cpcihp_generic.c

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/*
 * cpcihp_generic.c
 *
 * Generic port I/O CompactPCI driver
 *
 * Copyright 2002 SOMA Networks, Inc.
 * Copyright 2001 Intel San Luis Obispo
 * Copyright 2000,2001 MontaVista Software Inc.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * This generic CompactPCI hotplug driver should allow using the PCI hotplug
 * mechanism on any CompactPCI board that exposes the #ENUM signal as a bit
 * in a system register that can be read through standard port I/O.
 *
 * Send feedback to <[email protected]>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/string.h>
#include "cpci_hotplug.h"

#define DRIVER_VERSION  "0.1"
#define DRIVER_AUTHOR   "Scott Murray <[email protected]>"
#define DRIVER_DESC "Generic port I/O CompactPCI Hot Plug Driver"

#if !defined(MODULE)
#define MY_NAME "cpcihp_generic"
#else
#define MY_NAME THIS_MODULE->name
#endif

#define dbg(format, arg...)                 \
    do {                            \
        if(debug)                   \
            printk (KERN_DEBUG "%s: " format "\n",  \
                MY_NAME , ## arg);      \
    } while(0)
#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg)

/* local variables */
static bool debug;
static char *bridge;
static u8 bridge_busnr;
static u8 bridge_slot;
static struct pci_bus *bus;
static u8 first_slot;
static u8 last_slot;
static u16 port;
static unsigned int enum_bit;
static u8 enum_mask;

static struct cpci_hp_controller_ops generic_hpc_ops;
static struct cpci_hp_controller generic_hpc;

static int __init validate_parameters(void)
{
    char* str;
    char* p;
    unsigned long tmp;

    if(!bridge) {
        info("not configured, disabling.");
        return -EINVAL;
    }
    str = bridge;
    if(!*str)
        return -EINVAL;

    tmp = simple_strtoul(str, &p, 16);
    if(p == str || tmp > 0xff) {
        err("Invalid hotplug bus bridge device bus number");
        return -EINVAL;
    }
    bridge_busnr = (u8) tmp;
    dbg("bridge_busnr = 0x%02x", bridge_busnr);
    if(*p != ':') {
        err("Invalid hotplug bus bridge device");
        return -EINVAL;
    }
    str = p + 1;
    tmp = simple_strtoul(str, &p, 16);
    if(p == str || tmp > 0x1f) {
        err("Invalid hotplug bus bridge device slot number");
        return -EINVAL;
    }
    bridge_slot = (u8) tmp;
    dbg("bridge_slot = 0x%02x", bridge_slot);

    dbg("first_slot = 0x%02x", first_slot);
    dbg("last_slot = 0x%02x", last_slot);
    if(!(first_slot && last_slot)) {
        err("Need to specify first_slot and last_slot");
        return -EINVAL;
    }
    if(last_slot < first_slot) {
        err("first_slot must be less than last_slot");
        return -EINVAL;
    }

    dbg("port = 0x%04x", port);
    dbg("enum_bit = 0x%02x", enum_bit);
    if(enum_bit > 7) {
        err("Invalid #ENUM bit");
        return -EINVAL;
    }
    enum_mask = 1 << enum_bit;
    return 0;
}

static int query_enum(void)
{
    u8 value;

    value = inb_p(port);
    return ((value & enum_mask) == enum_mask);
}

static int __init cpcihp_generic_init(void)
{
    int status;
    struct resource* r;
    struct pci_dev* dev;

    info(DRIVER_DESC " version: " DRIVER_VERSION);
    status = validate_parameters();
    if (status)
        return status;

    r = request_region(port, 1, "#ENUM hotswap signal register");
    if(!r)
        return -EBUSY;

    dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
                      PCI_DEVFN(bridge_slot, 0));
    if(!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
        err("Invalid bridge device %s", bridge);
        pci_dev_put(dev);
        return -EINVAL;
    }
    bus = dev->subordinate;
    pci_dev_put(dev);

    memset(&generic_hpc, 0, sizeof (struct cpci_hp_controller));
    generic_hpc_ops.query_enum = query_enum;
    generic_hpc.ops = &generic_hpc_ops;

    status = cpci_hp_register_controller(&generic_hpc);
    if(status != 0) {
        err("Could not register cPCI hotplug controller");
        return -ENODEV;
    }
    dbg("registered controller");

    status = cpci_hp_register_bus(bus, first_slot, last_slot);
    if(status != 0) {
        err("Could not register cPCI hotplug bus");
        goto init_bus_register_error;
    }
    dbg("registered bus");

    status = cpci_hp_start();
    if(status != 0) {
        err("Could not started cPCI hotplug system");
        goto init_start_error;
    }
    dbg("started cpci hp system");
    return 0;
init_start_error:
    cpci_hp_unregister_bus(bus);
init_bus_register_error:
    cpci_hp_unregister_controller(&generic_hpc);
    err("status = %d", status);
    return status;

}

static void __exit cpcihp_generic_exit(void)
{
    cpci_hp_stop();
    cpci_hp_unregister_bus(bus);
    cpci_hp_unregister_controller(&generic_hpc);
    release_region(port, 1);
}

module_init(cpcihp_generic_init);
module_exit(cpcihp_generic_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
module_param(bridge, charp, 0);
MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
module_param(first_slot, byte, 0);
MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
module_param(last_slot, byte, 0);
MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
module_param(port, ushort, 0);
MODULE_PARM_DESC(port, "#ENUM signal I/O port");
module_param(enum_bit, uint, 0);
MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");