xref: /openbmc/linux/drivers/ata/pata_parport/epat.c (revision 404e077a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * (c) 1997-1998  Grant R. Guenther <grant@torque.net>
4  *
5  * This is the low level protocol driver for the EPAT parallel
6  * to IDE adapter from Shuttle Technologies.  This adapter is
7  * used in many popular parallel port disk products such as the
8  * SyQuest EZ drives, the Avatar Shark and the Imation SuperDisk.
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/types.h>
16 #include <linux/wait.h>
17 #include <asm/io.h>
18 #include "pata_parport.h"
19 
20 #define j44(a, b)	(((a >> 4) & 0x0f) + (b & 0xf0))
21 #define j53(a, b)	(((a >> 3) & 0x1f) + ((b << 4) & 0xe0))
22 
23 static int epatc8;
24 
25 module_param(epatc8, int, 0);
26 MODULE_PARM_DESC(epatc8,
27 		 "support for the Shuttle EP1284 chip, "
28 		 "used in any recent Imation SuperDisk (LS-120) drive.");
29 
30 /*
31  * cont =  0   IDE register file
32  * cont =  1   IDE control registers
33  * cont =  2   internal EPAT registers
34  */
35 static int cont_map[3] = { 0x18, 0x10, 0 };
36 
37 static void epat_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
38 {
39 	int r = regr + cont_map[cont];
40 
41 	switch (pi->mode) {
42 	case 0:
43 	case 1:
44 	case 2:
45 		w0(0x60+r); w2(1); w0(val); w2(4);
46 		break;
47 	case 3:
48 	case 4:
49 	case 5:
50 		w3(0x40+r); w4(val);
51 		break;
52 	}
53 }
54 
55 static int epat_read_regr(struct pi_adapter *pi, int cont, int regr)
56 {
57 	int  a, b, r;
58 
59 	r = regr + cont_map[cont];
60 
61 	switch (pi->mode) {
62 
63 	case 0:
64 		w0(r); w2(1); w2(3);
65 		a = r1(); w2(4); b = r1();
66 		return j44(a, b);
67 	case 1:
68 		w0(0x40+r); w2(1); w2(4);
69 		a = r1(); b = r2(); w0(0xff);
70 		return j53(a, b);
71 	case 2:
72 		w0(0x20+r); w2(1); w2(0x25);
73 		a = r0(); w2(4);
74 		return a;
75 	case 3:
76 	case 4:
77 	case 5:
78 		w3(r); w2(0x24); a = r4(); w2(4);
79 		return a;
80 	}
81 
82 	return -1;	/* never gets here */
83 }
84 
85 static void epat_read_block(struct pi_adapter *pi, char *buf, int count)
86 {
87 	int  k, ph, a, b;
88 
89 	switch (pi->mode) {
90 
91 	case 0:
92 		w0(7); w2(1); w2(3); w0(0xff);
93 		ph = 0;
94 		for (k = 0; k < count; k++) {
95 			if (k == count-1)
96 				w0(0xfd);
97 			w2(6 + ph); a = r1();
98 			if (a & 8) {
99 				b = a;
100 			} else {
101 				w2(4+ph); b = r1();
102 			}
103 			buf[k] = j44(a, b);
104 			ph =  1 - ph;
105 		}
106 		w0(0); w2(4);
107 		break;
108 
109 	case 1:
110 		w0(0x47); w2(1); w2(5); w0(0xff);
111 		ph = 0;
112 		for (k = 0; k < count; k++) {
113 			if (k == count - 1)
114 				w0(0xfd);
115 			w2(4 + ph);
116 			a = r1(); b = r2();
117 			buf[k] = j53(a, b);
118 			ph = 1 - ph;
119 		}
120 		w0(0); w2(4);
121 		break;
122 
