xref: /openbmc/linux/drivers/ata/pata_parport/aten.c (revision 078b39c9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * (c) 1997-8  Grant R. Guenther <grant@torque.net>
4  *
5  * aten.c is a low-level protocol driver for the ATEN EH-100
6  * parallel port adapter.  The EH-100 supports 4-bit and 8-bit
7  * modes only.  There is also an EH-132 which supports EPP mode
8  * transfers.  The EH-132 is not yet supported.
9  */
10 
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/delay.h>
14 #include <linux/kernel.h>
15 #include <linux/wait.h>
16 #include <linux/types.h>
17 #include <asm/io.h>
18 #include "pata_parport.h"
19 
20 #define j44(a,b)                ((((a>>4)&0x0f)|(b&0xf0))^0x88)
21 
22 /*
23  * cont = 0 - access the IDE register file
24  * cont = 1 - access the IDE command set
25  */
26 static int  cont_map[2] = { 0x08, 0x20 };
27 
28 static void aten_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
29 {
30 	int r = regr + cont_map[cont] + 0x80;
31 
32 	w0(r); w2(0xe); w2(6); w0(val); w2(7); w2(6); w2(0xc);
33 }
34 
35 static int aten_read_regr(struct pi_adapter *pi, int cont, int regr)
36 {
37 	int  a, b, r;
38 
39 	r = regr + cont_map[cont] + 0x40;
40 
41 	switch (pi->mode) {
42 
43 	case 0:
44 		w0(r); w2(0xe); w2(6);
45 		w2(7); w2(6); w2(0);
46 		a = r1(); w0(0x10); b = r1(); w2(0xc);
47 		return j44(a,b);
48 
49 	case 1:
50 		r |= 0x10;
51 		w0(r); w2(0xe); w2(6); w0(0xff);
52 		w2(0x27); w2(0x26); w2(0x20);
53 		a = r0();
54 		w2(0x26); w2(0xc);
55 		return a;
56 	}
57 	return -1;
58 }
59 
60 static void aten_read_block(struct pi_adapter *pi, char *buf, int count)
61 {
62 	int  k, a, b, c, d;
63 
64 	switch (pi->mode) {
65 
66 	case 0:
67 		w0(0x48); w2(0xe); w2(6);
68 		for (k = 0; k < count / 2; k++) {
69 			w2(7); w2(6); w2(2);
70 			a = r1(); w0(0x58); b = r1();
71 			w2(0); d = r1(); w0(0x48); c = r1();
72 			buf[2 * k] = j44(c, d);
73 			buf[2 * k + 1] = j44(a, b);
74 		}
75 		w2(0xc);
76 		break;
77 
78 	case 1:
79 		w0(0x58); w2(0xe); w2(6);
80 		for (k = 0; k < count / 2; k++) {
81 			w2(0x27); w2(0x26); w2(0x22);
82 			a = r0(); w2(0x20); b = r0();
83 			buf[2 * k] = b;
84 			buf[2 * k + 1] = a;
85 		}
86 		w2(0x26); w2(0xc);
87 		break;
88 	}
89 }
90 
91 static void aten_write_block(struct pi_adapter *pi, char *buf, int count)
92 {
93 	int k;
94 
95 	w0(0x88); w2(0xe); w2(6);
96 	for (k = 0; k < count / 2; k++) {
97 		w0(buf[2 * k + 1]); w2(0xe); w2(6);
98 		w0(buf[2 * k]); w2(7); w2(6);
99 	}
100 	w2(0xc);
101 }
102 
103 static void aten_connect(struct pi_adapter *pi)
104 {
105 	pi->saved_r0 = r0();
106 	pi->saved_r2 = r2();
107 	w2(0xc);
108 }
109 
110 static void aten_disconnect(struct pi_adapter *pi)
111 {
112 	w0(pi->saved_r0);
113 	w2(pi->saved_r2);
114 }
115 
116 static void aten_log_adapter(struct pi_adapter *pi)
117 {
118 	char *mode_string[2] = { "4-bit", "8-bit" };
119 
120 	dev_info(&pi->dev,
121 		 "ATEN EH-100 at 0x%x, mode %d (%s), delay %d\n",
122 		 pi->port, pi->mode, mode_string[pi->mode], pi->delay);
123 }
124 
125 static struct pi_protocol aten = {
126 	.owner		= THIS_MODULE,
127 	.name		= "aten",
128 	.max_mode	= 2,
129 	.epp_first	= 2,
130 	.default_delay	= 1,
131 	.max_units	= 1,
132 	.write_regr	= aten_write_regr,
133 	.read_regr	= aten_read_regr,
134 	.write_block	= aten_write_block,
135 	.read_block	= aten_read_block,
136 	.connect	= aten_connect,
137 	.disconnect	= aten_disconnect,
138 	.log_adapter	= aten_log_adapter,
139 };
140 
141 MODULE_LICENSE("GPL");
142 module_pata_parport_driver(aten);
143