Import 2.3.18pre1

[davej-history.git] / drivers / block / pdc4030.c

/*  -*- linux-c -*-
 *  linux/drivers/block/pdc4030.c       Version 0.90  May 27, 1999
 *
 *  Copyright (C) 1995-1999  Linus Torvalds & authors (see below)
 */

/*
 *  Principal Author/Maintainer:  peterd@pnd-pc.demon.co.uk
 *
 *  This file provides support for the second port and cache of Promise
 *  IDE interfaces, e.g. DC4030VL, DC4030VL-1 and DC4030VL-2.
 *
 *  Thanks are due to Mark Lord for advice and patiently answering stupid
 *  questions, and all those mugs^H^H^H^Hbrave souls who've tested this,
 *  especially Andre Hedrick.
 *
 *  Version 0.01        Initial version, #include'd in ide.c rather than
 *                      compiled separately.
 *                      Reads use Promise commands, writes as before. Drives
 *                      on second channel are read-only.
 *  Version 0.02        Writes working on second channel, reads on both
 *                      channels. Writes fail under high load. Suspect
 *                      transfers of >127 sectors don't work.
 *  Version 0.03        Brought into line with ide.c version 5.27.
 *                      Other minor changes.
 *  Version 0.04        Updated for ide.c version 5.30
 *                      Changed initialization strategy
 *  Version 0.05        Kernel integration.  -ml
 *  Version 0.06        Ooops. Add hwgroup to direct call of ide_intr() -ml
 *  Version 0.07        Added support for DC4030 variants
 *                      Secondary interface autodetection
 *  Version 0.08        Renamed to pdc4030.c
 *  Version 0.09        Obsolete - never released - did manual write request
 *                      splitting before max_sectors[major][minor] available.
 *  Version 0.10        Updated for 2.1 series of kernels
 *  Version 0.11        Updated for 2.3 series of kernels
 *                      Autodetection code added.
 *
 *  Version 0.90        Transition to BETA code. No lost/unexpected interrupts
 */

/*
 * Once you've compiled it in, you'll have to also enable the interface
 * setup routine from the kernel command line, as in 
 *
 *      'linux ide0=dc4030' or 'linux ide1=dc4030'
 *
 * It should now work as a second controller also ('ide1=dc4030') but only
 * if you DON'T have BIOS V4.44, which has a bug. If you have this version
 * and EPROM programming facilities, you need to fix 4 bytes:
 *      2496:   81      81
 *      2497:   3E      3E
 *      2498:   22      98      *
 *      2499:   06      05      *
 *      249A:   F0      F0
 *      249B:   01      01
 *      ...
 *      24A7:   81      81
 *      24A8:   3E      3E
 *      24A9:   22      98      *
 *      24AA:   06      05      *
 *      24AB:   70      70
 *      24AC:   01      01
 *
 * As of January 1999, Promise Technology Inc. have finally supplied me with
 * some technical information which has shed a glimmer of light on some of the
 * problems I was having, especially with writes. 
 *
 * There are still problems with the robustness and efficiency of this driver
 * because I still don't understand what the card is doing with interrupts.
 */

#define DEBUG_READ
#define DEBUG_WRITE

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/ide.h>

#include <asm/io.h>
#include <asm/irq.h>

#include "pdc4030.h"

/*
 * promise_selectproc() is invoked by ide.c
 * in preparation for access to the specified drive.
 */
static void promise_selectproc (ide_drive_t *drive)
{
        unsigned int number;

        number = (HWIF(drive)->channel << 1) + drive->select.b.unit;
        OUT_BYTE(number,IDE_FEATURE_REG);
}

