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
 36static 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
 43static 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
 63static 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
 86static 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
 98static void fit2_connect(struct pi_adapter *pi)
 99{
100	pi->saved_r0 = r0();
101	pi->saved_r2 = r2();
102	w2(0xcc);
103}
104
105static void fit2_disconnect(struct pi_adapter *pi)
106{
107	w0(pi->saved_r0);
108	w2(pi->saved_r2);
109}
110
111static 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
118static 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
134MODULE_LICENSE("GPL");
135MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
136MODULE_DESCRIPTION("Fidelity International Technology parallel port IDE adapter"
137		   "(older models) protocol driver");
138module_pata_parport_driver(fit2);