/* $Id: gpio.c,v 1.16 2005/06/19 17:06:49 starvik Exp $
 *
 * ETRAX CRISv32 general port I/O device
 *
 * Copyright (c) 1999, 2000, 2001, 2002, 2003 Axis Communications AB
 *
 * Authors:    Bjorn Wesen      (initial version)
 *             Ola Knutsson     (LED handling)
 *             Johan Adolfsson  (read/set directions, write, port G,
 *                               port to ETRAX FS.
 *
 * $Log: gpio.c,v $
 * Revision 1.16  2005/06/19 17:06:49  starvik
 * Merge of Linux 2.6.12.
 *
 * Revision 1.15  2005/05/25 08:22:20  starvik
 * Changed GPIO port order to fit packages/devices/axis-2.4.
 *
 * Revision 1.14  2005/04/24 18:35:08  starvik
 * Updated with final register headers.
 *
 * Revision 1.13  2005/03/15 15:43:00  starvik
 * dev_id needs to be supplied for shared IRQs.
 *
 * Revision 1.12  2005/03/10 17:12:00  starvik
 * Protect alarm list with spinlock.
 *
 * Revision 1.11  2005/01/05 06:08:59  starvik
 * No need to do local_irq_disable after local_irq_save.
 *
 * Revision 1.10  2004/11/19 08:38:31  starvik
 * Removed old crap.
 *
 * Revision 1.9  2004/05/14 07:58:02  starvik
 * Merge of changes from 2.4
 *
 * Revision 1.8  2003/09/11 07:29:50  starvik
 * Merge of Linux 2.6.0-test5
 *
 * Revision 1.7  2003/07/10 13:25:46  starvik
 * Compiles for 2.5.74
 * Lindented ethernet.c
 *
 * Revision 1.6  2003/07/04 08:27:46  starvik
 * Merge of Linux 2.5.74
 *
 * Revision 1.5  2003/06/10 08:26:37  johana
 * Etrax -> ETRAX CRISv32
 *
 * Revision 1.4  2003/06/05 14:22:48  johana
 * Initialise some_alarms.
 *
 * Revision 1.3  2003/06/05 10:15:46  johana
 * New INTR_VECT macros.
 * Enable interrupts in global config.
 *
 * Revision 1.2  2003/06/03 15:52:50  johana
 * Initial CRIS v32 version.
 *
 * Revision 1.1  2003/06/03 08:53:15  johana
 * Copy of os/lx25/arch/cris/arch-v10/drivers/gpio.c version 1.7.
 *
 */


#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>

#include <asm/etraxgpio.h>
#include <asm/arch/hwregs/reg_map.h>
#include <asm/arch/hwregs/reg_rdwr.h>
#include <asm/arch/hwregs/gio_defs.h>
#include <asm/arch/hwregs/intr_vect_defs.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/irq.h>

/* The following gio ports on ETRAX FS is available:
 * pa  8 bits, supports interrupts off, hi, low, set, posedge, negedge anyedge
 * pb 18 bits
 * pc 18 bits
 * pd 18 bits
 * pe 18 bits
 * each port has a rw_px_dout, r_px_din and rw_px_oe register.
 */

#define GPIO_MAJOR 120  /* experimental MAJOR number */

#define D(x)

#if 0
static int dp_cnt;
#define DP(x) do { dp_cnt++; if (dp_cnt % 1000 == 0) x; }while(0)
#else
#define DP(x)
#endif

static char gpio_name[] = "etrax gpio";

#if 0
static wait_queue_head_t *gpio_wq;
#endif

static int gpio_ioctl(struct inode *inode, struct file *file,
                      unsigned int cmd, unsigned long arg);
static ssize_t gpio_write(struct file * file, const char * buf, size_t count,
                          loff_t *off);
static int gpio_open(struct inode *inode, struct file *filp);
static int gpio_release(struct inode *inode, struct file *filp);
static unsigned int gpio_poll(struct file *filp, struct poll_table_struct *wait);

/* private data per open() of this driver */

struct gpio_private {
        struct gpio_private *next;
        /* The IO_CFG_WRITE_MODE_VALUE only support 8 bits: */
        unsigned char clk_mask;
        unsigned char data_mask;
        unsigned char write_msb;
        unsigned char pad1;
        /* These fields are generic */
        unsigned long highalarm, lowalarm;
        wait_queue_head_t alarm_wq;
        int minor;
};