/*
 * pdc4030_cmd handles the set of vendor specific commands that are initiated
 * by command F0. They all have the same success/failure notification -
 * 'P' (=0x50) on success, 'p' (=0x70) on failure.
 */
int pdc4030_cmd(ide_drive_t *drive, byte cmd)
{
        unsigned long timeout, timer;
        byte status_val;

        promise_selectproc(drive);      /* redundant? */
        OUT_BYTE(0xF3,IDE_SECTOR_REG);
        OUT_BYTE(cmd,IDE_SELECT_REG);
        OUT_BYTE(PROMISE_EXTENDED_COMMAND,IDE_COMMAND_REG);
        timeout = HZ * 10;
        timeout += jiffies;
        do {
                if(time_after(jiffies, timeout)) {
                        return 2; /* device timed out */
                }
                /* This is out of delay_10ms() */
                /* Delays at least 10ms to give interface a chance */
                timer = jiffies + (HZ + 99)/100 + 1;
                while (time_after(timer, jiffies));
                status_val = IN_BYTE(IDE_SECTOR_REG);
        } while (status_val != 0x50 && status_val != 0x70);

        if(status_val == 0x50)
                return 0; /* device returned success */
        else
                return 1; /* device returned failure */
}

/*
 * pdc4030_identify sends a vendor-specific IDENTIFY command to the drive
 */
int pdc4030_identify(ide_drive_t *drive)
{
        return pdc4030_cmd(drive, PROMISE_IDENTIFY);
}

int enable_promise_support = 0;

void __init init_pdc4030 (void)
{
        enable_promise_support = 1;
}

/*
 * setup_pdc4030()
 * Completes the setup of a Promise DC4030 controller card, once found.
 */
int __init setup_pdc4030 (ide_hwif_t *hwif)
{
        ide_drive_t *drive;
        ide_hwif_t *hwif2;
        struct dc_ident ident;
        int i;
        
        if (!hwif) return 0;

        drive = &hwif->drives[0];
        hwif2 = &ide_hwifs[hwif->index+1];
        if (hwif->chipset == ide_pdc4030) /* we've already been found ! */
                return 1;

        if (IN_BYTE(IDE_NSECTOR_REG) == 0xFF || IN_BYTE(IDE_SECTOR_REG) == 0xFF) {
                return 0;
        }
        OUT_BYTE(0x08,IDE_CONTROL_REG);
        if (pdc4030_cmd(drive,PROMISE_GET_CONFIG)) {
                return 0;
        }
        if (ide_wait_stat(drive,DATA_READY,BAD_W_STAT,WAIT_DRQ)) {
                printk(KERN_INFO
                        "%s: Failed Promise read config!\n",hwif->name);
                return 0;
        }
        ide_input_data(drive,&ident,SECTOR_WORDS);
        if (ident.id[1] != 'P' || ident.id[0] != 'T') {
                return 0;
        }
        printk(KERN_INFO "%s: Promise caching controller, ",hwif->name);
        switch(ident.type) {
                case 0x43:      printk("DC4030VL-2, "); break;
                case 0x41:      printk("DC4030VL-1, "); break;
                case 0x40:      printk("DC4030VL, "); break;
                default:
                        printk("unknown - type 0x%02x - please report!\n"
                               ,ident.type);
                        printk("Please e-mail the following data to "
                               "promise@pnd-pc.demon.co.uk along with\n"
                               "a description of your card and drives:\n");
                        for (i=0; i < 0x90; i++) {
                                printk("%02x ", ((unsigned char *)&ident)[i]);
                                if ((i & 0x0f) == 0x0f) printk("\n");
                        }
                        return 0;
        }
        printk("%dKB cache, ",(int)ident.cache_mem);
        switch(ident.irq) {
            case 0x00: hwif->irq = 14; break;
            case 0x01: hwif->irq = 12; break;
            default:   hwif->irq = 15; break;
        }
        printk("on IRQ %d\n",hwif->irq);

        /*
         * Once found and identified, we set up the next hwif in the array
         * (hwif2 = ide_hwifs[hwif->index+1]) with the same io ports, irq
         * and other settings as the main hwif. This gives us two "mated"
         * hwifs pointing to the Promise card.
         *
         * We also have to shift the default values for the remaining
         * interfaces "up by one" to make room for the second interface on the
         * same set of values.
         */

        hwif->chipset   = hwif2->chipset = ide_pdc4030;
        hwif->mate      = hwif2;
        hwif2->mate     = hwif;
        hwif2->channel  = 1;
        hwif->selectproc = hwif2->selectproc = &promise_selectproc;
        hwif->serialized = hwif2->serialized = 1;