123 	case 2:
124 		w0(0x27); w2(1); w2(0x25); w0(0);
125 		ph = 0;
126 		for (k = 0; k < count - 1; k++) {
127 			w2(0x24 + ph);
128 			buf[k] = r0();
129 			ph = 1 - ph;
130 		}
131 		w2(0x26); w2(0x27);
132 		buf[count - 1] = r0();
133 		w2(0x25); w2(4);
134 		break;
135 
136 	case 3:
137 		w3(0x80); w2(0x24);
138 		for (k = 0; k < count - 1; k++)
139 			buf[k] = r4();
140 		w2(4); w3(0xa0); w2(0x24);
141 		buf[count - 1] = r4();
142 		w2(4);
143 		break;
144 
145 	case 4:
146 		w3(0x80); w2(0x24);
147 		for (k = 0; k < count / 2 - 1; k++)
148 			((u16 *)buf)[k] = r4w();
149 		buf[count - 2] = r4();
150 		w2(4); w3(0xa0); w2(0x24);
151 		buf[count - 1] = r4();
152 		w2(4);
153 		break;
154 
155 	case 5:
156 		w3(0x80); w2(0x24);
157 		for (k = 0; k < count / 4 - 1; k++)
158 			((u32 *)buf)[k] = r4l();
159 		for (k = count - 4; k < count - 1; k++)
160 			buf[k] = r4();
161 		w2(4); w3(0xa0); w2(0x24);
162 		buf[count - 1] = r4();
163 		w2(4);
164 		break;
165 	}
166 }
167 
168 static void epat_write_block(struct pi_adapter *pi, char *buf, int count)
169 {
170 	int ph, k;
171 
172 	switch (pi->mode) {
173 	case 0:
174 	case 1:
175 	case 2:
176 		w0(0x67); w2(1); w2(5);
177 		ph = 0;
178 		for (k = 0; k < count; k++) {
179 		  	w0(buf[k]);
180 			w2(4 + ph);
181 			ph = 1 - ph;
182 		}
183 		w2(7); w2(4);
184 		break;
185 	case 3:
186 		w3(0xc0);
187 		for (k = 0; k < count; k++)
188 			w4(buf[k]);
189 		w2(4);
190 		break;
191 	case 4:
192 		w3(0xc0);
193 		for (k = 0; k < count / 2; k++)
194 			w4w(((u16 *)buf)[k]);
195 		w2(4);
196 		break;
197 	case 5:
198 		w3(0xc0);
199 		for (k = 0; k < count / 4; k++)
200 			w4l(((u32 *)buf)[k]);
201 		w2(4);
202 		break;
203 	}
204 }
205 
206 /* these macros access the EPAT registers in native addressing */
207 
208 #define	WR(r, v)	epat_write_regr(pi, 2, r, v)
209 #define	RR(r)		epat_read_regr(pi, 2, r)
210 
211 /* and these access the IDE task file */
212 
213 #define WRi(r, v)	epat_write_regr(pi, 0, r, v)
214 #define RRi(r)		epat_read_regr(pi, 0, r)
215 
216 /* FIXME:  the CPP stuff should be fixed to handle multiple EPATs on a chain */
217 
218 #define CPP(x)					\
219 	do {					\
220 		w2(4); w0(0x22); w0(0xaa);	\
221 		w0(0x55); w0(0); w0(0xff);	\
222 		w0(0x87); w0(0x78); w0(x);	\
223 		w2(4); w2(5); w2(4); w0(0xff);	\
224 	} while (0)
225 
226 static void epat_connect(struct pi_adapter *pi)
227 {
228 	pi->saved_r0 = r0();
229 	pi->saved_r2 = r2();
230 
231  	/* Initialize the chip */
232 	CPP(0);
233 
234 	if (epatc8) {
235 		CPP(0x40); CPP(0xe0);
236 		w0(0); w2(1); w2(4);
237 		WR(0x8, 0x12);
238 		WR(0xc, 0x14);
239 		WR(0x12, 0x10);
240 		WR(0xe, 0xf);
241 		WR(0xf, 4);
242 		/* WR(0xe,0xa);WR(0xf,4); */
243 		WR(0xe, 0xd);
244 		WR(0xf, 0);
245 		/* CPP(0x30); */
246 	}
247 
