drivers/ata/pata_parport/bpck.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * (c) 1996-1998  Grant R. Guenther <grant@torque.net>
  *
  * bpck.c is a low-level protocol driver for the MicroSolutions
  * "backpack" parallel port IDE adapter.
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/wait.h>
 #include <asm/io.h>
 #include "pata_parport.h"

 #undef r2
 #undef w2
 #undef PC

 #define PC			pi->private
 #define r2()			(PC=(in_p(2) & 0xff))
 #define w2(byte)  		{out_p(2,byte); PC = byte;}
 #define t2(pat)   		{PC ^= pat; out_p(2,PC);}
 #define e2()			{PC &= 0xfe; out_p(2,PC);}
 #define o2()			{PC |= 1; out_p(2,PC);}

 #define j44(l,h)     (((l>>3)&0x7)|((l>>4)&0x8)|((h<<1)&0x70)|(h&0x80))

 /*
  * cont = 0 - access the IDE register file
  * cont = 1 - access the IDE command set
  * cont = 2 - use internal bpck register addressing
  */
 static int  cont_map[3] = { 0x40, 0x48, 0 };

 static int bpck_read_regr(struct pi_adapter *pi, int cont, int regr)
 {
 	int r, l, h;

 	r = regr + cont_map[cont];

 	switch (pi->mode) {
 	case 0:
 		w0(r & 0xf); w0(r); t2(2); t2(4);
 	        l = r1();
 		t2(4);
 		h = r1();
 		return j44(l, h);
 	case 1:
 		w0(r & 0xf); w0(r); t2(2);
 		e2(); t2(0x20);
 		t2(4); h = r0();
 		t2(1); t2(0x20);
 		return h;
 	case 2:
 	case 3:
 	case 4:
 		w0(r); w2(9); w2(0); w2(0x20);
 		h = r4();
 		w2(0);
 		return h;

 	}
 	return -1;
 }

 static void bpck_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
 {
 	int r;

         r = regr + cont_map[cont];

 	switch (pi->mode) {
 	case 0:
 	case 1: w0(r);
 		t2(2);
 		w0(val);
 		o2(); t2(4); t2(1);
 		break;
 	case 2:
 	case 3:
 	case 4: w0(r); w2(9); w2(0);
 		w0(val); w2(1); w2(3); w2(0);
 		break;

 	}
 }

 /* These macros access the bpck registers in native addressing */

 #define WR(r,v)		bpck_write_regr(pi,2,r,v)
 #define RR(r)		(bpck_read_regr(pi,2,r))

 static void bpck_write_block(struct pi_adapter *pi, char *buf, int count)
 {
 	int i;

 	switch (pi->mode) {

 	case 0:
 		WR(4, 0x40);
 		w0(0x40); t2(2); t2(1);
 		for (i = 0; i < count; i++) {
 			w0(buf[i]);
 			t2(4);
 		}
 		WR(4, 0);
 		break;

 	case 1:
 		WR(4, 0x50);
 		w0(0x40); t2(2); t2(1);
 		for (i = 0; i < count; i++) {
 			w0(buf[i]);
 			t2(4);
 		}
 		WR(4, 0x10);
 		break;

 	case 2:
 		WR(4, 0x48);
 		w0(0x40); w2(9); w2(0); w2(1);
 		for (i = 0; i < count; i++)
 			w4(buf[i]);
 		w2(0);
 		WR(4, 8);
 		break;

 	case 3:
 		WR(4, 0x48);
 		w0(0x40); w2(9); w2(0); w2(1);
 		for (i = 0; i < count / 2; i++)
 			w4w(((u16 *)buf)[i]);
 		w2(0);
 		WR(4, 8);
 		break;

 	case 4:
 		WR(4, 0x48);
 		w0(0x40); w2(9); w2(0); w2(1);
 		for (i = 0; i < count / 4; i++)
 			w4l(((u32 *)buf)[i]);
 		w2(0);
 		WR(4, 8);
 		break;
  	}
 }

