1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (c) 1996-1998  Grant R. Guenther <grant@torque.net>
4 *
5 * on20.c is a low-level protocol driver for the
6 * Onspec 90c20 parallel to 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#define op(f)					\
19	do {					\
20		w2(4); w0(f); w2(5); w2(0xd);	\
21		w2(5); w2(0xd); w2(5); w2(4);	\
22	} while (0)
23
24#define vl(v)					\
25	do {					\
26		w2(4); w0(v); w2(5);		\
27		w2(7); w2(5); w2(4);		\
28	} while (0)
29
30#define j44(a, b)	(((a >> 4) & 0x0f) | (b & 0xf0))
31
32/*
33 * cont = 0 - access the IDE register file
34 * cont = 1 - access the IDE command set
35 */
36
37static int on20_read_regr(struct pi_adapter *pi, int cont, int regr)
38{
39	int h, l, r;
40
41	r = (regr << 2) + 1 + cont;
42
43	op(1); vl(r); op(0);
44
45	switch (pi->mode) {
46	case 0:
47		w2(4); w2(6); l = r1();
48		w2(4); w2(6); h = r1();
49		w2(4); w2(6); w2(4); w2(6); w2(4);
50		return j44(l, h);
51	case 1:
52		w2(4); w2(0x26); r = r0();
53		w2(4); w2(0x26); w2(4);
54		return r;
55	}
56
57	return -1;
58}
59
60static void on20_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
61{
62	int r = (regr << 2) + 1 + cont;
63
64	op(1); vl(r);
65	op(0); vl(val);
66	op(0); vl(val);
67}
68
69static void on20_connect(struct pi_adapter *pi)
70{
71	pi->saved_r0 = r0();
72	pi->saved_r2 = r2();
73
74	w2(4); w0(0); w2(0xc); w2(4); w2(6); w2(4); w2(6); w2(4);
75	if (pi->mode) {
76		op(2); vl(8); op(2); vl(9);
77	} else {
78		op(2); vl(0); op(2); vl(8);
79	}
80}
81
82static void on20_disconnect(struct pi_adapter *pi)
83{
84	w2(4); w0(7); w2(4); w2(0xc); w2(4);
85	w0(pi->saved_r0);
86	w2(pi->saved_r2);
87}
88
89static void on20_read_block(struct pi_adapter *pi, char *buf, int count)
90{
91	int k, l, h;
92
93	op(1); vl(1); op(0);
94
95	for (k = 0; k < count; k++) {
96		if (pi->mode) {
97			w2(4); w2(0x26); buf[k] = r0();
98		} else {
99			w2(6); l = r1(); w2(4);
100			w2(6); h = r1(); w2(4);
101			buf[k] = j44(l, h);
102		}
103	}
104	w2(4);
105}
106
107static void on20_write_block(struct pi_adapter *pi, char *buf, int count)
108{
109	int k;
110
111	op(1); vl(1); op(0);
112
113	for (k = 0; k < count; k++) {
114		w2(5); w0(buf[k]); w2(7);
115	}
116	w2(4);
117}
118
119static void on20_log_adapter(struct pi_adapter *pi)
120{
121	char *mode_string[2] = { "4-bit", "8-bit" };
122
123	dev_info(&pi->dev,
124		 "OnSpec 90c20 at 0x%x, mode %d (%s), delay %d\n",
125		 pi->port, pi->mode, mode_string[pi->mode], pi->delay);
126}
127
128static struct pi_protocol on20 = {
129	.owner		= THIS_MODULE,
130	.name		= "on20",
131	.max_mode	= 2,
132	.epp_first	= 2,
133	.default_delay	= 1,
134	.max_units	= 1,
135	.write_regr	= on20_write_regr,
136	.read_regr	= on20_read_regr,
137	.write_block	= on20_write_block,
138	.read_block	= on20_read_block,
139	.connect	= on20_connect,
140	.disconnect	= on20_disconnect,
141	.log_adapter	= on20_log_adapter,
142};
143
144MODULE_LICENSE("GPL");
145MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
146MODULE_DESCRIPTION("Onspec 90c20 parallel port IDE adapter protocol driver");
147module_pata_parport_driver(on20);
148