   iiWriteWord8(pB, value)
// Parameters: pB    - pointer to board structure
//             value - data to write
//
// Returns:    True if everything appears copacetic.
//             False if there is any error: the pB->i2eError field has the error
//
// Description:
//
// Writes the word 'value' to the data fifo specified by the board-structure
// pointer pB. Uses two 8-bit operations (writes LSB first). Is called
// indirectly through pB->i2eWriteWord.
//
//******************************************************************************
static void
iiWriteWord8(i2eBordStrPtr pB, unsigned short value)
{
        BYTE_TO(pB, (char)value);
        BYTE_TO(pB, (char)(value >> 8) );
}

//******************************************************************************
// Function:   iiWaitForTxEmptyII(pB, mSdelay)
// Parameters: pB      - pointer to board structure
//             mSdelay - period to wait before returning
//
// Returns:    True if the FIFO is empty.
//             False if it not empty in the required time: the pB->i2eError
//             field has the error.
//
// Description:
//
// Waits up to "mSdelay" milliseconds for the outgoing FIFO to become empty; if
// not empty by the required time, returns false and error in pB->i2eError,
// otherwise returns true.
//
// mSdelay == 0 is taken to mean must be empty on the first test.
//
// This version operates on IntelliPort-II - style FIFO's
//
// Note this routine is organized so that if status is ok there is no delay at
// all called either before or after the test.  Is called indirectly through
// pB->i2eWaitForTxEmpty.
//
//******************************************************************************
static int
iiWaitForTxEmptyII(i2eBordStrPtr pB, int mSdelay)
{
        unsigned long   flags;
        int itemp;

        for (;;)
        {
                // This routine hinges on being able to see the "other" status register
                // (as seen by the local processor).  His incoming fifo is our outgoing
                // FIFO.
                //
                // By the nature of this routine, you would be using this as part of a
                // larger atomic context: i.e., you would use this routine to ensure the
                // fifo empty, then act on this information. Between these two halves, 
                // you will generally not want to service interrupts or in any way 
                // disrupt the assumptions implicit in the larger context.
                //
                // Even worse, however, this routine "shifts" the status register to 
                // point to the local status register which is not the usual situation.
                // Therefore for extra safety, we force the critical section to be
                // completely atomic, and pick up after ourselves before allowing any
                // interrupts of any kind.


                WRITE_LOCK_IRQSAVE(&Dl_spinlock,flags)
                OUTB(pB->i2ePointer, SEL_COMMAND);
                OUTB(pB->i2ePointer, SEL_CMD_SH);

                itemp = INB(pB->i2eStatus);

                OUTB(pB->i2ePointer, SEL_COMMAND);
                OUTB(pB->i2ePointer, SEL_CMD_UNSH);

                if (itemp & ST_IN_EMPTY)
                {
                        UPDATE_FIFO_ROOM(pB);
                        WRITE_UNLOCK_IRQRESTORE(&Dl_spinlock,flags)
                        COMPLETE(pB, I2EE_GOOD);
                }

                WRITE_UNLOCK_IRQRESTORE(&Dl_spinlock,flags)

                if (mSdelay-- == 0)
                        break;

                iiDelay(pB, 1);      /* 1 mS granularity on checking condition */
        }
        COMPLETE(pB, I2EE_TXE_TIME);
}

//******************************************************************************
// Function:   iiWaitForTxEmptyIIEX(pB, mSdelay)
// Parameters: pB      - pointer to board structure
//             mSdelay - period to wait before returning
//
// Returns:    True if the FIFO is empty.
//             False if it not empty in the required time: the pB->i2eError
//             field has the error.
//
// Description:
//
// Waits up to "mSdelay" milliseconds for the outgoing FIFO to become empty; if
// not empty by the required time, returns false and error in pB->i2eError,
// otherwise returns true.
//
// mSdelay == 0 is taken to mean must be empty on the first test.
//
// This version operates on IntelliPort-IIEX - style FIFO's
//
// Note this routine is organized so that if status is ok there is no delay at
// all called either before or after the test.  Is called indirectly through
// pB->i2eWaitForTxEmpty.
//
//******************************************************************************
static int
iiWaitForTxEmptyIIEX(i2eBordStrPtr pB, int mSdelay)
{
        unsigned long   flags;

        for (;;)
        {
                // By the nature of this routine, you would be using this as part of a
                // larger atomic context: i.e., you would use this routine to ensure the
                // fifo empty, then act on this information. Between these two halves,
                // you will generally not want to service interrupts or in any way
                // disrupt the assumptions implicit in the larger context.