 static void bpck_read_block(struct pi_adapter *pi, char *buf, int count)
 {
 	int i, l, h;

 	switch (pi->mode) {

 	case 0:
 		WR(4, 0x40);
 		w0(0x40); t2(2);
 		for (i = 0; i < count; i++) {
 			t2(4); l = r1();
 			t2(4); h = r1();
 			buf[i] = j44(l, h);
 		}
 		WR(4, 0);
 		break;

 	case 1:
 		WR(4, 0x50);
 		w0(0x40); t2(2); t2(0x20);
 		for (i = 0; i < count; i++) {
 			t2(4);
 			buf[i] = r0();
 		}
 		t2(1); t2(0x20);
 		WR(4, 0x10);
 		break;

 	case 2:
 		WR(4, 0x48);
 		w0(0x40); w2(9); w2(0); w2(0x20);
 		for (i = 0; i < count; i++)
 			buf[i] = r4();
 		w2(0);
 		WR(4, 8);
 		break;

 	case 3:
 		WR(4, 0x48);
 		w0(0x40); w2(9); w2(0); w2(0x20);
 		for (i = 0; i < count / 2; i++)
 			((u16 *)buf)[i] = r4w();
 		w2(0);
 		WR(4, 8);
 		break;

 	case 4:
 		WR(4, 0x48);
 		w0(0x40); w2(9); w2(0); w2(0x20);
 		for (i = 0; i < count / 4; i++)
 			((u32 *)buf)[i] = r4l();
 		w2(0);
 		WR(4, 8);
 		break;

 	}
 }

 static int bpck_probe_unit(struct pi_adapter *pi)
 {
 	int o1, o0, f7, id;
 	int t, s;

 	id = pi->unit;
 	s = 0;
 	w2(4); w2(0xe); r2(); t2(2);
 	o1 = r1()&0xf8;
 	o0 = r0();
 	w0(255-id); w2(4); w0(id);
 	t2(8); t2(8); t2(8);
 	t2(2); t = r1()&0xf8;
 	f7 = ((id % 8) == 7);
 	if ((f7) || (t != o1)) {
 		t2(2);
 		s = r1() & 0xf8;
 	}
 	if ((t == o1) && ((!f7) || (s == o1)))  {
 		w2(0x4c); w0(o0);
 		return 0;
 	}
 	t2(8); w0(0); t2(2); w2(0x4c); w0(o0);
 	return 1;
 }

 static void bpck_connect(struct pi_adapter *pi)
 {
 	pi->saved_r0 = r0();
 	w0(0xff-pi->unit); w2(4); w0(pi->unit);
 	t2(8); t2(8); t2(8);
 	t2(2); t2(2);

 	switch (pi->mode) {
 	case 0:
 		t2(8); WR(4, 0);
 		break;
 	case 1:
 		t2(8); WR(4, 0x10);
 		break;
 	case 2:
 	case 3:
 	case 4:
 		w2(0); WR(4, 8);
 		break;
 	}

 	WR(5,8);

 	/*
 	 * Possibly wrong, purpose unknown (fiddle with ESS logic ???)
 	 * if (pi->devtype == PI_PCD) {
 	 */
 	WR(0x46, 0x10);
 	WR(0x4c, 0x38);
 	WR(0x4d, 0x88);
 	WR(0x46, 0xa0);
 	WR(0x41, 0);
 	WR(0x4e, 8);
 	/* } */
 }

 static void bpck_disconnect(struct pi_adapter *pi)
 {
 	w0(0);
 	if (pi->mode >= 2) {
 		w2(9); w2(0);
 	} else {
 		t2(2);
 	}
 	w2(0x4c); w0(pi->saved_r0);
 }

 static void bpck_force_spp(struct pi_adapter *pi)
 {
 	/* This fakes the EPP protocol to turn off EPP ... */
 	pi->saved_r0 = r0();
 	w0(0xff-pi->unit); w2(4); w0(pi->unit);
 	t2(8); t2(8); t2(8);
 	t2(2); t2(2);

 	w2(0);
 	w0(4); w2(9); w2(0);
 	w0(0); w2(1); w2(3); w2(0);
 	w0(0); w2(9); w2(0);
 	w2(0x4c); w0(pi->saved_r0);
 }

