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-rw-r--r--drivers/ata/libata-pata-timings.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/ata/libata-pata-timings.c b/drivers/ata/libata-pata-timings.c
new file mode 100644
index 000000000..af341226c
--- /dev/null
+++ b/drivers/ata/libata-pata-timings.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Helper library for PATA timings
+ *
+ * Copyright 2003-2004 Red Hat, Inc. All rights reserved.
+ * Copyright 2003-2004 Jeff Garzik
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/libata.h>
+
+/*
+ * This mode timing computation functionality is ported over from
+ * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
+ */
+/*
+ * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
+ * These were taken from ATA/ATAPI-6 standard, rev 0a, except
+ * for UDMA6, which is currently supported only by Maxtor drives.
+ *
+ * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
+ */
+
+static const struct ata_timing ata_timing[] = {
+/* { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 0, 960, 0 }, */
+ { XFER_PIO_0, 70, 290, 240, 600, 165, 150, 0, 600, 0 },
+ { XFER_PIO_1, 50, 290, 93, 383, 125, 100, 0, 383, 0 },
+ { XFER_PIO_2, 30, 290, 40, 330, 100, 90, 0, 240, 0 },
+ { XFER_PIO_3, 30, 80, 70, 180, 80, 70, 0, 180, 0 },
+ { XFER_PIO_4, 25, 70, 25, 120, 70, 25, 0, 120, 0 },
+ { XFER_PIO_5, 15, 65, 25, 100, 65, 25, 0, 100, 0 },
+ { XFER_PIO_6, 10, 55, 20, 80, 55, 20, 0, 80, 0 },
+
+ { XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 50, 960, 0 },
+ { XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 30, 480, 0 },
+ { XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 20, 240, 0 },
+
+ { XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 20, 480, 0 },
+ { XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 5, 150, 0 },
+ { XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 5, 120, 0 },
+ { XFER_MW_DMA_3, 25, 0, 0, 0, 65, 25, 5, 100, 0 },
+ { XFER_MW_DMA_4, 25, 0, 0, 0, 55, 20, 5, 80, 0 },
+
+/* { XFER_UDMA_SLOW, 0, 0, 0, 0, 0, 0, 0, 0, 150 }, */
+ { XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 0, 120 },
+ { XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 0, 80 },
+ { XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 0, 60 },
+ { XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 0, 45 },
+ { XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 0, 30 },
+ { XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 0, 20 },
+ { XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 0, 15 },
+
+ { 0xFF }
+};
+
+#define ENOUGH(v, unit) (((v)-1)/(unit)+1)
+#define EZ(v, unit) ((v)?ENOUGH(((v) * 1000), unit):0)
+
+static void ata_timing_quantize(const struct ata_timing *t,
+ struct ata_timing *q, int T, int UT)
+{
+ q->setup = EZ(t->setup, T);
+ q->act8b = EZ(t->act8b, T);
+ q->rec8b = EZ(t->rec8b, T);
+ q->cyc8b = EZ(t->cyc8b, T);
+ q->active = EZ(t->active, T);
+ q->recover = EZ(t->recover, T);
+ q->dmack_hold = EZ(t->dmack_hold, T);
+ q->cycle = EZ(t->cycle, T);
+ q->udma = EZ(t->udma, UT);
+}
+
+void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
+ struct ata_timing *m, unsigned int what)
+{
+ if (what & ATA_TIMING_SETUP)
+ m->setup = max(a->setup, b->setup);
+ if (what & ATA_TIMING_ACT8B)
+ m->act8b = max(a->act8b, b->act8b);
+ if (what & ATA_TIMING_REC8B)
+ m->rec8b = max(a->rec8b, b->rec8b);
+ if (what & ATA_TIMING_CYC8B)
+ m->cyc8b = max(a->cyc8b, b->cyc8b);
+ if (what & ATA_TIMING_ACTIVE)
+ m->active = max(a->active, b->active);
+ if (what & ATA_TIMING_RECOVER)
+ m->recover = max(a->recover, b->recover);
+ if (what & ATA_TIMING_DMACK_HOLD)
+ m->dmack_hold = max(a->dmack_hold, b->dmack_hold);
+ if (what & ATA_TIMING_CYCLE)
+ m->cycle = max(a->cycle, b->cycle);
+ if (what & ATA_TIMING_UDMA)
+ m->udma = max(a->udma, b->udma);
+}
+EXPORT_SYMBOL_GPL(ata_timing_merge);
+
+const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
+{
+ const struct ata_timing *t = ata_timing;
+
+ while (xfer_mode > t->mode)
+ t++;
+
+ if (xfer_mode == t->mode)
+ return t;
+
+ WARN_ONCE(true, "%s: unable to find timing for xfer_mode 0x%x\n",
+ __func__, xfer_mode);
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(ata_timing_find_mode);
+
+int ata_timing_compute(struct ata_device *adev, unsigned short speed,
+ struct ata_timing *t, int T, int UT)
+{
+ const u16 *id = adev->id;
+ const struct ata_timing *s;
+ struct ata_timing p;
+
+ /*
+ * Find the mode.
+ */
+ s = ata_timing_find_mode(speed);
+ if (!s)
+ return -EINVAL;
+
+ memcpy(t, s, sizeof(*s));
+
+ /*
+ * If the drive is an EIDE drive, it can tell us it needs extended
+ * PIO/MW_DMA cycle timing.
+ */
+
+ if (id[ATA_ID_FIELD_VALID] & 2) { /* EIDE drive */
+ memset(&p, 0, sizeof(p));
+
+ if (speed >= XFER_PIO_0 && speed < XFER_SW_DMA_0) {
+ if (speed <= XFER_PIO_2)
+ p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];
+ else if ((speed <= XFER_PIO_4) ||
+ (speed == XFER_PIO_5 && !ata_id_is_cfa(id)))
+ 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];
+
+ ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
+ }
+
+ /*
+ * Convert the timing to bus clock counts.
+ */
+
+ ata_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_PIO_6) {
+ ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
+ ata_timing_merge(&p, t, t, ATA_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;
+ }
+
+ /*
+ * In a few cases quantisation may produce enough errors to
+ * leave t->cycle too low for the sum of active and recovery
+ * if so we must correct this.
+ */
+ if (t->active + t->recover > t->cycle)
+ t->cycle = t->active + t->recover;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ata_timing_compute);