/*
 * leon_pci_grpci2.c: GRPCI2 Host PCI driver
 *
 * Copyright (C) 2011 Aeroflex Gaisler AB, Daniel Hellstrom
 *
 */

#include <linux/of_device.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <asm/io.h>
#include <asm/leon.h>
#include <asm/vaddrs.h>
#include <asm/sections.h>
#include <asm/leon_pci.h>

#include "irq.h"

struct grpci2_barcfg {
        unsigned long pciadr;   /* PCI Space Address */
        unsigned long ahbadr;   /* PCI Base address mapped to this AHB addr */
};

/* Device Node Configuration options:
 *  - barcfgs    : Custom Configuration of Host's 6 target BARs
 *  - irq_mask   : Limit which PCI interrupts are enabled
 *  - do_reset   : Force PCI Reset on startup
 *
 * barcfgs
 * =======
 *
 * Optional custom Target BAR configuration (see struct grpci2_barcfg). All
 * addresses are physical. Array always contains 6 elements (len=2*4*6 bytes)
 *
 * -1 means not configured (let host driver do default setup).
 *
 * [i*2+0] = PCI Address of BAR[i] on target interface
 * [i*2+1] = Accessing PCI address of BAR[i] result in this AMBA address
 *
 *
 * irq_mask
 * ========
 *
 * Limit which PCI interrupts are enabled. 0=Disable, 1=Enable. By default
 * all are enabled. Use this when PCI interrupt pins are floating on PCB.
 * int, len=4.
 *  bit0 = PCI INTA#
 *  bit1 = PCI INTB#
 *  bit2 = PCI INTC#
 *  bit3 = PCI INTD#
 *
 *
 * reset
 * =====
 *
 * Force PCI reset on startup. int, len=4
 */

/* Enable Debugging Configuration Space Access */
#undef GRPCI2_DEBUG_CFGACCESS

/*
 * GRPCI2 APB Register MAP
 */
struct grpci2_regs {
        unsigned int ctrl;              /* 0x00 Control */
        unsigned int sts_cap;           /* 0x04 Status / Capabilities */
        int res1;                       /* 0x08 */
        unsigned int io_map;            /* 0x0C I/O Map address */
        unsigned int dma_ctrl;          /* 0x10 DMA */
        unsigned int dma_bdbase;        /* 0x14 DMA */
        int res2[2];                    /* 0x18 */
        unsigned int bars[6];           /* 0x20 read-only PCI BARs */
        int res3[2];                    /* 0x38 */
        unsigned int ahbmst_map[16];    /* 0x40 AHB->PCI Map per AHB Master */

        /* PCI Trace Buffer Registers (OPTIONAL) */
        unsigned int t_ctrl;            /* 0x80 */
        unsigned int t_cnt;             /* 0x84 */
        unsigned int t_adpat;           /* 0x88 */
        unsigned int t_admask;          /* 0x8C */
        unsigned int t_sigpat;          /* 0x90 */
        unsigned int t_sigmask;         /* 0x94 */
        unsigned int t_adstate;         /* 0x98 */
        unsigned int t_sigstate;        /* 0x9C */
};

#define REGLOAD(a)      (be32_to_cpu(__raw_readl(&(a))))
#define REGSTORE(a, v)  (__raw_writel(cpu_to_be32(v), &(a)))

#define CTRL_BUS_BIT 16

#define CTRL_RESET (1<<31)
#define CTRL_SI (1<<27)
#define CTRL_PE (1<<26)
#define CTRL_EI (1<<25)
#define CTRL_ER (1<<24)
#define CTRL_BUS (0xff<<CTRL_BUS_BIT)
#define CTRL_HOSTINT 0xf

#define STS_HOST_BIT    31
#define STS_MST_BIT     30
#define STS_TAR_BIT     29
#define STS_DMA_BIT     28
#define STS_DI_BIT      27
#define STS_HI_BIT      26
#define STS_IRQMODE_BIT 24
#define STS_TRACE_BIT   23
#define STS_CFGERRVALID_BIT 20
#define STS_CFGERR_BIT  19
#define STS_INTTYPE_BIT 12
#define STS_INTSTS_BIT  8
#define STS_FDEPTH_BIT  2
#define STS_FNUM_BIT    0

