s3c2410 4X4矩阵键盘驱动

参考了一些例子,写了一个GEC2410 上的4X4矩阵键盘的驱动,中间因为使用了开发板自带内核中的一些中断设置函数而导致错误不断,事实证明,不要去相信任何东西~~

//驱动代码如下.主设备号设为232 ,适用GEC2410 十六键矩阵键盘

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <asm/io.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <asm/system.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <asm-arm/arch-s3c2410/regs-gpio.h>
#include <asm-arm/arch-s3c2410/irqs.h>
#include <asm-arm/arch-s3c2410/regs-irq.h>
#include <linux/ioport.h>
#include <linux/miscdevice.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <asm/hardware.h>
#include <linux/interrupt.h>
#include <asm/signal.h>

#define S3C2410_GPG11 S3C2410_GPIONO(S3C2410_GPIO_BANKG, 11) // S3C2410_GPG11 undefined in regs-gpio.h

#define DEVICE_NAME "matrix_button"
#define BUTTON_MAJOR 232

unsigned int s3c2410_gpio_getpin(unsigned int pin)
{
unsigned long base = S3C2410_GPIO_BASE(pin);
unsigned long offs = S3C2410_GPIO_OFFSET(pin);
return __raw_readl(base + 0x04) & (1<< offs);
}

void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int function)
{
unsigned long base = S3C2410_GPIO_BASE(pin);
unsigned long mask;
unsigned long con;
unsigned long flags;
if(pin<S3C2410_GPIO_BANKB)
mask=1<<S3C2410_GPIO_OFFSET(pin);
else
mask =3<< (S3C2410_GPIO_OFFSET(pin)*2);
local_irq_save(flags);

con = __raw_readl(base + 0x00);

con &= ~mask;
con |= function;

__raw_writel(con, base + 0x00);

local_irq_restore(flags);
}

void s3c2410_gpio_setpin(unsigned int pin, unsigned int to)
{
unsigned long base = S3C2410_GPIO_BASE(pin);
unsigned long offs = S3C2410_GPIO_OFFSET(pin);
unsigned long flags;
unsigned long dat;

local_irq_save(flags);

dat = __raw_readl(base + 0x04);
dat &= ~(1 << offs);
dat |= to << offs;
__raw_writel(dat, base + 0x04);

local_irq_restore(flags);
}

#define EXTINT_OFF (IRQ_EINT4 - 4)

// clear SRCPND&INTPND
void s3c_irq_ack(unsigned int irqno)
{
unsigned long bitval = 1UL << (irqno - IRQ_EINT0);
__raw_writel(bitval, S3C2410_SRCPND);
__raw_writel(bitval, S3C2410_INTPND);
return;
}
void s3c_irqext_ack(unsigned int irqno)
{
unsigned long req;
unsigned long bit;
bit = 1UL << (irqno - EXTINT_OFF);
__raw_writel(bit, S3C2410_EINTPEND);
req = __raw_readl(S3C2410_EINTPEND);
if (irqno <= IRQ_EINT7 )
{
if ((req & 0xf0) == 0)
s3c_irq_ack(IRQ_EINT4t7);
}
else
{
if ((req >> 8) == 0)
s3c_irq_ack(IRQ_EINT8t23);
}
return;
}

// set external interrupt mode, trigger type and gpio registers
int realarm_interrupt_init(unsigned int irq, unsigned int type)
{
unsigned long gpcon_reg;
unsigned long gpcon_offset;
unsigned long extint_reg;
unsigned long extint_offset;
unsigned long newvalue = 0;
unsigned long value;
if ((irq >= IRQ_EINT0) && (irq <= IRQ_EINT3))
{
gpcon_reg = S3C2410_GPFCON;
extint_reg = S3C2410_EXTINT0;
gpcon_offset = (irq - IRQ_EINT0) * 2;
extint_offset = (irq - IRQ_EINT0) * 4;
}
else if ((irq >= IRQ_EINT4) && (irq <= IRQ_EINT7))
{
gpcon_reg = S3C2410_GPFCON;
extint_reg = S3C2410_EXTINT0;
gpcon_offset = (irq - EXTINT_OFF) * 2;
extint_offset = (irq - EXTINT_OFF) * 4;
}
else if ((irq >= IRQ_EINT8) && (irq <= IRQ_EINT15))
{
gpcon_reg = S3C2410_GPGCON;
extint_reg = S3C2410_EXTINT1;
gpcon_offset = (irq - IRQ_EINT8) * 2;
extint_offset = (irq - IRQ_EINT8) * 4;
}
else if ((irq >= IRQ_EINT16) && (irq <= IRQ_EINT23))
{
gpcon_reg = S3C2410_GPGCON;
extint_reg = S3C2410_EXTINT2;
gpcon_offset = (irq - IRQ_EINT8) * 2;
extint_offset = (irq - IRQ_EINT16) * 4;
} else
{
return -1;
}
/* Set the GPIO to external interrupt mode */
value = __raw_readl(gpcon_reg);
value = (value & ~(3 << gpcon_offset)) | (0x02 << gpcon_offset);
__raw_writel(value, gpcon_reg);
/* Set the external interrupt to pointed trigger type */
switch (type)
{
case IRQT_NOEDGE:
printk(KERN_WARNING "No edge setting!/n");
break;
case IRQT_RISING:
newvalue = S3C2410_EXTINT_RISEEDGE;
break;
case IRQT_FALLING:
newvalue = S3C2410_EXTINT_FALLEDGE;
break;
case IRQT_BOTHEDGE:
newvalue = S3C2410_EXTINT_BOTHEDGE;
break;
case IRQT_LOW:
newvalue = S3C2410_EXTINT_LOWLEV;
break;
case IRQT_HIGH:
newvalue = S3C2410_EXTINT_HILEV;
break;
default:
printk(KERN_ERR "No such irq type %d", type);
return -1;
}
value = __raw_readl(extint_reg);
value = (value & ~(7 << extint_offset)) | (newvalue << extint_offset);
__raw_writel(value, extint_reg);
return 0;
}

