// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for Western Digital WD7193, WD7197 and WD7296 SCSI cards
 * Copyright 2013 Ondrej Zary
 *
 * Original driver by
 * Aaron Dewell <dewell@woods.net>
 * Gaerti <Juergen.Gaertner@mbox.si.uni-hannover.de>
 *
 * HW documentation available in book:
 *
 * SPIDER Command Protocol
 * by Chandru M. Sippy
 * SCSI Storage Products (MCP)
 * Western Digital Corporation
 * 09-15-95
 *
 * http://web.archive.org/web/20070717175254/http://sun1.rrzn.uni-hannover.de/gaertner.juergen/wd719x/Linux/Docu/Spider/
 */

/*
 * Driver workflow:
 * 1. SCSI command is transformed to SCB (Spider Control Block) by the
 *    queuecommand function.
 * 2. The address of the SCB is stored in a list to be able to access it, if
 *    something goes wrong.
 * 3. The address of the SCB is written to the Controller, which loads the SCB
 *    via BM-DMA and processes it.
 * 4. After it has finished, it generates an interrupt, and sets registers.
 *
 * flaws:
 *  - abort/reset functions
 *
 * ToDo:
 *  - tagged queueing
 */

#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/firmware.h>
#include <linux/eeprom_93cx6.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include "wd719x.h"

/* low-level register access */
static inline u8 wd719x_readb(struct wd719x *wd, u8 reg)
{
        return ioread8(wd->base + reg);
}

static inline u32 wd719x_readl(struct wd719x *wd, u8 reg)
{
        return ioread32(wd->base + reg);
}

static inline void wd719x_writeb(struct wd719x *wd, u8 reg, u8 val)
{
        iowrite8(val, wd->base + reg);
}

static inline void wd719x_writew(struct wd719x *wd, u8 reg, u16 val)
{
        iowrite16(val, wd->base + reg);
}

static inline void wd719x_writel(struct wd719x *wd, u8 reg, u32 val)
{
        iowrite32(val, wd->base + reg);
}

/* wait until the command register is ready */
static inline int wd719x_wait_ready(struct wd719x *wd)
{
        int i = 0;

        do {
                if (wd719x_readb(wd, WD719X_AMR_COMMAND) == WD719X_CMD_READY)
                        return 0;
                udelay(1);
        } while (i++ < WD719X_WAIT_FOR_CMD_READY);

        dev_err(&wd->pdev->dev, "command register is not ready: 0x%02x\n",
                wd719x_readb(wd, WD719X_AMR_COMMAND));

        return -ETIMEDOUT;
}

/* poll interrupt status register until command finishes */
static inline int wd719x_wait_done(struct wd719x *wd, int timeout)
{
        u8 status;

        while (timeout > 0) {
                status = wd719x_readb(wd, WD719X_AMR_INT_STATUS);
                if (status)
                        break;
                timeout--;
                udelay(1);
        }

        if (timeout <= 0) {
                dev_err(&wd->pdev->dev, "direct command timed out\n");
                return -ETIMEDOUT;
        }

        if (status != WD719X_INT_NOERRORS) {
                u8 sue = wd719x_readb(wd, WD719X_AMR_SCB_ERROR);
                /* we get this after wd719x_dev_reset, it's not an error */
                if (sue == WD719X_SUE_TERM)
                        return 0;
                /* we get this after wd719x_bus_reset, it's not an error */
                if (sue == WD719X_SUE_RESET)
                        return 0;
                dev_err(&wd->pdev->dev, "direct command failed, status 0x%02x, SUE 0x%02x\n",
                        status, sue);
                return -EIO;
        }

        return 0;
}

static int wd719x_direct_cmd(struct wd719x *wd, u8 opcode, u8 dev, u8 lun,
                             u8 tag, dma_addr_t data, int timeout)
{
        int ret = 0;

        /* clear interrupt status register (allow command register to clear) */
        wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);

        /* Wait for the Command register to become free */
        if (wd719x_wait_ready(wd))
                return -ETIMEDOUT;

        /* disable interrupts except for RESET/ABORT (it breaks them) */
        if (opcode != WD719X_CMD_BUSRESET && opcode != WD719X_CMD_ABORT &&
            opcode != WD719X_CMD_ABORT_TAG && opcode != WD719X_CMD_RESET)
                dev |= WD719X_DISABLE_INT;
        wd719x_writeb(wd, WD719X_AMR_CMD_PARAM, dev);
        wd719x_writeb(wd, WD719X_AMR_CMD_PARAM_2, lun);
        wd719x_writeb(wd, WD719X_AMR_CMD_PARAM_3, tag);
        if (data)
                wd719x_writel(wd, WD719X_AMR_SCB_IN, data);

        /* clear interrupt status register again */
        wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);