 #define TEST_LEN  16

 static int bpck_test_proto(struct pi_adapter *pi)
 {
 	int i, e, l, h, om;
 	char buf[TEST_LEN];

 	bpck_force_spp(pi);

 	switch (pi->mode) {

 	case 0:
 		bpck_connect(pi);
 		WR(0x13, 0x7f);
 		w0(0x13); t2(2);
 		for (i = 0; i < TEST_LEN; i++) {
 			t2(4); l = r1();
 			t2(4); h = r1();
 			buf[i] = j44(l, h);
 		}
 		bpck_disconnect(pi);
 		break;

 	case 1:
 		bpck_connect(pi);
 		WR(0x13, 0x7f);
 		w0(0x13); t2(2); t2(0x20);
 		for (i = 0; i < TEST_LEN; i++) {
 			t2(4);
 			buf[i] = r0();
 		}
 		t2(1); t2(0x20);
 		bpck_disconnect(pi);
 		break;

 	case 2:
 	case 3:
 	case 4:
 		om = pi->mode;
 		pi->mode = 0;
 		bpck_connect(pi);
 		WR(7, 3);
 		WR(4, 8);
 		bpck_disconnect(pi);

 		pi->mode = om;
 		bpck_connect(pi);
 		w0(0x13); w2(9); w2(1); w0(0); w2(3); w2(0); w2(0xe0);

 		switch (pi->mode) {
 		case 2:
 			for (i = 0; i < TEST_LEN; i++)
 				buf[i] = r4();
 			break;
 		case 3:
 			for (i = 0; i < TEST_LEN / 2; i++)
 				((u16 *)buf)[i] = r4w();
 			break;
 		case 4:
 			for (i = 0; i < TEST_LEN / 4; i++)
 				((u32 *)buf)[i] = r4l();
 			break;
 		}

 		w2(0);
 		WR(7, 0);
 		bpck_disconnect(pi);
 		break;

 	}

 	dev_dbg(&pi->dev, "bpck: 0x%x unit %d mode %d: ",
 		pi->port, pi->unit, pi->mode);
 	print_hex_dump_debug("bpck: ", DUMP_PREFIX_NONE, TEST_LEN, 1, buf,
 			     TEST_LEN, false);

 	e = 0;
 	for (i = 0; i < TEST_LEN; i++) {
 		if (buf[i] != i + 1)
 			e++;
 	}

 	return e;
 }

 static void bpck_read_eeprom(struct pi_adapter *pi, char *buf)
 {
 	int i, j, k, p, v, f, om, od;

 	bpck_force_spp(pi);

 	om = pi->mode;  od = pi->delay;
 	pi->mode = 0; pi->delay = 6;

 	bpck_connect(pi);

 	WR(4, 0);
 	for (i = 0; i < 64; i++) {
 		WR(6, 8);
 		WR(6, 0xc);
 		p = 0x100;
 		for (k = 0; k < 9; k++) {
 			f = (((i + 0x180) & p) != 0) * 2;
 			WR(6, f + 0xc);
 			WR(6, f + 0xd);
 			WR(6, f + 0xc);
 			p = (p >> 1);
 		}
 		for (j = 0; j < 2; j++) {
 			v = 0;
 			for (k = 0; k < 8; k++) {
 				WR(6, 0xc);
 				WR(6, 0xd);
 				WR(6, 0xc);
 				f = RR(0);
 				v = 2 * v + (f == 0x84);
 			}
 			buf[2 * i + 1 - j] = v;
 		}
 	}
 	WR(6, 8);
 	WR(6, 0);
 	WR(5, 8);

 	bpck_disconnect(pi);

         if (om >= 2) {
 		bpck_connect(pi);
 		WR(7, 3);
 		WR(4, 8);
 		bpck_disconnect(pi);
         }

 	pi->mode = om; pi->delay = od;
 }

 static int bpck_test_port(struct pi_adapter *pi)
 {
 	int i, r, m;

