1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (c) 1996-1998  Grant R. Guenther <grant@torque.net>
4 *
5 * bpck.c is a low-level protocol driver for the MicroSolutions
6 * "backpack" parallel port IDE adapter.
7 */
8
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/delay.h>
12#include <linux/kernel.h>
13#include <linux/types.h>
14#include <linux/wait.h>
15#include <asm/io.h>
16#include "pata_parport.h"
17
18#undef r2
19#undef w2
20#undef PC
21
22#define PC			pi->private
23#define r2()			(PC=(in_p(2) & 0xff))
24#define w2(byte)  		{out_p(2,byte); PC = byte;}
25#define t2(pat)   		{PC ^= pat; out_p(2,PC);}
26#define e2()			{PC &= 0xfe; out_p(2,PC);}
27#define o2()			{PC |= 1; out_p(2,PC);}
28
29#define j44(l,h)     (((l>>3)&0x7)|((l>>4)&0x8)|((h<<1)&0x70)|(h&0x80))
30
31/*
32 * cont = 0 - access the IDE register file
33 * cont = 1 - access the IDE command set
34 * cont = 2 - use internal bpck register addressing
35 */
36static int  cont_map[3] = { 0x40, 0x48, 0 };
37
38static int bpck_read_regr(struct pi_adapter *pi, int cont, int regr)
39{
40	int r, l, h;
41
42	r = regr + cont_map[cont];
43
44	switch (pi->mode) {
45	case 0:
46		w0(r & 0xf); w0(r); t2(2); t2(4);
47	        l = r1();
48		t2(4);
49		h = r1();
50		return j44(l, h);
51	case 1:
52		w0(r & 0xf); w0(r); t2(2);
53		e2(); t2(0x20);
54		t2(4); h = r0();
55		t2(1); t2(0x20);
56		return h;
57	case 2:
58	case 3:
59	case 4:
60		w0(r); w2(9); w2(0); w2(0x20);
61		h = r4();
62		w2(0);
63		return h;
64
65	}
66	return -1;
67}
68
69static void bpck_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
70{
71	int r;
72
73        r = regr + cont_map[cont];
74
75	switch (pi->mode) {
76	case 0:
77	case 1: w0(r);
78		t2(2);
79		w0(val);
80		o2(); t2(4); t2(1);
81		break;
82	case 2:
83	case 3:
84	case 4: w0(r); w2(9); w2(0);
85		w0(val); w2(1); w2(3); w2(0);
86		break;
87
88	}
89}
90
91/* These macros access the bpck registers in native addressing */
92
93#define WR(r,v)		bpck_write_regr(pi,2,r,v)
94#define RR(r)		(bpck_read_regr(pi,2,r))
95
96static void bpck_write_block(struct pi_adapter *pi, char *buf, int count)
97{
98	int i;
99
100	switch (pi->mode) {
101
102	case 0:
103		WR(4, 0x40);
104		w0(0x40); t2(2); t2(1);
105		for (i = 0; i < count; i++) {
106			w0(buf[i]);
107			t2(4);
108		}
109		WR(4, 0);
110		break;
111
112	case 1:
113		WR(4, 0x50);
114		w0(0x40); t2(2); t2(1);
115		for (i = 0; i < count; i++) {
116			w0(buf[i]);
117			t2(4);
118		}
119		WR(4, 0x10);
120		break;
121
122	case 2:
123		WR(4, 0x48);
124		w0(0x40); w2(9); w2(0); w2(1);
125		for (i = 0; i < count; i++)
126			w4(buf[i]);
127		w2(0);
128		WR(4, 8);
129		break;
130
131	case 3:
132		WR(4, 0x48);
133		w0(0x40); w2(9); w2(0); w2(1);
134		for (i = 0; i < count / 2; i++)
135			w4w(((u16 *)buf)[i]);
136		w2(0);
137		WR(4, 8);
138		break;
139
140	case 4:
141		WR(4, 0x48);
142		w0(0x40); w2(9); w2(0); w2(1);
143		for (i = 0; i < count / 4; i++)
144			w4l(((u32 *)buf)[i]);
145		w2(0);
146		WR(4, 8);
147		break;
148 	}
149}
150
151static void bpck_read_block(struct pi_adapter *pi, char *buf, int count)
152{
153	int i, l, h;
154
155	switch (pi->mode) {
156
157	case 0:
158		WR(4, 0x40);
159		w0(0x40); t2(2);
160		for (i = 0; i < count; i++) {
161			t2(4); l = r1();
162			t2(4); h = r1();
163			buf[i] = j44(l, h);
164		}
165		WR(4, 0);
166		break;
167
168	case 1:
169		WR(4, 0x50);
170		w0(0x40); t2(2); t2(0x20);