/* linked list of alarms to check for */

static struct gpio_private *alarmlist = 0;

static int gpio_some_alarms = 0; /* Set if someone uses alarm */
static unsigned long gpio_pa_high_alarms = 0;
static unsigned long gpio_pa_low_alarms = 0;

static DEFINE_SPINLOCK(alarm_lock);

#define NUM_PORTS (GPIO_MINOR_LAST+1)
#define GIO_REG_RD_ADDR(reg) (volatile unsigned long*) (regi_gio + REG_RD_ADDR_gio_##reg )
#define GIO_REG_WR_ADDR(reg) (volatile unsigned long*) (regi_gio + REG_RD_ADDR_gio_##reg )
unsigned long led_dummy;

static volatile unsigned long *data_out[NUM_PORTS] = {
        GIO_REG_WR_ADDR(rw_pa_dout),
        GIO_REG_WR_ADDR(rw_pb_dout),
        &led_dummy,
        GIO_REG_WR_ADDR(rw_pc_dout),
        GIO_REG_WR_ADDR(rw_pd_dout),
        GIO_REG_WR_ADDR(rw_pe_dout),
};

static volatile unsigned long *data_in[NUM_PORTS] = {
        GIO_REG_RD_ADDR(r_pa_din),
        GIO_REG_RD_ADDR(r_pb_din),
        &led_dummy,
        GIO_REG_RD_ADDR(r_pc_din),
        GIO_REG_RD_ADDR(r_pd_din),
        GIO_REG_RD_ADDR(r_pe_din),
};

static unsigned long changeable_dir[NUM_PORTS] = {
        CONFIG_ETRAX_PA_CHANGEABLE_DIR,
        CONFIG_ETRAX_PB_CHANGEABLE_DIR,
        0,
        CONFIG_ETRAX_PC_CHANGEABLE_DIR,
        CONFIG_ETRAX_PD_CHANGEABLE_DIR,
        CONFIG_ETRAX_PE_CHANGEABLE_DIR,
};

static unsigned long changeable_bits[NUM_PORTS] = {
        CONFIG_ETRAX_PA_CHANGEABLE_BITS,
        CONFIG_ETRAX_PB_CHANGEABLE_BITS,
        0,
        CONFIG_ETRAX_PC_CHANGEABLE_BITS,
        CONFIG_ETRAX_PD_CHANGEABLE_BITS,
        CONFIG_ETRAX_PE_CHANGEABLE_BITS,
};

static volatile unsigned long *dir_oe[NUM_PORTS] = {
        GIO_REG_WR_ADDR(rw_pa_oe),
        GIO_REG_WR_ADDR(rw_pb_oe),
        &led_dummy,
        GIO_REG_WR_ADDR(rw_pc_oe),
        GIO_REG_WR_ADDR(rw_pd_oe),
        GIO_REG_WR_ADDR(rw_pe_oe),
};



static unsigned int
gpio_poll(struct file *file,
          poll_table *wait)
{
        unsigned int mask = 0;
        struct gpio_private *priv = (struct gpio_private *)file->private_data;
        unsigned long data;
        poll_wait(file, &priv->alarm_wq, wait);
        if (priv->minor == GPIO_MINOR_A) {
                reg_gio_rw_intr_cfg intr_cfg;
                unsigned long tmp;
                unsigned long flags;

                local_irq_save(flags);
                data = REG_TYPE_CONV(unsigned long, reg_gio_r_pa_din, REG_RD(gio, regi_gio, r_pa_din));
                /* PA has support for interrupt
                 * lets activate high for those low and with highalarm set
                 */
                intr_cfg = REG_RD(gio, regi_gio, rw_intr_cfg);

