// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  sata_vsc.c - Vitesse VSC7174 4 port DPA SATA
 *
 *  Maintained by:  Jeremy Higdon @ SGI
 *                  Please ALWAYS copy linux-ide@vger.kernel.org
 *                  on emails.
 *
 *  Copyright 2004 SGI
 *
 *  Bits from Jeff Garzik, Copyright RedHat, Inc.
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/driver-api/libata.rst
 *
 *  Vitesse hardware documentation presumably available under NDA.
 *  Intel 31244 (same hardware interface) documentation presumably
 *  available from http://developer.intel.com/
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME        "sata_vsc"
#define DRV_VERSION     "2.3"

enum {
        VSC_MMIO_BAR                    = 0,

        /* Interrupt register offsets (from chip base address) */
        VSC_SATA_INT_STAT_OFFSET        = 0x00,
        VSC_SATA_INT_MASK_OFFSET        = 0x04,

        /* Taskfile registers offsets */
        VSC_SATA_TF_CMD_OFFSET          = 0x00,
        VSC_SATA_TF_DATA_OFFSET         = 0x00,
        VSC_SATA_TF_ERROR_OFFSET        = 0x04,
        VSC_SATA_TF_FEATURE_OFFSET      = 0x06,
        VSC_SATA_TF_NSECT_OFFSET        = 0x08,
        VSC_SATA_TF_LBAL_OFFSET         = 0x0c,
        VSC_SATA_TF_LBAM_OFFSET         = 0x10,
        VSC_SATA_TF_LBAH_OFFSET         = 0x14,
        VSC_SATA_TF_DEVICE_OFFSET       = 0x18,
        VSC_SATA_TF_STATUS_OFFSET       = 0x1c,
        VSC_SATA_TF_COMMAND_OFFSET      = 0x1d,
        VSC_SATA_TF_ALTSTATUS_OFFSET    = 0x28,
        VSC_SATA_TF_CTL_OFFSET          = 0x29,

        /* DMA base */
        VSC_SATA_UP_DESCRIPTOR_OFFSET   = 0x64,
        VSC_SATA_UP_DATA_BUFFER_OFFSET  = 0x6C,
        VSC_SATA_DMA_CMD_OFFSET         = 0x70,

        /* SCRs base */
        VSC_SATA_SCR_STATUS_OFFSET      = 0x100,
        VSC_SATA_SCR_ERROR_OFFSET       = 0x104,
        VSC_SATA_SCR_CONTROL_OFFSET     = 0x108,

        /* Port stride */
        VSC_SATA_PORT_OFFSET            = 0x200,

        /* Error interrupt status bit offsets */
        VSC_SATA_INT_ERROR_CRC          = 0x40,
        VSC_SATA_INT_ERROR_T            = 0x20,
        VSC_SATA_INT_ERROR_P            = 0x10,
        VSC_SATA_INT_ERROR_R            = 0x8,
        VSC_SATA_INT_ERROR_E            = 0x4,
        VSC_SATA_INT_ERROR_M            = 0x2,
        VSC_SATA_INT_PHY_CHANGE         = 0x1,
        VSC_SATA_INT_ERROR = (VSC_SATA_INT_ERROR_CRC  | VSC_SATA_INT_ERROR_T | \
                              VSC_SATA_INT_ERROR_P    | VSC_SATA_INT_ERROR_R | \
                              VSC_SATA_INT_ERROR_E    | VSC_SATA_INT_ERROR_M | \
                              VSC_SATA_INT_PHY_CHANGE),
};

static int vsc_sata_scr_read(struct ata_link *link,
                             unsigned int sc_reg, u32 *val)
{
        if (sc_reg > SCR_CONTROL)
                return -EINVAL;
        *val = readl(link->ap->ioaddr.scr_addr + (sc_reg * 4));
        return 0;
}


