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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 | ||
2665b891 | 30 | #include <linux/kernel.h> |
1da177e4 LT |
31 | #include <linux/hdreg.h> |
32 | ||
33 | #define XFER_PIO_5 0x0d | |
34 | #define XFER_UDMA_SLOW 0x4f | |
35 | ||
36 | struct 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 | ||
55 | static 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 | ||
2665b891 CB |
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) | |
1da177e4 LT |
103 | |
104 | #define XFER_MODE 0xf0 | |
1da177e4 | 105 | #define XFER_MWDMA 0x20 |
1da177e4 LT |
106 | #define XFER_EPIO 0x01 |
107 | #define XFER_PIO 0x00 | |
108 | ||
75b1d975 | 109 | static short ide_find_best_pio_mode(ide_drive_t *drive) |
1da177e4 LT |
110 | { |
111 | struct hd_driveid *id = drive->id; | |
112 | short best = 0; | |
113 | ||
75b1d975 | 114 | if (id->field_valid & 2) { /* EIDE PIO modes */ |
1da177e4 LT |
115 | |
116 | if ((best = (drive->id->eide_pio_modes & 4) ? XFER_PIO_5 : | |
117 | (drive->id->eide_pio_modes & 2) ? XFER_PIO_4 : | |
118 | (drive->id->eide_pio_modes & 1) ? XFER_PIO_3 : 0)) return best; | |
119 | } | |
120 | ||
121 | return (drive->id->tPIO == 2) ? XFER_PIO_2 : | |
122 | (drive->id->tPIO == 1) ? XFER_PIO_1 : | |
123 | (drive->id->tPIO == 0) ? XFER_PIO_0 : XFER_PIO_SLOW; | |
124 | } | |
125 | ||
126 | static void ide_timing_quantize(struct ide_timing *t, struct ide_timing *q, int T, int UT) | |
127 | { | |
128 | q->setup = EZ(t->setup * 1000, T); | |
129 | q->act8b = EZ(t->act8b * 1000, T); | |
130 | q->rec8b = EZ(t->rec8b * 1000, T); | |
131 | q->cyc8b = EZ(t->cyc8b * 1000, T); | |
132 | q->active = EZ(t->active * 1000, T); | |
133 | q->recover = EZ(t->recover * 1000, T); | |
134 | q->cycle = EZ(t->cycle * 1000, T); | |
135 | q->udma = EZ(t->udma * 1000, UT); | |
136 | } | |
137 | ||
138 | static void ide_timing_merge(struct ide_timing *a, struct ide_timing *b, struct ide_timing *m, unsigned int what) | |
139 | { | |
2665b891 CB |
140 | if (what & IDE_TIMING_SETUP ) m->setup = max(a->setup, b->setup); |
141 | if (what & IDE_TIMING_ACT8B ) m->act8b = max(a->act8b, b->act8b); | |
142 | if (what & IDE_TIMING_REC8B ) m->rec8b = max(a->rec8b, b->rec8b); | |
143 | if (what & IDE_TIMING_CYC8B ) m->cyc8b = max(a->cyc8b, b->cyc8b); | |
144 | if (what & IDE_TIMING_ACTIVE ) m->active = max(a->active, b->active); | |
145 | if (what & IDE_TIMING_RECOVER) m->recover = max(a->recover, b->recover); | |
146 | if (what & IDE_TIMING_CYCLE ) m->cycle = max(a->cycle, b->cycle); | |
147 | if (what & IDE_TIMING_UDMA ) m->udma = max(a->udma, b->udma); | |
1da177e4 LT |
148 | } |
149 | ||
150 | static struct ide_timing* ide_timing_find_mode(short speed) | |
151 | { | |
152 | struct ide_timing *t; | |
153 | ||
154 | for (t = ide_timing; t->mode != speed; t++) | |
155 | if (t->mode < 0) | |
156 | return NULL; | |
157 | return t; | |
158 | } | |
159 | ||
160 | static int ide_timing_compute(ide_drive_t *drive, short speed, struct ide_timing *t, int T, int UT) | |
161 | { | |
162 | struct hd_driveid *id = drive->id; | |
163 | struct ide_timing *s, p; | |
164 | ||
165 | /* | |
166 | * Find the mode. | |
167 | */ | |
168 | ||
169 | if (!(s = ide_timing_find_mode(speed))) | |
170 | return -EINVAL; | |
171 | ||
17c1033d SS |
172 | /* |
173 | * Copy the timing from the table. | |
174 | */ | |
175 | ||
176 | *t = *s; | |
177 | ||
1da177e4 LT |
178 | /* |
179 | * If the drive is an EIDE drive, it can tell us it needs extended | |
180 | * PIO/MWDMA cycle timing. | |
181 | */ | |
182 | ||
183 | if (id && id->field_valid & 2) { /* EIDE drive */ | |
184 | ||
185 | memset(&p, 0, sizeof(p)); | |
186 | ||
187 | switch (speed & XFER_MODE) { | |
188 | ||
189 | case XFER_PIO: | |
190 | if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = id->eide_pio; | |
191 | else p.cycle = p.cyc8b = id->eide_pio_iordy; | |
192 | break; | |
193 | ||
194 | case XFER_MWDMA: | |
195 | p.cycle = id->eide_dma_min; | |
196 | break; | |
197 | } | |
198 | ||
199 | ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B); | |
200 | } | |
201 | ||
202 | /* | |
203 | * Convert the timing to bus clock counts. | |
204 | */ | |
205 | ||
17c1033d | 206 | ide_timing_quantize(t, t, T, UT); |
1da177e4 LT |
207 | |
208 | /* | |
209 | * Even in DMA/UDMA modes we still use PIO access for IDENTIFY, S.M.A.R.T | |
210 | * and some other commands. We have to ensure that the DMA cycle timing is | |
211 | * slower/equal than the fastest PIO timing. | |
212 | */ | |
213 | ||
214 | if ((speed & XFER_MODE) != XFER_PIO) { | |
75b1d975 | 215 | ide_timing_compute(drive, ide_find_best_pio_mode(drive), &p, T, UT); |
1da177e4 LT |
216 | ide_timing_merge(&p, t, t, IDE_TIMING_ALL); |
217 | } | |
218 | ||
219 | /* | |
220 | * Lenghten active & recovery time so that cycle time is correct. | |
221 | */ | |
222 | ||
223 | if (t->act8b + t->rec8b < t->cyc8b) { | |
224 | t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2; | |
225 | t->rec8b = t->cyc8b - t->act8b; | |
226 | } | |
227 | ||
228 | if (t->active + t->recover < t->cycle) { | |
229 | t->active += (t->cycle - (t->active + t->recover)) / 2; | |
230 | t->recover = t->cycle - t->active; | |
231 | } | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | #endif |