#define STS_HOST        (1<<STS_HOST_BIT)
#define STS_MST         (1<<STS_MST_BIT)
#define STS_TAR         (1<<STS_TAR_BIT)
#define STS_DMA         (1<<STS_DMA_BIT)
#define STS_DI          (1<<STS_DI_BIT)
#define STS_HI          (1<<STS_HI_BIT)
#define STS_IRQMODE     (0x3<<STS_IRQMODE_BIT)
#define STS_TRACE       (1<<STS_TRACE_BIT)
#define STS_CFGERRVALID (1<<STS_CFGERRVALID_BIT)
#define STS_CFGERR      (1<<STS_CFGERR_BIT)
#define STS_INTTYPE     (0x3f<<STS_INTTYPE_BIT)
#define STS_INTSTS      (0xf<<STS_INTSTS_BIT)
#define STS_FDEPTH      (0x7<<STS_FDEPTH_BIT)
#define STS_FNUM        (0x3<<STS_FNUM_BIT)

#define STS_ISYSERR     (1<<17)
#define STS_IDMA        (1<<16)
#define STS_IDMAERR     (1<<15)
#define STS_IMSTABRT    (1<<14)
#define STS_ITGTABRT    (1<<13)
#define STS_IPARERR     (1<<12)

#define STS_ERR_IRQ (STS_ISYSERR | STS_IMSTABRT | STS_ITGTABRT | STS_IPARERR)

struct grpci2_bd_chan {
        unsigned int ctrl;      /* 0x00 DMA Control */
        unsigned int nchan;     /* 0x04 Next DMA Channel Address */
        unsigned int nbd;       /* 0x08 Next Data Descriptor in chan */
        unsigned int res;       /* 0x0C Reserved */
};

#define BD_CHAN_EN              0x80000000
#define BD_CHAN_TYPE            0x00300000
#define BD_CHAN_BDCNT           0x0000ffff
#define BD_CHAN_EN_BIT          31
#define BD_CHAN_TYPE_BIT        20
#define BD_CHAN_BDCNT_BIT       0

struct grpci2_bd_data {
        unsigned int ctrl;      /* 0x00 DMA Data Control */
        unsigned int pci_adr;   /* 0x04 PCI Start Address */
        unsigned int ahb_adr;   /* 0x08 AHB Start address */
        unsigned int next;      /* 0x0C Next Data Descriptor in chan */
};

#define BD_DATA_EN              0x80000000
#define BD_DATA_IE              0x40000000
#define BD_DATA_DR              0x20000000
#define BD_DATA_TYPE            0x00300000
#define BD_DATA_ER              0x00080000
#define BD_DATA_LEN             0x0000ffff
#define BD_DATA_EN_BIT          31
#define BD_DATA_IE_BIT          30
#define BD_DATA_DR_BIT          29
#define BD_DATA_TYPE_BIT        20
#define BD_DATA_ER_BIT          19
#define BD_DATA_LEN_BIT         0

/* GRPCI2 Capability */
struct grpci2_cap_first {
        unsigned int ctrl;
        unsigned int pci2ahb_map[6];
        unsigned int ext2ahb_map;
        unsigned int io_map;
        unsigned int pcibar_size[6];
};
#define CAP9_CTRL_OFS 0
#define CAP9_BAR_OFS 0x4
#define CAP9_IOMAP_OFS 0x20
#define CAP9_BARSIZE_OFS 0x24

#define TGT 256

struct grpci2_priv {
        struct leon_pci_info    info; /* must be on top of this structure */
        struct grpci2_regs __iomem *regs;
        char                    irq;
        char                    irq_mode; /* IRQ Mode from CAPSTS REG */
        char                    bt_enabled;
        char                    do_reset;
        char                    irq_mask;
        u32                     pciid; /* PCI ID of Host */
        unsigned char           irq_map[4];

        /* Virtual IRQ numbers */
        unsigned int            virq_err;
        unsigned int            virq_dma;

        /* AHB PCI Windows */
        unsigned long           pci_area;       /* MEMORY */
        unsigned long           pci_area_end;
        unsigned long           pci_io;         /* I/O */
        unsigned long           pci_conf;       /* CONFIGURATION */
        unsigned long           pci_conf_end;
        unsigned long           pci_io_va;

        struct grpci2_barcfg    tgtbars[6];
};

static DEFINE_SPINLOCK(grpci2_dev_lock);
static struct grpci2_priv *grpci2priv;

static int grpci2_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
        struct grpci2_priv *priv = dev->bus->sysdata;
        int irq_group;