        /* Now, write the command */
        wd719x_writeb(wd, WD719X_AMR_COMMAND, opcode);

        if (timeout)    /* wait for the command to complete */
                ret = wd719x_wait_done(wd, timeout);

        /* clear interrupt status register (clean up) */
        if (opcode != WD719X_CMD_READ_FIRMVER)
                wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);

        return ret;
}

static void wd719x_destroy(struct wd719x *wd)
{
        /* stop the RISC */
        if (wd719x_direct_cmd(wd, WD719X_CMD_SLEEP, 0, 0, 0, 0,
                              WD719X_WAIT_FOR_RISC))
                dev_warn(&wd->pdev->dev, "RISC sleep command failed\n");
        /* disable RISC */
        wd719x_writeb(wd, WD719X_PCI_MODE_SELECT, 0);

        WARN_ON_ONCE(!list_empty(&wd->active_scbs));

        /* free internal buffers */
        dma_free_coherent(&wd->pdev->dev, wd->fw_size, wd->fw_virt,
                          wd->fw_phys);
        wd->fw_virt = NULL;
        dma_free_coherent(&wd->pdev->dev, WD719X_HASH_TABLE_SIZE, wd->hash_virt,
                          wd->hash_phys);
        wd->hash_virt = NULL;
        dma_free_coherent(&wd->pdev->dev, sizeof(struct wd719x_host_param),
                          wd->params, wd->params_phys);
        wd->params = NULL;
        free_irq(wd->pdev->irq, wd);
}

/* finish a SCSI command, unmap buffers */
static void wd719x_finish_cmd(struct wd719x_scb *scb, int result)
{
        struct scsi_cmnd *cmd = scb->cmd;
        struct wd719x *wd = shost_priv(cmd->device->host);

        list_del(&scb->list);

        dma_unmap_single(&wd->pdev->dev, scb->phys,
                        sizeof(struct wd719x_scb), DMA_BIDIRECTIONAL);
        scsi_dma_unmap(cmd);
        dma_unmap_single(&wd->pdev->dev, cmd->SCp.dma_handle,
                         SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);

        cmd->result = result << 16;
        cmd->scsi_done(cmd);
}

/* Build a SCB and send it to the card */
static int wd719x_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
{
        int i, count_sg;
        unsigned long flags;
        struct wd719x_scb *scb = scsi_cmd_priv(cmd);
        struct wd719x *wd = shost_priv(sh);

        scb->cmd = cmd;

        scb->CDB_tag = 0;       /* Tagged queueing not supported yet */
        scb->devid = cmd->device->id;
        scb->lun = cmd->device->lun;

        /* copy the command */
        memcpy(scb->CDB, cmd->cmnd, cmd->cmd_len);

        /* map SCB */
        scb->phys = dma_map_single(&wd->pdev->dev, scb, sizeof(*scb),
                                   DMA_BIDIRECTIONAL);

        if (dma_mapping_error(&wd->pdev->dev, scb->phys))
                goto out_error;

        /* map sense buffer */
        scb->sense_buf_length = SCSI_SENSE_BUFFERSIZE;
        cmd->SCp.dma_handle = dma_map_single(&wd->pdev->dev, cmd->sense_buffer,
                        SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
        if (dma_mapping_error(&wd->pdev->dev, cmd->SCp.dma_handle))
                goto out_unmap_scb;
        scb->sense_buf = cpu_to_le32(cmd->SCp.dma_handle);

        /* request autosense */
        scb->SCB_options |= WD719X_SCB_FLAGS_AUTO_REQUEST_SENSE;

        /* check direction */
        if (cmd->sc_data_direction == DMA_TO_DEVICE)
                scb->SCB_options |= WD719X_SCB_FLAGS_CHECK_DIRECTION
                                 |  WD719X_SCB_FLAGS_PCI_TO_SCSI;
        else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
                scb->SCB_options |= WD719X_SCB_FLAGS_CHECK_DIRECTION;

        /* Scather/gather */
        count_sg = scsi_dma_map(cmd);
        if (count_sg < 0)
                goto out_unmap_sense;
        BUG_ON(count_sg > WD719X_SG);

        if (count_sg) {
                struct scatterlist *sg;

                scb->data_length = cpu_to_le32(count_sg *
                                               sizeof(struct wd719x_sglist));
                scb->data_p = cpu_to_le32(scb->phys +
                                          offsetof(struct wd719x_scb, sg_list));

                scsi_for_each_sg(cmd, sg, count_sg, i) {
                        scb->sg_list[i].ptr = cpu_to_le32(sg_dma_address(sg));
                        scb->sg_list[i].length = cpu_to_le32(sg_dma_len(sg));
                }
                scb->SCB_options |= WD719X_SCB_FLAGS_DO_SCATTER_GATHER;
        } else { /* zero length */
                scb->data_length = 0;
                scb->data_p = 0;
        }

        spin_lock_irqsave(wd->sh->host_lock, flags);

