// SPDX-License-Identifier: GPL-2.0-only
/*
 * pata_serverworks.c   - Serverworks PATA for new ATA layer
 *                        (C) 2005 Red Hat Inc
 *                        (C) 2010 Bartlomiej Zolnierkiewicz
 *
 * based upon
 *
 * serverworks.c
 *
 * Copyright (C) 1998-2000 Michel Aubry
 * Copyright (C) 1998-2000 Andrzej Krzysztofowicz
 * Copyright (C) 1998-2000 Andre Hedrick <andre@linux-ide.org>
 * Portions copyright (c) 2001 Sun Microsystems
 *
 *
 * RCC/ServerWorks IDE driver for Linux
 *
 *   OSB4: `Open South Bridge' IDE Interface (fn 1)
 *         supports UDMA mode 2 (33 MB/s)
 *
 *   CSB5: `Champion South Bridge' IDE Interface (fn 1)
 *         all revisions support UDMA mode 4 (66 MB/s)
 *         revision A2.0 and up support UDMA mode 5 (100 MB/s)
 *
 *         *** The CSB5 does not provide ANY register ***
 *         *** to detect 80-conductor cable presence. ***
 *
 *   CSB6: `Champion South Bridge' IDE Interface (optional: third channel)
 *
 * Documentation:
 *      Available under NDA only. Errata info very hard to get.
 */

#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_serverworks"
#define DRV_VERSION "0.4.3"

#define SVWKS_CSB5_REVISION_NEW 0x92 /* min PCI_REVISION_ID for UDMA5 (A2.0) */
#define SVWKS_CSB6_REVISION     0xa0 /* min PCI_REVISION_ID for UDMA4 (A1.0) */

/*
 * Seagate Barracuda ATA IV Family drives in UDMA mode 5
 * can overrun their FIFOs when used with the CSB5.
 */
static const char * const csb_bad_ata100[] = {
        "ST320011A",
        "ST340016A",
        "ST360021A",
        "ST380021A",
        NULL
};

/**
 *      oem_cable       -       Dell/Sun serverworks cable detection
 *      @ap: ATA port to do cable detect
 *
 *      Dell PowerEdge and Sun Cobalt 'Alpine' hide the 40/80 pin select
 *      for their interfaces in the top two bits of the subsystem ID.
 */

static int oem_cable(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        if (pdev->subsystem_device & (1 << (ap->port_no + 14)))
                return ATA_CBL_PATA80;
        return ATA_CBL_PATA40;
}

struct sv_cable_table {
        int device;
        int subvendor;
        int (*cable_detect)(struct ata_port *ap);
};

static struct sv_cable_table cable_detect[] = {
        { PCI_DEVICE_ID_SERVERWORKS_CSB5IDE,   PCI_VENDOR_ID_DELL, oem_cable },
        { PCI_DEVICE_ID_SERVERWORKS_CSB6IDE,   PCI_VENDOR_ID_DELL, oem_cable },
        { PCI_DEVICE_ID_SERVERWORKS_CSB5IDE,   PCI_VENDOR_ID_SUN,  oem_cable },
        { PCI_DEVICE_ID_SERVERWORKS_OSB4IDE,   PCI_ANY_ID, ata_cable_40wire  },
        { PCI_DEVICE_ID_SERVERWORKS_CSB5IDE,   PCI_ANY_ID, ata_cable_unknown },
        { PCI_DEVICE_ID_SERVERWORKS_CSB6IDE,   PCI_ANY_ID, ata_cable_unknown },
        { PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2,  PCI_ANY_ID, ata_cable_unknown },
        { PCI_DEVICE_ID_SERVERWORKS_HT1000IDE, PCI_ANY_ID, ata_cable_unknown },
        { }
};

/**
 *      serverworks_cable_detect        -       cable detection
 *      @ap: ATA port
 *
 *      Perform cable detection according to the device and subvendor
 *      identifications
 */

static int serverworks_cable_detect(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct sv_cable_table *cb = cable_detect;

        while(cb->device) {
                if (cb->device == pdev->device &&
                    (cb->subvendor == pdev->subsystem_vendor ||
                      cb->subvendor == PCI_ANY_ID)) {
                        return cb->cable_detect(ap);
                }
                cb++;
        }

