root/trunk/freewrt/package/broadcom-diag/diag.c

/*
 * diag.c - GPIO interface driver for Broadcom boards
 *
 * Copyright (C) 2006 Mike Baker <mbm@openwrt.org>,
 *                    Felix Fietkau <nbd@openwrt.org>
 *
 * 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Id: diag.c 6562 2007-03-14 01:19:24Z nbd $
 */
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kmod.h>
#include <linux/proc_fs.h>
#include <linux/timer.h>
#include <linux/version.h>
#include <asm/uaccess.h>

//#define hotplug_path uevent_helper

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
#include <linux/kobject.h>
#include <linux/workqueue.h>
#else
#include <linux/tqueue.h>
#define INIT_WORK INIT_TQUEUE
#define schedule_work schedule_task
#define work_struct tq_struct
#endif

#include "gpio.h"
#include "diag.h"
#define getvar(str) (nvram_get(str)?:"")

static unsigned int gpiomask = 0;
module_param(gpiomask, int, 0644);

enum {
        /* Linksys */
        WAP54GV1,
        WAP54GV3,
        WRT54GV1,
        WRT54G,
        WRTSL54GS,
        WRT54G3G,
        WRT350N,
        
        /* ASUS */
        WLHDD,
        WL300G,
        WL500G,
        WL500GD,
        WL500GP,
        WL500W,
        ASUS_4702,
        WL700GE,
        
        /* Buffalo */
        WBR2_G54,
        WHR_G54S,
        WHR_HP_G54,
        WHR2_A54G54,
        WLA2_G54L,
        WZR_G300N,
        WZR_RS_G54,
        WZR_RS_G54HP,
        BUFFALO_UNKNOWN,
        BUFFALO_UNKNOWN_4710,

        /* Siemens */
        SE505V1,
        SE505V2,
        
        /* US Robotics */
        USR5461,

        /* Dell */
        TM2300,

        /* Motorola */
        WE800G,
        WR850GV1,
        WR850GV2V3,

        /* Belkin */
        BELKIN_UNKNOWN,

        /* Netgear */
        WGT634U,

        /* Trendware */
        TEW411BRPP,
        
        /* SimpleTech */
        STI_NAS,
};

static void __init bcm4780_init(void) {
                int pin = 1 << 3;

                /* Enables GPIO 3 that controls HDD and led power on ASUS WL-700gE */
                printk(MODULE_NAME ": Spinning up HDD and enabling leds\n");
                gpio_outen(pin, pin);
                gpio_control(pin, 0);
                gpio_out(pin, pin);

                /* Wait 5s, so the HDD can spin up */
                set_current_state(TASK_INTERRUPTIBLE);
                schedule_timeout(HZ * 5);
}