 	/* Check for 8-bit port */
 	w2(0x2c); i = r0(); w0(255-i); r = r0(); w0(i);
 	m = -1;
 	if (r == i)
 		m = 2;
 	if (r == (255-i))
 		m = 0;

 	w2(0xc);
 	i = r0();
 	w0(255-i);
 	r = r0();
 	w0(i);
 	if (r != (255-i))
 		m = -1;

 	if (m == 0) {
 		w2(6);
 		w2(0xc);
 		r = r0();
 		w0(0xaa);
 		w0(r);
 		w0(0xaa);
 	}
 	if (m == 2) {
 		w2(0x26);
 		w2(0xc);
 	}

 	if (m == -1)
 		return 0;

 	return 5;
 }

 static void bpck_log_adapter(struct pi_adapter *pi)
 {
 	char *mode_str[5] = { "4-bit", "8-bit", "EPP-8", "EPP-16", "EPP-32" };
 	char scratch[128];

 	bpck_read_eeprom(pi,scratch);
 	print_hex_dump_bytes("bpck EEPROM: ", DUMP_PREFIX_NONE, scratch, 128);
 	dev_info(&pi->dev,
 		 "backpack %8.8s unit %d at 0x%x, mode %d (%s), delay %d\n",
 		 &scratch[110], pi->unit, pi->port, pi->mode,
 		 mode_str[pi->mode], pi->delay);
 }

 static struct pi_protocol bpck = {
 	.owner		= THIS_MODULE,
 	.name		= "bpck",
 	.max_mode	= 5,
 	.epp_first	= 2,
 	.default_delay	= 4,
 	.max_units	= 255,
 	.write_regr	= bpck_write_regr,
 	.read_regr	= bpck_read_regr,
 	.write_block	= bpck_write_block,
 	.read_block	= bpck_read_block,
 	.connect	= bpck_connect,
 	.disconnect	= bpck_disconnect,
 	.test_port	= bpck_test_port,
 	.probe_unit	= bpck_probe_unit,
 	.test_proto	= bpck_test_proto,
 	.log_adapter	= bpck_log_adapter,
 };

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
 MODULE_DESCRIPTION("MicroSolutions BACKPACK parallel port IDE adapter protocol driver");
 module_pata_parport_driver(bpck);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* (c) 1996-1998 Grant R. Guenther <grant@torque.net>
	*
	* bpck.c is a low-level protocol driver for the MicroSolutions
	* "backpack" parallel port IDE adapter.
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/delay.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/wait.h>
	#include <asm/io.h>
	#include "pata_parport.h"

	#undef r2
	#undef w2
	#undef PC

	#define PC pi->private
	#define r2() (PC=(in_p(2) & 0xff))
	#define w2(byte) {out_p(2,byte); PC = byte;}
	#define t2(pat) {PC ^= pat; out_p(2,PC);}
	#define e2() {PC &= 0xfe; out_p(2,PC);}
	#define o2() {PC \|= 1; out_p(2,PC);}

	#define j44(l,h) (((l>>3)&0x7)\|((l>>4)&0x8)\|((h<<1)&0x70)\|(h&0x80))

	/*
	* cont = 0 - access the IDE register file
	* cont = 1 - access the IDE command set
	* cont = 2 - use internal bpck register addressing
	*/
	static int cont_map[3] = { 0x40, 0x48, 0 };

	static int bpck_read_regr(struct pi_adapter *pi, int cont, int regr)
	{
	int r, l, h;

	r = regr + cont_map[cont];

	switch (pi->mode) {
	case 0:
	w0(r & 0xf); w0(r); t2(2); t2(4);
	l = r1();
	t2(4);
	h = r1();
	return j44(l, h);
	case 1:
	w0(r & 0xf); w0(r); t2(2);
	e2(); t2(0x20);
	t2(4); h = r0();
	t2(1); t2(0x20);
	return h;
	case 2:
	case 3:
	case 4:
	w0(r); w2(9); w2(0); w2(0x20);
	h = r4();
	w2(0);
	return h;