                tmp = ~data & priv->highalarm & 0xFF;
                if (tmp & (1 << 0)) {
                        intr_cfg.pa0 = regk_gio_hi;
                }
                if (tmp & (1 << 1)) {
                        intr_cfg.pa1 = regk_gio_hi;
                }
                if (tmp & (1 << 2)) {
                        intr_cfg.pa2 = regk_gio_hi;
                }
                if (tmp & (1 << 3)) {
                        intr_cfg.pa3 = regk_gio_hi;
                }
                if (tmp & (1 << 4)) {
                        intr_cfg.pa4 = regk_gio_hi;
                }
                if (tmp & (1 << 5)) {
                        intr_cfg.pa5 = regk_gio_hi;
                }
                if (tmp & (1 << 6)) {
                        intr_cfg.pa6 = regk_gio_hi;
                }
                if (tmp & (1 << 7)) {
                        intr_cfg.pa7 = regk_gio_hi;
                }
                /*
                 * lets activate low for those high and with lowalarm set
                 */
                tmp = data & priv->lowalarm & 0xFF;
                if (tmp & (1 << 0)) {
                        intr_cfg.pa0 = regk_gio_lo;
                }
                if (tmp & (1 << 1)) {
                        intr_cfg.pa1 = regk_gio_lo;
                }
                if (tmp & (1 << 2)) {
                        intr_cfg.pa2 = regk_gio_lo;
                }
                if (tmp & (1 << 3)) {
                        intr_cfg.pa3 = regk_gio_lo;
                }
                if (tmp & (1 << 4)) {
                        intr_cfg.pa4 = regk_gio_lo;
                }
                if (tmp & (1 << 5)) {
                        intr_cfg.pa5 = regk_gio_lo;
                }
                if (tmp & (1 << 6)) {
                        intr_cfg.pa6 = regk_gio_lo;
                }
                if (tmp & (1 << 7)) {
                        intr_cfg.pa7 = regk_gio_lo;
                }

                REG_WR(gio, regi_gio, rw_intr_cfg, intr_cfg);
                local_irq_restore(flags);
        } else if (priv->minor <= GPIO_MINOR_E)
                data = *data_in[priv->minor];
        else
                return 0;

        if ((data & priv->highalarm) ||
            (~data & priv->lowalarm)) {
                mask = POLLIN|POLLRDNORM;
        }

        DP(printk("gpio_poll ready: mask 0x%08X\n", mask));
        return mask;
}

int etrax_gpio_wake_up_check(void)
{
        struct gpio_private *priv = alarmlist;
        unsigned long data = 0;
        int ret = 0;
        while (priv) {
                data = *data_in[priv->minor];
                if ((data & priv->highalarm) ||
                    (~data & priv->lowalarm)) {
                        DP(printk("etrax_gpio_wake_up_check %i\n",priv->minor));
                        wake_up_interruptible(&priv->alarm_wq);
                        ret = 1;
                }
                priv = priv->next;
        }
        return ret;
}

static irqreturn_t
gpio_poll_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        if (gpio_some_alarms) {
                return IRQ_RETVAL(etrax_gpio_wake_up_check());
        }
        return IRQ_NONE;
}

static irqreturn_t
gpio_pa_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        reg_gio_rw_intr_mask intr_mask;
        reg_gio_r_masked_intr masked_intr;
        reg_gio_rw_ack_intr ack_intr;
        unsigned long tmp;
        unsigned long tmp2;

        /* Find what PA interrupts are active */
        masked_intr = REG_RD(gio, regi_gio, r_masked_intr);
        tmp = REG_TYPE_CONV(unsigned long, reg_gio_r_masked_intr, masked_intr);

        /* Find those that we have enabled */
        spin_lock(&alarm_lock);
        tmp &= (gpio_pa_high_alarms | gpio_pa_low_alarms);
        spin_unlock(&alarm_lock);

        /* Ack them */
        ack_intr = REG_TYPE_CONV(reg_gio_rw_ack_intr, unsigned long, tmp);
        REG_WR(gio, regi_gio, rw_ack_intr, ack_intr);

        /* Disable those interrupts.. */
        intr_mask = REG_RD(gio, regi_gio, rw_intr_mask);
        tmp2 = REG_TYPE_CONV(unsigned long, reg_gio_rw_intr_mask, intr_mask);
        tmp2 &= ~tmp;
        intr_mask = REG_TYPE_CONV(reg_gio_rw_intr_mask, unsigned long, tmp2);
        REG_WR(gio, regi_gio, rw_intr_mask, intr_mask);

        if (gpio_some_alarms) {
                return IRQ_RETVAL(etrax_gpio_wake_up_check());
        }
        return IRQ_NONE;
}