static struct platform_t __initdata platforms[] = {
        /* Linksys */
        [WAP54GV1] = {
                .name           = "Linksys WAP54G V1",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 0 },
                },
                .leds           = { 
                        { .name = "diag",       .gpio = 1 << 3 },
                        { .name = "wlan",       .gpio = 1 << 4 },
                },
        },
        [WAP54GV3] = {
                .name           = "Linksys WAP54G V3",
                .buttons        = {
                        /* FIXME: verify this */
                        { .name = "reset",      .gpio = 1 << 7 },
                        { .name = "ses",        .gpio = 1 << 0 },
                },
                .leds           = { 
                        /* FIXME: diag? */
                        { .name = "ses",        .gpio = 1 << 1 },
                },
        },
        [WRT54GV1] = {
                .name           = "Linksys WRT54G V1.x",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                },
                .leds           = { 
                        { .name = "diag",       .gpio = 0x13 | GPIO_TYPE_EXTIF, .polarity = NORMAL },
                        { .name = "dmz",        .gpio = 0x12 | GPIO_TYPE_EXTIF, .polarity = NORMAL },
                },
        },
        [WRT54G] = {
                .name           = "Linksys WRT54G/GS/GL",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                        { .name = "ses",        .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 1, .polarity = NORMAL },
                        { .name = "dmz",        .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "ses_white",  .gpio = 1 << 2, .polarity = REVERSE },
                        { .name = "ses_orange", .gpio = 1 << 3, .polarity = REVERSE },
                        { .name = "wlan",       .gpio = 1 << 0, .polarity = REVERSE },
                },
        },
        [WRTSL54GS] = {
                .name           = "Linksys WRTSL54GS",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                        { .name = "ses",        .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 1, .polarity = NORMAL },
                        { .name = "dmz",        .gpio = 1 << 0, .polarity = REVERSE },
                        { .name = "ses_white",  .gpio = 1 << 5, .polarity = REVERSE },
                        { .name = "ses_orange", .gpio = 1 << 7, .polarity = REVERSE },
                },
        },
        [WRT54G3G] = {
                .name           = "Linksys WRT54G3G",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                        { .name = "3g",         .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 1, .polarity = NORMAL },
                        { .name = "dmz",        .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "3g_green",   .gpio = 1 << 2, .polarity = NORMAL },
                        { .name = "3g_blue",    .gpio = 1 << 3, .polarity = NORMAL },
                        { .name = "3g_blink",   .gpio = 1 << 5, .polarity = NORMAL },
                },
        },
        [WRT350N] = {
                .name           = "Linksys WRT350N",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                        { .name = "ses",        .gpio = 1 << 8 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 1, .polarity = NORMAL },
                        { .name = "ses",        .gpio = 1 << 3, .polarity = REVERSE },
                },
        },
        /* Asus */
        [WLHDD] = {
                .name           = "ASUS WL-HDD",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 0, .polarity = REVERSE },
                        { .name = "usb",        .gpio = 1 << 2, .polarity = NORMAL },
                },
        },
        [WL300G] = {
                .name           = "ASUS WL-300g",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 0, .polarity = REVERSE },
                },
        },
        [WL500G] = {
                .name           = "ASUS WL-500g",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 0, .polarity = REVERSE },
                },
        },
        [WL500GD] = {
                .name           = "ASUS WL-500g Deluxe",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 0, .polarity = REVERSE },
                },
        },
        [WL500GP] = {
                .name           = "ASUS WL-500g Premium",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 0 },
                        { .name = "ses",        .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [WL500W] = {
                .name           = "ASUS WL-500W",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                        { .name = "ses",        .gpio = 1 << 7 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 5, .polarity = REVERSE },
                },
        },
        [ASUS_4702] = {
                .name           = "ASUS (unknown, BCM4702)",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 6 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 0, .polarity = REVERSE },
                },
        },
        [WL700GE] = {
                .name           = "ASUS WL-700gE",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 7 }, // on back, hardwired, always resets device regardless OS state
                        { .name = "ses",        .gpio = 1 << 4 }, // on back, actual name ezsetup
                        { .name = "power",      .gpio = 1 << 0 }, // on front
                        { .name = "copy",       .gpio = 1 << 6 }, // on front
                },
                .leds           = {
#if 0
                        // GPIO that controls power led also enables/disables some essential functions
                        // - power to HDD
                        // - switch leds
                        { .name = "power",      .gpio = 1 << 3, .polarity = NORMAL },  // actual name power
#endif
                        { .name = "diag",       .gpio = 1 << 1, .polarity = REVERSE }, // actual name ready
                },
                .platform_init = bcm4780_init,
        },
        /* Buffalo */
        [WHR_G54S] = {
                .name           = "Buffalo WHR-G54S",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 4 },
                        { .name = "bridge",     .gpio = 1 << 5 },
                        { .name = "ses",        .gpio = 1 << 0 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "internal",   .gpio = 1 << 3, .polarity = REVERSE },
                        { .name = "ses",        .gpio = 1 << 6, .polarity = REVERSE },
                        { .name = "bridge",     .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [WBR2_G54] = {
                .name           = "Buffalo WBR2-G54",
                /* FIXME: verify */
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 7 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [WHR_HP_G54] = {
                .name           = "Buffalo WHR-HP-G54",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 4 },
                        { .name = "bridge",     .gpio = 1 << 5 },
                        { .name = "ses",        .gpio = 1 << 0 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "bridge",     .gpio = 1 << 1, .polarity = REVERSE },
                        { .name = "ses",        .gpio = 1 << 6, .polarity = REVERSE },
