comm.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * (c) 1997-1998  Grant R. Guenther <grant@torque.net>
  4 *
  5 * comm.c is a low-level protocol driver for some older models of the DataStor
  6 * "Commuter" parallel to IDE adapter. Some of the parallel port devices
  7 * marketed by Arista currently use this adapter.
  8 */
  9
 10#include <linux/module.h>
 11#include <linux/init.h>
 12#include <linux/delay.h>
 13#include <linux/kernel.h>
 14#include <linux/types.h>
 15#include <linux/wait.h>
 16#include <asm/io.h>
 17#include "pata_parport.h"
 18
 19/*
 20 * mode codes:  0  nybble reads, 8-bit writes
 21 *              1  8-bit reads and writes
 22 *              2  8-bit EPP mode
 23 */
 24
 25#define j44(a, b)	(((a >> 3) & 0x0f) | ((b << 1) & 0xf0))
 26
 27#define P1	w2(5);w2(0xd);w2(0xd);w2(5);w2(4);
 28#define P2	w2(5);w2(7);w2(7);w2(5);w2(4);
 29
 30/*
 31 * cont = 0 - access the IDE register file
 32 * cont = 1 - access the IDE command set
 33 */
 34static int  cont_map[2] = { 0x08, 0x10 };
 35
 36static int comm_read_regr(struct pi_adapter *pi, int cont, int regr)
 37{
 38	int l, h, r;
 39
 40	r = regr + cont_map[cont];
 41
 42	switch (pi->mode) {
 43	case 0:
 44		w0(r); P1; w0(0);
 45		w2(6); l = r1(); w0(0x80); h = r1(); w2(4);
 46		return j44(l, h);
 47
 48	case 1:
 49		w0(r+0x20); P1;
 50		w0(0); w2(0x26); h = r0(); w2(4);
 51		return h;
 52
 53	case 2:
 54	case 3:
 55	case 4:
 56		w3(r+0x20); (void)r1();
 57		w2(0x24); h = r4(); w2(4);
 58		return h;
 59	}
 60
 61	return -1;
 62}
 63
 64static void comm_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
 65{
 66	int r = regr + cont_map[cont];
 67
 68	switch (pi->mode) {
 69	case 0:
 70	case 1:
 71		w0(r); P1; w0(val); P2;
 72		break;
 73	case 2:
 74	case 3:
 75	case 4:
 76		w3(r); (void)r1(); w4(val);
 77		break;
 78	}
 79}
 80
 81static void comm_connect(struct pi_adapter *pi)
 82{
 83	pi->saved_r0 = r0();
 84	pi->saved_r2 = r2();
 85	w2(4); w0(0xff); w2(6);
 86	w2(4); w0(0xaa); w2(6);
 87	w2(4); w0(0x00); w2(6);
 88	w2(4); w0(0x87); w2(6);
 89	w2(4); w0(0xe0); w2(0xc); w2(0xc); w2(4);
 90}
 91
 92static void comm_disconnect(struct pi_adapter *pi)
 93{
 94	w2(0); w2(0); w2(0); w2(4);
 95	w0(pi->saved_r0);
 96	w2(pi->saved_r2);
 97}
 98
 99static void comm_read_block(struct pi_adapter *pi, char *buf, int count)
100{
101	int i, l, h;
102
103	switch (pi->mode) {
104	case 0:
105		w0(0x48); P1;
106		for (i = 0; i < count; i++) {
107			w0(0); w2(6); l = r1();
108			w0(0x80); h = r1(); w2(4);
109			buf[i] = j44(l, h);
110		}
111		break;
112	case 1:
113		w0(0x68); P1; w0(0);
114		for (i = 0; i < count; i++) {
115			w2(0x26);
116			buf[i] = r0();
117			w2(0x24);
118		}
119		w2(4);
120		break;
121	case 2:
122		w3(0x68); (void)r1(); w2(0x24);
123		for (i = 0; i < count; i++)
124			buf[i] = r4();
125		w2(4);
126		break;
127	case 3:
128		w3(0x68); (void)r1(); w2(0x24);
129		for (i = 0; i < count / 2; i++)
130			((u16 *)buf)[i] = r4w();
131		w2(4);
132		break;
133	case 4:
134		w3(0x68); (void)r1(); w2(0x24);
135		for (i = 0; i < count / 4; i++)
136			((u32 *)buf)[i] = r4l();
137		w2(4);
138		break;
139	}
140}
141
142/* NB: Watch out for the byte swapped writes ! */
143static void comm_write_block(struct pi_adapter *pi, char *buf, int count)
144{
145	int k;
146
147	switch (pi->mode) {
148	case 0:
149	case 1:
150		w0(0x68); P1;
151		for (k = 0; k < count; k++) {
152			w2(5);
153			w0(buf[k ^ 1]);
154			w2(7);
155		}
156		w2(5); w2(4);
157		break;
158	case 2:
159		w3(0x48); (void)r1();
160		for (k = 0; k < count; k++)
161			w4(buf[k ^ 1]);
162		break;
163	case 3:
164		w3(0x48); (void)r1();
165		for (k = 0; k < count / 2; k++)
166			w4w(swab16(((u16 *)buf)[k]));
167		break;
168	case 4:
169		w3(0x48); (void)r1();
170		for (k = 0; k < count / 4; k++)
171			w4l(swab16(((u16 *)buf)[2 * k]) |
172			    swab16(((u16 *)buf)[2 * k + 1]) << 16);
173		break;
174	}
175}
176
177static void comm_log_adapter(struct pi_adapter *pi)
178{
179	char *mode_string[5] = { "4-bit", "8-bit", "EPP-8", "EPP-16", "EPP-32" };
180
181	dev_info(&pi->dev,
182		 "DataStor Commuter at 0x%x, mode %d (%s), delay %d\n",
183		 pi->port, pi->mode, mode_string[pi->mode], pi->delay);
184}
185
186static struct pi_protocol comm = {
187	.owner		= THIS_MODULE,
188	.name		= "comm",
189	.max_mode	= 5,
190	.epp_first	= 2,
191	.default_delay	= 1,
192	.max_units	= 1,
193	.write_regr	= comm_write_regr,
194	.read_regr	= comm_read_regr,
195	.write_block	= comm_write_block,
196	.read_block	= comm_read_block,
197	.connect	= comm_connect,
198	.disconnect	= comm_disconnect,
199	.log_adapter	= comm_log_adapter,
200};
201
202MODULE_LICENSE("GPL");
203MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
204MODULE_DESCRIPTION("DataStor Commuter parallel port IDE adapter protocol driver");
205module_pata_parport_driver(comm);