aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/ide/ide-timing.h
blob: 2fcfac6e967aa221fec1053568c4d6e48715e2e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
#ifndef _IDE_TIMING_H
#define _IDE_TIMING_H

/*
 * $Id: ide-timing.h,v 1.6 2001/12/23 22:47:56 vojtech Exp $
 *
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <linux/kernel.h>
#include <linux/hdreg.h>

#define XFER_PIO_5		0x0d
#define XFER_UDMA_SLOW		0x4f

struct ide_timing {
	short mode;
	short setup;	/* t1 */
	short act8b;	/* t2 for 8-bit io */
	short rec8b;	/* t2i for 8-bit io */
	short cyc8b;	/* t0 for 8-bit io */
	short active;	/* t2 or tD */
	short recover;	/* t2i or tK */
	short cycle;	/* t0 */
	short udma;	/* t2CYCTYP/2 */
};

/*
 * PIO 0-5, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
 * These were taken from ATA/ATAPI-6 standard, rev 0a, except
 * for PIO 5, which is a nonstandard extension and UDMA6, which
 * is currently supported only by Maxtor drives. 
 */

static struct ide_timing ide_timing[] = {

	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },

	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },

	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 },
                                          
	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
                                          
	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },

	{ XFER_PIO_5,     20,  50,  30, 100,  50,  30, 100,   0 },
	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },

	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },

	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 },

	{ -1 }
};

#define IDE_TIMING_SETUP	0x01
#define IDE_TIMING_ACT8B	0x02
#define IDE_TIMING_REC8B	0x04
#define IDE_TIMING_CYC8B	0x08
#define IDE_TIMING_8BIT		0x0e
#define IDE_TIMING_ACTIVE	0x10
#define IDE_TIMING_RECOVER	0x20
#define IDE_TIMING_CYCLE	0x40
#define IDE_TIMING_UDMA		0x80
#define IDE_TIMING_ALL		0xff

#define FIT(v,vmin,vmax)	max_t(short,min_t(short,v,vmax),vmin)
#define ENOUGH(v,unit)		(((v)-1)/(unit)+1)
#define EZ(v,unit)		((v)?ENOUGH(v,unit):0)

#define XFER_MODE	0xf0
#define XFER_UDMA_133	0x48
#define XFER_UDMA_100	0x44
#define XFER_UDMA_66	0x42
#define XFER_UDMA	0x40
#define XFER_MWDMA	0x20
#define XFER_SWDMA	0x10
#define XFER_EPIO	0x01
#define XFER_PIO	0x00

static short ide_find_best_mode(ide_drive_t *drive, int map)
{
	struct hd_driveid *id = drive->id;
	short best = 0;

	if (!id)
		return XFER_PIO_SLOW;

	if ((map & XFER_UDMA) && (id->field_valid & 4)) {	/* Want UDMA and UDMA bitmap valid */

		if ((map & XFER_UDMA_133) == XFER_UDMA_133)
			if ((best = (id->dma_ultra & 0x0040) ? XFER_UDMA_6 : 0)) return best;

		if ((map & XFER_UDMA_100) == XFER_UDMA_100)
			if ((best = (id->dma_ultra & 0x0020) ? XFER_UDMA_5 : 0)) return best;

		if ((map & XFER_UDMA_66) == XFER_UDMA_66)
			if ((best = (id->dma_ultra & 0x0010) ? XFER_UDMA_4 :
                	    	    (id->dma_ultra & 0x0008) ? XFER_UDMA_3 : 0)) return best;

                if ((best = (id->dma_ultra & 0x0004) ? XFER_UDMA_2 :
                	    (id->dma_ultra & 0x0002) ? XFER_UDMA_1 :
                	    (id->dma_ultra & 0x0001) ? XFER_UDMA_0 : 0)) return best;
	}

	if ((map & XFER_MWDMA) && (id->field_valid & 2)) {	/* Want MWDMA and drive has EIDE fields */

		if ((best = (id->dma_mword & 0x0004) ? XFER_MW_DMA_2 :
                	    (id->dma_mword & 0x0002) ? XFER_MW_DMA_1 :
                	    (id->dma_mword & 0x0001) ? XFER_MW_DMA_0 : 0)) return best;
	}

