ide: add Toshiba TC86C001 IDE driver (take 2)

This is the driver for the Toshiba TC86C001 GOKU-S PCI IDE controller,
completely reworked from the original brain-damaged Toshiba's 2.4 version.

This single channel UltraDMA/66 controller is very simple in programming,
yet Toshiba managed to plant many interesting bugs in it.  The particularly
nasty "limitation 5" (as they call the errata) caused me to abuse the IDE
core in a possibly most interesting way so far.  However, this is still
better than the #ifdef mess in drivers/ide/ide-io.c that the original
version included (well, it had much more mess)...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 308 insertions, 0 deletions

diff --git a/drivers/ide/pci/tc86c001.c b/drivers/ide/pci/tc86c001.c
new file mode 100644
index 000000000000..b6566534a31f
--- /dev/null
+++ b/drivers/ide/pci/tc86c001.c
@@ -0,0 +1,308 @@
+/*
+ * drivers/ide/pci/tc86c001.c   Version 1.00    Dec 12, 2006
+ *
+ * Copyright (C) 2002 Toshiba Corporation
+ * Copyright (C) 2005-2006 MontaVista Software, Inc. <source@mvista.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/ide.h>
+
+static inline u8 tc86c001_ratemask(ide_drive_t *drive)
+{
+        return eighty_ninty_three(drive) ? 2 : 1;
+}
+
+static int tc86c001_tune_chipset(ide_drive_t *drive, u8 speed)
+{
+        ide_hwif_t *hwif        = HWIF(drive);
+        unsigned long scr_port  = hwif->config_data + (drive->dn ? 0x02 : 0x00);
+        u16 mode, scr           = hwif->INW(scr_port);
+
+        speed = ide_rate_filter(tc86c001_ratemask(drive), speed);
+
+        switch (speed) {
+                case XFER_UDMA_4:       mode = 0x00c0; break;
+                case XFER_UDMA_3:       mode = 0x00b0; break;
+                case XFER_UDMA_2:       mode = 0x00a0; break;
+                case XFER_UDMA_1:       mode = 0x0090; break;
+                case XFER_UDMA_0:       mode = 0x0080; break;
+                case XFER_MW_DMA_2:     mode = 0x0070; break;
+                case XFER_MW_DMA_1:     mode = 0x0060; break;
+                case XFER_MW_DMA_0:     mode = 0x0050; break;
+                case XFER_PIO_4:        mode = 0x0400; break;
+                case XFER_PIO_3:        mode = 0x0300; break;
+                case XFER_PIO_2:        mode = 0x0200; break;
+                case XFER_PIO_1:        mode = 0x0100; break;
+                case XFER_PIO_0:
+                default:                mode = 0x0000; break;
+        }
+
+        scr &= (speed < XFER_MW_DMA_0) ? 0xf8ff : 0xff0f;
+        scr |= mode;
+        hwif->OUTW(scr, scr_port);
+
+        return ide_config_drive_speed(drive, speed);
+}
+
+static void tc86c001_tune_drive(ide_drive_t *drive, u8 pio)
+{
+        pio =  ide_get_best_pio_mode(drive, pio, 4, NULL);
+        (void) tc86c001_tune_chipset(drive, XFER_PIO_0 + pio);
+}
+
+/*
+ * HACKITY HACK
+ *
+ * This is a workaround for the limitation 5 of the TC86C001 IDE controller:
+ * if a DMA transfer terminates prematurely, the controller leaves the device's
+ * interrupt request (INTRQ) pending and does not generate a PCI interrupt (or
+ * set the interrupt bit in the DMA status register), thus no PCI interrupt
+ * will occur until a DMA transfer has been successfully completed.
+ *
+ * We work around this by initiating dummy, zero-length DMA transfer on
+ * a DMA timeout expiration. I found no better way to do this with the current
+ * IDE core than to temporarily replace a higher level driver's timer expiry
+ * handler with our own backing up to that handler in case our recovery fails.