        /* Use default IRQ decoding on PCI BUS0 according slot numbering */
        irq_group = slot & 0x3;
        pin = ((pin - 1) + irq_group) & 0x3;

        return priv->irq_map[pin];
}

static int grpci2_cfg_r32(struct grpci2_priv *priv, unsigned int bus,
                                unsigned int devfn, int where, u32 *val)
{
        unsigned int *pci_conf;
        unsigned long flags;
        u32 tmp;

        if (where & 0x3)
                return -EINVAL;

        if (bus == 0) {
                devfn += (0x8 * 6); /* start at AD16=Device0 */
        } else if (bus == TGT) {
                bus = 0;
                devfn = 0; /* special case: bridge controller itself */
        }

        /* Select bus */
        spin_lock_irqsave(&grpci2_dev_lock, flags);
        REGSTORE(priv->regs->ctrl, (REGLOAD(priv->regs->ctrl) & ~(0xff << 16)) |
                                   (bus << 16));
        spin_unlock_irqrestore(&grpci2_dev_lock, flags);

        /* clear old status */
        REGSTORE(priv->regs->sts_cap, (STS_CFGERR | STS_CFGERRVALID));

        pci_conf = (unsigned int *) (priv->pci_conf |
                                                (devfn << 8) | (where & 0xfc));
        tmp = LEON3_BYPASS_LOAD_PA(pci_conf);

        /* Wait until GRPCI2 signals that CFG access is done, it should be
         * done instantaneously unless a DMA operation is ongoing...
         */
        while ((REGLOAD(priv->regs->sts_cap) & STS_CFGERRVALID) == 0)
                ;

        if (REGLOAD(priv->regs->sts_cap) & STS_CFGERR) {
                *val = 0xffffffff;
        } else {
                /* Bus always little endian (unaffected by byte-swapping) */
                *val = swab32(tmp);
        }

        return 0;
}

static int grpci2_cfg_r16(struct grpci2_priv *priv, unsigned int bus,
                                unsigned int devfn, int where, u32 *val)
{
        u32 v;
        int ret;

        if (where & 0x1)
                return -EINVAL;
        ret = grpci2_cfg_r32(priv, bus, devfn, where & ~0x3, &v);
        *val = 0xffff & (v >> (8 * (where & 0x3)));
        return ret;
}

static int grpci2_cfg_r8(struct grpci2_priv *priv, unsigned int bus,
                                unsigned int devfn, int where, u32 *val)
{
        u32 v;
        int ret;

        ret = grpci2_cfg_r32(priv, bus, devfn, where & ~0x3, &v);
        *val = 0xff & (v >> (8 * (where & 3)));

        return ret;
}

static int grpci2_cfg_w32(struct grpci2_priv *priv, unsigned int bus,
                                unsigned int devfn, int where, u32 val)
{
        unsigned int *pci_conf;
        unsigned long flags;

        if (where & 0x3)
                return -EINVAL;

        if (bus == 0) {
                devfn += (0x8 * 6); /* start at AD16=Device0 */
        } else if (bus == TGT) {
                bus = 0;
                devfn = 0; /* special case: bridge controller itself */
        }

        /* Select bus */
        spin_lock_irqsave(&grpci2_dev_lock, flags);
        REGSTORE(priv->regs->ctrl, (REGLOAD(priv->regs->ctrl) & ~(0xff << 16)) |
                                   (bus << 16));
        spin_unlock_irqrestore(&grpci2_dev_lock, flags);

        /* clear old status */
        REGSTORE(priv->regs->sts_cap, (STS_CFGERR | STS_CFGERRVALID));

        pci_conf = (unsigned int *) (priv->pci_conf |
                                                (devfn << 8) | (where & 0xfc));
        LEON3_BYPASS_STORE_PA(pci_conf, swab32(val));