	if (map & XFER_SWDMA) {					/* Want SWDMA */

 		if (id->field_valid & 2) {			/* EIDE SWDMA */

			if ((best = (id->dma_1word & 0x0004) ? XFER_SW_DMA_2 :
      				    (id->dma_1word & 0x0002) ? XFER_SW_DMA_1 :
				    (id->dma_1word & 0x0001) ? XFER_SW_DMA_0 : 0)) return best;
		}

		if (id->capability & 1) {			/* Pre-EIDE style SWDMA */

			if ((best = (id->tDMA == 2) ? XFER_SW_DMA_2 :
				    (id->tDMA == 1) ? XFER_SW_DMA_1 :
				    (id->tDMA == 0) ? XFER_SW_DMA_0 : 0)) return best;
		}
	}


	if ((map & XFER_EPIO) && (id->field_valid & 2)) {	/* EIDE PIO modes */

		if ((best = (drive->id->eide_pio_modes & 4) ? XFER_PIO_5 :
			    (drive->id->eide_pio_modes & 2) ? XFER_PIO_4 :
			    (drive->id->eide_pio_modes & 1) ? XFER_PIO_3 : 0)) return best;
	}
	
	return  (drive->id->tPIO == 2) ? XFER_PIO_2 :
		(drive->id->tPIO == 1) ? XFER_PIO_1 :
		(drive->id->tPIO == 0) ? XFER_PIO_0 : XFER_PIO_SLOW;
}

static void ide_timing_quantize(struct ide_timing *t, struct ide_timing *q, int T, int UT)
{
	q->setup   = EZ(t->setup   * 1000,  T);
	q->act8b   = EZ(t->act8b   * 1000,  T);
	q->rec8b   = EZ(t->rec8b   * 1000,  T);
	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
	q->active  = EZ(t->active  * 1000,  T);
	q->recover = EZ(t->recover * 1000,  T);
	q->cycle   = EZ(t->cycle   * 1000,  T);
	q->udma    = EZ(t->udma    * 1000, UT);
}

static void ide_timing_merge(struct ide_timing *a, struct ide_timing *b, struct ide_timing *m, unsigned int what)
{
	if (what & IDE_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
	if (what & IDE_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
	if (what & IDE_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
	if (what & IDE_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
	if (what & IDE_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
	if (what & IDE_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
	if (what & IDE_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
	if (what & IDE_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
}

static struct ide_timing* ide_timing_find_mode(short speed)
{
	struct ide_timing *t;

	for (t = ide_timing; t->mode != speed; t++)
		if (t->mode < 0)
			return NULL;
	return t; 
}

static int ide_timing_compute(ide_drive_t *drive, short speed, struct ide_timing *t, int T, int UT)
{
	struct hd_driveid *id = drive->id;
	struct ide_timing *s, p;

/*
 * Find the mode.
 */

	if (!(s = ide_timing_find_mode(speed)))
		return -EINVAL;

/*
 * If the drive is an EIDE drive, it can tell us it needs extended
 * PIO/MWDMA cycle timing.
 */

	if (id && id->field_valid & 2) {	/* EIDE drive */

		memset(&p, 0, sizeof(p));

		switch (speed & XFER_MODE) {

			case XFER_PIO:
				if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = id->eide_pio;
						    else p.cycle = p.cyc8b = id->eide_pio_iordy;
				break;

			case XFER_MWDMA:
				p.cycle = id->eide_dma_min;
				break;
		}

		ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B);
	}

/*
 * Convert the timing to bus clock counts.
 */

	ide_timing_quantize(s, t, T, UT);

/*
 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY, S.M.A.R.T
 * and some other commands. We have to ensure that the DMA cycle timing is
 * slower/equal than the fastest PIO timing.
 */

	if ((speed & XFER_MODE) != XFER_PIO) {
		ide_timing_compute(drive, ide_find_best_mode(drive, XFER_PIO | XFER_EPIO), &p, T, UT);
		ide_timing_merge(&p, t, t, IDE_TIMING_ALL);
	}

/*
 * Lenghten active & recovery time so that cycle time is correct.
 */

	if (t->act8b + t->rec8b < t->cyc8b) {
		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
		t->rec8b = t->cyc8b - t->act8b;
	}

	if (t->active + t->recover < t->cycle) {
		t->active += (t->cycle - (t->active + t->recover)) / 2;
		t->recover = t->cycle - t->active;
	}

	return 0;
}

#endif