+ */
+static int tc86c001_timer_expiry(ide_drive_t *drive)
+{
+        ide_hwif_t *hwif        = HWIF(drive);
+        ide_expiry_t *expiry    = ide_get_hwifdata(hwif);
+        ide_hwgroup_t *hwgroup  = HWGROUP(drive);
+        u8 dma_stat             = hwif->INB(hwif->dma_status);
+
+        /* Restore a higher level driver's expiry handler first. */
+        hwgroup->expiry = expiry;
+
+        if ((dma_stat & 5) == 1) {      /* DMA active and no interrupt */
+                unsigned long sc_base   = hwif->config_data;
+                unsigned long twcr_port = sc_base + (drive->dn ? 0x06 : 0x04);
+                u8 dma_cmd              = hwif->INB(hwif->dma_command);
+
+                printk(KERN_WARNING "%s: DMA interrupt possibly stuck, "
+                       "attempting recovery...\n", drive->name);
+
+                /* Stop DMA */
+                hwif->OUTB(dma_cmd & ~0x01, hwif->dma_command);
+
+                /* Setup the dummy DMA transfer */
+                hwif->OUTW(0, sc_base + 0x0a);  /* Sector Count */
+                hwif->OUTW(0, twcr_port);       /* Transfer Word Count 1 or 2 */
+
+                /* Start the dummy DMA transfer */
+                hwif->OUTB(0x00, hwif->dma_command); /* clear R_OR_WCTR for write */
+                hwif->OUTB(0x01, hwif->dma_command); /* set START_STOPBM */
+
+                /*
+                 * If an interrupt was pending, it should come thru shortly.
+                 * If not, a higher level driver's expiry handler should
+                 * eventually cause some kind of recovery from the DMA stall.
+                 */
+                return WAIT_MIN_SLEEP;
+        }
+
+        /* Chain to the restored expiry handler if DMA wasn't active. */
+        if (likely(expiry != NULL))
+                return expiry(drive);
+
+        /* If there was no handler, "emulate" that for ide_timer_expiry()... */
+        return -1;
+}
+
+static void tc86c001_dma_start(ide_drive_t *drive)
+{
+        ide_hwif_t *hwif        = HWIF(drive);
+        ide_hwgroup_t *hwgroup  = HWGROUP(drive);
+        unsigned long sc_base   = hwif->config_data;
+        unsigned long twcr_port = sc_base + (drive->dn ? 0x06 : 0x04);
+        unsigned long nsectors  = hwgroup->rq->nr_sectors;
+
+        /*
+         * We have to manually load the sector count and size into
+         * the appropriate system control registers for DMA to work
+         * with LBA48 and ATAPI devices...
+         */
+        hwif->OUTW(nsectors, sc_base + 0x0a);   /* Sector Count */
+        hwif->OUTW(SECTOR_SIZE / 2, twcr_port); /* Transfer Word Count 1/2 */
+
+        /* Install our timeout expiry hook, saving the current handler... */
+        ide_set_hwifdata(hwif, hwgroup->expiry);
+        hwgroup->expiry = &tc86c001_timer_expiry;
+
+        ide_dma_start(drive);
+}
+
+static int tc86c001_busproc(ide_drive_t *drive, int state)
+{
+        ide_hwif_t *hwif        = HWIF(drive);
+        unsigned long sc_base   = hwif->config_data;
+        u16 scr1;
+
+        /* System Control 1 Register bit 11 (ATA Hard Reset) read */
+        scr1 = hwif->INW(sc_base + 0x00);
+
+        switch (state) {
+                case BUSSTATE_ON:
+                        if (!(scr1 & 0x0800))
+                                return 0;
+                        scr1 &= ~0x0800;
+
+                        hwif->drives[0].failures = hwif->drives[1].failures = 0;
+                        break;
+                case BUSSTATE_OFF:
+                        if (scr1 & 0x0800)
+                                return 0;
+                        scr1 |= 0x0800;
+
+                        hwif->drives[0].failures = hwif->drives[0].max_failures + 1;
+                        hwif->drives[1].failures = hwif->drives[1].max_failures + 1;
+                        break;
+                default:
+                        return -EINVAL;
+        }
+
+        /* System Control 1 Register bit 11 (ATA Hard Reset) write */
+        hwif->OUTW(scr1, sc_base + 0x00);
+        return 0;
+}
+
+static int config_chipset_for_dma(ide_drive_t *drive)
+{
+        u8 speed = ide_dma_speed(drive, tc86c001_ratemask(drive));
+
