/*
 * Libata driver for the HighPoint 371N, 372N, and 302N UDMA66 ATA controllers.
 *
 * This driver is heavily based upon:
 *
 * linux/drivers/ide/pci/hpt366.c               Version 0.36    April 25, 2003
 *
 * Copyright (C) 1999-2003              Andre Hedrick <andre@linux-ide.org>
 * Portions Copyright (C) 2001          Sun Microsystems, Inc.
 * Portions Copyright (C) 2003          Red Hat Inc
 * Portions Copyright (C) 2005-2010     MontaVista Software, Inc.
 *
 *
 * TODO
 *      Work out best PLL policy
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME        "pata_hpt3x2n"
#define DRV_VERSION     "0.3.15"

enum {
        HPT_PCI_FAST    =       (1 << 31),
        PCI66           =       (1 << 1),
        USE_DPLL        =       (1 << 0)
};

struct hpt_clock {
        u8      xfer_speed;
        u32     timing;
};

struct hpt_chip {
        const char *name;
        struct hpt_clock *clocks[3];
};

/* key for bus clock timings
 * bit
 * 0:3    data_high_time. Inactive time of DIOW_/DIOR_ for PIO and MW DMA.
 *        cycles = value + 1
 * 4:8    data_low_time. Active time of DIOW_/DIOR_ for PIO and MW DMA.
 *        cycles = value + 1
 * 9:12   cmd_high_time. Inactive time of DIOW_/DIOR_ during task file
 *        register access.
 * 13:17  cmd_low_time. Active time of DIOW_/DIOR_ during task file
 *        register access.
 * 18:20  udma_cycle_time. Clock cycles for UDMA xfer.
 * 21     CLK frequency for UDMA: 0=ATA clock, 1=dual ATA clock.
 * 22:24  pre_high_time. Time to initialize 1st cycle for PIO and MW DMA xfer.
 * 25:27  cmd_pre_high_time. Time to initialize 1st PIO cycle for task file
 *        register access.
 * 28     UDMA enable.
 * 29     DMA  enable.
 * 30     PIO_MST enable. If set, the chip is in bus master mode during
 *        PIO xfer.
 * 31     FIFO enable. Only for PIO.
 */

/* 66MHz DPLL clocks */

static struct hpt_clock hpt3x2n_clocks[] = {
        {       XFER_UDMA_7,    0x1c869c62      },
        {       XFER_UDMA_6,    0x1c869c62      },
        {       XFER_UDMA_5,    0x1c8a9c62      },
        {       XFER_UDMA_4,    0x1c8a9c62      },
        {       XFER_UDMA_3,    0x1c8e9c62      },
        {       XFER_UDMA_2,    0x1c929c62      },
        {       XFER_UDMA_1,    0x1c9a9c62      },
        {       XFER_UDMA_0,    0x1c829c62      },

        {       XFER_MW_DMA_2,  0x2c829c62      },
        {       XFER_MW_DMA_1,  0x2c829c66      },
        {       XFER_MW_DMA_0,  0x2c829d2e      },

        {       XFER_PIO_4,     0x0c829c62      },
        {       XFER_PIO_3,     0x0c829c84      },
        {       XFER_PIO_2,     0x0c829ca6      },
        {       XFER_PIO_1,     0x0d029d26      },
        {       XFER_PIO_0,     0x0d029d5e      },
};

/**
 *      hpt3x2n_find_mode       -       reset the hpt3x2n bus
 *      @ap: ATA port
 *      @speed: transfer mode
 *
 *      Return the 32bit register programming information for this channel
 *      that matches the speed provided. For the moment the clocks table
 *      is hard coded but easy to change. This will be needed if we use
 *      different DPLLs
 */

static u32 hpt3x2n_find_mode(struct ata_port *ap, int speed)
{
        struct hpt_clock *clocks = hpt3x2n_clocks;

        while (clocks->xfer_speed) {
                if (clocks->xfer_speed == speed)
                        return clocks->timing;
                clocks++;
        }
        BUG();
        return 0xffffffffU;     /* silence compiler warning */
}