        /* check if the Command register is free */
        if (wd719x_readb(wd, WD719X_AMR_COMMAND) != WD719X_CMD_READY) {
                spin_unlock_irqrestore(wd->sh->host_lock, flags);
                return SCSI_MLQUEUE_HOST_BUSY;
        }

        list_add(&scb->list, &wd->active_scbs);

        /* write pointer to the AMR */
        wd719x_writel(wd, WD719X_AMR_SCB_IN, scb->phys);
        /* send SCB opcode */
        wd719x_writeb(wd, WD719X_AMR_COMMAND, WD719X_CMD_PROCESS_SCB);

        spin_unlock_irqrestore(wd->sh->host_lock, flags);
        return 0;

out_unmap_sense:
        dma_unmap_single(&wd->pdev->dev, cmd->SCp.dma_handle,
                         SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
out_unmap_scb:
        dma_unmap_single(&wd->pdev->dev, scb->phys, sizeof(*scb),
                         DMA_BIDIRECTIONAL);
out_error:
        cmd->result = DID_ERROR << 16;
        cmd->scsi_done(cmd);
        return 0;
}

static int wd719x_chip_init(struct wd719x *wd)
{
        int i, ret;
        u32 risc_init[3];
        const struct firmware *fw_wcs, *fw_risc;
        const char fwname_wcs[] = "wd719x-wcs.bin";
        const char fwname_risc[] = "wd719x-risc.bin";

        memset(wd->hash_virt, 0, WD719X_HASH_TABLE_SIZE);

        /* WCS (sequencer) firmware */
        ret = request_firmware(&fw_wcs, fwname_wcs, &wd->pdev->dev);
        if (ret) {
                dev_err(&wd->pdev->dev, "Unable to load firmware %s: %d\n",
                        fwname_wcs, ret);
                return ret;
        }
        /* RISC firmware */
        ret = request_firmware(&fw_risc, fwname_risc, &wd->pdev->dev);
        if (ret) {
                dev_err(&wd->pdev->dev, "Unable to load firmware %s: %d\n",
                        fwname_risc, ret);
                release_firmware(fw_wcs);
                return ret;
        }
        wd->fw_size = ALIGN(fw_wcs->size, 4) + fw_risc->size;

        if (!wd->fw_virt)
                wd->fw_virt = dma_alloc_coherent(&wd->pdev->dev, wd->fw_size,
                                                 &wd->fw_phys, GFP_KERNEL);
        if (!wd->fw_virt) {
                ret = -ENOMEM;
                goto wd719x_init_end;
        }

        /* make a fresh copy of WCS and RISC code */
        memcpy(wd->fw_virt, fw_wcs->data, fw_wcs->size);
        memcpy(wd->fw_virt + ALIGN(fw_wcs->size, 4), fw_risc->data,
                fw_risc->size);

        /* Reset the Spider Chip and adapter itself */
        wd719x_writeb(wd, WD719X_PCI_PORT_RESET, WD719X_PCI_RESET);
        udelay(WD719X_WAIT_FOR_RISC);
        /* Clear PIO mode bits set by BIOS */
        wd719x_writeb(wd, WD719X_AMR_CMD_PARAM, 0);
        /* ensure RISC is not running */
        wd719x_writeb(wd, WD719X_PCI_MODE_SELECT, 0);
        /* ensure command port is ready */
        wd719x_writeb(wd, WD719X_AMR_COMMAND, 0);
        if (wd719x_wait_ready(wd)) {
                ret = -ETIMEDOUT;
                goto wd719x_init_end;
        }

        /* Transfer the first 2K words of RISC code to kick start the uP */
        risc_init[0] = wd->fw_phys;                             /* WCS FW */
        risc_init[1] = wd->fw_phys + ALIGN(fw_wcs->size, 4);    /* RISC FW */
        risc_init[2] = wd->hash_phys;                           /* hash table */

        /* clear DMA status */
        wd719x_writeb(wd, WD719X_PCI_CHANNEL2_3STATUS, 0);

        /* address to read firmware from */
        wd719x_writel(wd, WD719X_PCI_EXTERNAL_ADDR, risc_init[1]);
        /* base address to write firmware to (on card) */
        wd719x_writew(wd, WD719X_PCI_INTERNAL_ADDR, WD719X_PRAM_BASE_ADDR);
        /* size: first 2K words */
        wd719x_writew(wd, WD719X_PCI_DMA_TRANSFER_SIZE, 2048 * 2);
        /* start DMA */
        wd719x_writeb(wd, WD719X_PCI_CHANNEL2_3CMD, WD719X_START_CHANNEL2_3DMA);