	}
	return -1;
	}

	static void bpck_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
	{
	int r;

	r = regr + cont_map[cont];

	switch (pi->mode) {
	case 0:
	case 1: w0(r);
	t2(2);
	w0(val);
	o2(); t2(4); t2(1);
	break;
	case 2:
	case 3:
	case 4: w0(r); w2(9); w2(0);
	w0(val); w2(1); w2(3); w2(0);
	break;

	}
	}

	/* These macros access the bpck registers in native addressing */

	#define WR(r,v) bpck_write_regr(pi,2,r,v)
	#define RR(r) (bpck_read_regr(pi,2,r))

	static void bpck_write_block(struct pi_adapter pi, char buf, int count)
	{
	int i;

	switch (pi->mode) {

	case 0:
	WR(4, 0x40);
	w0(0x40); t2(2); t2(1);
	for (i = 0; i < count; i++) {
	w0(buf[i]);
	t2(4);
	}
	WR(4, 0);
	break;

	case 1:
	WR(4, 0x50);
	w0(0x40); t2(2); t2(1);
	for (i = 0; i < count; i++) {
	w0(buf[i]);
	t2(4);
	}
	WR(4, 0x10);
	break;

	case 2:
	WR(4, 0x48);
	w0(0x40); w2(9); w2(0); w2(1);
	for (i = 0; i < count; i++)
	w4(buf[i]);
	w2(0);
	WR(4, 8);
	break;

	case 3:
	WR(4, 0x48);
	w0(0x40); w2(9); w2(0); w2(1);
	for (i = 0; i < count / 2; i++)
	w4w(((u16 *)buf)[i]);
	w2(0);
	WR(4, 8);
	break;

	case 4:
	WR(4, 0x48);
	w0(0x40); w2(9); w2(0); w2(1);
	for (i = 0; i < count / 4; i++)
	w4l(((u32 *)buf)[i]);
	w2(0);
	WR(4, 8);
	break;
	}
	}

	static void bpck_read_block(struct pi_adapter pi, char buf, int count)
	{
	int i, l, h;

	switch (pi->mode) {

	case 0:
	WR(4, 0x40);
	w0(0x40); t2(2);
	for (i = 0; i < count; i++) {
	t2(4); l = r1();
	t2(4); h = r1();
	buf[i] = j44(l, h);
	}
	WR(4, 0);
	break;

	case 1:
	WR(4, 0x50);
	w0(0x40); t2(2); t2(0x20);
	for (i = 0; i < count; i++) {
	t2(4);
	buf[i] = r0();
	}
	t2(1); t2(0x20);
	WR(4, 0x10);
	break;

	case 2:
	WR(4, 0x48);
	w0(0x40); w2(9); w2(0); w2(0x20);
	for (i = 0; i < count; i++)
	buf[i] = r4();
	w2(0);
	WR(4, 8);
	break;

	case 3:
	WR(4, 0x48);
	w0(0x40); w2(9); w2(0); w2(0x20);
	for (i = 0; i < count / 2; i++)
	((u16 *)buf)[i] = r4w();
	w2(0);
	WR(4, 8);
	break;

	case 4:
	WR(4, 0x48);
	w0(0x40); w2(9); w2(0); w2(0x20);
	for (i = 0; i < count / 4; i++)
	((u32 *)buf)[i] = r4l();
	w2(0);
	WR(4, 8);
	break;

