/*
* cycx_main.c   Cyclades Cyclom 2X WAN Link Driver. Main module.
*
* Author:       Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* Copyright:    (c) 1998-2003 Arnaldo Carvalho de Melo
*
* Based on sdlamain.c by Gene Kozin <genek@compuserve.com> &
*                        Jaspreet Singh <jaspreet@sangoma.com>
*
*               This program is free software; you can redistribute it and/or
*               modify it under the terms of the GNU General Public License
*               as published by the Free Software Foundation; either version
*               2 of the License, or (at your option) any later version.
* ============================================================================
* Please look at the bitkeeper changelog (or any other scm tool that ends up
* importing bitkeeper changelog or that replaces bitkeeper in the future as
* main tool for linux development).
* 
* 2001/05/09    acme            Fix MODULE_DESC for debug, .bss nitpicks,
*                               some cleanups
* 2000/07/13    acme            remove useless #ifdef MODULE and crap
*                               #if KERNEL_VERSION > blah
* 2000/07/06    acme            __exit at cyclomx_cleanup
* 2000/04/02    acme            dprintk and cycx_debug
*                               module_init/module_exit
* 2000/01/21    acme            rename cyclomx_open to cyclomx_mod_inc_use_count
*                               and cyclomx_close to cyclomx_mod_dec_use_count
* 2000/01/08    acme            cleanup
* 1999/11/06    acme            cycx_down back to life (it needs to be
*                               called to iounmap the dpmbase)
* 1999/08/09    acme            removed references to enable_tx_int
*                               use spinlocks instead of cli/sti in
*                               cyclomx_set_state
* 1999/05/19    acme            works directly linked into the kernel
*                               init_waitqueue_head for 2.3.* kernel
* 1999/05/18    acme            major cleanup (polling not needed), etc
* 1998/08/28    acme            minor cleanup (ioctls for firmware deleted)
*                               queue_task activated
* 1998/08/08    acme            Initial version.
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/stddef.h>       /* offsetof(), etc. */
#include <linux/errno.h>        /* return codes */
#include <linux/string.h>       /* inline memset(), etc. */
#include <linux/slab.h>         /* kmalloc(), kfree() */
#include <linux/kernel.h>       /* printk(), and other useful stuff */
#include <linux/module.h>       /* support for loadable modules */
#include <linux/ioport.h>       /* request_region(), release_region() */
#include <linux/wanrouter.h>    /* WAN router definitions */
#include <linux/cyclomx.h>      /* cyclomx common user API definitions */
#include <linux/init.h>         /* __init (when not using as a module) */
#include <linux/interrupt.h>

unsigned int cycx_debug;

MODULE_AUTHOR("Arnaldo Carvalho de Melo");
MODULE_DESCRIPTION("Cyclom 2X Sync Card Driver.");
MODULE_LICENSE("GPL");
module_param(cycx_debug, int, 0);
MODULE_PARM_DESC(cycx_debug, "cyclomx debug level");

/* Defines & Macros */

#define CYCX_DRV_VERSION        0       /* version number */
#define CYCX_DRV_RELEASE        11      /* release (minor version) number */
#define CYCX_MAX_CARDS          1       /* max number of adapters */

#define CONFIG_CYCX_CARDS 1

/* Function Prototypes */

/* WAN link driver entry points */
static int cycx_wan_setup(struct wan_device *wandev, wandev_conf_t *conf);
static int cycx_wan_shutdown(struct wan_device *wandev);

/* Miscellaneous functions */
static irqreturn_t cycx_isr(int irq, void *dev_id);

/* Global Data
 * Note: All data must be explicitly initialized!!!
 */

/* private data */
static const char cycx_drvname[] = "cyclomx";
static const char cycx_fullname[] = "CYCLOM 2X(tm) Sync Card Driver";
static const char cycx_copyright[] = "(c) 1998-2003 Arnaldo Carvalho de Melo "
                          "<acme@conectiva.com.br>";
static int cycx_ncards = CONFIG_CYCX_CARDS;
static struct cycx_device *cycx_card_array;     /* adapter data space */

/* Kernel Loadable Module Entry Points */

/*
 * Module 'insert' entry point.
 * o print announcement
 * o allocate adapter data space
 * o initialize static data
 * o register all cards with WAN router
 * o calibrate Cyclom 2X shared memory access delay.
 *
 * Return:      0       Ok
 *              < 0     error.
 * Context:     process
 */
static int __init cycx_init(void)
{
        int cnt, err = -ENOMEM;

        pr_info("%s v%u.%u %s\n",
                cycx_fullname, CYCX_DRV_VERSION, CYCX_DRV_RELEASE,
                cycx_copyright);

        /* Verify number of cards and allocate adapter data space */
        cycx_ncards = min_t(int, cycx_ncards, CYCX_MAX_CARDS);
        cycx_ncards = max_t(int, cycx_ncards, 1);
        cycx_card_array = kcalloc(cycx_ncards, sizeof(struct cycx_device), GFP_KERNEL);
        if (!cycx_card_array)
                goto out;


        /* Register adapters with WAN router */
        for (cnt = 0; cnt < cycx_ncards; ++cnt) {
                struct cycx_device *card = &cycx_card_array[cnt];
                struct wan_device *wandev = &card->wandev;

                sprintf(card->devname, "%s%d", cycx_drvname, cnt + 1);
                wandev->magic    = ROUTER_MAGIC;
                wandev->name     = card->devname;
                wandev->private  = card;
                wandev->setup    = cycx_wan_setup;
                wandev->shutdown = cycx_wan_shutdown;
                err = register_wan_device(wandev);

                if (err) {
                        pr_err("%s registration failed with error %d!\n",
                               card->devname, err);
                        break;
                }
        }

        err = -ENODEV;
        if (!cnt) {
                kfree(cycx_card_array);
                goto out;
        }
        err = 0;
        cycx_ncards = cnt;      /* adjust actual number of cards */
out:    return err;
}