        /* wait for DMA to complete */
        i = WD719X_WAIT_FOR_RISC;
        while (i-- > 0) {
                u8 status = wd719x_readb(wd, WD719X_PCI_CHANNEL2_3STATUS);
                if (status == WD719X_START_CHANNEL2_3DONE)
                        break;
                if (status == WD719X_START_CHANNEL2_3ABORT) {
                        dev_warn(&wd->pdev->dev, "RISC bootstrap failed: DMA aborted\n");
                        ret = -EIO;
                        goto wd719x_init_end;
                }
                udelay(1);
        }
        if (i < 1) {
                dev_warn(&wd->pdev->dev, "RISC bootstrap failed: DMA timeout\n");
                ret = -ETIMEDOUT;
                goto wd719x_init_end;
        }

        /* firmware is loaded, now initialize and wake up the RISC */
        /* write RISC initialization long words to Spider */
        wd719x_writel(wd, WD719X_AMR_SCB_IN, risc_init[0]);
        wd719x_writel(wd, WD719X_AMR_SCB_IN + 4, risc_init[1]);
        wd719x_writel(wd, WD719X_AMR_SCB_IN + 8, risc_init[2]);

        /* disable interrupts during initialization of RISC */
        wd719x_writeb(wd, WD719X_AMR_CMD_PARAM, WD719X_DISABLE_INT);

        /* issue INITIALIZE RISC comand */
        wd719x_writeb(wd, WD719X_AMR_COMMAND, WD719X_CMD_INIT_RISC);
        /* enable advanced mode (wake up RISC) */
        wd719x_writeb(wd, WD719X_PCI_MODE_SELECT, WD719X_ENABLE_ADVANCE_MODE);
        udelay(WD719X_WAIT_FOR_RISC);

        ret = wd719x_wait_done(wd, WD719X_WAIT_FOR_RISC);
        /* clear interrupt status register */
        wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);
        if (ret) {
                dev_warn(&wd->pdev->dev, "Unable to initialize RISC\n");
                goto wd719x_init_end;
        }
        /* RISC is up and running */

        /* Read FW version from RISC */
        ret = wd719x_direct_cmd(wd, WD719X_CMD_READ_FIRMVER, 0, 0, 0, 0,
                                WD719X_WAIT_FOR_RISC);
        if (ret) {
                dev_warn(&wd->pdev->dev, "Unable to read firmware version\n");
                goto wd719x_init_end;
        }
        dev_info(&wd->pdev->dev, "RISC initialized with firmware version %.2x.%.2x\n",
                        wd719x_readb(wd, WD719X_AMR_SCB_OUT + 1),
                        wd719x_readb(wd, WD719X_AMR_SCB_OUT));

        /* RESET SCSI bus */
        ret = wd719x_direct_cmd(wd, WD719X_CMD_BUSRESET, 0, 0, 0, 0,
                                WD719X_WAIT_FOR_SCSI_RESET);
        if (ret) {
                dev_warn(&wd->pdev->dev, "SCSI bus reset failed\n");
                goto wd719x_init_end;
        }

        /* use HostParameter structure to set Spider's Host Parameter Block */
        ret = wd719x_direct_cmd(wd, WD719X_CMD_SET_PARAM, 0,
                                sizeof(struct wd719x_host_param), 0,
                                wd->params_phys, WD719X_WAIT_FOR_RISC);
        if (ret) {
                dev_warn(&wd->pdev->dev, "Failed to set HOST PARAMETERS\n");
                goto wd719x_init_end;
        }

        /* initiate SCAM (does nothing if disabled in BIOS) */
        /* bug?: we should pass a mask of static IDs which we don't have */
        ret = wd719x_direct_cmd(wd, WD719X_CMD_INIT_SCAM, 0, 0, 0, 0,
                                WD719X_WAIT_FOR_SCSI_RESET);
        if (ret) {
                dev_warn(&wd->pdev->dev, "SCAM initialization failed\n");
                goto wd719x_init_end;
        }

        /* clear AMR_BIOS_SHARE_INT register */
        wd719x_writeb(wd, WD719X_AMR_BIOS_SHARE_INT, 0);

wd719x_init_end:
        release_firmware(fw_wcs);
        release_firmware(fw_risc);

        return ret;
}

static int wd719x_abort(struct scsi_cmnd *cmd)
{
        int action, result;
        unsigned long flags;
        struct wd719x_scb *scb = scsi_cmd_priv(cmd);
        struct wd719x *wd = shost_priv(cmd->device->host);

        dev_info(&wd->pdev->dev, "abort command, tag: %x\n", cmd->tag);

        action = /*cmd->tag ? WD719X_CMD_ABORT_TAG : */WD719X_CMD_ABORT;

        spin_lock_irqsave(wd->sh->host_lock, flags);
        result = wd719x_direct_cmd(wd, action, cmd->device->id,
                                   cmd->device->lun, cmd->tag, scb->phys, 0);
        wd719x_finish_cmd(scb, DID_ABORT);
        spin_unlock_irqrestore(wd->sh->host_lock, flags);
        if (result)
                return FAILED;