+        if (!speed)
+                return 0;
+
+        (void) tc86c001_tune_chipset(drive, speed);
+        return ide_dma_enable(drive);
+}
+
+static int tc86c001_config_drive_xfer_rate(ide_drive_t *drive)
+{
+        ide_hwif_t *hwif        = HWIF(drive);
+        struct hd_driveid *id   = drive->id;
+
+        if ((id->capability & 1) && drive->autodma) {
+
+                if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+                        return hwif->ide_dma_on(drive);
+
+                goto fast_ata_pio;
+
+        } else if ((id->capability & 8) || (id->field_valid & 2)) {
+fast_ata_pio:
+                tc86c001_tune_drive(drive, 255);
+                return hwif->ide_dma_off_quietly(drive);
+        }
+        /* IORDY not supported */
+        return 0;
+}
+
+void __devinit init_hwif_tc86c001(ide_hwif_t *hwif)
+{
+        unsigned long sc_base   = pci_resource_start(hwif->pci_dev, 5);
+        u16 scr1                = hwif->INW(sc_base + 0x00);;
+
+        /* System Control 1 Register bit 15 (Soft Reset) set */
+        hwif->OUTW(scr1 |  0x8000, sc_base + 0x00);
+
+        /* System Control 1 Register bit 14 (FIFO Reset) set */
+        hwif->OUTW(scr1 |  0x4000, sc_base + 0x00);
+
+        /* System Control 1 Register: reset clear */
+        hwif->OUTW(scr1 & ~0xc000, sc_base + 0x00);
+
+        /* Store the system control register base for convenience... */
+        hwif->config_data = sc_base;
+
+        hwif->tuneproc  = &tc86c001_tune_drive;
+        hwif->speedproc = &tc86c001_tune_chipset;
+        hwif->busproc   = &tc86c001_busproc;
+
+        hwif->drives[0].autotune = hwif->drives[1].autotune = 1;
+
+        if (!hwif->dma_base)
+                return;
+
+        /*
+         * Sector Count Control Register bits 0 and 1 set:
+         * software sets Sector Count Register for master and slave device
+         */
+        hwif->OUTW(0x0003, sc_base + 0x0c);
+
+        /* Sector Count Register limit */
+        hwif->rqsize     = 0xffff;
+
+        hwif->atapi_dma  = 1;
+        hwif->ultra_mask = 0x1f;
+        hwif->mwdma_mask = 0x07;
+
+        hwif->ide_dma_check     = &tc86c001_config_drive_xfer_rate;
+        hwif->dma_start         = &tc86c001_dma_start;
+
+        if (!hwif->udma_four) {
+                /*
+                 * System Control  1 Register bit 13 (PDIAGN):
+                 * 0=80-pin cable, 1=40-pin cable
+                 */
+                scr1 = hwif->INW(sc_base + 0x00);
+                hwif->udma_four = (scr1 & 0x2000) ? 0 : 1;
+        }
+
+        if (!noautodma)
+                hwif->autodma = 1;
+        hwif->drives[0].autodma = hwif->drives[1].autodma = hwif->autodma;
+}
+
+static unsigned int init_chipset_tc86c001(struct pci_dev *dev, const char *name)
+{
+        int err = pci_request_region(dev, 5, name);
+
+        if (err)
+                printk(KERN_ERR "%s: system control regs already in use", name);
+        return err;
+}
+
+static ide_pci_device_t tc86c001_chipset __devinitdata = {
+        .name           = "TC86C001",
+        .init_chipset   = init_chipset_tc86c001,
+        .init_hwif      = init_hwif_tc86c001,
+        .channels       = 1,
+        .autodma        = AUTODMA,
+        .bootable       = OFF_BOARD
+};
+
+static int __devinit tc86c001_init_one(struct pci_dev *dev,
+                                       const struct pci_device_id *id)
+{
+        return ide_setup_pci_device(dev, &tc86c001_chipset);
+}
+
+static struct pci_device_id tc86c001_pci_tbl[] = {
+        { PCI_VENDOR_ID_TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_TC86C001_IDE,
+          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+        { 0, }
+};
+MODULE_DEVICE_TABLE(pci, tc86c001_pci_tbl);
+
+static struct pci_driver driver = {
+        .name           = "TC86C001",
+        .id_table       = tc86c001_pci_tbl,
+        .probe          = tc86c001_init_one
+};
+
+static int tc86c001_ide_init(void)
+{
+        return ide_pci_register_driver(&driver);
+}
+module_init(tc86c001_ide_init);
+
+MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
+MODULE_DESCRIPTION("PCI driver module for TC86C001 IDE");
+MODULE_LICENSE("GPL");