        /* Wait until GRPCI2 signals that CFG access is done, it should be
         * done instantaneously unless a DMA operation is ongoing...
         */
        while ((REGLOAD(priv->regs->sts_cap) & STS_CFGERRVALID) == 0)
                ;

        return 0;
}

static int grpci2_cfg_w16(struct grpci2_priv *priv, unsigned int bus,
                                unsigned int devfn, int where, u32 val)
{
        int ret;
        u32 v;

        if (where & 0x1)
                return -EINVAL;
        ret = grpci2_cfg_r32(priv, bus, devfn, where&~3, &v);
        if (ret)
                return ret;
        v = (v & ~(0xffff << (8 * (where & 0x3)))) |
            ((0xffff & val) << (8 * (where & 0x3)));
        return grpci2_cfg_w32(priv, bus, devfn, where & ~0x3, v);
}

static int grpci2_cfg_w8(struct grpci2_priv *priv, unsigned int bus,
                                unsigned int devfn, int where, u32 val)
{
        int ret;
        u32 v;

        ret = grpci2_cfg_r32(priv, bus, devfn, where & ~0x3, &v);
        if (ret != 0)
                return ret;
        v = (v & ~(0xff << (8 * (where & 0x3)))) |
            ((0xff & val) << (8 * (where & 0x3)));
        return grpci2_cfg_w32(priv, bus, devfn, where & ~0x3, v);
}

/* Read from Configuration Space. When entering here the PCI layer has taken
 * the pci_lock spinlock and IRQ is off.
 */
static int grpci2_read_config(struct pci_bus *bus, unsigned int devfn,
                              int where, int size, u32 *val)
{
        struct grpci2_priv *priv = grpci2priv;
        unsigned int busno = bus->number;
        int ret;

        if (PCI_SLOT(devfn) > 15 || busno > 255) {
                *val = ~0;
                return 0;
        }

        switch (size) {
        case 1:
                ret = grpci2_cfg_r8(priv, busno, devfn, where, val);
                break;
        case 2:
                ret = grpci2_cfg_r16(priv, busno, devfn, where, val);
                break;
        case 4:
                ret = grpci2_cfg_r32(priv, busno, devfn, where, val);
                break;
        default:
                ret = -EINVAL;
                break;
        }

#ifdef GRPCI2_DEBUG_CFGACCESS
        printk(KERN_INFO "grpci2_read_config: [%02x:%02x:%x] ofs=%d val=%x "
                "size=%d\n", busno, PCI_SLOT(devfn), PCI_FUNC(devfn), where,
                *val, size);
#endif

        return ret;
}

/* Write to Configuration Space. When entering here the PCI layer has taken
 * the pci_lock spinlock and IRQ is off.
 */
static int grpci2_write_config(struct pci_bus *bus, unsigned int devfn,
                               int where, int size, u32 val)
{
        struct grpci2_priv *priv = grpci2priv;
        unsigned int busno = bus->number;

        if (PCI_SLOT(devfn) > 15 || busno > 255)
                return 0;

#ifdef GRPCI2_DEBUG_CFGACCESS
        printk(KERN_INFO "grpci2_write_config: [%02x:%02x:%x] ofs=%d size=%d "
                "val=%x\n", busno, PCI_SLOT(devfn), PCI_FUNC(devfn),
                where, size, val);
#endif

        switch (size) {
        default:
                return -EINVAL;
        case 1:
                return grpci2_cfg_w8(priv, busno, devfn, where, val);
        case 2:
                return grpci2_cfg_w16(priv, busno, devfn, where, val);
        case 4:
                return grpci2_cfg_w32(priv, busno, devfn, where, val);
        }
}

static struct pci_ops grpci2_ops = {
        .read =         grpci2_read_config,
        .write =        grpci2_write_config,
};

/* GENIRQ IRQ chip implementation for GRPCI2 irqmode=0..2. In configuration
 * 3 where all PCI Interrupts has a separate IRQ on the system IRQ controller
 * this is not needed and the standard IRQ controller can be used.
 */

static void grpci2_mask_irq(struct irq_data *data)
{
        unsigned long flags;
        unsigned int irqidx;
        struct grpci2_priv *priv = grpci2priv;

        irqidx = (unsigned int)data->chip_data - 1;
        if (irqidx > 3) /* only mask PCI interrupts here */
                return;

        spin_lock_irqsave(&grpci2_dev_lock, flags);
        REGSTORE(priv->regs->ctrl, REGLOAD(priv->regs->ctrl) & ~(1 << irqidx));
        spin_unlock_irqrestore(&grpci2_dev_lock, flags);
}

static void grpci2_unmask_irq(struct irq_data *data)
{
        unsigned long flags;
        unsigned int irqidx;
        struct grpci2_priv *priv = grpci2priv;

