/* * Copyright (c) 1999-2001 Vojtech Pavlik * Copyright (c) 2007-2008 Bartlomiej Zolnierkiewicz * * 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/ide.h> #include <linux/module.h> /* * 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_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 }, { 0xff } }; struct ide_timing *ide_timing_find_mode(u8 speed) { struct ide_timing *t; for (t = ide_timing; t->mode != speed; t++) if (t->mode == 0xff) return NULL; return t; } EXPORT_SYMBOL_GPL(ide_timing_find_mode); u16 ide_pio_cycle_time(ide_drive_t *drive, u8 pio) { u16 *id = drive->id; struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio); u16 cycle = 0; if (id[ATA_ID_FIELD_VALID] & 2) { if (ata_id_has_iordy(drive->id)) cycle = id[ATA_ID_EIDE_PIO_IORDY]; else cycle = id[ATA_ID_EIDE_PIO]; /* conservative "downgrade" for all pre-ATA2 drives */ if (pio < 3 && cycle < t->cycle) cycle = 0; /* use standard timing */ } return cycle ? cycle : t->cycle; } EXPORT_SYMBOL_GPL(ide_pio_cycle_time); #define ENOUGH(v, unit) (((v) - 1) / (unit) + 1) #define EZ(v, unit) ((v) ? ENOUGH(v, unit) : 0) 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); } 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); } EXPORT_SYMBOL_GPL(ide_timing_merge); int ide_timing_compute(ide_drive_t *drive, u8 speed, struct ide_timing *t, int T, int UT) { u16 *id = drive->id; struct ide_timing *s, p; /* * Find the mode. */ s = ide_timing_find_mode(speed); if (s == NULL) return -EINVAL; /* * Copy the timing from the table. */ *t = *s; /* * If the drive is an EIDE drive, it can tell us it needs extended * PIO/MWDMA cycle timing. */ if (id[ATA_ID_FIELD_VALID] & 2) { /* EIDE drive */ memset(&p, 0, sizeof(p)); if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO]; else if (speed <= XFER_PIO_5) p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY]; else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) p.cycle = id[ATA_ID_EIDE_DMA_MIN]; ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B); } /* * Convert the timing to bus clock counts. */ ide_timing_quantize(t, 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_SW_DMA_0) { u8 pio = ide_get_best_pio_mode(drive, 255, 5); ide_timing_compute(drive, XFER_PIO_0 + pio, &p, T, UT); ide_timing_merge(&p, t, t, IDE_TIMING_ALL); } /* * Lengthen 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; } EXPORT_SYMBOL_GPL(ide_timing_compute);