        BUG();
        return -1;      /* kill compiler warning */
}

/**
 *      serverworks_is_csb      -       Check for CSB or OSB
 *      @pdev: PCI device to check
 *
 *      Returns true if the device being checked is known to be a CSB
 *      series device.
 */

static u8 serverworks_is_csb(struct pci_dev *pdev)
{
        switch (pdev->device) {
                case PCI_DEVICE_ID_SERVERWORKS_CSB5IDE:
                case PCI_DEVICE_ID_SERVERWORKS_CSB6IDE:
                case PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2:
                case PCI_DEVICE_ID_SERVERWORKS_HT1000IDE:
                        return 1;
                default:
                        break;
        }
        return 0;
}

/**
 *      serverworks_osb4_filter -       mode selection filter
 *      @adev: ATA device
 *      @mask: Mask of proposed modes
 *
 *      Filter the offered modes for the device to apply controller
 *      specific rules. OSB4 requires no UDMA for disks due to a FIFO
 *      bug we hit.
 */

static unsigned int serverworks_osb4_filter(struct ata_device *adev, unsigned int mask)
{
        if (adev->class == ATA_DEV_ATA)
                mask &= ~ATA_MASK_UDMA;
        return mask;
}


/**
 *      serverworks_csb_filter  -       mode selection filter
 *      @adev: ATA device
 *      @mask: Mask of proposed modes
 *
 *      Check the list of devices with broken UDMA5 and
 *      disable UDMA5 if matched.
 */
static unsigned int serverworks_csb_filter(struct ata_device *adev,
                                           unsigned int mask)
{
        const char *p;
        char model_num[ATA_ID_PROD_LEN + 1];
        int i;

        /* Disk, UDMA */
        if (adev->class != ATA_DEV_ATA)
                return mask;

        /* Actually do need to check */
        ata_id_c_string(adev->id, model_num, ATA_ID_PROD, sizeof(model_num));

        for (i = 0; (p = csb_bad_ata100[i]) != NULL; i++) {
                if (!strcmp(p, model_num))
                        mask &= ~(0xE0 << ATA_SHIFT_UDMA);
        }
        return mask;
}

/**
 *      serverworks_set_piomode -       set initial PIO mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Program the OSB4/CSB5 timing registers for PIO. The PIO register
 *      load is done as a simple lookup.
 */
static void serverworks_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        static const u8 pio_mode[] = { 0x5d, 0x47, 0x34, 0x22, 0x20 };
        int offset = 1 + 2 * ap->port_no - adev->devno;
        int devbits = (2 * ap->port_no + adev->devno) * 4;
        u16 csb5_pio;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int pio = adev->pio_mode - XFER_PIO_0;

        pci_write_config_byte(pdev, 0x40 + offset, pio_mode[pio]);

        /* The OSB4 just requires the timing but the CSB series want the
           mode number as well */
        if (serverworks_is_csb(pdev)) {
                pci_read_config_word(pdev, 0x4A, &csb5_pio);
                csb5_pio &= ~(0x0F << devbits);
                pci_write_config_word(pdev, 0x4A, csb5_pio | (pio << devbits));
        }
}

/**
 *      serverworks_set_dmamode -       set initial DMA mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Program the MWDMA/UDMA modes for the serverworks OSB4/CSB5
 *      chipset. The MWDMA mode values are pulled from a lookup table
 *      while the chipset uses mode number for UDMA.
 */

static void serverworks_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        static const u8 dma_mode[] = { 0x77, 0x21, 0x20 };
        int offset = 1 + 2 * ap->port_no - adev->devno;
        int devbits = 2 * ap->port_no + adev->devno;
        u8 ultra;
        u8 ultra_cfg;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        pci_read_config_byte(pdev, 0x54, &ultra_cfg);
        pci_read_config_byte(pdev, 0x56 + ap->port_no, &ultra);
        ultra &= ~(0x0F << (adev->devno * 4));

        if (adev->dma_mode >= XFER_UDMA_0) {
                pci_write_config_byte(pdev, 0x44 + offset,  0x20);