	}
	}

	static int bpck_probe_unit(struct pi_adapter *pi)
	{
	int o1, o0, f7, id;
	int t, s;

	id = pi->unit;
	s = 0;
	w2(4); w2(0xe); r2(); t2(2);
	o1 = r1()&0xf8;
	o0 = r0();
	w0(255-id); w2(4); w0(id);
	t2(8); t2(8); t2(8);
	t2(2); t = r1()&0xf8;
	f7 = ((id % 8) == 7);
	if ((f7) \|\| (t != o1)) {
	t2(2);
	s = r1() & 0xf8;
	}
	if ((t == o1) && ((!f7) \|\| (s == o1))) {
	w2(0x4c); w0(o0);
	return 0;
	}
	t2(8); w0(0); t2(2); w2(0x4c); w0(o0);
	return 1;
	}

	static void bpck_connect(struct pi_adapter *pi)
	{
	pi->saved_r0 = r0();
	w0(0xff-pi->unit); w2(4); w0(pi->unit);
	t2(8); t2(8); t2(8);
	t2(2); t2(2);

	switch (pi->mode) {
	case 0:
	t2(8); WR(4, 0);
	break;
	case 1:
	t2(8); WR(4, 0x10);
	break;
	case 2:
	case 3:
	case 4:
	w2(0); WR(4, 8);
	break;
	}

	WR(5,8);

	/*
	* Possibly wrong, purpose unknown (fiddle with ESS logic ???)
	* if (pi->devtype == PI_PCD) {
	*/
	WR(0x46, 0x10);
	WR(0x4c, 0x38);
	WR(0x4d, 0x88);
	WR(0x46, 0xa0);
	WR(0x41, 0);
	WR(0x4e, 8);
	/* } */
	}

	static void bpck_disconnect(struct pi_adapter *pi)
	{
	w0(0);
	if (pi->mode >= 2) {
	w2(9); w2(0);
	} else {
	t2(2);
	}
	w2(0x4c); w0(pi->saved_r0);
	}

	static void bpck_force_spp(struct pi_adapter *pi)
	{
	/* This fakes the EPP protocol to turn off EPP ... */
	pi->saved_r0 = r0();
	w0(0xff-pi->unit); w2(4); w0(pi->unit);
	t2(8); t2(8); t2(8);
	t2(2); t2(2);

	w2(0);
	w0(4); w2(9); w2(0);
	w0(0); w2(1); w2(3); w2(0);
	w0(0); w2(9); w2(0);
	w2(0x4c); w0(pi->saved_r0);
	}

	#define TEST_LEN 16

	static int bpck_test_proto(struct pi_adapter *pi)
	{
	int i, e, l, h, om;
	char buf[TEST_LEN];

	bpck_force_spp(pi);

	switch (pi->mode) {

	case 0:
	bpck_connect(pi);
	WR(0x13, 0x7f);
	w0(0x13); t2(2);
	for (i = 0; i < TEST_LEN; i++) {
	t2(4); l = r1();
	t2(4); h = r1();
	buf[i] = j44(l, h);
	}
	bpck_disconnect(pi);
	break;

	case 1:
	bpck_connect(pi);
	WR(0x13, 0x7f);
	w0(0x13); t2(2); t2(0x20);
	for (i = 0; i < TEST_LEN; i++) {
	t2(4);
	buf[i] = r0();
	}
	t2(1); t2(0x20);
	bpck_disconnect(pi);
	break;

	case 2:
	case 3:
	case 4:
	om = pi->mode;
	pi->mode = 0;
	bpck_connect(pi);
	WR(7, 3);
	WR(4, 8);
	bpck_disconnect(pi);

	pi->mode = om;
	bpck_connect(pi);
	w0(0x13); w2(9); w2(1); w0(0); w2(3); w2(0); w2(0xe0);

	switch (pi->mode) {
	case 2:
	for (i = 0; i < TEST_LEN; i++)
	buf[i] = r4();
	break;
	case 3:
	for (i = 0; i < TEST_LEN / 2; i++)
	((u16 *)buf)[i] = r4w();
	break;
	case 4:
	for (i = 0; i < TEST_LEN / 4; i++)
	((u32 *)buf)[i] = r4l();
	break;
	}

	w2(0);
	WR(7, 0);
	bpck_disconnect(pi);
	break;