static struct key_info {
int irq_no;
unsigned int gpio_port;
int function_inp;
int function_eintn;
}key_info_tab[4]={
{ IRQ_EINT0, S3C2410_GPF0,S3C2410_GPF0_INP,S3C2410_GPF0_EINT0},
{ IRQ_EINT2, S3C2410_GPF2,S3C2410_GPF2_INP,S3C2410_GPF2_EINT2},
{ IRQ_EINT11,S3C2410_GPG3,S3C2410_GPG3_INP,S3C2410_GPG3_EINT11 },
{ IRQ_EINT19,S3C2410_GPG11,S3C2410_GPG11_INP,S3C2410_GPG11_EINT19}};

struct matrix_button
{
int key_value;
int ready;
int open_count;
wait_queue_head_t buttons_wait;
struct cdev cdev;
struct semaphore sem;
};

static struct matrix_button* matrix_button_dev;

static struct output_pin
{
unsigned int gpio_pin;
int function_outp;
}output_pin_tab[4]={
{S3C2410_GPE11,S3C2410_GPE11_OUTP},
{S3C2410_GPG6,S3C2410_GPG6_OUTP},
{S3C2410_GPE13,S3C2410_GPE13_OUTP},
{S3C2410_GPG2,S3C2410_GPG2_OUTP}
};

static int key_scan(void)
{

int i,j,k,ret=0;
for(i=0;i<4;i++)
{

for(j=0;j<4;j++)
{
if(i==j)s3c2410_gpio_setpin(output_pin_tab[j].gpio_pin,0);
else s3c2410_gpio_setpin(output_pin_tab[j].gpio_pin,1);
}
for(k=0;k<4;k++)
{
if(s3c2410_gpio_getpin(key_info_tab[k].gpio_port)==0)
{
ret=i*10+k+1;
return ret;
}
}
}
return ret;
}

static void port_init(void)
{
int i;
for(i=0;i<4;i++)
{
s3c2410_gpio_cfgpin(output_pin_tab[i].gpio_pin,output_pin_tab[i].function_outp);
s3c2410_gpio_setpin(output_pin_tab[i].gpio_pin,0);
s3c2410_gpio_cfgpin(key_info_tab[i].gpio_port,key_info_tab[i].function_eintn);
realarm_interrupt_init(key_info_tab[i].irq_no,IRQT_FALLING);
}
}

static irqreturn_t matrix_button_irq(int irq, void *dev_id, struct pt_regs *reg)
{
struct matrix_button *dev=dev_id;
struct key_info *k;
int i;
int found = 0;
int flags;
down(&dev->sem);
for (i = 0; i < sizeof(key_info_tab)/ sizeof(key_info_tab[0]); i++)
{
k = key_info_tab + i;
if (k->irq_no == irq)
{
found = 1;
break;
}
}
if (!found)
{
printk(KERN_NOTICE "bad irq %d in button/n", irq);
return IRQ_HANDLED;
}
save_flags(flags); // save CPSR
cli(); // Close interrupt
if(k->irq_no<IRQ_EINT3)
s3c_irq_ack(k->irq_no);
else
s3c_irqext_ack(k->irq_no);
for(i=0;i<sizeof(key_info_tab)/sizeof(key_info_tab[0]);i++)
{
k=key_info_tab+i;
s3c2410_gpio_cfgpin(k->gpio_port,k->function_inp);
}
mdelay(100);
dev->key_value=key_scan();
if(dev->key_value==0)
{
up(&dev->sem);
port_init();
restore_flags(flags);
return IRQ_HANDLED;
}
dev->ready=1;
up(&dev->sem);
wake_up(&dev->buttons_wait);
port_init();
restore_flags(flags);
return IRQ_HANDLED;
}