                },
        },
        [WHR2_A54G54] = {
                .name           = "Buffalo WHR2-A54G54",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                },
        },
        [WLA2_G54L] = {
                .name           = "Buffalo WLA2-G54L",
                /* FIXME: verify */
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 7 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [WZR_G300N] = {
                .name           = "Buffalo WZR-G300N",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "bridge",     .gpio = 1 << 1, .polarity = REVERSE },
                        { .name = "ses",        .gpio = 1 << 6, .polarity = REVERSE },
                },
        },
        [WZR_RS_G54] = {
                .name           = "Buffalo WZR-RS-G54",
                .buttons        = {
                        { .name = "ses",        .gpio = 1 << 0 },
                        { .name = "reset",      .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "ses",        .gpio = 1 << 6, .polarity = REVERSE },
                        { .name = "vpn",        .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [WZR_RS_G54HP] = {
                .name           = "Buffalo WZR-RS-G54HP",
                .buttons        = {
                        { .name = "ses",        .gpio = 1 << 0 },
                        { .name = "reset",      .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                        { .name = "ses",        .gpio = 1 << 6, .polarity = REVERSE },
                        { .name = "vpn",        .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [BUFFALO_UNKNOWN] = {
                .name           = "Buffalo (unknown)",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 7 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        [BUFFALO_UNKNOWN_4710] = {
                .name           = "Buffalo (unknown, BCM4710)",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 4 },
                },
                .leds           = {
                        { .name = "diag",       .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        /* Siemens */
        [SE505V1] = {
                .name           = "Siemens SE505 V1",
                .buttons        = {
                        /* No usable buttons */
                },
                .leds           = {
                        { .name = "dmz",        .gpio = 1 << 4, .polarity = REVERSE },
                        { .name = "wlan",       .gpio = 1 << 3, .polarity = REVERSE },
                },
        },
        [SE505V2] = {
                .name           = "Siemens SE505 V2",
                .buttons        = {
                        /* No usable buttons */
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 5, .polarity = REVERSE },
                        { .name = "dmz",        .gpio = 1 << 0, .polarity = REVERSE },
                        { .name = "wlan",       .gpio = 1 << 3, .polarity = REVERSE },
                },
        },
        /* US Robotics */
        [USR5461] = {
                .name           = "U.S. Robotics USR5461",
                .buttons        = {
                        /* No usable buttons */
                },
                .leds           = {
                        { .name = "wlan",       .gpio = 1 << 0, .polarity = REVERSE },
                        { .name = "printer",    .gpio = 1 << 1, .polarity = REVERSE },
                },
        },
        /* Dell */
        [TM2300] = {
                .name           = "Dell TrueMobile 2300",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 0 },
                },
                .leds           = {
                        { .name = "wlan",       .gpio = 1 << 6, .polarity = REVERSE },
                        { .name = "power",      .gpio = 1 << 7, .polarity = REVERSE },
                },
        },
        /* Motorola */
        [WE800G] = {
                .name           = "Motorola WE800G",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 0 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 4, .polarity = NORMAL },
                        { .name = "diag",       .gpio = 1 << 2, .polarity = REVERSE },
                        { .name = "wlan_amber", .gpio = 1 << 1, .polarity = NORMAL },
                },
        },
        [WR850GV1] = {
                .name           = "Motorola WR850G V1",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 0 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 4, .polarity = NORMAL },
                        { .name = "diag",       .gpio = 1 << 3, .polarity = REVERSE },
                        { .name = "dmz",        .gpio = 1 << 6, .polarity = NORMAL },
                        { .name = "wlan_red",   .gpio = 1 << 5, .polarity = REVERSE },
                        { .name = "wlan_green", .gpio = 1 << 7, .polarity = REVERSE },
                },
        },
        [WR850GV2V3] = {
                .name           = "Motorola WR850G V2/V3",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 5 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 1, .polarity = NORMAL },
                        { .name = "wlan",       .gpio = 1 << 0, .polarity = REVERSE },
                        { .name = "dmz",        .gpio = 1 << 6, .polarity = REVERSE },
                        { .name = "diag",       .gpio = 1 << 7, .polarity = REVERSE },
                },
        },
        /* Belkin */
        [BELKIN_UNKNOWN] = {
                .name           = "Belkin (unknown)",
                /* FIXME: verify & add detection */
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 7 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 5, .polarity = NORMAL },
                        { .name = "wlan",       .gpio = 1 << 3, .polarity = NORMAL },
                        { .name = "connected",  .gpio = 1 << 0, .polarity = NORMAL },
                },
        },
        /* Netgear */
        [WGT634U] = {
                .name           = "Netgear WGT634U",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 2 },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 3, .polarity = REVERSE },
                },
        },
        /* Trendware */
        [TEW411BRPP] = {
                .name           = "Trendware TEW411BRP+",
                .buttons        = {
                        { /* No usable buttons */ },
                },
                .leds           = {
                        { .name = "power",      .gpio = 1 << 7, .polarity = NORMAL },
                        { .name = "wlan",       .gpio = 1 << 1, .polarity = NORMAL },
                        { .name = "bridge",     .gpio = 1 << 6, .polarity = NORMAL },
                },
        },
        /* SimpleTech */
        [STI_NAS] = {
                .name      = "SimpleTech SimpleShare NAS",
                .buttons        = {
                        { .name = "reset",      .gpio = 1 << 7 }, // on back, hardwired, always resets device regardless OS state
                        { .name = "power",      .gpio = 1 << 0 }, // on back
                },
                .leds      = {
                        { .name = "diag",       .gpio = 1 << 1, .polarity = REVERSE }, // actual name ready
                },
                .platform_init = bcm4780_init,
        },
};