                WRITE_LOCK_IRQSAVE(&Dl_spinlock,flags)

                if (INB(pB->i2eStatus) & STE_OUT_MT) {
                        UPDATE_FIFO_ROOM(pB);
                        WRITE_UNLOCK_IRQRESTORE(&Dl_spinlock,flags)
                        COMPLETE(pB, I2EE_GOOD);
                }
                WRITE_UNLOCK_IRQRESTORE(&Dl_spinlock,flags)

                if (mSdelay-- == 0)
                        break;

                iiDelay(pB, 1);      // 1 mS granularity on checking condition
        }
        COMPLETE(pB, I2EE_TXE_TIME);
}

//******************************************************************************
// Function:   iiTxMailEmptyII(pB)
// Parameters: pB      - pointer to board structure
//
// Returns:    True if the transmit mailbox is empty.
//             False if it not empty.
//
// Description:
//
// Returns true or false according to whether the transmit mailbox is empty (and
// therefore able to accept more mail)
//
// This version operates on IntelliPort-II - style FIFO's
//
//******************************************************************************
static int
iiTxMailEmptyII(i2eBordStrPtr pB)
{
        int port = pB->i2ePointer;
        OUTB ( port, SEL_OUTMAIL );
        return ( INB(port) == 0 );
}

//******************************************************************************
// Function:   iiTxMailEmptyIIEX(pB)
// Parameters: pB      - pointer to board structure
//
// Returns:    True if the transmit mailbox is empty.
//             False if it not empty.
//
// Description:
//
// Returns true or false according to whether the transmit mailbox is empty (and
// therefore able to accept more mail)
//
// This version operates on IntelliPort-IIEX - style FIFO's
//
//******************************************************************************
static int
iiTxMailEmptyIIEX(i2eBordStrPtr pB)
{
        return !(INB(pB->i2eStatus) & STE_OUT_MAIL);
}

//******************************************************************************
// Function:   iiTrySendMailII(pB,mail)
// Parameters: pB   - pointer to board structure
//             mail - value to write to mailbox
//
// Returns:    True if the transmit mailbox is empty, and mail is sent.
//             False if it not empty.
//
// Description:
//
// If outgoing mailbox is empty, sends mail and returns true. If outgoing
// mailbox is not empty, returns false.
//
// This version operates on IntelliPort-II - style FIFO's
//
//******************************************************************************
static int
iiTrySendMailII(i2eBordStrPtr pB, unsigned char mail)
{
        int port = pB->i2ePointer;

        OUTB(port, SEL_OUTMAIL);
        if (INB(port) == 0) {
                OUTB(port, SEL_OUTMAIL);
                OUTB(port, mail);
                return 1;
        }
        return 0;
}

//******************************************************************************
// Function:   iiTrySendMailIIEX(pB,mail)
// Parameters: pB   - pointer to board structure
//             mail - value to write to mailbox
//
// Returns:    True if the transmit mailbox is empty, and mail is sent.
//             False if it not empty.
//
// Description:
//
// If outgoing mailbox is empty, sends mail and returns true. If outgoing
// mailbox is not empty, returns false.
//
// This version operates on IntelliPort-IIEX - style FIFO's
//
//******************************************************************************
static int
iiTrySendMailIIEX(i2eBordStrPtr pB, unsigned char mail)
{
        if(INB(pB->i2eStatus) & STE_OUT_MAIL) {
                return 0;
        }
        OUTB(pB->i2eXMail, mail);
        return 1;
}

//******************************************************************************
// Function:   iiGetMailII(pB,mail)
// Parameters: pB   - pointer to board structure
//
// Returns:    Mailbox data or NO_MAIL_HERE.
//
// Description:
//
// If no mail available, returns NO_MAIL_HERE otherwise returns the data from
// the mailbox, which is guaranteed != NO_MAIL_HERE.
//
// This version operates on IntelliPort-II - style FIFO's
//
//******************************************************************************
static unsigned short
iiGetMailII(i2eBordStrPtr pB)
{
        if (HAS_MAIL(pB)) {
                OUTB(pB->i2ePointer, SEL_INMAIL);
                return INB(pB->i2ePointer);
        } else {
                return NO_MAIL_HERE;
        }
}

//******************************************************************************
// Function:   iiGetMailIIEX(pB,mail)
// Parameters: pB   - pointer to board structure
//
// Returns:    Mailbox data or NO_MAIL_HERE.
//
// Description:
//
// If no mail available, returns NO_MAIL_HERE otherwise returns the data from
// the mailbox, which is guaranteed != NO_MAIL_HERE.
//
// This version operates on IntelliPort-IIEX - style FIFO's
//
//******************************************************************************
static unsigned short
iiGetMailIIEX(i2eBordStrPtr pB)
{
        if (HAS_MAIL(pB)) {
                return INB(pB->i2eXMail);
        } else {
                return NO_MAIL_HERE;
        }
}