/* Shift the remaining interfaces down by one */
        for (i=MAX_HWIFS-1 ; i > hwif->index+1 ; i--) {
                ide_hwif_t *h = &ide_hwifs[i];

#ifdef DEBUG
                printk(KERN_DEBUG "Shifting i/f %d values to i/f %d\n",i-1,i);
#endif
                ide_init_hwif_ports(&h->hw, (h-1)->io_ports[IDE_DATA_OFFSET], 0, NULL);
                memcpy(h->io_ports, h->hw.io_ports, sizeof(h->io_ports));
                h->noprobe = (h-1)->noprobe;
        }
        ide_init_hwif_ports(&hwif2->hw, hwif->io_ports[IDE_DATA_OFFSET], 0, NULL);
        memcpy(hwif2->io_ports, hwif->hw.io_ports, sizeof(hwif2->io_ports));
        hwif2->irq = hwif->irq;
        hwif2->hw.irq = hwif->hw.irq = hwif->irq;
        for (i=0; i<2 ; i++) {
                hwif->drives[i].io_32bit = 3;
                hwif2->drives[i].io_32bit = 3;
                hwif->drives[i].keep_settings = 1;
                hwif2->drives[i].keep_settings = 1;
                if (!ident.current_tm[i].cyl)
                        hwif->drives[i].noprobe = 1;
                if (!ident.current_tm[i+2].cyl)
                        hwif2->drives[i].noprobe = 1;
        }
        return 1;
}

/*
 * detect_pdc4030()
 * Tests for the presence of a DC4030 Promise card on this interface
 * Returns: 1 if found, 0 if not found
 */
int __init detect_pdc4030(ide_hwif_t *hwif)
{
        ide_drive_t *drive = &hwif->drives[0];

        if (IDE_DATA_REG == 0) { /* Skip test for non-existent interface */
                return 0;
        }
        OUT_BYTE(0xF3, IDE_SECTOR_REG);
        OUT_BYTE(0x14, IDE_SELECT_REG);
        OUT_BYTE(PROMISE_EXTENDED_COMMAND, IDE_COMMAND_REG);
        
        ide_delay_50ms();

        if (IN_BYTE(IDE_ERROR_REG) == 'P' &&
            IN_BYTE(IDE_NSECTOR_REG) == 'T' &&
            IN_BYTE(IDE_SECTOR_REG) == 'I') {
                return 1;
        } else {
                return 0;
        }
}

void __init ide_probe_for_pdc4030(void)
{
        unsigned int    index;
        ide_hwif_t      *hwif;

        if (enable_promise_support == 0)
                return;
        for (index = 0; index < MAX_HWIFS; index++) {
                hwif = &ide_hwifs[index];
                if (hwif->chipset == ide_unknown && detect_pdc4030(hwif)) {
                        setup_pdc4030(hwif);
                }
        }
}



/*
 * promise_read_intr() is the handler for disk read/multread interrupts
 */
static void promise_read_intr (ide_drive_t *drive)
{
        byte stat;
        int total_remaining;
        unsigned int sectors_left, sectors_avail, nsect;
        struct request *rq;

        if (!OK_STAT(stat=GET_STAT(),DATA_READY,BAD_R_STAT)) {
                ide_error(drive, "promise_read_intr", stat);
                return;
        }

read_again:
        do {
                sectors_left = IN_BYTE(IDE_NSECTOR_REG);
                IN_BYTE(IDE_SECTOR_REG);
        } while (IN_BYTE(IDE_NSECTOR_REG) != sectors_left);
        rq = HWGROUP(drive)->rq;
        sectors_avail = rq->nr_sectors - sectors_left;
        if (!sectors_avail)
                goto read_again;