static ssize_t gpio_write(struct file * file, const char * buf, size_t count,
                          loff_t *off)
{
        struct gpio_private *priv = (struct gpio_private *)file->private_data;
        unsigned char data, clk_mask, data_mask, write_msb;
        unsigned long flags;
        unsigned long shadow;
        volatile unsigned long *port;
        ssize_t retval = count;
        /* Only bits 0-7 may be used for write operations but allow all
           devices except leds... */
        if (priv->minor == GPIO_MINOR_LEDS) {
                return -EFAULT;
        }

        if (!access_ok(VERIFY_READ, buf, count)) {
                return -EFAULT;
        }
        clk_mask = priv->clk_mask;
        data_mask = priv->data_mask;
        /* It must have been configured using the IO_CFG_WRITE_MODE */
        /* Perhaps a better error code? */
        if (clk_mask == 0 || data_mask == 0) {
                return -EPERM;
        }
        write_msb = priv->write_msb;
        D(printk("gpio_write: %lu to data 0x%02X clk 0x%02X msb: %i\n",count, data_mask, clk_mask, write_msb));
        port = data_out[priv->minor];

        while (count--) {
                int i;
                data = *buf++;
                if (priv->write_msb) {
                        for (i = 7; i >= 0;i--) {
                                local_irq_save(flags);
                                shadow = *port;
                                *port = shadow &= ~clk_mask;
                                if (data & 1<<i)
                                        *port = shadow |= data_mask;
                                else
                                        *port = shadow &= ~data_mask;
                        /* For FPGA: min 5.0ns (DCC) before CCLK high */
                                *port = shadow |= clk_mask;
                                local_irq_restore(flags);
                        }
                } else {
                        for (i = 0; i <= 7;i++) {
                                local_irq_save(flags);
                                shadow = *port;
                                *port = shadow &= ~clk_mask;
                                if (data & 1<<i)
                                        *port = shadow |= data_mask;
                                else
                                        *port = shadow &= ~data_mask;
                        /* For FPGA: min 5.0ns (DCC) before CCLK high */
                                *port = shadow |= clk_mask;
                                local_irq_restore(flags);
                        }
                }
        }
        return retval;
}



static int
gpio_open(struct inode *inode, struct file *filp)
{
        struct gpio_private *priv;
        int p = iminor(inode);

        if (p > GPIO_MINOR_LAST)
                return -EINVAL;

        priv = kmalloc(sizeof(struct gpio_private),
                                              GFP_KERNEL);

        if (!priv)
                return -ENOMEM;

        priv->minor = p;

        /* initialize the io/alarm struct and link it into our alarmlist */

        priv->next = alarmlist;
        alarmlist = priv;
        priv->clk_mask = 0;
        priv->data_mask = 0;
        priv->highalarm = 0;
        priv->lowalarm = 0;
        init_waitqueue_head(&priv->alarm_wq);

        filp->private_data = (void *)priv;

        return 0;
}

static int
gpio_release(struct inode *inode, struct file *filp)
{
        struct gpio_private *p = alarmlist;
        struct gpio_private *todel = (struct gpio_private *)filp->private_data;
        /* local copies while updating them: */
        unsigned long a_high, a_low;
        unsigned long some_alarms;

        /* unlink from alarmlist and free the private structure */

        if (p == todel) {
                alarmlist = todel->next;
        } else {
                while (p->next != todel)
                        p = p->next;
                p->next = todel->next;
        }

        kfree(todel);
        /* Check if there are still any alarms set */
        p = alarmlist;
        some_alarms = 0;
        a_high = 0;
        a_low = 0;
        while (p) {
                if (p->minor == GPIO_MINOR_A) {
                        a_high |= p->highalarm;
                        a_low |= p->lowalarm;
                }

                if (p->highalarm | p->lowalarm) {
                        some_alarms = 1;
                }
                p = p->next;
        }

        spin_lock(&alarm_lock);
        gpio_some_alarms = some_alarms;
        gpio_pa_high_alarms = a_high;
        gpio_pa_low_alarms = a_low;
        spin_unlock(&alarm_lock);

        return 0;
}

/* Main device API. ioctl's to read/set/clear bits, as well as to
 * set alarms to wait for using a subsequent select().
 */

unsigned long inline setget_input(struct gpio_private *priv, unsigned long arg)
{
        /* Set direction 0=unchanged 1=input,
         * return mask with 1=input
         */
        unsigned long flags;
        unsigned long dir_shadow;

        local_irq_save(flags);
        dir_shadow = *dir_oe[priv->minor];
        dir_shadow &= ~(arg & changeable_dir[priv->minor]);
        *dir_oe[priv->minor] = dir_shadow;
        local_irq_restore(flags);

        if (priv->minor == GPIO_MINOR_A)
                dir_shadow ^= 0xFF;    /* Only 8 bits */
        else
                dir_shadow ^= 0x3FFFF; /* Only 18 bits */
        return dir_shadow;