        irqidx = (unsigned int)data->chip_data - 1;
        if (irqidx > 3) /* only unmask PCI interrupts here */
                return;

        spin_lock_irqsave(&grpci2_dev_lock, flags);
        REGSTORE(priv->regs->ctrl, REGLOAD(priv->regs->ctrl) | (1 << irqidx));
        spin_unlock_irqrestore(&grpci2_dev_lock, flags);
}

static unsigned int grpci2_startup_irq(struct irq_data *data)
{
        grpci2_unmask_irq(data);
        return 0;
}

static void grpci2_shutdown_irq(struct irq_data *data)
{
        grpci2_mask_irq(data);
}

static struct irq_chip grpci2_irq = {
        .name           = "grpci2",
        .irq_startup    = grpci2_startup_irq,
        .irq_shutdown   = grpci2_shutdown_irq,
        .irq_mask       = grpci2_mask_irq,
        .irq_unmask     = grpci2_unmask_irq,
};

/* Handle one or multiple IRQs from the PCI core */
static void grpci2_pci_flow_irq(struct irq_desc *desc)
{
        struct grpci2_priv *priv = grpci2priv;
        int i, ack = 0;
        unsigned int ctrl, sts_cap, pci_ints;

        ctrl = REGLOAD(priv->regs->ctrl);
        sts_cap = REGLOAD(priv->regs->sts_cap);

        /* Error Interrupt? */
        if (sts_cap & STS_ERR_IRQ) {
                generic_handle_irq(priv->virq_err);
                ack = 1;
        }

        /* PCI Interrupt? */
        pci_ints = ((~sts_cap) >> STS_INTSTS_BIT) & ctrl & CTRL_HOSTINT;
        if (pci_ints) {
                /* Call respective PCI Interrupt handler */
                for (i = 0; i < 4; i++) {
                        if (pci_ints & (1 << i))
                                generic_handle_irq(priv->irq_map[i]);
                }
                ack = 1;
        }

        /*
         * Decode DMA Interrupt only when shared with Err and PCI INTX#, when
         * the DMA is a unique IRQ the DMA interrupts doesn't end up here, they
         * goes directly to DMA ISR.
         */
        if ((priv->irq_mode == 0) && (sts_cap & (STS_IDMA | STS_IDMAERR))) {
                generic_handle_irq(priv->virq_dma);
                ack = 1;
        }

        /*
         * Call "first level" IRQ chip end-of-irq handler. It will ACK LEON IRQ
         * Controller, this must be done after IRQ sources have been handled to
         * avoid double IRQ generation
         */
        if (ack)
                desc->irq_data.chip->irq_eoi(&desc->irq_data);
}

/* Create a virtual IRQ */
static unsigned int grpci2_build_device_irq(unsigned int irq)
{
        unsigned int virq = 0, pil;

        pil = 1 << 8;
        virq = irq_alloc(irq, pil);
        if (virq == 0)
                goto out;

        irq_set_chip_and_handler_name(virq, &grpci2_irq, handle_simple_irq,
                                      "pcilvl");
        irq_set_chip_data(virq, (void *)irq);

out:
        return virq;
}

static void grpci2_hw_init(struct grpci2_priv *priv)
{
        u32 ahbadr, pciadr, bar_sz, capptr, io_map, data;
        struct grpci2_regs __iomem *regs = priv->regs;
        int i;
        struct grpci2_barcfg *barcfg = priv->tgtbars;

        /* Reset any earlier setup */
        if (priv->do_reset) {
                printk(KERN_INFO "GRPCI2: Resetting PCI bus\n");
                REGSTORE(regs->ctrl, CTRL_RESET);
                ssleep(1); /* Wait for boards to settle */
        }
        REGSTORE(regs->ctrl, 0);
        REGSTORE(regs->sts_cap, ~0); /* Clear Status */
        REGSTORE(regs->dma_ctrl, 0);
        REGSTORE(regs->dma_bdbase, 0);

        /* Translate I/O accesses to 0, I/O Space always @ PCI low 64Kbytes */
        REGSTORE(regs->io_map, REGLOAD(regs->io_map) & 0x0000ffff);

        /* set 1:1 mapping between AHB -> PCI memory space, for all Masters
         * Each AHB master has it's own mapping registers. Max 16 AHB masters.
         */
        for (i = 0; i < 16; i++)
                REGSTORE(regs->ahbmst_map[i], priv->pci_area);

