xref: /openbmc/linux/drivers/ata/pata_parport/on20.c (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
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  
on20_read_regr(struct pi_adapter * pi,int cont,int regr)37  static 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  
on20_write_regr(struct pi_adapter * pi,int cont,int regr,int val)60  static 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  
on20_connect(struct pi_adapter * pi)69  static 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  
on20_disconnect(struct pi_adapter * pi)82  static 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  
on20_read_block(struct pi_adapter * pi,char * buf,int count)89  static 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  
on20_write_block(struct pi_adapter * pi,char * buf,int count)107  static 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  
on20_log_adapter(struct pi_adapter * pi)119  static 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  
128  static 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  
144  MODULE_LICENSE("GPL");
145  MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
146  MODULE_DESCRIPTION("Onspec 90c20 parallel port IDE adapter protocol driver");
147  module_pata_parport_driver(on20);
148