                ultra |= (adev->dma_mode - XFER_UDMA_0)
                                        << (adev->devno * 4);
                ultra_cfg |=  (1 << devbits);
        } else {
                pci_write_config_byte(pdev, 0x44 + offset,
                        dma_mode[adev->dma_mode - XFER_MW_DMA_0]);
                ultra_cfg &= ~(1 << devbits);
        }
        pci_write_config_byte(pdev, 0x56 + ap->port_no, ultra);
        pci_write_config_byte(pdev, 0x54, ultra_cfg);
}

static const struct scsi_host_template serverworks_osb4_sht = {
        ATA_BASE_SHT(DRV_NAME),
        .sg_tablesize   = LIBATA_DUMB_MAX_PRD,
        .dma_boundary   = ATA_DMA_BOUNDARY,
};

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

static struct ata_port_operations serverworks_osb4_port_ops = {
        .inherits       = &ata_bmdma_port_ops,
        .qc_prep        = ata_bmdma_dumb_qc_prep,
        .cable_detect   = serverworks_cable_detect,
        .mode_filter    = serverworks_osb4_filter,
        .set_piomode    = serverworks_set_piomode,
        .set_dmamode    = serverworks_set_dmamode,
};

static struct ata_port_operations serverworks_csb_port_ops = {
        .inherits       = &serverworks_osb4_port_ops,
        .qc_prep        = ata_bmdma_qc_prep,
        .mode_filter    = serverworks_csb_filter,
};

static int serverworks_fixup_osb4(struct pci_dev *pdev)
{
        u32 reg;
        struct pci_dev *isa_dev = pci_get_device(PCI_VENDOR_ID_SERVERWORKS,
                  PCI_DEVICE_ID_SERVERWORKS_OSB4, NULL);
        if (isa_dev) {
                pci_read_config_dword(isa_dev, 0x64, &reg);
                reg &= ~0x00002000; /* disable 600ns interrupt mask */
                if (!(reg & 0x00004000))
                        dev_info(&pdev->dev, "UDMA not BIOS enabled.\n");
                reg |=  0x00004000; /* enable UDMA/33 support */
                pci_write_config_dword(isa_dev, 0x64, reg);
                pci_dev_put(isa_dev);
                return 0;
        }
        dev_warn(&pdev->dev, "Unable to find bridge.\n");
        return -ENODEV;
}

static int serverworks_fixup_csb(struct pci_dev *pdev)
{
        u8 btr;

        /* Third Channel Test */
        if (!(PCI_FUNC(pdev->devfn) & 1)) {
                struct pci_dev * findev = NULL;
                u32 reg4c = 0;
                findev = pci_get_device(PCI_VENDOR_ID_SERVERWORKS,
                        PCI_DEVICE_ID_SERVERWORKS_CSB5, NULL);
                if (findev) {
                        pci_read_config_dword(findev, 0x4C, &reg4c);
                        reg4c &= ~0x000007FF;
                        reg4c |=  0x00000040;
                        reg4c |=  0x00000020;
                        pci_write_config_dword(findev, 0x4C, reg4c);
                        pci_dev_put(findev);
                }
        } else {
                struct pci_dev * findev = NULL;
                u8 reg41 = 0;

                findev = pci_get_device(PCI_VENDOR_ID_SERVERWORKS,
                                PCI_DEVICE_ID_SERVERWORKS_CSB6, NULL);
                if (findev) {
                        pci_read_config_byte(findev, 0x41, &reg41);
                        reg41 &= ~0x40;
                        pci_write_config_byte(findev, 0x41, reg41);
                        pci_dev_put(findev);
                }
        }
        /* setup the UDMA Control register
         *
         * 1. clear bit 6 to enable DMA
         * 2. enable DMA modes with bits 0-1
         *      00 : legacy
         *      01 : udma2
         *      10 : udma2/udma4
         *      11 : udma2/udma4/udma5
         */
        pci_read_config_byte(pdev, 0x5A, &btr);
        btr &= ~0x40;
        if (!(PCI_FUNC(pdev->devfn) & 1))
                btr |= 0x2;
        else
                btr |= (pdev->revision >= SVWKS_CSB5_REVISION_NEW) ? 0x3 : 0x2;
        pci_write_config_byte(pdev, 0x5A, btr);

        return btr;
}

static void serverworks_fixup_ht1000(struct pci_dev *pdev)
{
        u8 btr;
        /* Setup HT1000 SouthBridge Controller - Single Channel Only */
        pci_read_config_byte(pdev, 0x5A, &btr);
        btr &= ~0x40;
        btr |= 0x3;
        pci_write_config_byte(pdev, 0x5A, btr);
}

static int serverworks_fixup(struct pci_dev *pdev)
{
        int rc = 0;