        return SUCCESS;
}

static int wd719x_reset(struct scsi_cmnd *cmd, u8 opcode, u8 device)
{
        int result;
        unsigned long flags;
        struct wd719x *wd = shost_priv(cmd->device->host);
        struct wd719x_scb *scb, *tmp;

        dev_info(&wd->pdev->dev, "%s reset requested\n",
                 (opcode == WD719X_CMD_BUSRESET) ? "bus" : "device");

        spin_lock_irqsave(wd->sh->host_lock, flags);
        result = wd719x_direct_cmd(wd, opcode, device, 0, 0, 0,
                                   WD719X_WAIT_FOR_SCSI_RESET);
        /* flush all SCBs (or all for a device if dev_reset) */
        list_for_each_entry_safe(scb, tmp, &wd->active_scbs, list) {
                if (opcode == WD719X_CMD_BUSRESET ||
                    scb->cmd->device->id == device)
                        wd719x_finish_cmd(scb, DID_RESET);
        }
        spin_unlock_irqrestore(wd->sh->host_lock, flags);
        if (result)
                return FAILED;

        return SUCCESS;
}

static int wd719x_dev_reset(struct scsi_cmnd *cmd)
{
        return wd719x_reset(cmd, WD719X_CMD_RESET, cmd->device->id);
}

static int wd719x_bus_reset(struct scsi_cmnd *cmd)
{
        return wd719x_reset(cmd, WD719X_CMD_BUSRESET, 0);
}

static int wd719x_host_reset(struct scsi_cmnd *cmd)
{
        struct wd719x *wd = shost_priv(cmd->device->host);
        struct wd719x_scb *scb, *tmp;
        unsigned long flags;

        dev_info(&wd->pdev->dev, "host reset requested\n");
        spin_lock_irqsave(wd->sh->host_lock, flags);
        /* stop the RISC */
        if (wd719x_direct_cmd(wd, WD719X_CMD_SLEEP, 0, 0, 0, 0,
                              WD719X_WAIT_FOR_RISC))
                dev_warn(&wd->pdev->dev, "RISC sleep command failed\n");
        /* disable RISC */
        wd719x_writeb(wd, WD719X_PCI_MODE_SELECT, 0);

        /* flush all SCBs */
        list_for_each_entry_safe(scb, tmp, &wd->active_scbs, list)
                wd719x_finish_cmd(scb, DID_RESET);
        spin_unlock_irqrestore(wd->sh->host_lock, flags);

        /* Try to reinit the RISC */
        return wd719x_chip_init(wd) == 0 ? SUCCESS : FAILED;
}

static int wd719x_biosparam(struct scsi_device *sdev, struct block_device *bdev,
                            sector_t capacity, int geom[])
{
        if (capacity >= 0x200000) {
                geom[0] = 255;  /* heads */
                geom[1] = 63;   /* sectors */
        } else {
                geom[0] = 64;   /* heads */
                geom[1] = 32;   /* sectors */
        }
        geom[2] = sector_div(capacity, geom[0] * geom[1]);      /* cylinders */

        return 0;
}

/* process a SCB-completion interrupt */
static inline void wd719x_interrupt_SCB(struct wd719x *wd,
                                        union wd719x_regs regs,
                                        struct wd719x_scb *scb)
{
        int result;