	}

	dev_dbg(&pi->dev, "bpck: 0x%x unit %d mode %d: ",
	pi->port, pi->unit, pi->mode);
	print_hex_dump_debug("bpck: ", DUMP_PREFIX_NONE, TEST_LEN, 1, buf,
	TEST_LEN, false);

	e = 0;
	for (i = 0; i < TEST_LEN; i++) {
	if (buf[i] != i + 1)
	e++;
	}

	return e;
	}

	static void bpck_read_eeprom(struct pi_adapter pi, char buf)
	{
	int i, j, k, p, v, f, om, od;

	bpck_force_spp(pi);

	om = pi->mode; od = pi->delay;
	pi->mode = 0; pi->delay = 6;

	bpck_connect(pi);

	WR(4, 0);
	for (i = 0; i < 64; i++) {
	WR(6, 8);
	WR(6, 0xc);
	p = 0x100;
	for (k = 0; k < 9; k++) {
	f = (((i + 0x180) & p) != 0) * 2;
	WR(6, f + 0xc);
	WR(6, f + 0xd);
	WR(6, f + 0xc);
	p = (p >> 1);
	}
	for (j = 0; j < 2; j++) {
	v = 0;
	for (k = 0; k < 8; k++) {
	WR(6, 0xc);
	WR(6, 0xd);
	WR(6, 0xc);
	f = RR(0);
	v = 2 * v + (f == 0x84);
	}
	buf[2 * i + 1 - j] = v;
	}
	}
	WR(6, 8);
	WR(6, 0);
	WR(5, 8);

	bpck_disconnect(pi);

	if (om >= 2) {
	bpck_connect(pi);
	WR(7, 3);
	WR(4, 8);
	bpck_disconnect(pi);
	}

	pi->mode = om; pi->delay = od;
	}

	static int bpck_test_port(struct pi_adapter *pi)
	{
	int i, r, m;

	/* Check for 8-bit port */
	w2(0x2c); i = r0(); w0(255-i); r = r0(); w0(i);
	m = -1;
	if (r == i)
	m = 2;
	if (r == (255-i))
	m = 0;

	w2(0xc);
	i = r0();
	w0(255-i);
	r = r0();
	w0(i);
	if (r != (255-i))
	m = -1;

	if (m == 0) {
	w2(6);
	w2(0xc);
	r = r0();
	w0(0xaa);
	w0(r);
	w0(0xaa);
	}
	if (m == 2) {
	w2(0x26);
	w2(0xc);
	}

	if (m == -1)
	return 0;

	return 5;
	}

	static void bpck_log_adapter(struct pi_adapter *pi)
	{
	char *mode_str[5] = { "4-bit", "8-bit", "EPP-8", "EPP-16", "EPP-32" };
	char scratch[128];

	bpck_read_eeprom(pi,scratch);
	print_hex_dump_bytes("bpck EEPROM: ", DUMP_PREFIX_NONE, scratch, 128);
	dev_info(&pi->dev,
	"backpack %8.8s unit %d at 0x%x, mode %d (%s), delay %d\n",
	&scratch[110], pi->unit, pi->port, pi->mode,
	mode_str[pi->mode], pi->delay);
	}

	static struct pi_protocol bpck = {
	.owner = THIS_MODULE,
	.name = "bpck",
	.max_mode = 5,
	.epp_first = 2,
	.default_delay = 4,
	.max_units = 255,
	.write_regr = bpck_write_regr,
	.read_regr = bpck_read_regr,
	.write_block = bpck_write_block,
	.read_block = bpck_read_block,
	.connect = bpck_connect,
	.disconnect = bpck_disconnect,
	.test_port = bpck_test_port,
	.probe_unit = bpck_probe_unit,
	.test_proto = bpck_test_proto,
	.log_adapter = bpck_log_adapter,
	};

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
	MODULE_DESCRIPTION("MicroSolutions BACKPACK parallel port IDE adapter protocol driver");
	module_pata_parport_driver(bpck);