static int request_irqs(struct matrix_button *dev)
{
struct key_info *k;
int i;
for (i = 0; i < sizeof(key_info_tab) / sizeof(key_info_tab[0]); i++)
{
k = key_info_tab + i;
if (request_irq(k->irq_no, &matrix_button_irq, SA_INTERRUPT, DEVICE_NAME, dev)) return -1;
}
return 0;
}

static void free_irqs(struct matrix_button *dev)
{
struct key_info *k;
int i;
for (i = 0; i < sizeof(key_info_tab) / sizeof(key_info_tab[0]); i++)
{
k = key_info_tab + i;
free_irq(k->irq_no,dev);
}
}

static int matrix_button_read(struct file * filp, char __user * buffer, size_t count, loff_t *f_pos)
{
struct matrix_button *dev=filp->private_data;
down(&dev->sem);
if(!dev->ready)
return -EAGAIN;
copy_to_user(buffer, &dev->key_value, sizeof(int));
dev->ready = 0;
up(&dev->sem);
return count;
}

static unsigned int matrix_button_poll( struct file *filp, struct poll_table_struct *wait)
{
struct matrix_button *dev=filp->private_data;
poll_wait(filp, &dev->buttons_wait, wait);
if (dev->ready)
return POLLIN;
else
return 0;
}

static int matrix_button_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
switch(cmd) {
default:
return -EINVAL;
}
}

static int matrix_button_open(struct inode *inode,struct file *filp)
{
int ret;
struct matrix_button *dev;
dev=container_of(inode->i_cdev,struct matrix_button,cdev);
down(&dev->sem);
filp->private_data=dev;
if(dev->open_count==0)
{
ret = request_irqs(dev);
if (ret)
{
cdev_del(&matrix_button_dev->cdev);
unregister_chrdev_region(MKDEV(BUTTON_MAJOR,0),1);
kfree(matrix_button_dev);
printk(DEVICE_NAME " can't request irqs/n");
return ret;
}
}
dev->open_count++;
up(&dev->sem);
return 0;
}

static int matrix_button_release(struct inode *inode,struct file *filp)
{
struct matrix_button *dev=filp->private_data;
down(&dev->sem);
if((dev->open_count--)==1)
free_irqs(dev);
up(&dev->sem);
return 0;
}

static struct file_operations matrix_button_fops = {
owner: THIS_MODULE,
ioctl: matrix_button_ioctl,
poll: matrix_button_poll,
read: matrix_button_read,
open: matrix_button_open,
release:matrix_button_release
};

static int __init matrix_button_init(void)
{
int ret;
dev_t dev=MKDEV(BUTTON_MAJOR,0);
ret=register_chrdev_region(dev,1,"matrix_button");
if(ret<0)
return ret;
matrix_button_dev=kmalloc(sizeof(struct matrix_button),GFP_KERNEL);
memset(matrix_button_dev,0,sizeof(struct matrix_button));
matrix_button_dev->ready=0;
matrix_button_dev->key_value=0;
matrix_button_dev->open_count=0;
init_waitqueue_head(&matrix_button_dev->buttons_wait);
init_MUTEX(&matrix_button_dev->sem);
cdev_init(&matrix_button_dev->cdev,&matrix_button_fops);
matrix_button_dev->cdev.owner=THIS_MODULE;
matrix_button_dev->cdev.ops=&matrix_button_fops;
port_init();
ret=cdev_add(&matrix_button_dev->cdev,dev,1);
if(ret)
printk(KERN_NOTICE "Error %d",ret);

return 0;
}

static void __exit matrix_button_exit(void)
{
cdev_del(&matrix_button_dev->cdev);
unregister_chrdev_region(MKDEV(BUTTON_MAJOR,0),1);
kfree(matrix_button_dev);
free_irqs(matrix_button_dev);
}

module_init(matrix_button_init);
module_exit(matrix_button_exit);
MODULE_LICENSE("GPL");

//以下为测试代码

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <errno.h>

int main(void)
{
int buttons_fd,i;
int key_value;
buttons_fd = open("/dev/matrix_button", 0);
if (buttons_fd < 0) {
perror("open device buttons");
exit(1);
}
for (;;)
{
fd_set rds;
int ret;
FD_ZERO(&rds);
FD_SET(buttons_fd, &rds);
ret = select(buttons_fd + 1, &rds, NULL, NULL, NULL);
if (ret < 0)
{
perror("select");
exit(1);
}
if (ret == 0)
{
printf("Timeout./n");
}
else if (FD_ISSET(buttons_fd, &rds))
{
int ret = read(buttons_fd, &key_value, sizeof key_value);
if (ret != sizeof key_value)
{
if (errno != EAGAIN)
perror("read buttons/n");
continue;
}
else
{
printf("buttons_value: %d/n", key_value);
}
}
}
close(buttons_fd);
return 0;
}