} /* setget_input */

unsigned long inline setget_output(struct gpio_private *priv, unsigned long arg)
{
        unsigned long flags;
        unsigned long dir_shadow;

        local_irq_save(flags);
        dir_shadow = *dir_oe[priv->minor];
        dir_shadow |=  (arg & changeable_dir[priv->minor]);
        *dir_oe[priv->minor] = dir_shadow;
        local_irq_restore(flags);
        return dir_shadow;
} /* setget_output */

static int
gpio_leds_ioctl(unsigned int cmd, unsigned long arg);

static int
gpio_ioctl(struct inode *inode, struct file *file,
           unsigned int cmd, unsigned long arg)
{
        unsigned long flags;
        unsigned long val;
        unsigned long shadow;
        struct gpio_private *priv = (struct gpio_private *)file->private_data;
        if (_IOC_TYPE(cmd) != ETRAXGPIO_IOCTYPE) {
                return -EINVAL;
        }

        switch (_IOC_NR(cmd)) {
        case IO_READBITS: /* Use IO_READ_INBITS and IO_READ_OUTBITS instead */
                // read the port
                return *data_in[priv->minor];
                break;
        case IO_SETBITS:
                local_irq_save(flags);
                if (arg & 0x04)
                  printk("GPIO SET 2\n");
                // set changeable bits with a 1 in arg
                shadow = *data_out[priv->minor];
                shadow |=  (arg & changeable_bits[priv->minor]);
                *data_out[priv->minor] = shadow;
                local_irq_restore(flags);
                break;
        case IO_CLRBITS:
                local_irq_save(flags);
                if (arg & 0x04)
                  printk("GPIO CLR 2\n");
                // clear changeable bits with a 1 in arg
                shadow = *data_out[priv->minor];
                shadow &=  ~(arg & changeable_bits[priv->minor]);
                *data_out[priv->minor] = shadow;
                local_irq_restore(flags);
                break;
        case IO_HIGHALARM:
                // set alarm when bits with 1 in arg go high
                priv->highalarm |= arg;
                spin_lock(&alarm_lock);
                gpio_some_alarms = 1;
                if (priv->minor == GPIO_MINOR_A) {
                        gpio_pa_high_alarms |= arg;
                }
                spin_unlock(&alarm_lock);
                break;
        case IO_LOWALARM:
                // set alarm when bits with 1 in arg go low
                priv->lowalarm |= arg;
                spin_lock(&alarm_lock);
                gpio_some_alarms = 1;
                if (priv->minor == GPIO_MINOR_A) {
                        gpio_pa_low_alarms |= arg;
                }
                spin_unlock(&alarm_lock);
                break;
        case IO_CLRALARM:
                // clear alarm for bits with 1 in arg
                priv->highalarm &= ~arg;
                priv->lowalarm  &= ~arg;
                spin_lock(&alarm_lock);
                if (priv->minor == GPIO_MINOR_A) {
                        if (gpio_pa_high_alarms & arg ||
                            gpio_pa_low_alarms & arg) {
                                /* Must update the gpio_pa_*alarms masks */
                        }
                }
                spin_unlock(&alarm_lock);
                break;
        case IO_READDIR: /* Use IO_SETGET_INPUT/OUTPUT instead! */
                /* Read direction 0=input 1=output */
                return *dir_oe[priv->minor];
        case IO_SETINPUT: /* Use IO_SETGET_INPUT instead! */
                /* Set direction 0=unchanged 1=input,
                 * return mask with 1=input
                 */
                return setget_input(priv, arg);
                break;
        case IO_SETOUTPUT: /* Use IO_SETGET_OUTPUT instead! */
                /* Set direction 0=unchanged 1=output,
                 * return mask with 1=output
                 */
                return setget_output(priv, arg);

        case IO_CFG_WRITE_MODE:
        {
                unsigned long dir_shadow;
                dir_shadow = *dir_oe[priv->minor];