        /* Get the GRPCI2 Host PCI ID */
        grpci2_cfg_r32(priv, TGT, 0, PCI_VENDOR_ID, &priv->pciid);

        /* Get address to first (always defined) capability structure */
        grpci2_cfg_r8(priv, TGT, 0, PCI_CAPABILITY_LIST, &capptr);

        /* Enable/Disable Byte twisting */
        grpci2_cfg_r32(priv, TGT, 0, capptr+CAP9_IOMAP_OFS, &io_map);
        io_map = (io_map & ~0x1) | (priv->bt_enabled ? 1 : 0);
        grpci2_cfg_w32(priv, TGT, 0, capptr+CAP9_IOMAP_OFS, io_map);

        /* Setup the Host's PCI Target BARs for other peripherals to access,
         * and do DMA to the host's memory. The target BARs can be sized and
         * enabled individually.
         *
         * User may set custom target BARs, but default is:
         * The first BARs is used to map kernel low (DMA is part of normal
         * region on sparc which is SRMMU_MAXMEM big) main memory 1:1 to the
         * PCI bus, the other BARs are disabled. We assume that the first BAR
         * is always available.
         */
        for (i = 0; i < 6; i++) {
                if (barcfg[i].pciadr != ~0 && barcfg[i].ahbadr != ~0) {
                        /* Target BARs must have the proper alignment */
                        ahbadr = barcfg[i].ahbadr;
                        pciadr = barcfg[i].pciadr;
                        bar_sz = ((pciadr - 1) & ~pciadr) + 1;
                } else {
                        if (i == 0) {
                                /* Map main memory */
                                bar_sz = 0xf0000008; /* 256MB prefetchable */
                                ahbadr = 0xf0000000 & (u32)__pa(PAGE_ALIGN(
                                        (unsigned long) &_end));
                                pciadr = ahbadr;
                        } else {
                                bar_sz = 0;
                                ahbadr = 0;
                                pciadr = 0;
                        }
                }
                grpci2_cfg_w32(priv, TGT, 0, capptr+CAP9_BARSIZE_OFS+i*4,
                                bar_sz);
                grpci2_cfg_w32(priv, TGT, 0, PCI_BASE_ADDRESS_0+i*4, pciadr);
                grpci2_cfg_w32(priv, TGT, 0, capptr+CAP9_BAR_OFS+i*4, ahbadr);
                printk(KERN_INFO "        TGT BAR[%d]: 0x%08x (PCI)-> 0x%08x\n",
                        i, pciadr, ahbadr);
        }

        /* set as bus master and enable pci memory responses */
        grpci2_cfg_r32(priv, TGT, 0, PCI_COMMAND, &data);
        data |= (PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
        grpci2_cfg_w32(priv, TGT, 0, PCI_COMMAND, data);

        /* Enable Error respone (CPU-TRAP) on illegal memory access. */
        REGSTORE(regs->ctrl, CTRL_ER | CTRL_PE);
}

static irqreturn_t grpci2_jump_interrupt(int irq, void *arg)
{
        printk(KERN_ERR "GRPCI2: Jump IRQ happened\n");
        return IRQ_NONE;
}

/* Handle GRPCI2 Error Interrupt */
static irqreturn_t grpci2_err_interrupt(int irq, void *arg)
{
        struct grpci2_priv *priv = arg;
        struct grpci2_regs __iomem *regs = priv->regs;
        unsigned int status;

        status = REGLOAD(regs->sts_cap);
        if ((status & STS_ERR_IRQ) == 0)
                return IRQ_NONE;

        if (status & STS_IPARERR)
                printk(KERN_ERR "GRPCI2: Parity Error\n");

        if (status & STS_ITGTABRT)
                printk(KERN_ERR "GRPCI2: Target Abort\n");

        if (status & STS_IMSTABRT)
                printk(KERN_ERR "GRPCI2: Master Abort\n");

        if (status & STS_ISYSERR)
                printk(KERN_ERR "GRPCI2: System Error\n");