read_next:
        rq = HWGROUP(drive)->rq;
        nsect = rq->current_nr_sectors;
        if (nsect > sectors_avail)
                nsect = sectors_avail;
        sectors_avail -= nsect;
        ide_input_data(drive, rq->buffer, nsect * SECTOR_WORDS);
#ifdef DEBUG_READ
        printk(KERN_DEBUG "%s:  promise_read: sectors(%ld-%ld), "
               "buf=0x%08lx, rem=%ld\n", drive->name, rq->sector,
               rq->sector+nsect-1, (unsigned long) rq->buffer,
               rq->nr_sectors-nsect);
#endif
        rq->sector += nsect;
        rq->buffer += nsect<<9;
        rq->errors = 0;
        rq->nr_sectors -= nsect;
        total_remaining = rq->nr_sectors;
        if ((rq->current_nr_sectors -= nsect) <= 0) {
                ide_end_request(1, HWGROUP(drive));
        }
/*
 * Now the data has been read in, do the following:
 * 
 * if there are still sectors left in the request, 
 *   if we know there are still sectors available from the interface,
 *     go back and read the next bit of the request.
 *   else if DRQ is asserted, there are more sectors available, so
 *     go back and find out how many, then read them in.
 *   else if BUSY is asserted, we are going to get an interrupt, so
 *     set the handler for the interrupt and just return
 */
        if (total_remaining > 0) {
                if (sectors_avail)
                        goto read_next;
                stat = GET_STAT();
                if (stat & DRQ_STAT)
                        goto read_again;
                if (stat & BUSY_STAT) {
                        ide_set_handler (drive, &promise_read_intr, WAIT_CMD);
#ifdef DEBUG_READ
                        printk(KERN_DEBUG "%s: promise_read: waiting for"
                               "interrupt\n", drive->name);
#endif 
                        return;
                }
                printk(KERN_ERR "%s: Eeek! promise_read_intr: sectors left "
                       "!DRQ !BUSY\n", drive->name);
                ide_error(drive, "promise read intr", stat);
        }
}

/*
 * promise_complete_pollfunc()
 * This is the polling function for waiting (nicely!) until drive stops
 * being busy. It is invoked at the end of a write, after the previous poll
 * has finished.
 *
 * Once not busy, the end request is called.
 */
static void promise_complete_pollfunc(ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        struct request *rq = hwgroup->rq;
        int i;

        if (GET_STAT() & BUSY_STAT) {
                if (time_before(jiffies, hwgroup->poll_timeout)) {
                        ide_set_handler(drive, &promise_complete_pollfunc, 1);
                        return; /* continue polling... */
                }
                hwgroup->poll_timeout = 0;
                printk(KERN_ERR "%s: completion timeout - still busy!\n",
                       drive->name);
                ide_error(drive, "busy timeout", GET_STAT());
                return;
        }

        hwgroup->poll_timeout = 0;
#ifdef DEBUG_WRITE
        printk(KERN_DEBUG "%s: Write complete - end_request\n", drive->name);
#endif
        for (i = rq->nr_sectors; i > 0; ) {
                i -= rq->current_nr_sectors;
                ide_end_request(1, hwgroup);
        }
}

/*
 * promise_write_pollfunc() is the handler for disk write completion polling.
 */
static void promise_write_pollfunc (ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);

        if (IN_BYTE(IDE_NSECTOR_REG) != 0) {
                if (time_before(jiffies, hwgroup->poll_timeout)) {
                        ide_set_handler (drive, &promise_write_pollfunc, 1);
                        return; /* continue polling... */
                }
                hwgroup->poll_timeout = 0;
                printk(KERN_ERR "%s: write timed-out!\n",drive->name);
                ide_error (drive, "write timeout", GET_STAT());
                return;
        }

        /*
         * Now write out last 4 sectors and poll for not BUSY
         */
        ide_multwrite(drive, 4);
        hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
        ide_set_handler(drive, &promise_complete_pollfunc, 1);
#ifdef DEBUG_WRITE
        printk(KERN_DEBUG "%s: Done last 4 sectors - status = %02x\n",
                drive->name, GET_STAT());
#endif
        return;
}