                priv->clk_mask = arg & 0xFF;
                priv->data_mask = (arg >> 8) & 0xFF;
                priv->write_msb = (arg >> 16) & 0x01;
                /* Check if we're allowed to change the bits and
                 * the direction is correct
                 */
                if (!((priv->clk_mask & changeable_bits[priv->minor]) &&
                      (priv->data_mask & changeable_bits[priv->minor]) &&
                      (priv->clk_mask & dir_shadow) &&
                      (priv->data_mask & dir_shadow)))
                {
                        priv->clk_mask = 0;
                        priv->data_mask = 0;
                        return -EPERM;
                }
                break;
        }
        case IO_READ_INBITS:
                /* *arg is result of reading the input pins */
                val = *data_in[priv->minor];
                if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                        return -EFAULT;
                return 0;
                break;
        case IO_READ_OUTBITS:
                 /* *arg is result of reading the output shadow */
                val = *data_out[priv->minor];
                if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                        return -EFAULT;
                break;
        case IO_SETGET_INPUT:
                /* bits set in *arg is set to input,
                 * *arg updated with current input pins.
                 */
                if (copy_from_user(&val, (unsigned long*)arg, sizeof(val)))
                        return -EFAULT;
                val = setget_input(priv, val);
                if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                        return -EFAULT;
                break;
        case IO_SETGET_OUTPUT:
                /* bits set in *arg is set to output,
                 * *arg updated with current output pins.
                 */
                if (copy_from_user(&val, (unsigned long*)arg, sizeof(val)))
                        return -EFAULT;
                val = setget_output(priv, val);
                if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                        return -EFAULT;
                break;
        default:
                if (priv->minor == GPIO_MINOR_LEDS)
                        return gpio_leds_ioctl(cmd, arg);
                else
                        return -EINVAL;
        } /* switch */

        return 0;
}

static int
gpio_leds_ioctl(unsigned int cmd, unsigned long arg)
{
        unsigned char green;
        unsigned char red;

        switch (_IOC_NR(cmd)) {
        case IO_LEDACTIVE_SET:
                green = ((unsigned char) arg) & 1;
                red   = (((unsigned char) arg) >> 1) & 1;
                LED_ACTIVE_SET_G(green);
                LED_ACTIVE_SET_R(red);
                break;

        default:
                return -EINVAL;
        } /* switch */

        return 0;
}

const struct file_operations gpio_fops = {
        .owner       = THIS_MODULE,
        .poll        = gpio_poll,
        .ioctl       = gpio_ioctl,
        .write       = gpio_write,
        .open        = gpio_open,
        .release     = gpio_release,
};


/* main driver initialization routine, called from mem.c */

static __init int
gpio_init(void)
{
        int res;
        reg_intr_vect_rw_mask intr_mask;

        /* do the formalities */

        res = register_chrdev(GPIO_MAJOR, gpio_name, &gpio_fops);
        if (res < 0) {
                printk(KERN_ERR "gpio: couldn't get a major number.\n");
                return res;
        }

        /* Clear all leds */
        LED_NETWORK_SET(0);
        LED_ACTIVE_SET(0);
        LED_DISK_READ(0);
        LED_DISK_WRITE(0);

        printk("ETRAX FS GPIO driver v2.5, (c) 2003-2005 Axis Communications AB\n");
        /* We call etrax_gpio_wake_up_check() from timer interrupt and
         * from cpu_idle() in kernel/process.c
         * The check in cpu_idle() reduces latency from ~15 ms to ~6 ms
         * in some tests.
         */
        if (request_irq(TIMER_INTR_VECT, gpio_poll_timer_interrupt,
                        IRQF_SHARED | IRQF_DISABLED,"gpio poll", &alarmlist)) {
                printk("err: timer0 irq for gpio\n");
        }
        if (request_irq(GEN_IO_INTR_VECT, gpio_pa_interrupt,
                        IRQF_SHARED | IRQF_DISABLED,"gpio PA", &alarmlist)) {
                printk("err: PA irq for gpio\n");
        }
        /* enable the gio and timer irq in global config */
        intr_mask = REG_RD(intr_vect, regi_irq, rw_mask);
        intr_mask.timer = 1;
        intr_mask.gen_io = 1;
        REG_WR(intr_vect, regi_irq, rw_mask, intr_mask);

        return res;
}

/* this makes sure that gpio_init is called during kernel boot */

module_init(gpio_init);