248         /* Connect to the chip */
249 	CPP(0xe0);
250 	w0(0); w2(1); w2(4); /* Idle into SPP */
251         if (pi->mode >= 3) {
252 		w0(0); w2(1); w2(4); w2(0xc);
253 		/* Request EPP */
254 		w0(0x40); w2(6); w2(7); w2(4); w2(0xc); w2(4);
255         }
256 
257 	if (!epatc8) {
258 		WR(8, 0x10);
259 		WR(0xc, 0x14);
260 		WR(0xa, 0x38);
261 		WR(0x12, 0x10);
262 	}
263 }
264 
265 static void epat_disconnect(struct pi_adapter *pi)
266 {
267 	CPP(0x30);
268 	w0(pi->saved_r0);
269 	w2(pi->saved_r2);
270 }
271 
272 static int epat_test_proto(struct pi_adapter *pi)
273 {
274 	int k, j, f, cc;
275 	int e[2] = { 0, 0 };
276 	char scratch[512];
277 
278 	epat_connect(pi);
279 	cc = RR(0xd);
280 	epat_disconnect(pi);
281 
282 	epat_connect(pi);
283 	for (j=0;j<2;j++) {
284 		WRi(6, 0xa0 + j * 0x10);
285 		for (k = 0; k < 256; k++) {
286 			WRi(2, k ^ 0xaa);
287 			WRi(3, k ^ 0x55);
288 			if (RRi(2) != (k ^ 0xaa))
289 				e[j]++;
290 		}
291 	}
292 	epat_disconnect(pi);
293 
294 	f = 0;
295 	epat_connect(pi);
296 	WR(0x13, 1); WR(0x13, 0); WR(0xa, 0x11);
297 	epat_read_block(pi, scratch, 512);
298 
299 	for (k = 0; k < 256; k++) {
300 		if ((scratch[2 * k] & 0xff) != k)
301 			f++;
302 		if ((scratch[2 * k + 1] & 0xff) != 0xff - k)
303 			f++;
304 	}
305 	epat_disconnect(pi);
306 
307 	dev_dbg(&pi->dev,
308 		"epat: port 0x%x, mode %d, ccr %x, test=(%d,%d,%d)\n",
309 		pi->port, pi->mode, cc, e[0], e[1], f);
310 
311 	return (e[0] && e[1]) || f;
312 }
313 
314 static void epat_log_adapter(struct pi_adapter *pi)
315 {
316 	int ver;
317 	char *mode_string[6] =
318 		{ "4-bit", "5/3", "8-bit", "EPP-8", "EPP-16", "EPP-32" };
319 
320 	epat_connect(pi);
321 	WR(0xa, 0x38);		/* read the version code */
322 	ver = RR(0xb);
323 	epat_disconnect(pi);
324 
325 	dev_info(&pi->dev,
326 		 "Shuttle EPAT chip %x at 0x%x, mode %d (%s), delay %d\n",
327 		 ver, pi->port, pi->mode, mode_string[pi->mode], pi->delay);
328 }
329 
330 static struct pi_protocol epat = {
331 	.owner		= THIS_MODULE,
332 	.name		= "epat",
333 	.max_mode	= 6,
334 	.epp_first	= 3,
335 	.default_delay	= 1,
336 	.max_units	= 1,
337 	.write_regr	= epat_write_regr,
338 	.read_regr	= epat_read_regr,
339 	.write_block	= epat_write_block,
340 	.read_block	= epat_read_block,
341 	.connect	= epat_connect,
342 	.disconnect	= epat_disconnect,
343 	.test_proto	= epat_test_proto,
344 	.log_adapter	= epat_log_adapter,
345 };
346 
347 static int __init epat_init(void)
348 {
349 #ifdef CONFIG_PATA_PARPORT_EPATC8
350 	epatc8 = 1;
351 #endif
352 	return pata_parport_register_driver(&epat);
353 }
354 
355 static void __exit epat_exit(void)
356 {
357 	pata_parport_unregister_driver(&epat);
358 }
359 
360 MODULE_LICENSE("GPL");
361 module_init(epat_init)
362 module_exit(epat_exit)
363