/*
 * Module 'remove' entry point.
 * o unregister all adapters from the WAN router
 * o release all remaining system resources
 */
static void __exit cycx_exit(void)
{
        int i = 0;

        for (; i < cycx_ncards; ++i) {
                struct cycx_device *card = &cycx_card_array[i];
                unregister_wan_device(card->devname);
        }

        kfree(cycx_card_array);
}

/* WAN Device Driver Entry Points */
/*
 * Setup/configure WAN link driver.
 * o check adapter state
 * o make sure firmware is present in configuration
 * o allocate interrupt vector
 * o setup Cyclom 2X hardware
 * o call appropriate routine to perform protocol-specific initialization
 *
 * This function is called when router handles ROUTER_SETUP IOCTL. The
 * configuration structure is in kernel memory (including extended data, if
 * any).
 */
static int cycx_wan_setup(struct wan_device *wandev, wandev_conf_t *conf)
{
        int rc = -EFAULT;
        struct cycx_device *card;
        int irq;

        /* Sanity checks */

        if (!wandev || !wandev->private || !conf)
                goto out;

        card = wandev->private;
        rc = -EBUSY;
        if (wandev->state != WAN_UNCONFIGURED)
                goto out;

        rc = -EINVAL;
        if (!conf->data_size || !conf->data) {
                pr_err("%s: firmware not found in configuration data!\n",
                       wandev->name);
                goto out;
        }

        if (conf->irq <= 0) {
                pr_err("%s: can't configure without IRQ!\n", wandev->name);
                goto out;
        }

        /* Allocate IRQ */
        irq = conf->irq == 2 ? 9 : conf->irq;   /* IRQ2 -> IRQ9 */

        if (request_irq(irq, cycx_isr, 0, wandev->name, card)) {
                pr_err("%s: can't reserve IRQ %d!\n", wandev->name, irq);
                goto out;
        }

        /* Configure hardware, load firmware, etc. */
        memset(&card->hw, 0, sizeof(card->hw));
        card->hw.irq     = irq;
        card->hw.dpmsize = CYCX_WINDOWSIZE;
        card->hw.fwid    = CFID_X25_2X;
        spin_lock_init(&card->lock);
        init_waitqueue_head(&card->wait_stats);

        rc = cycx_setup(&card->hw, conf->data, conf->data_size, conf->maddr);
        if (rc)
                goto out_irq;

        /* Initialize WAN device data space */
        wandev->irq       = irq;
        wandev->dma       = wandev->ioport = 0;
        wandev->maddr     = (unsigned long)card->hw.dpmbase;
        wandev->msize     = card->hw.dpmsize;
        wandev->hw_opt[2] = 0;
        wandev->hw_opt[3] = card->hw.fwid;

        /* Protocol-specific initialization */
        switch (card->hw.fwid) {
#ifdef CONFIG_CYCLOMX_X25
        case CFID_X25_2X:
                rc = cycx_x25_wan_init(card, conf);
                break;
#endif
        default:
                pr_err("%s: this firmware is not supported!\n", wandev->name);
                rc = -EINVAL;
        }

        if (rc) {
                cycx_down(&card->hw);
                goto out_irq;
        }

        rc = 0;
out:
        return rc;
out_irq:
        free_irq(irq, card);
        goto out;
}

/*
 * Shut down WAN link driver.
 * o shut down adapter hardware
 * o release system resources.
 *
 * This function is called by the router when device is being unregistered or
 * when it handles ROUTER_DOWN IOCTL.
 */
static int cycx_wan_shutdown(struct wan_device *wandev)
{
        int ret = -EFAULT;
        struct cycx_device *card;

        /* sanity checks */
        if (!wandev || !wandev->private)
                goto out;

        ret = 0;
        if (wandev->state == WAN_UNCONFIGURED)
                goto out;

        card = wandev->private;
        wandev->state = WAN_UNCONFIGURED;
        cycx_down(&card->hw);
        pr_info("%s: irq %d being freed!\n", wandev->name, wandev->irq);
        free_irq(wandev->irq, card);
out:    return ret;
}

/* Miscellaneous */
/*
 * Cyclom 2X Interrupt Service Routine.
 * o acknowledge Cyclom 2X hardware interrupt.
 * o call protocol-specific interrupt service routine, if any.
 */
static irqreturn_t cycx_isr(int irq, void *dev_id)
{
        struct cycx_device *card = dev_id;

        if (card->wandev.state == WAN_UNCONFIGURED)
                goto out;

        if (card->in_isr) {
                pr_warn("%s: interrupt re-entrancy on IRQ %d!\n",
                        card->devname, card->wandev.irq);
                goto out;
        }

        if (card->isr)
                card->isr(card);
        return IRQ_HANDLED;
out:
        return IRQ_NONE;
}

/* Set WAN device state.  */
void cycx_set_state(struct cycx_device *card, int state)
{
        unsigned long flags;
        char *string_state = NULL;

        spin_lock_irqsave(&card->lock, flags);

        if (card->wandev.state != state) {
                switch (state) {
                case WAN_CONNECTED:
                        string_state = "connected!";
                        break;
                case WAN_DISCONNECTED:
                        string_state = "disconnected!";
                        break;
                }
                pr_info("%s: link %s\n", card->devname, string_state);
                card->wandev.state = state;
        }

        card->state_tick = jiffies;
        spin_unlock_irqrestore(&card->lock, flags);
}

module_init(cycx_init);
module_exit(cycx_exit);