/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 2005 Silicon Graphics, Inc.  All rights reserved.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/proc_fs.h>
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/addrs.h>
#include <asm/sn/io.h>
#include <asm/sn/types.h>
#include <asm/sn/shubio.h>
#include <asm/sn/tiocx.h>
#include <asm/sn/l1.h>
#include <asm/sn/module.h>
#include "tio.h"
#include "xtalk/xwidgetdev.h"
#include "xtalk/hubdev.h"

#define CX_DEV_NONE 0
#define DEVICE_NAME "tiocx"
#define WIDGET_ID 0
#define TIOCX_DEBUG 0

#if TIOCX_DEBUG
#define DBG(fmt...)    printk(KERN_ALERT fmt)
#else
#define DBG(fmt...)
#endif

struct device_attribute dev_attr_cxdev_control;

/**
 * tiocx_match - Try to match driver id list with device.
 * @dev: device pointer
 * @drv: driver pointer
 *
 * Returns 1 if match, 0 otherwise.
 */
static int tiocx_match(struct device *dev, struct device_driver *drv)
{
        struct cx_dev *cx_dev = to_cx_dev(dev);
        struct cx_drv *cx_drv = to_cx_driver(drv);
        const struct cx_device_id *ids = cx_drv->id_table;

        if (!ids)
                return 0;

        while (ids->part_num) {
                if (ids->part_num == cx_dev->cx_id.part_num)
                        return 1;
                ids++;
        }
        return 0;

}

static int tiocx_uevent(struct device *dev, struct kobj_uevent_env *env)
{
        return -ENODEV;
}

static void tiocx_bus_release(struct device *dev)
{
        kfree(to_cx_dev(dev));
}

/**
 * cx_device_match - Find cx_device in the id table.
 * @ids: id table from driver
 * @cx_device: part/mfg id for the device
 *
 */
static const struct cx_device_id *cx_device_match(const struct cx_device_id
                                                  *ids,
                                                  struct cx_dev *cx_device)
{
        /*
         * NOTES: We may want to check for CX_ANY_ID too.
         *        Do we want to match against nasid too?
         *        CX_DEV_NONE == 0, if the driver tries to register for
         *        part/mfg == 0 we should return no-match (NULL) here.
         */
        while (ids->part_num && ids->mfg_num) {
                if (ids->part_num == cx_device->cx_id.part_num &&
                    ids->mfg_num == cx_device->cx_id.mfg_num)
                        return ids;
                ids++;
        }

        return NULL;
}

/**
 * cx_device_probe - Look for matching device.
 *                      Call driver probe routine if found.
 * @cx_driver: driver table (cx_drv struct) from driver
 * @cx_device: part/mfg id for the device
 */
static int cx_device_probe(struct device *dev)
{
        const struct cx_device_id *id;
        struct cx_drv *cx_drv = to_cx_driver(dev->driver);
        struct cx_dev *cx_dev = to_cx_dev(dev);
        int error = 0;

        if (!cx_dev->driver && cx_drv->probe) {
                id = cx_device_match(cx_drv->id_table, cx_dev);
                if (id) {
                        if ((error = cx_drv->probe(cx_dev, id)) < 0)
                                return error;
                        else
                                cx_dev->driver = cx_drv;
                }
        }

        return error;
}

/**
 * cx_driver_remove - Remove driver from device struct.
 * @dev: device
 */
static int cx_driver_remove(struct device *dev)
{
        struct cx_dev *cx_dev = to_cx_dev(dev);
        struct cx_drv *cx_drv = cx_dev->driver;
        if (cx_drv->remove)
                cx_drv->remove(cx_dev);
        cx_dev->driver = NULL;
        return 0;
}

struct bus_type tiocx_bus_type = {
        .name = "tiocx",
        .match = tiocx_match,
        .uevent = tiocx_uevent,
        .probe = cx_device_probe,
        .remove = cx_driver_remove,
};

/**
 * cx_driver_register - Register the driver.
 * @cx_driver: driver table (cx_drv struct) from driver
 * 
 * Called from the driver init routine to register a driver.
 * The cx_drv struct contains the driver name, a pointer to
 * a table of part/mfg numbers and a pointer to the driver's
 * probe/attach routine.
 */
int cx_driver_register(struct cx_drv *cx_driver)
{
        cx_driver->driver.name = cx_driver->name;
        cx_driver->driver.bus = &tiocx_bus_type;

        return driver_register(&cx_driver->driver);
}

/**
 * cx_driver_unregister - Unregister the driver.
 * @cx_driver: driver table (cx_drv struct) from driver
 */
int cx_driver_unregister(struct cx_drv *cx_driver)
{
        driver_unregister(&cx_driver->driver);
        return 0;
}