171		for (i = 0; i < count; i++) {
172			t2(4);
173			buf[i] = r0();
174		}
175		t2(1); t2(0x20);
176		WR(4, 0x10);
177		break;
178
179	case 2:
180		WR(4, 0x48);
181		w0(0x40); w2(9); w2(0); w2(0x20);
182		for (i = 0; i < count; i++)
183			buf[i] = r4();
184		w2(0);
185		WR(4, 8);
186		break;
187
188	case 3:
189		WR(4, 0x48);
190		w0(0x40); w2(9); w2(0); w2(0x20);
191		for (i = 0; i < count / 2; i++)
192			((u16 *)buf)[i] = r4w();
193		w2(0);
194		WR(4, 8);
195		break;
196
197	case 4:
198		WR(4, 0x48);
199		w0(0x40); w2(9); w2(0); w2(0x20);
200		for (i = 0; i < count / 4; i++)
201			((u32 *)buf)[i] = r4l();
202		w2(0);
203		WR(4, 8);
204		break;
205
206	}
207}
208
209static int bpck_probe_unit(struct pi_adapter *pi)
210{
211	int o1, o0, f7, id;
212	int t, s;
213
214	id = pi->unit;
215	s = 0;
216	w2(4); w2(0xe); r2(); t2(2);
217	o1 = r1()&0xf8;
218	o0 = r0();
219	w0(255-id); w2(4); w0(id);
220	t2(8); t2(8); t2(8);
221	t2(2); t = r1()&0xf8;
222	f7 = ((id % 8) == 7);
223	if ((f7) || (t != o1)) {
224		t2(2);
225		s = r1() & 0xf8;
226	}
227	if ((t == o1) && ((!f7) || (s == o1)))  {
228		w2(0x4c); w0(o0);
229		return 0;
230	}
231	t2(8); w0(0); t2(2); w2(0x4c); w0(o0);
232	return 1;
233}
234
235static void bpck_connect(struct pi_adapter *pi)
236{
237	pi->saved_r0 = r0();
238	w0(0xff-pi->unit); w2(4); w0(pi->unit);
239	t2(8); t2(8); t2(8);
240	t2(2); t2(2);
241
242	switch (pi->mode) {
243	case 0:
244		t2(8); WR(4, 0);
245		break;
246	case 1:
247		t2(8); WR(4, 0x10);
248		break;
249	case 2:
250	case 3:
251	case 4:
252		w2(0); WR(4, 8);
253		break;
254	}
255
256	WR(5,8);
257
258	/*
259	 * Possibly wrong, purpose unknown (fiddle with ESS logic ???)
260	 * if (pi->devtype == PI_PCD) {
261	 */
262	WR(0x46, 0x10);
263	WR(0x4c, 0x38);
264	WR(0x4d, 0x88);
265	WR(0x46, 0xa0);
266	WR(0x41, 0);
267	WR(0x4e, 8);
268	/* } */
269}
270
271static void bpck_disconnect(struct pi_adapter *pi)
272{
273	w0(0);
274	if (pi->mode >= 2) {
275		w2(9); w2(0);
276	} else {
277		t2(2);
278	}
279	w2(0x4c); w0(pi->saved_r0);
280}
281
282static void bpck_force_spp(struct pi_adapter *pi)
283{
284	/* This fakes the EPP protocol to turn off EPP ... */
285	pi->saved_r0 = r0();
286	w0(0xff-pi->unit); w2(4); w0(pi->unit);
287	t2(8); t2(8); t2(8);
288	t2(2); t2(2);
289
290	w2(0);
291	w0(4); w2(9); w2(0);
292	w0(0); w2(1); w2(3); w2(0);
293	w0(0); w2(9); w2(0);
294	w2(0x4c); w0(pi->saved_r0);
295}
296
297#define TEST_LEN  16
298
299static int bpck_test_proto(struct pi_adapter *pi)
300{
301	int i, e, l, h, om;
302	char buf[TEST_LEN];
303
304	bpck_force_spp(pi);
305
306	switch (pi->mode) {
307
308	case 0:
309		bpck_connect(pi);
310		WR(0x13, 0x7f);
311		w0(0x13); t2(2);
312		for (i = 0; i < TEST_LEN; i++) {
313			t2(4); l = r1();
314			t2(4); h = r1();
315			buf[i] = j44(l, h);
316		}
317		bpck_disconnect(pi);
318		break;
319
320	case 1:
321		bpck_connect(pi);
322		WR(0x13, 0x7f);
323		w0(0x13); t2(2); t2(0x20);
324		for (i = 0; i < TEST_LEN; i++) {
325			t2(4);
326			buf[i] = r0();
327		}
328		t2(1); t2(0x20);
329		bpck_disconnect(pi);
330		break;
331
332	case 2:
333	case 3:
334	case 4:
335		om = pi->mode;
336		pi->mode = 0;
337		bpck_connect(pi);
338		WR(7, 3);
339		WR(4, 8);
340		bpck_disconnect(pi);
341
342		pi->mode = om;
343		bpck_connect(pi);
344		w0(0x13); w2(9); w2(1); w0(0); w2(3); w2(0); w2(0xe0);
345
346		switch (pi->mode) {
347		case 2:
348			for (i = 0; i < TEST_LEN; i++)