//******************************************************************************
// Function:   iiEnableMailIrqII(pB)
// Parameters: pB - pointer to board structure
//
// Returns:    Nothing
//
// Description:
//
// Enables board to interrupt host (only) by writing to host's in-bound mailbox.
//
// This version operates on IntelliPort-II - style FIFO's
//
//******************************************************************************
static void
iiEnableMailIrqII(i2eBordStrPtr pB)
{
        OUTB(pB->i2ePointer, SEL_MASK);
        OUTB(pB->i2ePointer, ST_IN_MAIL);
}

//******************************************************************************
// Function:   iiEnableMailIrqIIEX(pB)
// Parameters: pB - pointer to board structure
//
// Returns:    Nothing
//
// Description:
//
// Enables board to interrupt host (only) by writing to host's in-bound mailbox.
//
// This version operates on IntelliPort-IIEX - style FIFO's
//
//******************************************************************************
static void
iiEnableMailIrqIIEX(i2eBordStrPtr pB)
{
        OUTB(pB->i2eXMask, MX_IN_MAIL);
}

//******************************************************************************
// Function:   iiWriteMaskII(pB)
// Parameters: pB - pointer to board structure
//
// Returns:    Nothing
//
// Description:
//
// Writes arbitrary value to the mask register.
//
// This version operates on IntelliPort-II - style FIFO's
//
//******************************************************************************
static void
iiWriteMaskII(i2eBordStrPtr pB, unsigned char value)
{
        OUTB(pB->i2ePointer, SEL_MASK);
        OUTB(pB->i2ePointer, value);
}

//******************************************************************************
// Function:   iiWriteMaskIIEX(pB)
// Parameters: pB - pointer to board structure
//
// Returns:    Nothing
//
// Description:
//
// Writes arbitrary value to the mask register.
//
// This version operates on IntelliPort-IIEX - style FIFO's
//
//******************************************************************************
static void
iiWriteMaskIIEX(i2eBordStrPtr pB, unsigned char value)
{
        OUTB(pB->i2eXMask, value);
}

//******************************************************************************
// Function:   iiDownloadBlock(pB, pSource, isStandard)
// Parameters: pB         - pointer to board structure
//             pSource    - loadware block to download
//             isStandard - True if "standard" loadware, else false.
//
// Returns:    Success or Failure
//
// Description:
//
// Downloads a single block (at pSource)to the board referenced by pB. Caller
// sets isStandard to true/false according to whether the "standard" loadware is
// what's being loaded. The normal process, then, is to perform an iiInitialize
// to the board, then perform some number of iiDownloadBlocks using the returned
// state to determine when download is complete.
//
// Possible return values: (see I2ELLIS.H)
// II_DOWN_BADVALID
// II_DOWN_BADFILE
// II_DOWN_CONTINUING
// II_DOWN_GOOD
// II_DOWN_BAD
// II_DOWN_BADSTATE
// II_DOWN_TIMEOUT
//
// Uses the i2eState and i2eToLoad fields (initialized at iiInitialize) to
// determine whether this is the first block, whether to check for magic
// numbers, how many blocks there are to go...
//
//******************************************************************************
static int
iiDownloadBlock ( i2eBordStrPtr pB, loadHdrStrPtr pSource, int isStandard)
{
        int itemp;
        int loadedFirst;

        if (pB->i2eValid != I2E_MAGIC) return II_DOWN_BADVALID;

        switch(pB->i2eState)
        {
        case II_STATE_READY:

                // Loading the first block after reset. Must check the magic number of the
                // loadfile, store the number of blocks we expect to load.
                if (pSource->e.loadMagic != MAGIC_LOADFILE)
                {
                        return II_DOWN_BADFILE;
                }

                // Next we store the total number of blocks to load, including this one.
                pB->i2eToLoad = 1 + pSource->e.loadBlocksMore;

                // Set the state, store the version numbers. ('Cause this may have come
                // from a file - we might want to report these versions and revisions in
                // case of an error!
                pB->i2eState = II_STATE_LOADING;
                pB->i2eLVersion = pSource->e.loadVersion;
                pB->i2eLRevision = pSource->e.loadRevision;
                pB->i2eLSub = pSource->e.loadSubRevision;