static int vsc_sata_scr_write(struct ata_link *link,
                              unsigned int sc_reg, u32 val)
{
        if (sc_reg > SCR_CONTROL)
                return -EINVAL;
        writel(val, link->ap->ioaddr.scr_addr + (sc_reg * 4));
        return 0;
}


static void vsc_freeze(struct ata_port *ap)
{
        void __iomem *mask_addr;

        mask_addr = ap->host->iomap[VSC_MMIO_BAR] +
                VSC_SATA_INT_MASK_OFFSET + ap->port_no;

        writeb(0, mask_addr);
}


static void vsc_thaw(struct ata_port *ap)
{
        void __iomem *mask_addr;

        mask_addr = ap->host->iomap[VSC_MMIO_BAR] +
                VSC_SATA_INT_MASK_OFFSET + ap->port_no;

        writeb(0xff, mask_addr);
}


static void vsc_intr_mask_update(struct ata_port *ap, u8 ctl)
{
        void __iomem *mask_addr;
        u8 mask;

        mask_addr = ap->host->iomap[VSC_MMIO_BAR] +
                VSC_SATA_INT_MASK_OFFSET + ap->port_no;
        mask = readb(mask_addr);
        if (ctl & ATA_NIEN)
                mask |= 0x80;
        else
                mask &= 0x7F;
        writeb(mask, mask_addr);
}


static void vsc_sata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;

        /*
         * The only thing the ctl register is used for is SRST.
         * That is not enabled or disabled via tf_load.
         * However, if ATA_NIEN is changed, then we need to change
         * the interrupt register.
         */
        if ((tf->ctl & ATA_NIEN) != (ap->last_ctl & ATA_NIEN)) {
                ap->last_ctl = tf->ctl;
                vsc_intr_mask_update(ap, tf->ctl & ATA_NIEN);
        }
        if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
                writew(tf->feature | (((u16)tf->hob_feature) << 8),
                       ioaddr->feature_addr);
                writew(tf->nsect | (((u16)tf->hob_nsect) << 8),
                       ioaddr->nsect_addr);
                writew(tf->lbal | (((u16)tf->hob_lbal) << 8),
                       ioaddr->lbal_addr);
                writew(tf->lbam | (((u16)tf->hob_lbam) << 8),
                       ioaddr->lbam_addr);
                writew(tf->lbah | (((u16)tf->hob_lbah) << 8),
                       ioaddr->lbah_addr);
        } else if (is_addr) {
                writew(tf->feature, ioaddr->feature_addr);
                writew(tf->nsect, ioaddr->nsect_addr);
                writew(tf->lbal, ioaddr->lbal_addr);
                writew(tf->lbam, ioaddr->lbam_addr);
                writew(tf->lbah, ioaddr->lbah_addr);
        }

        if (tf->flags & ATA_TFLAG_DEVICE)
                writeb(tf->device, ioaddr->device_addr);

        ata_wait_idle(ap);
}


static void vsc_sata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        u16 nsect, lbal, lbam, lbah, error;

        tf->status = ata_sff_check_status(ap);
        tf->device = readw(ioaddr->device_addr);
        error = readw(ioaddr->error_addr);
        nsect = readw(ioaddr->nsect_addr);
        lbal = readw(ioaddr->lbal_addr);
        lbam = readw(ioaddr->lbam_addr);
        lbah = readw(ioaddr->lbah_addr);

        tf->error = error;
        tf->nsect = nsect;
        tf->lbal = lbal;
        tf->lbam = lbam;
        tf->lbah = lbah;

        if (tf->flags & ATA_TFLAG_LBA48) {
                tf->hob_feature = error >> 8;
                tf->hob_nsect = nsect >> 8;
                tf->hob_lbal = lbal >> 8;
                tf->hob_lbam = lbam >> 8;
                tf->hob_lbah = lbah >> 8;
        }
}

static inline void vsc_error_intr(u8 port_status, struct ata_port *ap)
{
        if (port_status & (VSC_SATA_INT_PHY_CHANGE | VSC_SATA_INT_ERROR_M))
                ata_port_freeze(ap);
        else
                ata_port_abort(ap);
}

static void vsc_port_intr(u8 port_status, struct ata_port *ap)
{
        struct ata_queued_cmd *qc;
        int handled = 0;

        if (unlikely(port_status & VSC_SATA_INT_ERROR)) {
                vsc_error_intr(port_status, ap);
                return;
        }

        qc = ata_qc_from_tag(ap, ap->link.active_tag);
        if (qc && likely(!(qc->tf.flags & ATA_TFLAG_POLLING)))
                handled = ata_bmdma_port_intr(ap, qc);