/**
 * cx_device_register - Register a device.
 * @nasid: device's nasid
 * @part_num: device's part number
 * @mfg_num: device's manufacturer number
 * @hubdev: hub info associated with this device
 * @bt: board type of the device
 *
 */
int
cx_device_register(nasid_t nasid, int part_num, int mfg_num,
                   struct hubdev_info *hubdev, int bt)
{
        struct cx_dev *cx_dev;
        int r;

        cx_dev = kzalloc(sizeof(struct cx_dev), GFP_KERNEL);
        DBG("cx_dev= 0x%p\n", cx_dev);
        if (cx_dev == NULL)
                return -ENOMEM;

        cx_dev->cx_id.part_num = part_num;
        cx_dev->cx_id.mfg_num = mfg_num;
        cx_dev->cx_id.nasid = nasid;
        cx_dev->hubdev = hubdev;
        cx_dev->bt = bt;

        cx_dev->dev.parent = NULL;
        cx_dev->dev.bus = &tiocx_bus_type;
        cx_dev->dev.release = tiocx_bus_release;
        dev_set_name(&cx_dev->dev, "%d", cx_dev->cx_id.nasid);
        r = device_register(&cx_dev->dev);
        if (r) {
                kfree(cx_dev);
                return r;
        }
        get_device(&cx_dev->dev);

        device_create_file(&cx_dev->dev, &dev_attr_cxdev_control);

        return 0;
}

/**
 * cx_device_unregister - Unregister a device.
 * @cx_dev: part/mfg id for the device
 */
int cx_device_unregister(struct cx_dev *cx_dev)
{
        put_device(&cx_dev->dev);
        device_unregister(&cx_dev->dev);
        return 0;
}

/**
 * cx_device_reload - Reload the device.
 * @nasid: device's nasid
 * @part_num: device's part number
 * @mfg_num: device's manufacturer number
 *
 * Remove the device associated with 'nasid' from device list and then
 * call device-register with the given part/mfg numbers.
 */
static int cx_device_reload(struct cx_dev *cx_dev)
{
        cx_device_unregister(cx_dev);
        return cx_device_register(cx_dev->cx_id.nasid, cx_dev->cx_id.part_num,
                                  cx_dev->cx_id.mfg_num, cx_dev->hubdev,
                                  cx_dev->bt);
}

static inline u64 tiocx_intr_alloc(nasid_t nasid, int widget,
                                        u64 sn_irq_info,
                                        int req_irq, nasid_t req_nasid,
                                        int req_slice)
{
        struct ia64_sal_retval rv;
        rv.status = 0;
        rv.v0 = 0;

        ia64_sal_oemcall_nolock(&rv, SN_SAL_IOIF_INTERRUPT,
                                SAL_INTR_ALLOC, nasid,
                                widget, sn_irq_info, req_irq,
                                req_nasid, req_slice);
        return rv.status;
}

static inline void tiocx_intr_free(nasid_t nasid, int widget,
                                   struct sn_irq_info *sn_irq_info)
{
        struct ia64_sal_retval rv;
        rv.status = 0;
        rv.v0 = 0;

        ia64_sal_oemcall_nolock(&rv, SN_SAL_IOIF_INTERRUPT,
                                SAL_INTR_FREE, nasid,
                                widget, sn_irq_info->irq_irq,
                                sn_irq_info->irq_cookie, 0, 0);
}

struct sn_irq_info *tiocx_irq_alloc(nasid_t nasid, int widget, int irq,
                                    nasid_t req_nasid, int slice)
{
        struct sn_irq_info *sn_irq_info;
        int status;
        int sn_irq_size = sizeof(struct sn_irq_info);

        if ((nasid & 1) == 0)
                return NULL;

        sn_irq_info = kzalloc(sn_irq_size, GFP_KERNEL);
        if (sn_irq_info == NULL)
                return NULL;

        status = tiocx_intr_alloc(nasid, widget, __pa(sn_irq_info), irq,
                                  req_nasid, slice);
        if (status) {
                kfree(sn_irq_info);
                return NULL;
        } else {
                return sn_irq_info;
        }
}

void tiocx_irq_free(struct sn_irq_info *sn_irq_info)
{
        u64 bridge = (u64) sn_irq_info->irq_bridge;
        nasid_t nasid = NASID_GET(bridge);
        int widget;

        if (nasid & 1) {
                widget = TIO_SWIN_WIDGETNUM(bridge);
                tiocx_intr_free(nasid, widget, sn_irq_info);
                kfree(sn_irq_info);
        }
}

u64 tiocx_dma_addr(u64 addr)
{
        return PHYS_TO_TIODMA(addr);
}

u64 tiocx_swin_base(int nasid)
{
        return TIO_SWIN_BASE(nasid, TIOCX_CORELET);
}

