xref: /openbmc/linux/drivers/ata/pata_parport/fit2.c (revision 078b39c9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * (c) 1998  Grant R. Guenther <grant@torque.net>
4  *
5  * fit2.c is a low-level protocol driver for the older version
6  * of the Fidelity International Technology parallel port adapter.
7  * This adapter is used in their TransDisk 2000 and older TransDisk
8  * 3000 portable hard-drives.  As far as I can tell, this device
9  * supports 4-bit mode _only_.
10  *
11  * Newer models of the FIT products use an enhanced protocol.
12  * The "fit3" protocol module should support current drives.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/delay.h>
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/wait.h>
21 #include <asm/io.h>
22 #include "pata_parport.h"
23 
24 #define j44(a, b)	(((a >> 4) & 0x0f) | (b & 0xf0))
25 
26 /*
27  * cont = 0 - access the IDE register file
28  * cont = 1 - access the IDE command set
29  *
30  * NB: The FIT adapter does not appear to use the control registers.
31  * So, we map ALT_STATUS to STATUS and NO-OP writes to the device
32  * control register - this means that IDE reset will not work on these
33  * devices.
34  */
35 
36 static void fit2_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
37 {
38 	if (cont == 1)
39 		return;
40 	w2(0xc); w0(regr); w2(4); w0(val); w2(5); w0(0); w2(4);
41 }
42 
43 static int fit2_read_regr(struct pi_adapter *pi, int cont, int regr)
44 {
45 	int  a, b, r;
46 
47 	if (cont) {
48 		if (regr != 6)
49 			return 0xff;
50 		r = 7;
51 	} else {
52 		r = regr + 0x10;
53 	}
54 
55 	w2(0xc); w0(r); w2(4); w2(5);
56 	w0(0); a = r1();
57 	w0(1); b = r1();
58 	w2(4);
59 
60 	return j44(a, b);
61 }
62 
63 static void fit2_read_block(struct pi_adapter *pi, char *buf, int count)
64 {
65 	int  k, a, b, c, d;
66 
67 	w2(0xc); w0(0x10);
68 
69 	for (k = 0; k < count / 4; k++) {
70 		w2(4); w2(5);
71 		w0(0); a = r1(); w0(1); b = r1();
72 		w0(3); c = r1(); w0(2); d = r1();
73 		buf[4 * k + 0] = j44(a, b);
74 		buf[4 * k + 1] = j44(d, c);
75 
76 		w2(4); w2(5);
77 		a = r1(); w0(3); b = r1();
78 		w0(1); c = r1(); w0(0); d = r1();
79 		buf[4 * k + 2] = j44(d, c);
80 		buf[4 * k + 3] = j44(a, b);
81 	}
82 
83 	w2(4);
84 }
85 
86 static void fit2_write_block(struct pi_adapter *pi, char *buf, int count)
87 {
88 	int k;
89 
90 	w2(0xc); w0(0);
91 	for (k = 0; k < count / 2; k++) {
92 		w2(4); w0(buf[2 * k]);
93 		w2(5); w0(buf[2 * k + 1]);
94 	}
95 	w2(4);
96 }
97 
98 static void fit2_connect(struct pi_adapter *pi)
99 {
100 	pi->saved_r0 = r0();
101 	pi->saved_r2 = r2();
102 	w2(0xcc);
103 }
104 
105 static void fit2_disconnect(struct pi_adapter *pi)
106 {
107 	w0(pi->saved_r0);
108 	w2(pi->saved_r2);
109 }
110 
111 static void fit2_log_adapter(struct pi_adapter *pi)
112 {
113 	dev_info(&pi->dev, "FIT 2000 adapter at 0x%x, delay %d\n",
114 		 pi->port, pi->delay);
115 
116 }
117 
118 static struct pi_protocol fit2 = {
119 	.owner		= THIS_MODULE,
120 	.name		= "fit2",
121 	.max_mode	= 1,
122 	.epp_first	= 2,
123 	.default_delay	= 1,
124 	.max_units	= 1,
125 	.write_regr	= fit2_write_regr,
126 	.read_regr	= fit2_read_regr,
127 	.write_block	= fit2_write_block,
128 	.read_block	= fit2_read_block,
129 	.connect	= fit2_connect,
130 	.disconnect	= fit2_disconnect,
131 	.log_adapter	= fit2_log_adapter,
132 };
133 
134 MODULE_LICENSE("GPL");
135 module_pata_parport_driver(fit2);
136