349				buf[i] = r4();
350			break;
351		case 3:
352			for (i = 0; i < TEST_LEN / 2; i++)
353				((u16 *)buf)[i] = r4w();
354			break;
355		case 4:
356			for (i = 0; i < TEST_LEN / 4; i++)
357				((u32 *)buf)[i] = r4l();
358			break;
359		}
360
361		w2(0);
362		WR(7, 0);
363		bpck_disconnect(pi);
364		break;
365
366	}
367
368	dev_dbg(&pi->dev, "bpck: 0x%x unit %d mode %d: ",
369		pi->port, pi->unit, pi->mode);
370	print_hex_dump_debug("bpck: ", DUMP_PREFIX_NONE, TEST_LEN, 1, buf,
371			     TEST_LEN, false);
372
373	e = 0;
374	for (i = 0; i < TEST_LEN; i++) {
375		if (buf[i] != i + 1)
376			e++;
377	}
378
379	return e;
380}
381
382static void bpck_read_eeprom(struct pi_adapter *pi, char *buf)
383{
384	int i, j, k, p, v, f, om, od;
385
386	bpck_force_spp(pi);
387
388	om = pi->mode;  od = pi->delay;
389	pi->mode = 0; pi->delay = 6;
390
391	bpck_connect(pi);
392
393	WR(4, 0);
394	for (i = 0; i < 64; i++) {
395		WR(6, 8);
396		WR(6, 0xc);
397		p = 0x100;
398		for (k = 0; k < 9; k++) {
399			f = (((i + 0x180) & p) != 0) * 2;
400			WR(6, f + 0xc);
401			WR(6, f + 0xd);
402			WR(6, f + 0xc);
403			p = (p >> 1);
404		}
405		for (j = 0; j < 2; j++) {
406			v = 0;
407			for (k = 0; k < 8; k++) {
408				WR(6, 0xc);
409				WR(6, 0xd);
410				WR(6, 0xc);
411				f = RR(0);
412				v = 2 * v + (f == 0x84);
413			}
414			buf[2 * i + 1 - j] = v;
415		}
416	}
417	WR(6, 8);
418	WR(6, 0);
419	WR(5, 8);
420
421	bpck_disconnect(pi);
422
423        if (om >= 2) {
424		bpck_connect(pi);
425		WR(7, 3);
426		WR(4, 8);
427		bpck_disconnect(pi);
428        }
429
430	pi->mode = om; pi->delay = od;
431}
432
433static int bpck_test_port(struct pi_adapter *pi)
434{
435	int i, r, m;
436
437	/* Check for 8-bit port */
438	w2(0x2c); i = r0(); w0(255-i); r = r0(); w0(i);
439	m = -1;
440	if (r == i)
441		m = 2;
442	if (r == (255-i))
443		m = 0;
444
445	w2(0xc);
446	i = r0();
447	w0(255-i);
448	r = r0();
449	w0(i);
450	if (r != (255-i))
451		m = -1;
452
453	if (m == 0) {
454		w2(6);
455		w2(0xc);
456		r = r0();
457		w0(0xaa);
458		w0(r);
459		w0(0xaa);
460	}
461	if (m == 2) {
462		w2(0x26);
463		w2(0xc);
464	}
465
466	if (m == -1)
467		return 0;
468
469	return 5;
470}
471
472static void bpck_log_adapter(struct pi_adapter *pi)
473{
474	char *mode_str[5] = { "4-bit", "8-bit", "EPP-8", "EPP-16", "EPP-32" };
475	char scratch[128];
476
477	bpck_read_eeprom(pi,scratch);
478	print_hex_dump_bytes("bpck EEPROM: ", DUMP_PREFIX_NONE, scratch, 128);
479	dev_info(&pi->dev,
480		 "backpack %8.8s unit %d at 0x%x, mode %d (%s), delay %d\n",
481		 &scratch[110], pi->unit, pi->port, pi->mode,
482		 mode_str[pi->mode], pi->delay);
483}
484
485static struct pi_protocol bpck = {
486	.owner		= THIS_MODULE,
487	.name		= "bpck",
488	.max_mode	= 5,
489	.epp_first	= 2,
490	.default_delay	= 4,
491	.max_units	= 255,
492	.write_regr	= bpck_write_regr,
493	.read_regr	= bpck_read_regr,
494	.write_block	= bpck_write_block,
495	.read_block	= bpck_read_block,
496	.connect	= bpck_connect,
497	.disconnect	= bpck_disconnect,
498	.test_port	= bpck_test_port,
499	.probe_unit	= bpck_probe_unit,
500	.test_proto	= bpck_test_proto,
501	.log_adapter	= bpck_log_adapter,
502};
503
504MODULE_LICENSE("GPL");
505MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
506MODULE_DESCRIPTION("MicroSolutions BACKPACK parallel port IDE adapter protocol driver");
507module_pata_parport_driver(bpck);
508