        /* Force master latency timer to 64 PCI clocks */
        pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0x40);

        switch (pdev->device) {
        case PCI_DEVICE_ID_SERVERWORKS_OSB4IDE:
                rc = serverworks_fixup_osb4(pdev);
                break;
        case PCI_DEVICE_ID_SERVERWORKS_CSB5IDE:
                ata_pci_bmdma_clear_simplex(pdev);
                fallthrough;
        case PCI_DEVICE_ID_SERVERWORKS_CSB6IDE:
        case PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2:
                rc = serverworks_fixup_csb(pdev);
                break;
        case PCI_DEVICE_ID_SERVERWORKS_HT1000IDE:
                serverworks_fixup_ht1000(pdev);
                break;
        }

        return rc;
}

static int serverworks_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        static const struct ata_port_info info[4] = {
                { /* OSB4 */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .udma_mask = ATA_UDMA2,
                        .port_ops = &serverworks_osb4_port_ops
                }, { /* OSB4 no UDMA */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        /* No UDMA */
                        .port_ops = &serverworks_osb4_port_ops
                }, { /* CSB5 */
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .udma_mask = ATA_UDMA4,
                        .port_ops = &serverworks_csb_port_ops
                }, { /* CSB5 - later revisions*/
                        .flags = ATA_FLAG_SLAVE_POSS,
                        .pio_mask = ATA_PIO4,
                        .mwdma_mask = ATA_MWDMA2,
                        .udma_mask = ATA_UDMA5,
                        .port_ops = &serverworks_csb_port_ops
                }
        };
        const struct ata_port_info *ppi[] = { &info[id->driver_data], NULL };
        const struct scsi_host_template *sht = &serverworks_csb_sht;
        int rc;

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

        rc = serverworks_fixup(pdev);

        /* OSB4 : South Bridge and IDE */
        if (pdev->device == PCI_DEVICE_ID_SERVERWORKS_OSB4IDE) {
                /* Select non UDMA capable OSB4 if we can't do fixups */
                if (rc < 0)
                        ppi[0] = &info[1];
                sht = &serverworks_osb4_sht;
        }
        /* setup CSB5/CSB6 : South Bridge and IDE option RAID */
        else if ((pdev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5IDE) ||
                 (pdev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE) ||
                 (pdev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2)) {

                 /* If the returned btr is the newer revision then
                    select the right info block */
                 if (rc == 3)
                        ppi[0] = &info[3];

                /* Is this the 3rd channel CSB6 IDE ? */
                if (pdev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2)
                        ppi[1] = &ata_dummy_port_info;
        }

        return ata_pci_bmdma_init_one(pdev, ppi, sht, NULL, 0);
}

#ifdef CONFIG_PM_SLEEP
static int serverworks_reinit_one(struct pci_dev *pdev)
{
        struct ata_host *host = pci_get_drvdata(pdev);
        int rc;

        rc = ata_pci_device_do_resume(pdev);
        if (rc)
                return rc;

        (void)serverworks_fixup(pdev);

        ata_host_resume(host);
        return 0;
}
#endif

static const struct pci_device_id serverworks[] = {
        { PCI_VDEVICE(SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_OSB4IDE), 0},
        { PCI_VDEVICE(SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB5IDE), 2},
        { PCI_VDEVICE(SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB6IDE), 2},
        { PCI_VDEVICE(SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2), 2},
        { PCI_VDEVICE(SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_HT1000IDE), 2},

        { },
};

static struct pci_driver serverworks_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = serverworks,
        .probe          = serverworks_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend        = ata_pci_device_suspend,
        .resume         = serverworks_reinit_one,
#endif
};

module_pci_driver(serverworks_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for Serverworks OSB4/CSB5/CSB6");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, serverworks);
MODULE_VERSION(DRV_VERSION);