static struct platform_t __init *platform_detect(void)
{
        char *boardnum, *boardtype, *buf;

        boardnum = getvar("boardnum");
        boardtype = getvar("boardtype");

        if (strcmp(getvar("nvram_type"), "cfe") == 0)
                return &platforms[WGT634U];
        
        if (strncmp(getvar("model_no"), "WL700",5) == 0)
                return &platforms[WL700GE];

        if (strncmp(getvar("pmon_ver"), "CFE", 3) == 0) {
                /* CFE based - newer hardware */
                if (!strcmp(boardnum, "42")) { /* Linksys */
                        if (!strcmp(boardtype, "0x478") && !strcmp(getvar("cardbus"), "1"))
                                return &platforms[WRT350N];

                        if (!strcmp(boardtype, "0x0101") && !strcmp(getvar("boot_ver"), "v3.6"))
                                return &platforms[WRT54G3G];

                        if (!strcmp(getvar("et1phyaddr"),"5") && !strcmp(getvar("et1mdcport"), "1"))
                                return &platforms[WRTSL54GS];
                        
                        /* default to WRT54G */
                        return &platforms[WRT54G];
                }
                
                if (!strcmp(boardnum, "45")) { /* ASUS */
                        if (!strcmp(boardtype,"0x042f"))
                                return &platforms[WL500GP];
                        else if (!strcmp(boardtype,"0x0472"))
                                return &platforms[WL500W];
                        else
                                return &platforms[WL500GD];
                }
                
                if (!strcmp(boardnum, "10496"))
                        return &platforms[USR5461];
        } else { /* PMON based - old stuff */

                /* Dell TrueMobile 2300 */
                if (!strcmp(getvar("ModelId"),"WX-5565"))
                        return &platforms[TM2300];
        
                if ((simple_strtoul(getvar("GemtekPmonVer"), NULL, 0) == 9) &&
                        (simple_strtoul(getvar("et0phyaddr"), NULL, 0) == 30)) {
                        if (!strncmp(getvar("ModelId"),"WE800G", 6))
                                return &platforms[WE800G];
                        else
                                return &platforms[WR850GV1];
                }
                if (!strncmp(boardtype, "bcm94710dev", 11)) {
                        if (!strcmp(boardnum, "42"))
                                return &platforms[WRT54GV1];
                        if (simple_strtoul(boardnum, NULL, 0) == 2)
                                return &platforms[WAP54GV1];
                }
                if (!strncmp(getvar("hardware_version"), "WL500-", 6))
                        return &platforms[WL500G];
                if (!strncmp(getvar("hardware_version"), "WL300-", 6)) {
                        /* Either WL-300g or WL-HDD, do more extensive checks */
                        if ((simple_strtoul(getvar("et0phyaddr"), NULL, 0) == 0) &&
                                (simple_strtoul(getvar("et1phyaddr"), NULL, 0) == 1))
                                return &platforms[WLHDD];
                        if ((simple_strtoul(getvar("et0phyaddr"), NULL, 0) == 0) &&
                                (simple_strtoul(getvar("et1phyaddr"), NULL, 0) == 10))
                                return &platforms[WL300G];
                }