/**
 *      hpt372n_filter  -       mode selection filter
 *      @adev: ATA device
 *      @mask: mode mask
 *
 *      The Marvell bridge chips used on the HighPoint SATA cards do not seem
 *      to support the UltraDMA modes 1, 2, and 3 as well as any MWDMA modes...
 */
static unsigned long hpt372n_filter(struct ata_device *adev, unsigned long mask)
{
        if (ata_id_is_sata(adev->id))
                mask &= ~((0xE << ATA_SHIFT_UDMA) | ATA_MASK_MWDMA);

        return mask;
}

/**
 *      hpt3x2n_cable_detect    -       Detect the cable type
 *      @ap: ATA port to detect on
 *
 *      Return the cable type attached to this port
 */

static int hpt3x2n_cable_detect(struct ata_port *ap)
{
        u8 scr2, ata66;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        pci_read_config_byte(pdev, 0x5B, &scr2);
        pci_write_config_byte(pdev, 0x5B, scr2 & ~0x01);

        udelay(10); /* debounce */

        /* Cable register now active */
        pci_read_config_byte(pdev, 0x5A, &ata66);
        /* Restore state */
        pci_write_config_byte(pdev, 0x5B, scr2);

        if (ata66 & (2 >> ap->port_no))
                return ATA_CBL_PATA40;
        else
                return ATA_CBL_PATA80;
}

/**
 *      hpt3x2n_pre_reset       -       reset the hpt3x2n bus
 *      @link: ATA link to reset
 *      @deadline: deadline jiffies for the operation
 *
 *      Perform the initial reset handling for the 3x2n series controllers.
 *      Reset the hardware and state machine,
 */

static int hpt3x2n_pre_reset(struct ata_link *link, unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        /* Reset the state machine */
        pci_write_config_byte(pdev, 0x50 + 4 * ap->port_no, 0x37);
        udelay(100);

        return ata_sff_prereset(link, deadline);
}

static void hpt3x2n_set_mode(struct ata_port *ap, struct ata_device *adev,
                             u8 mode)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u32 addr1, addr2;
        u32 reg, timing, mask;
        u8 fast;

        addr1 = 0x40 + 4 * (adev->devno + 2 * ap->port_no);
        addr2 = 0x51 + 4 * ap->port_no;

        /* Fast interrupt prediction disable, hold off interrupt disable */
        pci_read_config_byte(pdev, addr2, &fast);
        fast &= ~0x07;
        pci_write_config_byte(pdev, addr2, fast);

        /* Determine timing mask and find matching mode entry */
        if (mode < XFER_MW_DMA_0)
                mask = 0xcfc3ffff;
        else if (mode < XFER_UDMA_0)
                mask = 0x31c001ff;
        else
                mask = 0x303c0000;

        timing = hpt3x2n_find_mode(ap, mode);

        pci_read_config_dword(pdev, addr1, &reg);
        reg = (reg & ~mask) | (timing & mask);
        pci_write_config_dword(pdev, addr1, reg);
}

/**
 *      hpt3x2n_set_piomode             -       PIO setup
 *      @ap: ATA interface
 *      @adev: device on the interface
 *
 *      Perform PIO mode setup.
 */

static void hpt3x2n_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        hpt3x2n_set_mode(ap, adev, adev->pio_mode);
}

/**
 *      hpt3x2n_set_dmamode             -       DMA timing setup
 *      @ap: ATA interface
 *      @adev: Device being configured
 *
 *      Set up the channel for MWDMA or UDMA modes.
 */

static void hpt3x2n_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        hpt3x2n_set_mode(ap, adev, adev->dma_mode);
}

/**
 *      hpt3x2n_bmdma_end               -       DMA engine stop
 *      @qc: ATA command
 *
 *      Clean up after the HPT3x2n and later DMA engine
 */

static void hpt3x2n_bmdma_stop(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int mscreg = 0x50 + 2 * ap->port_no;
        u8 bwsr_stat, msc_stat;

        pci_read_config_byte(pdev, 0x6A, &bwsr_stat);
        pci_read_config_byte(pdev, mscreg, &msc_stat);
        if (bwsr_stat & (1 << ap->port_no))
                pci_write_config_byte(pdev, mscreg, msc_stat | 0x30);
        ata_bmdma_stop(qc);
}

