linux-imx

/*

 *  Copyright (C) 1995-2000  Linus Torvalds & author (see below)

 */

​

/*

 *  HT-6560B EIDE-controller support

 *  To activate controller support use kernel parameter "ide0=ht6560b".

 *  Use hdparm utility to enable PIO mode support.

 *

 *  Author:    Mikko Ala-Fossi            <maf@iki.fi>

 *             Jan Evert van Grootheest   <j.e.van.grootheest@caiway.nl>

 *

 */

​

#define DRV_NAME    "ht6560b"

#define HT6560B_VERSION "v0.08"

​

#include <linux/module.h>

#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/ide.h>

#include <linux/init.h>

​

#include <asm/io.h>

​

/* #define DEBUG */  /* remove comments for DEBUG messages */

​

/*

 * The special i/o-port that HT-6560B uses to configuration:

 *    bit0 (0x01): "1" selects secondary interface

 *    bit2 (0x04): "1" enables FIFO function

 *    bit5 (0x20): "1" enables prefetched data read function  (???)

 *

 * The special i/o-port that HT-6560A uses to configuration:

 *    bit0 (0x01): "1" selects secondary interface

 *    bit1 (0x02): "1" enables prefetched data read function

 *    bit2 (0x04): "0" enables multi-master system        (?)

 *    bit3 (0x08): "1" 3 cycle time, "0" 2 cycle time         (?)

 */

#define HT_CONFIG_PORT    0x3e6

​

static inline u8 HT_CONFIG(ide_drive_t *drive)

{

    return ((unsigned long)ide_get_drivedata(drive) & 0xff00) >> 8;

}

​

/*

 * FIFO + PREFETCH (both a/b-model)

 */

#define HT_CONFIG_DEFAULT 0x1c /* no prefetch */

/* #define HT_CONFIG_DEFAULT 0x3c */ /* with prefetch */

#define HT_SECONDARY_IF   0x01

#define HT_PREFETCH_MODE  0x20

​

/*

 * ht6560b Timing values:

 *

 * I reviewed some assembler source listings of htide drivers and found

 * out how they setup those cycle time interfacing values, as they at Holtek

 * call them. IDESETUP.COM that is supplied with the drivers figures out

 * optimal values and fetches those values to drivers. I found out that

 * they use Select register to fetch timings to the ide board right after

 * interface switching. After that it was quite easy to add code to

 * ht6560b.c.

 *

 * IDESETUP.COM gave me values 0x24, 0x45, 0xaa, 0xff that worked fine

 * for hda and hdc. But hdb needed higher values to work, so I guess

 * that sometimes it is necessary to give higher value than IDESETUP

 * gives.   [see cmd640.c for an extreme example of this. -ml]

 *

 * Perhaps I should explain something about these timing values:

 * The higher nibble of value is the Recovery Time  (rt) and the lower nibble

 * of the value is the Active Time  (at). Minimum value 2 is the fastest and

 * the maximum value 15 is the slowest. Default values should be 15 for both.

 * So 0x24 means 2 for rt and 4 for at. Each of the drives should have

 * both values, and IDESETUP gives automatically rt=15 st=15 for CDROMs or

 * similar. If value is too small there will be all sorts of failures.

 *

 * Timing byte consists of

 *  High nibble:  Recovery Cycle Time  (rt)

 *       The valid values range from 2 to 15. The default is 15.

 *

 *  Low nibble:   Active Cycle Time    (at)

 *       The valid values range from 2 to 15. The default is 15.

 *

 * You can obtain optimized timing values by running Holtek IDESETUP.COM

 * for DOS. DOS drivers get their timing values from command line, where