/*
 * promise_write() transfers a block of one or more sectors of data to a
 * drive as part of a disk write operation. All but 4 sectors are transfered
 * in the first attempt, then the interface is polled (nicely!) for completion
 * before the final 4 sectors are transfered. There is no interrupt generated
 * on writes (at least on the DC4030VL-2), we just have to poll for NOT BUSY.
 */
static void promise_write (ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        struct request *rq = &hwgroup->wrq;

#ifdef DEBUG_WRITE
        printk(KERN_DEBUG "%s: promise_write: sectors(%ld-%ld), "
               "buffer=0x%08x\n", drive->name, rq->sector,
               rq->sector + rq->nr_sectors - 1, (unsigned int)rq->buffer);
#endif

        /*
         * If there are more than 4 sectors to transfer, do n-4 then go into
         * the polling strategy as defined above.
         */
        if (rq->nr_sectors > 4) {
                ide_multwrite(drive, rq->nr_sectors - 4);
                hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
                ide_set_handler (drive, &promise_write_pollfunc, 1);
        } else {
        /*
         * There are 4 or fewer sectors to transfer, do them all in one go
         * and wait for NOT BUSY.
         */
                ide_multwrite(drive, rq->nr_sectors);
                hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
                ide_set_handler(drive, &promise_complete_pollfunc, 1);
#ifdef DEBUG_WRITE
                printk(KERN_DEBUG "%s: promise_write: <= 4 sectors, "
                        "status = %02x\n", drive->name, GET_STAT());
#endif
        }
}

/*
 * do_pdc4030_io() is called from do_rw_disk, having had the block number
 * already set up. It issues a READ or WRITE command to the Promise
 * controller, assuming LBA has been used to set up the block number.
 */
void do_pdc4030_io (ide_drive_t *drive, struct request *rq)
{
        unsigned long timeout;
        byte stat;

        if (rq->cmd == READ) {
                OUT_BYTE(PROMISE_READ, IDE_COMMAND_REG);
/*
 * The card's behaviour is odd at this point. If the data is
 * available, DRQ will be true, and no interrupt will be
 * generated by the card. If this is the case, we need to call the 
 * "interrupt" handler (promise_read_intr) directly. Otherwise, if
 * an interrupt is going to occur, bit0 of the SELECT register will
 * be high, so we can set the handler the just return and be interrupted.
 * If neither of these is the case, we wait for up to 50ms (badly I'm
 * afraid!) until one of them is.
 */
                timeout = jiffies + HZ/20; /* 50ms wait */
                do {
                        stat=GET_STAT();
                        if (stat & DRQ_STAT) {
                                udelay(1);
                                promise_read_intr(drive);
                                return;
                        }
                        if (IN_BYTE(IDE_SELECT_REG) & 0x01) {
#ifdef DEBUG_READ
                                printk(KERN_DEBUG "%s: read: waiting for "
                                                  "interrupt\n", drive->name);
#endif
                                ide_set_handler(drive, &promise_read_intr, WAIT_CMD);
                                return;
                        }
                        udelay(1);
                } while (time_before(jiffies, timeout));

                printk(KERN_ERR "%s: reading: No DRQ and not waiting - Odd!\n",
                        drive->name);

        } else if (rq->cmd == WRITE) {
                OUT_BYTE(PROMISE_WRITE, IDE_COMMAND_REG);
                if (ide_wait_stat(drive, DATA_READY, drive->bad_wstat, WAIT_DRQ)) {
                        printk(KERN_ERR "%s: no DRQ after issuing "
                               "PROMISE_WRITE\n", drive->name);
                        return;
                }
                if (!drive->unmask)
                        __cli();        /* local CPU only */
                HWGROUP(drive)->wrq = *rq; /* scratchpad */
                promise_write(drive);

        } else {
                printk("KERN_WARNING %s: bad command: %d\n",
                       drive->name, rq->cmd);
                ide_end_request(0, HWGROUP(drive));
        }
}