/**
 *      hpt3x2n_set_clock       -       clock control
 *      @ap: ATA port
 *      @source: 0x21 or 0x23 for PLL or PCI sourced clock
 *
 *      Switch the ATA bus clock between the PLL and PCI clock sources
 *      while correctly isolating the bus and resetting internal logic
 *
 *      We must use the DPLL for
 *      -       writing
 *      -       second channel UDMA7 (SATA ports) or higher
 *      -       66MHz PCI
 *
 *      or we will underclock the device and get reduced performance.
 */

static void hpt3x2n_set_clock(struct ata_port *ap, int source)
{
        void __iomem *bmdma = ap->ioaddr.bmdma_addr - ap->port_no * 8;

        /* Tristate the bus */
        iowrite8(0x80, bmdma+0x73);
        iowrite8(0x80, bmdma+0x77);

        /* Switch clock and reset channels */
        iowrite8(source, bmdma+0x7B);
        iowrite8(0xC0, bmdma+0x79);

        /* Reset state machines, avoid enabling the disabled channels */
        iowrite8(ioread8(bmdma+0x70) | 0x32, bmdma+0x70);
        iowrite8(ioread8(bmdma+0x74) | 0x32, bmdma+0x74);

        /* Complete reset */
        iowrite8(0x00, bmdma+0x79);

        /* Reconnect channels to bus */
        iowrite8(0x00, bmdma+0x73);
        iowrite8(0x00, bmdma+0x77);
}

static int hpt3x2n_use_dpll(struct ata_port *ap, int writing)
{
        long flags = (long)ap->host->private_data;

        /* See if we should use the DPLL */
        if (writing)
                return USE_DPLL;        /* Needed for write */
        if (flags & PCI66)
                return USE_DPLL;        /* Needed at 66Mhz */
        return 0;
}

static int hpt3x2n_qc_defer(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ata_port *alt = ap->host->ports[ap->port_no ^ 1];
        int rc, flags = (long)ap->host->private_data;
        int dpll = hpt3x2n_use_dpll(ap, qc->tf.flags & ATA_TFLAG_WRITE);

        /* First apply the usual rules */
        rc = ata_std_qc_defer(qc);
        if (rc != 0)
                return rc;

        if ((flags & USE_DPLL) != dpll && alt->qc_active)
                return ATA_DEFER_PORT;
        return 0;
}

static unsigned int hpt3x2n_qc_issue(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        int flags = (long)ap->host->private_data;
        int dpll = hpt3x2n_use_dpll(ap, qc->tf.flags & ATA_TFLAG_WRITE);

        if ((flags & USE_DPLL) != dpll) {
                flags &= ~USE_DPLL;
                flags |= dpll;
                ap->host->private_data = (void *)(long)flags;

                hpt3x2n_set_clock(ap, dpll ? 0x21 : 0x23);
        }
        return ata_bmdma_qc_issue(qc);
}

static struct scsi_host_template hpt3x2n_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

/*
 *      Configuration for HPT302N/371N.
 */

static struct ata_port_operations hpt3xxn_port_ops = {
        .inherits       = &ata_bmdma_port_ops,

        .bmdma_stop     = hpt3x2n_bmdma_stop,

        .qc_defer       = hpt3x2n_qc_defer,
        .qc_issue       = hpt3x2n_qc_issue,

        .cable_detect   = hpt3x2n_cable_detect,
        .set_piomode    = hpt3x2n_set_piomode,
        .set_dmamode    = hpt3x2n_set_dmamode,
        .prereset       = hpt3x2n_pre_reset,
};

/*
 *      Configuration for HPT372N. Same as 302N/371N but we have a mode filter.
 */

static struct ata_port_operations hpt372n_port_ops = {
        .inherits       = &hpt3xxn_port_ops,
        .mode_filter    = &hpt372n_filter,
};