        /* We received an interrupt during a polled command,
         * or some other spurious condition.  Interrupt reporting
         * with this hardware is fairly reliable so it is safe to
         * simply clear the interrupt
         */
        if (unlikely(!handled))
                ap->ops->sff_check_status(ap);
}

/*
 * vsc_sata_interrupt
 *
 * Read the interrupt register and process for the devices that have
 * them pending.
 */
static irqreturn_t vsc_sata_interrupt(int irq, void *dev_instance)
{
        struct ata_host *host = dev_instance;
        unsigned int i;
        unsigned int handled = 0;
        u32 status;

        status = readl(host->iomap[VSC_MMIO_BAR] + VSC_SATA_INT_STAT_OFFSET);

        if (unlikely(status == 0xffffffff || status == 0)) {
                if (status)
                        dev_err(host->dev,
                                ": IRQ status == 0xffffffff, PCI fault or device removal?\n");
                goto out;
        }

        spin_lock(&host->lock);

        for (i = 0; i < host->n_ports; i++) {
                u8 port_status = (status >> (8 * i)) & 0xff;
                if (port_status) {
                        vsc_port_intr(port_status, host->ports[i]);
                        handled++;
                }
        }

        spin_unlock(&host->lock);
out:
        return IRQ_RETVAL(handled);
}


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


static struct ata_port_operations vsc_sata_ops = {
        .inherits               = &ata_bmdma_port_ops,
        /* The IRQ handling is not quite standard SFF behaviour so we
           cannot use the default lost interrupt handler */
        .lost_interrupt         = ATA_OP_NULL,
        .sff_tf_load            = vsc_sata_tf_load,
        .sff_tf_read            = vsc_sata_tf_read,
        .freeze                 = vsc_freeze,
        .thaw                   = vsc_thaw,
        .scr_read               = vsc_sata_scr_read,
        .scr_write              = vsc_sata_scr_write,
};

static void vsc_sata_setup_port(struct ata_ioports *port, void __iomem *base)
{
        port->cmd_addr          = base + VSC_SATA_TF_CMD_OFFSET;
        port->data_addr         = base + VSC_SATA_TF_DATA_OFFSET;
        port->error_addr        = base + VSC_SATA_TF_ERROR_OFFSET;
        port->feature_addr      = base + VSC_SATA_TF_FEATURE_OFFSET;
        port->nsect_addr        = base + VSC_SATA_TF_NSECT_OFFSET;
        port->lbal_addr         = base + VSC_SATA_TF_LBAL_OFFSET;
        port->lbam_addr         = base + VSC_SATA_TF_LBAM_OFFSET;
        port->lbah_addr         = base + VSC_SATA_TF_LBAH_OFFSET;
        port->device_addr       = base + VSC_SATA_TF_DEVICE_OFFSET;
        port->status_addr       = base + VSC_SATA_TF_STATUS_OFFSET;
        port->command_addr      = base + VSC_SATA_TF_COMMAND_OFFSET;
        port->altstatus_addr    = base + VSC_SATA_TF_ALTSTATUS_OFFSET;
        port->ctl_addr          = base + VSC_SATA_TF_CTL_OFFSET;
        port->bmdma_addr        = base + VSC_SATA_DMA_CMD_OFFSET;
        port->scr_addr          = base + VSC_SATA_SCR_STATUS_OFFSET;
        writel(0, base + VSC_SATA_UP_DESCRIPTOR_OFFSET);
        writel(0, base + VSC_SATA_UP_DATA_BUFFER_OFFSET);
}