        /* Clear handled INT TYPE IRQs */
        REGSTORE(regs->sts_cap, status & STS_ERR_IRQ);

        return IRQ_HANDLED;
}

static int grpci2_of_probe(struct platform_device *ofdev)
{
        struct grpci2_regs __iomem *regs;
        struct grpci2_priv *priv;
        int err, i, len;
        const int *tmp;
        unsigned int capability;

        if (grpci2priv) {
                printk(KERN_ERR "GRPCI2: only one GRPCI2 core supported\n");
                return -ENODEV;
        }

        if (ofdev->num_resources < 3) {
                printk(KERN_ERR "GRPCI2: not enough APB/AHB resources\n");
                return -EIO;
        }

        /* Find Device Address */
        regs = of_ioremap(&ofdev->resource[0], 0,
                          resource_size(&ofdev->resource[0]),
                          "grlib-grpci2 regs");
        if (regs == NULL) {
                printk(KERN_ERR "GRPCI2: ioremap failed\n");
                return -EIO;
        }

        /*
         * Check that we're in Host Slot and that we can act as a Host Bridge
         * and not only as target.
         */
        capability = REGLOAD(regs->sts_cap);
        if ((capability & STS_HOST) || !(capability & STS_MST)) {
                printk(KERN_INFO "GRPCI2: not in host system slot\n");
                err = -EIO;
                goto err1;
        }

        priv = grpci2priv = kzalloc(sizeof(struct grpci2_priv), GFP_KERNEL);
        if (grpci2priv == NULL) {
                err = -ENOMEM;
                goto err1;
        }
        priv->regs = regs;
        priv->irq = ofdev->archdata.irqs[0]; /* BASE IRQ */
        priv->irq_mode = (capability & STS_IRQMODE) >> STS_IRQMODE_BIT;

        printk(KERN_INFO "GRPCI2: host found at %p, irq%d\n", regs, priv->irq);

        /* Byte twisting should be made configurable from kernel command line */
        priv->bt_enabled = 1;

        /* Let user do custom Target BAR assignment */
        tmp = of_get_property(ofdev->dev.of_node, "barcfg", &len);
        if (tmp && (len == 2*4*6))
                memcpy(priv->tgtbars, tmp, 2*4*6);
        else
                memset(priv->tgtbars, -1, 2*4*6);

        /* Limit IRQ unmasking in irq_mode 2 and 3 */
        tmp = of_get_property(ofdev->dev.of_node, "irq_mask", &len);
        if (tmp && (len == 4))
                priv->do_reset = *tmp;
        else
                priv->irq_mask = 0xf;

        /* Optional PCI reset. Force PCI reset on startup */
        tmp = of_get_property(ofdev->dev.of_node, "reset", &len);
        if (tmp && (len == 4))
                priv->do_reset = *tmp;
        else
                priv->do_reset = 0;

        /* Find PCI Memory, I/O and Configuration Space Windows */
        priv->pci_area = ofdev->resource[1].start;
        priv->pci_area_end = ofdev->resource[1].end+1;
        priv->pci_io = ofdev->resource[2].start;
        priv->pci_conf = ofdev->resource[2].start + 0x10000;
        priv->pci_conf_end = priv->pci_conf + 0x10000;
        priv->pci_io_va = (unsigned long)ioremap(priv->pci_io, 0x10000);
        if (!priv->pci_io_va) {
                err = -EIO;
                goto err2;
        }

        printk(KERN_INFO
                "GRPCI2: MEMORY SPACE [0x%08lx - 0x%08lx]\n"
                "        I/O    SPACE [0x%08lx - 0x%08lx]\n"
                "        CONFIG SPACE [0x%08lx - 0x%08lx]\n",
                priv->pci_area, priv->pci_area_end-1,
                priv->pci_io, priv->pci_conf-1,
                priv->pci_conf, priv->pci_conf_end-1);

        /*
         * I/O Space resources in I/O Window mapped into Virtual Adr Space
         * We never use low 4KB because some devices seem have problems using
         * address 0.
         */
        memset(&priv->info.io_space, 0, sizeof(struct resource));
        priv->info.io_space.name = "GRPCI2 PCI I/O Space";
        priv->info.io_space.start = priv->pci_io_va + 0x1000;
        priv->info.io_space.end = priv->pci_io_va + 0x10000 - 1;
        priv->info.io_space.flags = IORESOURCE_IO;