/**
 *      hpt3xn_calibrate_dpll           -       Calibrate the DPLL loop
 *      @dev: PCI device
 *
 *      Perform a calibration cycle on the HPT3xN DPLL. Returns 1 if this
 *      succeeds
 */

static int hpt3xn_calibrate_dpll(struct pci_dev *dev)
{
        u8 reg5b;
        u32 reg5c;
        int tries;

        for (tries = 0; tries < 0x5000; tries++) {
                udelay(50);
                pci_read_config_byte(dev, 0x5b, &reg5b);
                if (reg5b & 0x80) {
                        /* See if it stays set */
                        for (tries = 0; tries < 0x1000; tries++) {
                                pci_read_config_byte(dev, 0x5b, &reg5b);
                                /* Failed ? */
                                if ((reg5b & 0x80) == 0)
                                        return 0;
                        }
                        /* Turn off tuning, we have the DPLL set */
                        pci_read_config_dword(dev, 0x5c, &reg5c);
                        pci_write_config_dword(dev, 0x5c, reg5c & ~0x100);
                        return 1;
                }
        }
        /* Never went stable */
        return 0;
}

static int hpt3x2n_pci_clock(struct pci_dev *pdev)
{
        unsigned long freq;
        u32 fcnt;
        unsigned long iobase = pci_resource_start(pdev, 4);

        fcnt = inl(iobase + 0x90);      /* Not PCI readable for some chips */
        if ((fcnt >> 12) != 0xABCDE) {
                int i;
                u16 sr;
                u32 total = 0;

                pr_warn("BIOS clock data not set\n");

                /* This is the process the HPT371 BIOS is reported to use */
                for (i = 0; i < 128; i++) {
                        pci_read_config_word(pdev, 0x78, &sr);
                        total += sr & 0x1FF;
                        udelay(15);
                }
                fcnt = total / 128;
        }
        fcnt &= 0x1FF;

        freq = (fcnt * 77) / 192;

        /* Clamp to bands */
        if (freq < 40)
                return 33;
        if (freq < 45)
                return 40;
        if (freq < 55)
                return 50;
        return 66;
}

/**
 *      hpt3x2n_init_one                -       Initialise an HPT37X/302
 *      @dev: PCI device
 *      @id: Entry in match table
 *
 *      Initialise an HPT3x2n device. There are some interesting complications
 *      here. Firstly the chip may report 366 and be one of several variants.
 *      Secondly all the timings depend on the clock for the chip which we must
 *      detect and look up
 *
 *      This is the known chip mappings. It may be missing a couple of later
 *      releases.
 *
 *      Chip version            PCI             Rev     Notes
 *      HPT372                  4 (HPT366)      5       Other driver
 *      HPT372N                 4 (HPT366)      6       UDMA133
 *      HPT372                  5 (HPT372)      1       Other driver
 *      HPT372N                 5 (HPT372)      2       UDMA133
 *      HPT302                  6 (HPT302)      *       Other driver
 *      HPT302N                 6 (HPT302)      > 1     UDMA133
 *      HPT371                  7 (HPT371)      *       Other driver
 *      HPT371N                 7 (HPT371)      > 1     UDMA133
 *      HPT374                  8 (HPT374)      *       Other driver
 *      HPT372N                 9 (HPT372N)     *       UDMA133
 *
 *      (1) UDMA133 support depends on the bus clock
 */

static int hpt3x2n_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
        /* HPT372N - UDMA133 */
        static const struct ata_port_info info_hpt372n = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA6,
                .port_ops = &hpt372n_port_ops
        };
        /* HPT302N and HPT371N - UDMA133 */
        static const struct ata_port_info info_hpt3xxn = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA6,
                .port_ops = &hpt3xxn_port_ops
        };
        const struct ata_port_info *ppi[] = { &info_hpt3xxn, NULL };
        u8 rev = dev->revision;
        u8 irqmask;
        unsigned int pci_mhz;
        unsigned int f_low, f_high;
        int adjust;
        unsigned long iobase = pci_resource_start(dev, 4);
        void *hpriv = (void *)USE_DPLL;
        int rc;

        rc = pcim_enable_device(dev);
        if (rc)
                return rc;

        switch (dev->device) {
        case PCI_DEVICE_ID_TTI_HPT366:
                /* 372N if rev >= 6 */
                if (rev < 6)
                        return -ENODEV;
                goto hpt372n;
        case PCI_DEVICE_ID_TTI_HPT371:
                /* 371N if rev >= 2 */
                if (rev < 2)
                        return -ENODEV;
                break;
        case PCI_DEVICE_ID_TTI_HPT372:
                /* 372N if rev >= 2 */
                if (rev < 2)
                        return -ENODEV;
                goto hpt372n;
        case PCI_DEVICE_ID_TTI_HPT302:
                /* 302N if rev >= 2 */
                if (rev < 2)
                        return -ENODEV;
                break;
        case PCI_DEVICE_ID_TTI_HPT372N:
hpt372n:
                ppi[0] = &info_hpt372n;
                break;
        default:
                pr_err("PCI table is bogus, please report (%d)\n", dev->device);
                return -ENODEV;
        }