static int vsc_sata_init_one(struct pci_dev *pdev,
                             const struct pci_device_id *ent)
{
        static const struct ata_port_info pi = {
                .flags          = ATA_FLAG_SATA,
                .pio_mask       = ATA_PIO4,
                .mwdma_mask     = ATA_MWDMA2,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &vsc_sata_ops,
        };
        const struct ata_port_info *ppi[] = { &pi, NULL };
        struct ata_host *host;
        void __iomem *mmio_base;
        int i, rc;
        u8 cls;

        ata_print_version_once(&pdev->dev, DRV_VERSION);

        /* allocate host */
        host = ata_host_alloc_pinfo(&pdev->dev, ppi, 4);
        if (!host)
                return -ENOMEM;

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

        /* check if we have needed resource mapped */
        if (pci_resource_len(pdev, 0) == 0)
                return -ENODEV;

        /* map IO regions and initialize host accordingly */
        rc = pcim_iomap_regions(pdev, 1 << VSC_MMIO_BAR, DRV_NAME);
        if (rc == -EBUSY)
                pcim_pin_device(pdev);
        if (rc)
                return rc;
        host->iomap = pcim_iomap_table(pdev);

        mmio_base = host->iomap[VSC_MMIO_BAR];

        for (i = 0; i < host->n_ports; i++) {
                struct ata_port *ap = host->ports[i];
                unsigned int offset = (i + 1) * VSC_SATA_PORT_OFFSET;

                vsc_sata_setup_port(&ap->ioaddr, mmio_base + offset);

                ata_port_pbar_desc(ap, VSC_MMIO_BAR, -1, "mmio");
                ata_port_pbar_desc(ap, VSC_MMIO_BAR, offset, "port");
        }

        /*
         * Use 32 bit DMA mask, because 64 bit address support is poor.
         */
        rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
        if (rc)
                return rc;

        /*
         * Due to a bug in the chip, the default cache line size can't be
         * used (unless the default is non-zero).
         */
        pci_read_config_byte(pdev, PCI_CACHE_LINE_SIZE, &cls);
        if (cls == 0x00)
                pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, 0x80);

        if (pci_enable_msi(pdev) == 0)
                pcim_intx(pdev, 0);

        /*
         * Config offset 0x98 is "Extended Control and Status Register 0"
         * Default value is (1 << 28).  All bits except bit 28 are reserved in
         * DPA mode.  If bit 28 is set, LED 0 reflects all ports' activity.
         * If bit 28 is clear, each port has its own LED.
         */
        pci_write_config_dword(pdev, 0x98, 0);

        pci_set_master(pdev);
        return ata_host_activate(host, pdev->irq, vsc_sata_interrupt,
                                 IRQF_SHARED, &vsc_sata_sht);
}

static const struct pci_device_id vsc_sata_pci_tbl[] = {
        { PCI_VENDOR_ID_VITESSE, 0x7174,
          PCI_ANY_ID, PCI_ANY_ID, 0x10600, 0xFFFFFF, 0 },
        { PCI_VENDOR_ID_INTEL, 0x3200,
          PCI_ANY_ID, PCI_ANY_ID, 0x10600, 0xFFFFFF, 0 },

        { }     /* terminate list */
};

static struct pci_driver vsc_sata_pci_driver = {
        .name                   = DRV_NAME,
        .id_table               = vsc_sata_pci_tbl,
        .probe                  = vsc_sata_init_one,
        .remove                 = ata_pci_remove_one,
};

module_pci_driver(vsc_sata_pci_driver);

MODULE_AUTHOR("Jeremy Higdon");
MODULE_DESCRIPTION("low-level driver for Vitesse VSC7174 SATA controller");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, vsc_sata_pci_tbl);
MODULE_VERSION(DRV_VERSION);