EXPORT_SYMBOL(cx_driver_register);
EXPORT_SYMBOL(cx_driver_unregister);
EXPORT_SYMBOL(cx_device_register);
EXPORT_SYMBOL(cx_device_unregister);
EXPORT_SYMBOL(tiocx_irq_alloc);
EXPORT_SYMBOL(tiocx_irq_free);
EXPORT_SYMBOL(tiocx_bus_type);
EXPORT_SYMBOL(tiocx_dma_addr);
EXPORT_SYMBOL(tiocx_swin_base);

static void tio_conveyor_set(nasid_t nasid, int enable_flag)
{
        u64 ice_frz;
        u64 disable_cb = (1ull << 61);

        if (!(nasid & 1))
                return;

        ice_frz = REMOTE_HUB_L(nasid, TIO_ICE_FRZ_CFG);
        if (enable_flag) {
                if (!(ice_frz & disable_cb))    /* already enabled */
                        return;
                ice_frz &= ~disable_cb;
        } else {
                if (ice_frz & disable_cb)       /* already disabled */
                        return;
                ice_frz |= disable_cb;
        }
        DBG(KERN_ALERT "TIO_ICE_FRZ_CFG= 0x%lx\n", ice_frz);
        REMOTE_HUB_S(nasid, TIO_ICE_FRZ_CFG, ice_frz);
}

#define tio_conveyor_enable(nasid) tio_conveyor_set(nasid, 1)
#define tio_conveyor_disable(nasid) tio_conveyor_set(nasid, 0)

static void tio_corelet_reset(nasid_t nasid, int corelet)
{
        if (!(nasid & 1))
                return;

        REMOTE_HUB_S(nasid, TIO_ICE_PMI_TX_CFG, 1 << corelet);
        udelay(2000);
        REMOTE_HUB_S(nasid, TIO_ICE_PMI_TX_CFG, 0);
        udelay(2000);
}

static int is_fpga_tio(int nasid, int *bt)
{
        u16 uninitialized_var(ioboard_type);    /* GCC be quiet */
        long rc;

        rc = ia64_sn_sysctl_ioboard_get(nasid, &ioboard_type);
        if (rc) {
                printk(KERN_WARNING "ia64_sn_sysctl_ioboard_get failed: %ld\n",
                       rc);
                return 0;
        }

        switch (ioboard_type) {
        case L1_BRICKTYPE_SA:
        case L1_BRICKTYPE_ATHENA:
        case L1_BOARDTYPE_DAYTONA:
                *bt = ioboard_type;
                return 1;
        }

        return 0;
}

static int bitstream_loaded(nasid_t nasid)
{
        u64 cx_credits;

        cx_credits = REMOTE_HUB_L(nasid, TIO_ICE_PMI_TX_DYN_CREDIT_STAT_CB3);
        cx_credits &= TIO_ICE_PMI_TX_DYN_CREDIT_STAT_CB3_CREDIT_CNT_MASK;
        DBG("cx_credits= 0x%lx\n", cx_credits);

        return (cx_credits == 0xf) ? 1 : 0;
}

static int tiocx_reload(struct cx_dev *cx_dev)
{
        int part_num = CX_DEV_NONE;
        int mfg_num = CX_DEV_NONE;
        nasid_t nasid = cx_dev->cx_id.nasid;

        if (bitstream_loaded(nasid)) {
                u64 cx_id;
                int rv;

                rv = ia64_sn_sysctl_tio_clock_reset(nasid);
                if (rv) {
                        printk(KERN_ALERT "CX port JTAG reset failed.\n");
                } else {
                        cx_id = *(volatile u64 *)
                                (TIO_SWIN_BASE(nasid, TIOCX_CORELET) +
                                          WIDGET_ID);
                        part_num = XWIDGET_PART_NUM(cx_id);
                        mfg_num = XWIDGET_MFG_NUM(cx_id);
                        DBG("part= 0x%x, mfg= 0x%x\n", part_num, mfg_num);
                        /* just ignore it if it's a CE */
                        if (part_num == TIO_CE_ASIC_PARTNUM)
                                return 0;
                }
        }

        cx_dev->cx_id.part_num = part_num;
        cx_dev->cx_id.mfg_num = mfg_num;

