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Linux kernel mirror (for testing)
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linux
1#ifndef _IDE_TIMING_H
2#define _IDE_TIMING_H
3
4/*
5 * $Id: ide-timing.h,v 1.6 2001/12/23 22:47:56 vojtech Exp $
6 *
7 * Copyright (c) 1999-2001 Vojtech Pavlik
8 */
9
10/*
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 *
25 * Should you need to contact me, the author, you can do so either by
26 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
27 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
28 */
29
30#include <linux/kernel.h>
31#include <linux/hdreg.h>
32
33#define XFER_PIO_5 0x0d
34#define XFER_UDMA_SLOW 0x4f
35
36struct ide_timing {
37 short mode;
38 short setup; /* t1 */
39 short act8b; /* t2 for 8-bit io */
40 short rec8b; /* t2i for 8-bit io */
41 short cyc8b; /* t0 for 8-bit io */
42 short active; /* t2 or tD */
43 short recover; /* t2i or tK */
44 short cycle; /* t0 */
45 short udma; /* t2CYCTYP/2 */
46};
47
48/*
49 * PIO 0-5, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
50 * These were taken from ATA/ATAPI-6 standard, rev 0a, except
51 * for PIO 5, which is a nonstandard extension and UDMA6, which
52 * is currently supported only by Maxtor drives.
53 */
54
55static struct ide_timing ide_timing[] = {
56
57 { XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 15 },
58 { XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 20 },
59 { XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 30 },
60 { XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 45 },
61
62 { XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 60 },
63 { XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 80 },
64 { XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 120 },
65
66 { XFER_UDMA_SLOW, 0, 0, 0, 0, 0, 0, 0, 150 },
67
68 { XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 120, 0 },
69 { XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 150, 0 },
70 { XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 480, 0 },
71
72 { XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 240, 0 },
73 { XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 480, 0 },
74 { XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 960, 0 },
75
76 { XFER_PIO_5, 20, 50, 30, 100, 50, 30, 100, 0 },
77 { XFER_PIO_4, 25, 70, 25, 120, 70, 25, 120, 0 },
78 { XFER_PIO_3, 30, 80, 70, 180, 80, 70, 180, 0 },
79
80 { XFER_PIO_2, 30, 290, 40, 330, 100, 90, 240, 0 },
81 { XFER_PIO_1, 50, 290, 93, 383, 125, 100, 383, 0 },
82 { XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0 },
83
84 { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960, 0 },
85
86 { -1 }
87};
88
89#define IDE_TIMING_SETUP 0x01
90#define IDE_TIMING_ACT8B 0x02
91#define IDE_TIMING_REC8B 0x04
92#define IDE_TIMING_CYC8B 0x08
93#define IDE_TIMING_8BIT 0x0e
94#define IDE_TIMING_ACTIVE 0x10
95#define IDE_TIMING_RECOVER 0x20
96#define IDE_TIMING_CYCLE 0x40
97#define IDE_TIMING_UDMA 0x80
98#define IDE_TIMING_ALL 0xff
99
100#define FIT(v,vmin,vmax) max_t(short,min_t(short,v,vmax),vmin)
101#define ENOUGH(v,unit) (((v)-1)/(unit)+1)
102#define EZ(v,unit) ((v)?ENOUGH(v,unit):0)
103
104#define XFER_MODE 0xf0
105#define XFER_MWDMA 0x20
106#define XFER_EPIO 0x01
107#define XFER_PIO 0x00
108
109static void ide_timing_quantize(struct ide_timing *t, struct ide_timing *q, int T, int UT)
110{
111 q->setup = EZ(t->setup * 1000, T);
112 q->act8b = EZ(t->act8b * 1000, T);
113 q->rec8b = EZ(t->rec8b * 1000, T);
114 q->cyc8b = EZ(t->cyc8b * 1000, T);
115 q->active = EZ(t->active * 1000, T);
116 q->recover = EZ(t->recover * 1000, T);
117 q->cycle = EZ(t->cycle * 1000, T);
118 q->udma = EZ(t->udma * 1000, UT);
119}
120
121static void ide_timing_merge(struct ide_timing *a, struct ide_timing *b, struct ide_timing *m, unsigned int what)
122{
123 if (what & IDE_TIMING_SETUP ) m->setup = max(a->setup, b->setup);
124 if (what & IDE_TIMING_ACT8B ) m->act8b = max(a->act8b, b->act8b);
125 if (what & IDE_TIMING_REC8B ) m->rec8b = max(a->rec8b, b->rec8b);
126 if (what & IDE_TIMING_CYC8B ) m->cyc8b = max(a->cyc8b, b->cyc8b);
127 if (what & IDE_TIMING_ACTIVE ) m->active = max(a->active, b->active);
128 if (what & IDE_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
129 if (what & IDE_TIMING_CYCLE ) m->cycle = max(a->cycle, b->cycle);
130 if (what & IDE_TIMING_UDMA ) m->udma = max(a->udma, b->udma);
131}
132
133static struct ide_timing* ide_timing_find_mode(short speed)
134{
135 struct ide_timing *t;
136
137 for (t = ide_timing; t->mode != speed; t++)
138 if (t->mode < 0)
139 return NULL;
140 return t;
141}
142
143static int ide_timing_compute(ide_drive_t *drive, short speed, struct ide_timing *t, int T, int UT)
144{
145 struct hd_driveid *id = drive->id;
146 struct ide_timing *s, p;
147
148/*
149 * Find the mode.
150 */
151
152 if (!(s = ide_timing_find_mode(speed)))
153 return -EINVAL;
154
155/*
156 * Copy the timing from the table.
157 */
158
159 *t = *s;
160
161/*
162 * If the drive is an EIDE drive, it can tell us it needs extended
163 * PIO/MWDMA cycle timing.
164 */
165
166 if (id && id->field_valid & 2) { /* EIDE drive */
167
168 memset(&p, 0, sizeof(p));
169
170 switch (speed & XFER_MODE) {
171
172 case XFER_PIO:
173 if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = id->eide_pio;
174 else p.cycle = p.cyc8b = id->eide_pio_iordy;
175 break;
176
177 case XFER_MWDMA:
178 p.cycle = id->eide_dma_min;
179 break;
180 }
181
182 ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B);
183 }
184
185/*
186 * Convert the timing to bus clock counts.
187 */
188
189 ide_timing_quantize(t, t, T, UT);
190
191/*
192 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY, S.M.A.R.T
193 * and some other commands. We have to ensure that the DMA cycle timing is
194 * slower/equal than the fastest PIO timing.
195 */
196
197 if ((speed & XFER_MODE) != XFER_PIO) {
198 u8 pio = ide_get_best_pio_mode(drive, 255, 5);
199 ide_timing_compute(drive, XFER_PIO_0 + pio, &p, T, UT);
200 ide_timing_merge(&p, t, t, IDE_TIMING_ALL);
201 }
202
203/*
204 * Lenghten active & recovery time so that cycle time is correct.
205 */
206
207 if (t->act8b + t->rec8b < t->cyc8b) {
208 t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
209 t->rec8b = t->cyc8b - t->act8b;
210 }
211
212 if (t->active + t->recover < t->cycle) {
213 t->active += (t->cycle - (t->active + t->recover)) / 2;
214 t->recover = t->cycle - t->active;
215 }
216
217 return 0;
218}
219
220#endif