android_kernel_xiaomi_sm8350/arch/cris/arch-v32/drivers/gpio.c
Arjan van de Ven 5dfe4c964a [PATCH] mark struct file_operations const 2
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@osdl.org: sparc64 fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:44 -08:00

766 lines
19 KiB
C

/* $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);