// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 1995-1996  Linus Torvalds & author (see below)
 */

/*
 *  Principal Author/Maintainer:  PODIEN@hml2.atlas.de (Wolfram Podien)
 *
 *  This file provides support for the advanced features
 *  of the UMC 8672 IDE interface.
 *
 *  Version 0.01	Initial version, hacked out of ide.c,
 *			and #include'd rather than compiled separately.
 *			This will get cleaned up in a subsequent release.
 *
 *  Version 0.02	now configs/compiles separate from ide.c  -ml
 *  Version 0.03	enhanced auto-tune, fix display bug
 *  Version 0.05	replace sti() with restore_flags()  -ml
 *			add detection of possible race condition  -ml
 */

/*
 * VLB Controller Support from
 * Wolfram Podien
 * Rohoefe 3
 * D28832 Achim
 * Germany
 *
 * To enable UMC8672 support there must a lilo line like
 * append="ide0=umc8672"...
 * To set the speed according to the abilities of the hardware there must be a
 * line like
 * #define UMC_DRIVE0 11
 * in the beginning of the driver, which sets the speed of drive 0 to 11 (there
 * are some lines present). 0 - 11 are allowed speed values. These values are
 * the results from the DOS speed test program supplied from UMC. 11 is the
 * highest speed (about PIO mode 3)
 */
#define REALLY_SLOW_IO		/* some systems can safely undef this */

#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 DRV_NAME "umc8672"

/*
 * Default speeds.  These can be changed with "auto-tune" and/or hdparm.
 */
#define UMC_DRIVE0      1              /* DOS measured drive speeds */
#define UMC_DRIVE1      1              /* 0 to 11 allowed */
#define UMC_DRIVE2      1              /* 11 = Fastest Speed */
#define UMC_DRIVE3      1              /* In case of crash reduce speed */

static u8 current_speeds[4] = {UMC_DRIVE0, UMC_DRIVE1, UMC_DRIVE2, UMC_DRIVE3};
static const u8 pio_to_umc [5] = {0, 3, 7, 10, 11};	/* rough guesses */

/*       0    1    2    3    4    5    6    7    8    9    10   11      */
static const u8 speedtab [3][12] = {
	{0x0f, 0x0b, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x1},
	{0x03, 0x02, 0x02, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x1},
	{0xff, 0xcb, 0xc0, 0x58, 0x36, 0x33, 0x23, 0x22, 0x21, 0x11, 0x10, 0x0}
};

static void out_umc(char port, char wert)
{
	outb_p(port, 0x108);
	outb_p(wert, 0x109);
}

static inline u8 in_umc(char port)
{
	outb_p(port, 0x108);
	return inb_p(0x109);
}

static void umc_set_speeds(u8 speeds[])
{
	int i, tmp;

	outb_p(0x5A, 0x108); /* enable umc */

	out_umc(0xd7, (speedtab[0][speeds[2]] | (speedtab[0][speeds[3]]<<4)));
	out_umc(0xd6, (speedtab[0][speeds[0]] | (speedtab[0][speeds[1]]<<4)));
	tmp = 0;
	for (i = 3; i >= 0; i--)
		tmp = (tmp << 2) | speedtab[1][speeds[i]];
	out_umc(0xdc, tmp);
	for (i = 0; i < 4; i++) {
		out_umc(0xd0 + i, speedtab[2][speeds[i]]);
		out_umc(0xd8 + i, speedtab[2][speeds[i]]);
	}
	outb_p(0xa5, 0x108); /* disable umc */

	printk("umc8672: drive speeds [0 to 11]: %d %d %d %d\n",
		speeds[0], speeds[1], speeds[2], speeds[3]);
}

static void umc_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
	ide_hwif_t *mate = hwif->mate;
	unsigned long uninitialized_var(flags);
	const u8 pio = drive->pio_mode - XFER_PIO_0;

	printk("%s: setting umc8672 to PIO mode%d (speed %d)\n",
		drive->name, pio, pio_to_umc[pio]);
	if (mate)
		spin_lock_irqsave(&mate->lock, flags);
	if (mate && mate->handler) {
		printk(KERN_ERR "umc8672: other interface is busy: exiting tune_umc()\n");
	} else {
		current_speeds[drive->name[2] - 'a'] = pio_to_umc[pio];
		umc_set_speeds(current_speeds);
	}
	if (mate)
		spin_unlock_irqrestore(&mate->lock, flags);
}

static const struct ide_port_ops umc8672_port_ops = {
	.set_pio_mode		= umc_set_pio_mode,
};

static const struct ide_port_info umc8672_port_info __initconst = {
	.name			= DRV_NAME,
	.chipset		= ide_umc8672,
	.port_ops		= &umc8672_port_ops,
	.host_flags		= IDE_HFLAG_NO_DMA,
	.pio_mask		= ATA_PIO4,
};

static int __init umc8672_probe(void)
{
	unsigned long flags;

	if (!request_region(0x108, 2, "umc8672")) {
		printk(KERN_ERR "umc8672: ports 0x108-0x109 already in use.\n");
		return 1;
	}
	local_irq_save(flags);
	outb_p(0x5A, 0x108); /* enable umc */
	if (in_umc (0xd5) != 0xa0) {
		local_irq_restore(flags);
		printk(KERN_ERR "umc8672: not found\n");
		release_region(0x108, 2);
		return 1;
	}
	outb_p(0xa5, 0x108); /* disable umc */

	umc_set_speeds(current_speeds);
	local_irq_restore(flags);

	return ide_legacy_device_add(&umc8672_port_info, 0);
}

static bool probe_umc8672;

module_param_named(probe, probe_umc8672, bool, 0);
MODULE_PARM_DESC(probe, "probe for UMC8672 chipset");

static int __init umc8672_init(void)
{
	if (probe_umc8672 == 0)
		goto out;

	if (umc8672_probe() == 0)
		return 0;
out:
	return -ENODEV;
}

module_init(umc8672_init);

MODULE_AUTHOR("Wolfram Podien");
MODULE_DESCRIPTION("Support for UMC 8672 IDE chipset");
MODULE_LICENSE("GPL");