                /* unknown asus stuff, probably bcm4702 */
                if (!strncmp(boardnum, "asusX", 5))
                        return &platforms[ASUS_4702];
        }

        if ((buf = (nvram_get("melco_id") ?: nvram_get("buffalo_id")))) {
                /* Buffalo hardware, check id for specific hardware matches */
                if (!strcmp(buf, "29bb0332"))
                        return &platforms[WBR2_G54];
                if (!strcmp(buf, "29129"))
                        return &platforms[WLA2_G54L];
                if (!strcmp(buf, "30189"))
                        return &platforms[WHR_HP_G54];
                if (!strcmp(buf, "30182"))
                        return &platforms[WHR_G54S];
                if (!strcmp(buf, "290441dd"))
                        return &platforms[WHR2_A54G54];
                if (!strcmp(buf, "31120"))
                        return &platforms[WZR_G300N];
                if (!strcmp(buf, "30083"))
                        return &platforms[WZR_RS_G54];
                if (!strcmp(buf, "30103"))
                        return &platforms[WZR_RS_G54HP];
        }

        if (buf || !strcmp(boardnum, "00")) {/* probably buffalo */
                if (!strncmp(boardtype, "bcm94710ap", 10))
                        return &platforms[BUFFALO_UNKNOWN_4710];
                else
                        return &platforms[BUFFALO_UNKNOWN];
        }

        if (!strcmp(getvar("CFEver"), "MotoWRv203") ||
                !strcmp(getvar("MOTO_BOARD_TYPE"), "WR_FEM1")) {

                return &platforms[WR850GV2V3];
        }

        if (!strcmp(boardnum, "44")) {  /* Trendware TEW-411BRP+ */
                return &platforms[TEW411BRPP];
        }

        if (!strncmp(boardnum, "04FN52", 6)) /* SimpleTech SimpleShare */
                return &platforms[STI_NAS];

        /* not found */
        return NULL;
}

static void register_buttons(struct button_t *b)
{
        for (; b->name; b++)
                platform.button_mask |= b->gpio;

        platform.button_mask &= ~gpiomask;

        gpio_outen(platform.button_mask, 0);
        gpio_control(platform.button_mask, 0);
        platform.button_polarity = gpio_in() & platform.button_mask;
        gpio_intpolarity(platform.button_mask, platform.button_polarity);
        gpio_intmask(platform.button_mask, platform.button_mask);

        gpio_set_irqenable(1, button_handler);
}

static void unregister_buttons(struct button_t *b)
{
        gpio_intmask(platform.button_mask, 0);

        gpio_set_irqenable(0, button_handler);
}

static void hotplug_button(struct event_t *event)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
        call_usermodehelper (event->argv[0], event->argv, event->envp, 1);
#else
        call_usermodehelper (event->argv[0], event->argv, event->envp);
#endif
        kfree(event);
}

static irqreturn_t button_handler(int irq, void *dev_id, struct pt_regs *regs)
{
        struct button_t *b;
        u32 in, changed;

        in = gpio_in() & platform.button_mask;
        gpio_intpolarity(platform.button_mask, in);
        changed = platform.button_polarity ^ in;
        platform.button_polarity = in;

        changed &= ~gpio_outen(0, 0);

        for (b = platform.buttons; b->name; b++) { 
                struct event_t *event;

                if (!(b->gpio & changed)) continue;

                b->pressed ^= 1;

                if ((event = (struct event_t *)kmalloc (sizeof(struct event_t), GFP_ATOMIC))) {
                        int i;
                        char *scratch = event->buf;

                        i = 0;
                        event->argv[i++] = hotplug_path;
                        event->argv[i++] = "button";
                        event->argv[i] = 0;

                        i = 0;
                        event->envp[i++] = "HOME=/";
                        event->envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
                        event->envp[i++] = scratch;
                        scratch += sprintf (scratch, "ACTION=%s", b->pressed?