        /* now have to find result from card */
        switch (regs.bytes.SUE) {
        case WD719X_SUE_NOERRORS:
                result = DID_OK;
                break;
        case WD719X_SUE_REJECTED:
                dev_err(&wd->pdev->dev, "command rejected\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_SCBQFULL:
                dev_err(&wd->pdev->dev, "SCB queue is full\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_TERM:
                dev_dbg(&wd->pdev->dev, "SCB terminated by direct command\n");
                result = DID_ABORT;     /* or DID_RESET? */
                break;
        case WD719X_SUE_CHAN1ABORT:
        case WD719X_SUE_CHAN23ABORT:
                result = DID_ABORT;
                dev_err(&wd->pdev->dev, "DMA abort\n");
                break;
        case WD719X_SUE_CHAN1PAR:
        case WD719X_SUE_CHAN23PAR:
                result = DID_PARITY;
                dev_err(&wd->pdev->dev, "DMA parity error\n");
                break;
        case WD719X_SUE_TIMEOUT:
                result = DID_TIME_OUT;
                dev_dbg(&wd->pdev->dev, "selection timeout\n");
                break;
        case WD719X_SUE_RESET:
                dev_dbg(&wd->pdev->dev, "bus reset occurred\n");
                result = DID_RESET;
                break;
        case WD719X_SUE_BUSERROR:
                dev_dbg(&wd->pdev->dev, "SCSI bus error\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_WRONGWAY:
                dev_err(&wd->pdev->dev, "wrong data transfer direction\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_BADPHASE:
                dev_err(&wd->pdev->dev, "invalid SCSI phase\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_TOOLONG:
                dev_err(&wd->pdev->dev, "record too long\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_BUSFREE:
                dev_err(&wd->pdev->dev, "unexpected bus free\n");
                result = DID_NO_CONNECT; /* or DID_ERROR ???*/
                break;
        case WD719X_SUE_ARSDONE:
                dev_dbg(&wd->pdev->dev, "auto request sense\n");
                if (regs.bytes.SCSI == 0)
                        result = DID_OK;
                else
                        result = DID_PARITY;
                break;
        case WD719X_SUE_IGNORED:
                dev_err(&wd->pdev->dev, "target id %d ignored command\n",
                        scb->cmd->device->id);
                result = DID_NO_CONNECT;
                break;
        case WD719X_SUE_WRONGTAGS:
                dev_err(&wd->pdev->dev, "reversed tags\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_BADTAGS:
                dev_err(&wd->pdev->dev, "tag type not supported by target\n");
                result = DID_ERROR;
                break;
        case WD719X_SUE_NOSCAMID:
                dev_err(&wd->pdev->dev, "no SCAM soft ID available\n");
                result = DID_ERROR;
                break;
        default:
                dev_warn(&wd->pdev->dev, "unknown SUE error code: 0x%x\n",
                         regs.bytes.SUE);
                result = DID_ERROR;
                break;
        }

        wd719x_finish_cmd(scb, result);
}

static irqreturn_t wd719x_interrupt(int irq, void *dev_id)
{
        struct wd719x *wd = dev_id;
        union wd719x_regs regs;
        unsigned long flags;
        u32 SCB_out;

        spin_lock_irqsave(wd->sh->host_lock, flags);
        /* read SCB pointer back from card */
        SCB_out = wd719x_readl(wd, WD719X_AMR_SCB_OUT);
        /* read all status info at once */
        regs.all = cpu_to_le32(wd719x_readl(wd, WD719X_AMR_OP_CODE));

        switch (regs.bytes.INT) {
        case WD719X_INT_NONE:
                spin_unlock_irqrestore(wd->sh->host_lock, flags);
                return IRQ_NONE;
        case WD719X_INT_LINKNOSTATUS:
                dev_err(&wd->pdev->dev, "linked command completed with no status\n");
                break;
        case WD719X_INT_BADINT:
                dev_err(&wd->pdev->dev, "unsolicited interrupt\n");
                break;
        case WD719X_INT_NOERRORS:
        case WD719X_INT_LINKNOERRORS:
        case WD719X_INT_ERRORSLOGGED:
        case WD719X_INT_SPIDERFAILED:
                /* was the cmd completed a direct or SCB command? */
                if (regs.bytes.OPC == WD719X_CMD_PROCESS_SCB) {
                        struct wd719x_scb *scb;
                        list_for_each_entry(scb, &wd->active_scbs, list)
                                if (SCB_out == scb->phys)
                                        break;
                        if (SCB_out == scb->phys)
                                wd719x_interrupt_SCB(wd, regs, scb);
                        else
                                dev_err(&wd->pdev->dev, "card returned invalid SCB pointer\n");
                } else
                        dev_dbg(&wd->pdev->dev, "direct command 0x%x completed\n",
                                 regs.bytes.OPC);
                break;
        case WD719X_INT_PIOREADY:
                dev_err(&wd->pdev->dev, "card indicates PIO data ready but we never use PIO\n");
                /* interrupt will not be cleared until all data is read */
                break;
        default:
                dev_err(&wd->pdev->dev, "unknown interrupt reason: %d\n",
                        regs.bytes.INT);

        }
        /* clear interrupt so another can happen */
        wd719x_writeb(wd, WD719X_AMR_INT_STATUS, WD719X_INT_NONE);
        spin_unlock_irqrestore(wd->sh->host_lock, flags);

        return IRQ_HANDLED;
}

static void wd719x_eeprom_reg_read(struct eeprom_93cx6 *eeprom)
{
        struct wd719x *wd = eeprom->data;
        u8 reg = wd719x_readb(wd, WD719X_PCI_GPIO_DATA);

        eeprom->reg_data_out = reg & WD719X_EE_DO;
}

static void wd719x_eeprom_reg_write(struct eeprom_93cx6 *eeprom)
{
        struct wd719x *wd = eeprom->data;
        u8 reg = 0;

        if (eeprom->reg_data_in)
                reg |= WD719X_EE_DI;
        if (eeprom->reg_data_clock)
                reg |= WD719X_EE_CLK;
        if (eeprom->reg_chip_select)
                reg |= WD719X_EE_CS;

        wd719x_writeb(wd, WD719X_PCI_GPIO_DATA, reg);
}

/* read config from EEPROM so it can be downloaded by the RISC on (re-)init */
static void wd719x_read_eeprom(struct wd719x *wd)
{
        struct eeprom_93cx6 eeprom;
        u8 gpio;
        struct wd719x_eeprom_header header;

        eeprom.data = wd;
        eeprom.register_read = wd719x_eeprom_reg_read;
        eeprom.register_write = wd719x_eeprom_reg_write;
        eeprom.width = PCI_EEPROM_WIDTH_93C46;