                // The time and date of compilation is also available but don't bother
                // storing it for normal purposes.
                loadedFirst = 1;
                break;

        case II_STATE_LOADING:
                loadedFirst = 0;
                break;

        default:
                return II_DOWN_BADSTATE;
        }

        // Now we must be in the II_STATE_LOADING state, and we assume i2eToLoad
        // must be positive still, because otherwise we would have cleaned up last
        // time and set the state to II_STATE_LOADED.
        if (!iiWaitForTxEmpty(pB, MAX_DLOAD_READ_TIME)) {
                return II_DOWN_TIMEOUT;
        }

        if (!iiWriteBuf(pB, pSource->c, LOADWARE_BLOCK_SIZE)) {
                return II_DOWN_BADVALID;
        }

        // If we just loaded the first block, wait for the fifo to empty an extra
        // long time to allow for any special startup code in the firmware, like
        // sending status messages to the LCD's.

        if (loadedFirst) {
                if (!iiWaitForTxEmpty(pB, MAX_DLOAD_START_TIME)) {
                        return II_DOWN_TIMEOUT;
                }
        }

        // Determine whether this was our last block!
        if (--(pB->i2eToLoad)) {
                return II_DOWN_CONTINUING;    // more to come...
        }

        // It WAS our last block: Clean up operations...
        // ...Wait for last buffer to drain from the board...
        if (!iiWaitForTxEmpty(pB, MAX_DLOAD_READ_TIME)) {
                return II_DOWN_TIMEOUT;
        }
        // If there were only a single block written, this would come back
        // immediately and be harmless, though not strictly necessary.
        itemp = MAX_DLOAD_ACK_TIME/10;
        while (--itemp) {
                if (HAS_INPUT(pB)) {
                        switch(BYTE_FROM(pB))
                        {
                        case LOADWARE_OK:
                                pB->i2eState =
                                        isStandard ? II_STATE_STDLOADED :II_STATE_LOADED;

                                // Some revisions of the bootstrap firmware (e.g. ISA-8 1.0.2)
                                // will, // if there is a debug port attached, require some
                                // time to send information to the debug port now. It will do
                                // this before // executing any of the code we just downloaded.
                                // It may take up to 700 milliseconds.
                                if (pB->i2ePom.e.porDiag2 & POR_DEBUG_PORT) {
                                        iiDelay(pB, 700);
                                }

                                return II_DOWN_GOOD;

                        case LOADWARE_BAD:
                        default:
                                return II_DOWN_BAD;
                        }
                }

                iiDelay(pB, 10);      // 10 mS granularity on checking condition
        }

        // Drop-through --> timed out waiting for firmware confirmation

        pB->i2eState = II_STATE_BADLOAD;
        return II_DOWN_TIMEOUT;
}

//******************************************************************************
// Function:   iiDownloadAll(pB, pSource, isStandard, size)
// Parameters: pB         - pointer to board structure
//             pSource    - loadware block to download
//             isStandard - True if "standard" loadware, else false.
//             size       - size of data to download (in bytes)
//
// Returns:    Success or Failure
//
// Description:
//
// Given a pointer to a board structure, a pointer to the beginning of some
// loadware, whether it is considered the "standard loadware", and the size of
// the array in bytes loads the entire array to the board as loadware.
//
// Assumes the board has been freshly reset and the power-up reset message read.
// (i.e., in II_STATE_READY). Complains if state is bad, or if there seems to be
// too much or too little data to load, or if iiDownloadBlock complains.
//******************************************************************************
static int
iiDownloadAll(i2eBordStrPtr pB, loadHdrStrPtr pSource, int isStandard, int size)
{
        int status;

        // We know (from context) board should be ready for the first block of
        // download.  Complain if not.
        if (pB->i2eState != II_STATE_READY) return II_DOWN_BADSTATE;

        while (size > 0) {
                size -= LOADWARE_BLOCK_SIZE;    // How much data should there be left to
                                                                                // load after the following operation ?

                // Note we just bump pSource by "one", because its size is actually that
                // of an entire block, same as LOADWARE_BLOCK_SIZE.
                status = iiDownloadBlock(pB, pSource++, isStandard);

                switch(status)
                {
                case II_DOWN_GOOD:
                        return ( (size > 0) ? II_DOWN_OVER : II_DOWN_GOOD);

                case II_DOWN_CONTINUING:
                        break;

                default:
                        return status;
                }
        }

        // We shouldn't drop out: it means "while" caught us with nothing left to
        // download, yet the previous DownloadBlock did not return complete. Ergo,
        // not enough data to match the size byte in the header.
        return II_DOWN_UNDER;
}