        /* Ok so this is a chip we support */

        pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, (L1_CACHE_BYTES / 4));
        pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x78);
        pci_write_config_byte(dev, PCI_MIN_GNT, 0x08);
        pci_write_config_byte(dev, PCI_MAX_LAT, 0x08);

        pci_read_config_byte(dev, 0x5A, &irqmask);
        irqmask &= ~0x10;
        pci_write_config_byte(dev, 0x5a, irqmask);

        /*
         * HPT371 chips physically have only one channel, the secondary one,
         * but the primary channel registers do exist!  Go figure...
         * So,  we manually disable the non-existing channel here
         * (if the BIOS hasn't done this already).
         */
        if (dev->device == PCI_DEVICE_ID_TTI_HPT371) {
                u8 mcr1;
                pci_read_config_byte(dev, 0x50, &mcr1);
                mcr1 &= ~0x04;
                pci_write_config_byte(dev, 0x50, mcr1);
        }

        /*
         * Tune the PLL. HPT recommend using 75 for SATA, 66 for UDMA133 or
         * 50 for UDMA100. Right now we always use 66
         */

        pci_mhz = hpt3x2n_pci_clock(dev);

        f_low = (pci_mhz * 48) / 66;    /* PCI Mhz for 66Mhz DPLL */
        f_high = f_low + 2;             /* Tolerance */

        pci_write_config_dword(dev, 0x5C, (f_high << 16) | f_low | 0x100);
        /* PLL clock */
        pci_write_config_byte(dev, 0x5B, 0x21);

        /* Unlike the 37x we don't try jiggling the frequency */
        for (adjust = 0; adjust < 8; adjust++) {
                if (hpt3xn_calibrate_dpll(dev))
                        break;
                pci_write_config_dword(dev, 0x5C, (f_high << 16) | f_low);
        }
        if (adjust == 8) {
                pr_err("DPLL did not stabilize!\n");
                return -ENODEV;
        }

        pr_info("bus clock %dMHz, using 66MHz DPLL\n", pci_mhz);

        /*
         * Set our private data up. We only need a few flags
         * so we use it directly.
         */
        if (pci_mhz > 60)
                hpriv = (void *)(PCI66 | USE_DPLL);

        /*
         * On  HPT371N, if ATA clock is 66 MHz we must set bit 2 in
         * the MISC. register to stretch the UltraDMA Tss timing.
         * NOTE: This register is only writeable via I/O space.
         */
        if (dev->device == PCI_DEVICE_ID_TTI_HPT371)
                outb(inb(iobase + 0x9c) | 0x04, iobase + 0x9c);

        /* Now kick off ATA set up */
        return ata_pci_bmdma_init_one(dev, ppi, &hpt3x2n_sht, hpriv, 0);
}

static const struct pci_device_id hpt3x2n[] = {
        { PCI_VDEVICE(TTI, PCI_DEVICE_ID_TTI_HPT366), },
        { PCI_VDEVICE(TTI, PCI_DEVICE_ID_TTI_HPT371), },
        { PCI_VDEVICE(TTI, PCI_DEVICE_ID_TTI_HPT372), },
        { PCI_VDEVICE(TTI, PCI_DEVICE_ID_TTI_HPT302), },
        { PCI_VDEVICE(TTI, PCI_DEVICE_ID_TTI_HPT372N), },

        { },
};

static struct pci_driver hpt3x2n_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = hpt3x2n,
        .probe          = hpt3x2n_init_one,
        .remove         = ata_pci_remove_one
};

module_pci_driver(hpt3x2n_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for the Highpoint HPT3xxN");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, hpt3x2n);
MODULE_VERSION(DRV_VERSION);