        /* set all outputs to low */
        wd719x_writeb(wd, WD719X_PCI_GPIO_DATA, 0);
        /* configure GPIO pins */
        gpio = wd719x_readb(wd, WD719X_PCI_GPIO_CONTROL);
        /* GPIO outputs */
        gpio &= (~(WD719X_EE_CLK | WD719X_EE_DI | WD719X_EE_CS));
        /* GPIO input */
        gpio |= WD719X_EE_DO;
        wd719x_writeb(wd, WD719X_PCI_GPIO_CONTROL, gpio);

        /* read EEPROM header */
        eeprom_93cx6_multireadb(&eeprom, 0, (u8 *)&header, sizeof(header));

        if (header.sig1 == 'W' && header.sig2 == 'D')
                eeprom_93cx6_multireadb(&eeprom, header.cfg_offset,
                                        (u8 *)wd->params,
                                        sizeof(struct wd719x_host_param));
        else { /* default EEPROM values */
                dev_warn(&wd->pdev->dev, "EEPROM signature is invalid (0x%02x 0x%02x), using default values\n",
                         header.sig1, header.sig2);
                wd->params->ch_1_th     = 0x10; /* 16 DWs = 64 B */
                wd->params->scsi_conf   = 0x4c; /* 48ma, spue, parity check */
                wd->params->own_scsi_id = 0x07; /* ID 7, SCAM disabled */
                wd->params->sel_timeout = 0x4d; /* 250 ms */
                wd->params->sleep_timer = 0x01;
                wd->params->cdb_size    = cpu_to_le16(0x5555);  /* all 6 B */
                wd->params->scsi_pad    = 0x1b;
                if (wd->type == WD719X_TYPE_7193) /* narrow card - disable */
                        wd->params->wide = cpu_to_le32(0x00000000);
                else    /* initiate & respond to WIDE messages */
                        wd->params->wide = cpu_to_le32(0xffffffff);
                wd->params->sync        = cpu_to_le32(0xffffffff);
                wd->params->soft_mask   = 0x00; /* all disabled */
                wd->params->unsol_mask  = 0x00; /* all disabled */
        }
        /* disable TAGGED messages */
        wd->params->tag_en = cpu_to_le16(0x0000);
}

/* Read card type from GPIO bits 1 and 3 */
static enum wd719x_card_type wd719x_detect_type(struct wd719x *wd)
{
        u8 card = wd719x_readb(wd, WD719X_PCI_GPIO_CONTROL);

        card |= WD719X_GPIO_ID_BITS;
        wd719x_writeb(wd, WD719X_PCI_GPIO_CONTROL, card);
        card = wd719x_readb(wd, WD719X_PCI_GPIO_DATA) & WD719X_GPIO_ID_BITS;
        switch (card) {
        case 0x08:
                return WD719X_TYPE_7193;
        case 0x02:
                return WD719X_TYPE_7197;
        case 0x00:
                return WD719X_TYPE_7296;
        default:
                dev_warn(&wd->pdev->dev, "unknown card type 0x%x\n", card);
                return WD719X_TYPE_UNKNOWN;
        }
}

static int wd719x_board_found(struct Scsi_Host *sh)
{
        struct wd719x *wd = shost_priv(sh);
        static const char * const card_types[] = {
                "Unknown card", "WD7193", "WD7197", "WD7296"
        };
        int ret;

        INIT_LIST_HEAD(&wd->active_scbs);

        sh->base = pci_resource_start(wd->pdev, 0);

        wd->type = wd719x_detect_type(wd);

        wd->sh = sh;
        sh->irq = wd->pdev->irq;
        wd->fw_virt = NULL;

        /* memory area for host (EEPROM) parameters */
        wd->params = dma_alloc_coherent(&wd->pdev->dev,
                                        sizeof(struct wd719x_host_param),
                                        &wd->params_phys, GFP_KERNEL);
        if (!wd->params) {
                dev_warn(&wd->pdev->dev, "unable to allocate parameter buffer\n");
                return -ENOMEM;
        }