        /*
         * Delete old device and register the new one.  It's ok if
         * part_num/mfg_num == CX_DEV_NONE.  We want to register
         * devices in the table even if a bitstream isn't loaded.
         * That allows use to see that a bitstream isn't loaded via
         * TIOCX_IOCTL_DEV_LIST.
         */
        return cx_device_reload(cx_dev);
}

static ssize_t show_cxdev_control(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct cx_dev *cx_dev = to_cx_dev(dev);

        return sprintf(buf, "0x%x 0x%x 0x%x 0x%x\n",
                       cx_dev->cx_id.nasid,
                       cx_dev->cx_id.part_num, cx_dev->cx_id.mfg_num,
                       cx_dev->bt);
}

static ssize_t store_cxdev_control(struct device *dev, struct device_attribute *attr, const char *buf,
                                   size_t count)
{
        int n;
        struct cx_dev *cx_dev = to_cx_dev(dev);

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (count <= 0)
                return 0;

        n = simple_strtoul(buf, NULL, 0);

        switch (n) {
        case 1:
                tio_corelet_reset(cx_dev->cx_id.nasid, TIOCX_CORELET);
                tiocx_reload(cx_dev);
                break;
        case 2:
                tiocx_reload(cx_dev);
                break;
        case 3:
                tio_corelet_reset(cx_dev->cx_id.nasid, TIOCX_CORELET);
                break;
        default:
                break;
        }

        return count;
}

DEVICE_ATTR(cxdev_control, 0644, show_cxdev_control, store_cxdev_control);

static int __init tiocx_init(void)
{
        cnodeid_t cnodeid;
        int found_tiocx_device = 0;
        int err;

        if (!ia64_platform_is("sn2"))
                return 0;

        err = bus_register(&tiocx_bus_type);
        if (err)
                return err;

        for (cnodeid = 0; cnodeid < num_cnodes; cnodeid++) {
                nasid_t nasid;
                int bt;

                nasid = cnodeid_to_nasid(cnodeid);

                if ((nasid & 0x1) && is_fpga_tio(nasid, &bt)) {
                        struct hubdev_info *hubdev;
                        struct xwidget_info *widgetp;

                        DBG("Found TIO at nasid 0x%x\n", nasid);

                        hubdev =
                            (struct hubdev_info *)(NODEPDA(cnodeid)->pdinfo);

                        widgetp = &hubdev->hdi_xwidget_info[TIOCX_CORELET];

                        /* The CE hangs off of the CX port but is not an FPGA */
                        if (widgetp->xwi_hwid.part_num == TIO_CE_ASIC_PARTNUM)
                                continue;

                        tio_corelet_reset(nasid, TIOCX_CORELET);
                        tio_conveyor_enable(nasid);

                        if (cx_device_register
                            (nasid, widgetp->xwi_hwid.part_num,
                             widgetp->xwi_hwid.mfg_num, hubdev, bt) < 0)
                                return -ENXIO;
                        else
                                found_tiocx_device++;
                }
        }

        /* It's ok if we find zero devices. */
        DBG("found_tiocx_device= %d\n", found_tiocx_device);

        return 0;
}

static int cx_remove_device(struct device * dev, void * data)
{
        struct cx_dev *cx_dev = to_cx_dev(dev);
        device_remove_file(dev, &dev_attr_cxdev_control);
        cx_device_unregister(cx_dev);
        return 0;
}

static void __exit tiocx_exit(void)
{
        DBG("tiocx_exit\n");

        /*
         * Unregister devices.
         */
        bus_for_each_dev(&tiocx_bus_type, NULL, NULL, cx_remove_device);
        bus_unregister(&tiocx_bus_type);
}

fs_initcall(tiocx_init);
module_exit(tiocx_exit);

/************************************************************************
 * Module licensing and description
 ************************************************************************/
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Bruce Losure <blosure@sgi.com>");
MODULE_DESCRIPTION("TIOCX module");
MODULE_SUPPORTED_DEVICE(DEVICE_NAME);