        /*
         * GRPCI2 has no prefetchable memory, map everything as
         * non-prefetchable memory
         */
        memset(&priv->info.mem_space, 0, sizeof(struct resource));
        priv->info.mem_space.name = "GRPCI2 PCI MEM Space";
        priv->info.mem_space.start = priv->pci_area;
        priv->info.mem_space.end = priv->pci_area_end - 1;
        priv->info.mem_space.flags = IORESOURCE_MEM;

        if (request_resource(&iomem_resource, &priv->info.mem_space) < 0)
                goto err3;
        if (request_resource(&ioport_resource, &priv->info.io_space) < 0)
                goto err4;

        /* setup maximum supported PCI buses */
        priv->info.busn.name = "GRPCI2 busn";
        priv->info.busn.start = 0;
        priv->info.busn.end = 255;

        grpci2_hw_init(priv);

        /*
         * Get PCI Interrupt to System IRQ mapping and setup IRQ handling
         * Error IRQ always on PCI INTA.
         */
        if (priv->irq_mode < 2) {
                /* All PCI interrupts are shared using the same system IRQ */
                leon_update_virq_handling(priv->irq, grpci2_pci_flow_irq,
                                         "pcilvl", 0);

                priv->irq_map[0] = grpci2_build_device_irq(1);
                priv->irq_map[1] = grpci2_build_device_irq(2);
                priv->irq_map[2] = grpci2_build_device_irq(3);
                priv->irq_map[3] = grpci2_build_device_irq(4);

                priv->virq_err = grpci2_build_device_irq(5);
                if (priv->irq_mode & 1)
                        priv->virq_dma = ofdev->archdata.irqs[1];
                else
                        priv->virq_dma = grpci2_build_device_irq(6);

                /* Enable IRQs on LEON IRQ controller */
                err = request_irq(priv->irq, grpci2_jump_interrupt, 0,
                                        "GRPCI2_JUMP", priv);
                if (err)
                        printk(KERN_ERR "GRPCI2: ERR IRQ request failed\n");
        } else {
                /* All PCI interrupts have an unique IRQ interrupt */
                for (i = 0; i < 4; i++) {
                        /* Make LEON IRQ layer handle level IRQ by acking */
                        leon_update_virq_handling(ofdev->archdata.irqs[i],
                                                 handle_fasteoi_irq, "pcilvl",
                                                 1);
                        priv->irq_map[i] = ofdev->archdata.irqs[i];
                }
                priv->virq_err = priv->irq_map[0];
                if (priv->irq_mode & 1)
                        priv->virq_dma = ofdev->archdata.irqs[4];
                else
                        priv->virq_dma = priv->irq_map[0];

                /* Unmask all PCI interrupts, request_irq will not do that */
                REGSTORE(regs->ctrl, REGLOAD(regs->ctrl)|(priv->irq_mask&0xf));
        }

        /* Setup IRQ handler for non-configuration space access errors */
        err = request_irq(priv->virq_err, grpci2_err_interrupt, IRQF_SHARED,
                                "GRPCI2_ERR", priv);
        if (err) {
                printk(KERN_DEBUG "GRPCI2: ERR VIRQ request failed: %d\n", err);
                goto err5;
        }

        /*
         * Enable Error Interrupts. PCI interrupts are unmasked once request_irq
         * is called by the PCI Device drivers
         */
        REGSTORE(regs->ctrl, REGLOAD(regs->ctrl) | CTRL_EI | CTRL_SI);

        /* Init common layer and scan buses */
        priv->info.ops = &grpci2_ops;
        priv->info.map_irq = grpci2_map_irq;
        leon_pci_init(ofdev, &priv->info);

        return 0;

err5:
        release_resource(&priv->info.io_space);
err4:
        release_resource(&priv->info.mem_space);
err3:
        err = -ENOMEM;
        iounmap((void __iomem *)priv->pci_io_va);
err2:
        kfree(priv);
err1:
        of_iounmap(&ofdev->resource[0], regs,
                resource_size(&ofdev->resource[0]));
        return err;
}

static struct of_device_id grpci2_of_match[] = {
        {
         .name = "GAISLER_GRPCI2",
         },
        {
         .name = "01_07c",
         },
        {},
};

static struct platform_driver grpci2_of_driver = {
        .driver = {
                .name = "grpci2",
                .of_match_table = grpci2_of_match,
        },
        .probe = grpci2_of_probe,
};

static int __init grpci2_init(void)
{
        return platform_driver_register(&grpci2_of_driver);
}

subsys_initcall(grpci2_init);