        /* memory area for the RISC for hash table of outstanding requests */
        wd->hash_virt = dma_alloc_coherent(&wd->pdev->dev,
                                           WD719X_HASH_TABLE_SIZE,
                                           &wd->hash_phys, GFP_KERNEL);
        if (!wd->hash_virt) {
                dev_warn(&wd->pdev->dev, "unable to allocate hash buffer\n");
                ret = -ENOMEM;
                goto fail_free_params;
        }

        ret = request_irq(wd->pdev->irq, wd719x_interrupt, IRQF_SHARED,
                          "wd719x", wd);
        if (ret) {
                dev_warn(&wd->pdev->dev, "unable to assign IRQ %d\n",
                         wd->pdev->irq);
                goto fail_free_hash;
        }

        /* read parameters from EEPROM */
        wd719x_read_eeprom(wd);

        ret = wd719x_chip_init(wd);
        if (ret)
                goto fail_free_irq;

        sh->this_id = wd->params->own_scsi_id & WD719X_EE_SCSI_ID_MASK;

        dev_info(&wd->pdev->dev, "%s at I/O 0x%lx, IRQ %u, SCSI ID %d\n",
                 card_types[wd->type], sh->base, sh->irq, sh->this_id);

        return 0;

fail_free_irq:
        free_irq(wd->pdev->irq, wd);
fail_free_hash:
        dma_free_coherent(&wd->pdev->dev, WD719X_HASH_TABLE_SIZE, wd->hash_virt,
                            wd->hash_phys);
fail_free_params:
        dma_free_coherent(&wd->pdev->dev, sizeof(struct wd719x_host_param),
                            wd->params, wd->params_phys);

        return ret;
}

static struct scsi_host_template wd719x_template = {
        .module                         = THIS_MODULE,
        .name                           = "Western Digital 719x",
        .cmd_size                       = sizeof(struct wd719x_scb),
        .queuecommand                   = wd719x_queuecommand,
        .eh_abort_handler               = wd719x_abort,
        .eh_device_reset_handler        = wd719x_dev_reset,
        .eh_bus_reset_handler           = wd719x_bus_reset,
        .eh_host_reset_handler          = wd719x_host_reset,
        .bios_param                     = wd719x_biosparam,
        .proc_name                      = "wd719x",
        .can_queue                      = 255,
        .this_id                        = 7,
        .sg_tablesize                   = WD719X_SG,
};

static int wd719x_pci_probe(struct pci_dev *pdev, const struct pci_device_id *d)
{
        int err;
        struct Scsi_Host *sh;
        struct wd719x *wd;

        err = pci_enable_device(pdev);
        if (err)
                goto fail;

        if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(32))) {
                dev_warn(&pdev->dev, "Unable to set 32-bit DMA mask\n");
                goto disable_device;
        }

        err = pci_request_regions(pdev, "wd719x");
        if (err)
                goto disable_device;
        pci_set_master(pdev);

        err = -ENODEV;
        if (pci_resource_len(pdev, 0) == 0)
                goto release_region;

        err = -ENOMEM;
        sh = scsi_host_alloc(&wd719x_template, sizeof(struct wd719x));
        if (!sh)
                goto release_region;

        wd = shost_priv(sh);
        wd->base = pci_iomap(pdev, 0, 0);
        if (!wd->base)
                goto free_host;
        wd->pdev = pdev;

        err = wd719x_board_found(sh);
        if (err)
                goto unmap;

        err = scsi_add_host(sh, &wd->pdev->dev);
        if (err)
                goto destroy;

        scsi_scan_host(sh);

        pci_set_drvdata(pdev, sh);
        return 0;

destroy:
        wd719x_destroy(wd);
unmap:
        pci_iounmap(pdev, wd->base);
free_host:
        scsi_host_put(sh);
release_region:
        pci_release_regions(pdev);
disable_device:
        pci_disable_device(pdev);
fail:
        return err;
}


static void wd719x_pci_remove(struct pci_dev *pdev)
{
        struct Scsi_Host *sh = pci_get_drvdata(pdev);
        struct wd719x *wd = shost_priv(sh);

        scsi_remove_host(sh);
        wd719x_destroy(wd);
        pci_iounmap(pdev, wd->base);
        pci_release_regions(pdev);
        pci_disable_device(pdev);

        scsi_host_put(sh);
}

static const struct pci_device_id wd719x_pci_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_WD, 0x3296) },
        {}
};

MODULE_DEVICE_TABLE(pci, wd719x_pci_table);

static struct pci_driver wd719x_pci_driver = {
        .name =         "wd719x",
        .id_table =     wd719x_pci_table,
        .probe =        wd719x_pci_probe,
        .remove =       wd719x_pci_remove,
};

module_pci_driver(wd719x_pci_driver);

MODULE_DESCRIPTION("Western Digital WD7193/7197/7296 SCSI driver");
MODULE_AUTHOR("Ondrej Zary, Aaron Dewell, Juergen Gaertner");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("wd719x-wcs.bin");
MODULE_FIRMWARE("wd719x-risc.bin");