在led驱动的基础上,继续学习按键驱动
Makefile
1
2 obj-m := s3c_button.o
3 KERNEL_DIR := ~/fl2440/kernel/linux-3.0.54/
4 PWD := $(shell pwd)
5 all:
6 make -C $(KERNEL_DIR) SUBDIRS=$(PWD) modules
7 clean:
8 rm *.o *.ko *.mod.c
9
10 .PHONY:clean
plat_button.c驱动内容
#include "s3c_driver.h"
#define DRV_AUTHOR "Guo Wenxue <guowenxue@gmail.com>"
#define DRV_DESC "S3C24XX button driver"
/* Driver version*/
#define DRV_MAJOR_VER 1
#define DRV_MINOR_VER 0
#define DRV_REVER_VER 0
#define DEV_NAME DEV_BUTTON_NAME
//#define DEV_MAJOR DEV_BUTTON_MAJOR
#ifndef DEV_MAJOR
#define DEV_MAJOR 0 /* dynamic major by default */
#endif
#define BUTTON_UP 0 /* Button status is up */
#define BUTTON_DOWN 1 /* Button status is pushed down */
#define BUTTON_UNCERTAIN 2 /* Button status uncerntain */
#define TIMER_DELAY_DOWN (HZ/50) /*Remove button push down dithering timer delay 20ms */
#define TIMER_DELAY_UP (HZ/10) /*Remove button up dithering timer delay 100ms */
static int debug = DISABLE;
static int dev_major = DEV_MAJOR;
static int dev_minor = 0;
/*============================ Platform Device part ===============================*/
/* Button hardware informtation structure*/
struct s3c_button_info
{
unsigned char num; /*Button nubmer */
char * name; /*Button nubmer */
int nIRQ; /*Button IRQ number*/
unsigned int setting; /*Button IRQ Pin Setting*/
unsigned int gpio; /*Button GPIO port */
};
/* The button plaotform device private data structure */
struct s3c_button_platform_data
{
struct s3c_button_info *buttons;
int nbuttons;
};
/* Button hardware informtation data*/
static struct s3c_button_info s3c_buttons[] = {
[0] = {
.num = 1,
.name = "KEY1",
.nIRQ = IRQ_EINT0,
.gpio = S3C2410_GPF(0),
.setting = S3C2410_GPF0_EINT0,
},
[1] = {
.num = 2,
.name = "KEY2",
.nIRQ = IRQ_EINT2,
.gpio = S3C2410_GPF(2),
.setting = S3C2410_GPF2_EINT2,
},
[2] = {
.num = 3,
.name = "KEY3",
.nIRQ = IRQ_EINT3,
.gpio = S3C2410_GPF(3),
.setting = S3C2410_GPF3_EINT3,
},
[3] = {
.num = 4,
.name = "KEY4",
.nIRQ = IRQ_EINT4,
.gpio = S3C2410_GPF(4),
.setting = S3C2410_GPF4_EINT4,
},
};
/* The button platform device private data */
static struct s3c_button_platform_data s3c_button_data = {
.buttons = s3c_buttons,//这边要改的和.c文件名一样
.nbuttons = ARRAY_SIZE(s3c_buttons),
};
struct button_device
{
unsigned char *status; /* The buttons Push down or up status */
struct s3c_button_platform_data *data; /* The buttons hardware information data */
struct timer_list *timers; /* The buttons remove dithering timers */
wait_queue_head_t waitq; /* Wait queue for poll() */
volatile int ev_press; /* Button pressed event */
struct cdev cdev;
struct class *dev_class;
} button_device;
static void platform_button_release(struct device * dev)
{
return;
}
static struct platform_device s3c_button_device = {
.name = "s3c_button",
.id = 1,
.dev =
{
.platform_data = &s3c_button_data,
.release = platform_button_release,
},
};
static irqreturn_t s3c_button_intterupt(int irq,void *de_id)
{
int i;
int found = 0;
struct s3c_button_platform_data *pdata = button_device.data;
for(i=0; i<pdata->nbuttons; i++)
{
if(irq == pdata->buttons[i].nIRQ)
{
found = 1;
break;
}
}
if(!found) /* An ERROR interrupt */
return IRQ_NONE;
/* Only when button is up then we will handle this event */
if(BUTTON_UP == button_device.status[i])
{
button_device.status[i] = BUTTON_UNCERTAIN;
mod_timer(&(button_device.timers[i]), jiffies+TIMER_DELAY_DOWN);
}
return IRQ_HANDLED;
}
static void button_timer_handler(unsigned long data)
{
struct s3c_button_platform_data *pdata = button_device.data;
int num =(int)data;
int status = s3c2410_gpio_getpin( pdata->buttons[num].gpio );
if(LOWLEVEL == status)
{
if(BUTTON_UNCERTAIN == button_device.status[num]) /* Come from interrupt */
{
//dbg_print("Key pressed!\n");
button_device.status[num] = BUTTON_DOWN;
printk("%s pressed.\n", pdata->buttons[num].name);
/* Wake up the wait queue for read()/poll() */
button_device.ev_press = 1;
wake_up_interruptible(&(button_device.waitq));
}
/* Cancel the dithering */
mod_timer(&(button_device.timers[num]), jiffies+TIMER_DELAY_UP);
}
else
{
//dbg_print("Key Released!\n");
button_device.status[num] = BUTTON_UP;
// enable_irq(pdata->buttons[num].nIRQ);
}
return ;
}
/*===================== Button device driver part ===========================*/
static int button_open(struct inode *inode, struct file *file)
{
struct button_device *pdev ;
struct s3c_button_platform_data *pdata;
int i, result;
pdev = container_of(inode->i_cdev,struct button_device, cdev);
pdata = pdev->data;
file->private_data = pdev;
/* Malloc for all the buttons remove dithering timer */
pdev->timers = (struct timer_list *) kmalloc(pdata->nbuttons*sizeof(struct timer_list), GFP_KERNEL);
if(NULL == pdev->timers)
{
printk("Alloc %s driver for timers failure.\n", DEV_NAME);
return -ENOMEM;
}
memset(pdev->timers, 0, pdata->nbuttons*sizeof(struct timer_list));
/* Malloc for all the buttons status buffer */
pdev->status = (unsigned char *)kmalloc(pdata->nbuttons*sizeof(unsigned char), GFP_KERNEL);
if(NULL == pdev->status)
{
printk("Alloc %s driver for status failure.\n", DEV_NAME);
result = -ENOMEM;
goto ERROR;
}
memset(pdev->status, 0, pdata->nbuttons*sizeof(unsigned char));
init_waitqueue_head(&(pdev->waitq));
for(i=0; i<pdata->nbuttons; i++)
{
/* Initialize all the buttons status to UP */
pdev->status[i] = BUTTON_UP;
/* Initialize all the buttons' remove dithering timer */
setup_timer(&(pdev->timers[i]), button_timer_handler, i);
/* Set all the buttons GPIO to EDGE_FALLING interrupt mode */
s3c2410_gpio_cfgpin(pdata->buttons[i].gpio, pdata->buttons[i].setting);
irq_set_irq_type(pdata->buttons[i].nIRQ, IRQ_TYPE_EDGE_FALLING);
/* Request for button GPIO pin interrupt */
result = request_irq(pdata->buttons[i].nIRQ, s3c_button_intterupt, IRQF_DISABLED, DEV_NAME, (void *)i);
if( result )
{
result = -EBUSY;
goto ERROR1;
}
}
return 0;
ERROR1:
kfree((unsigned char *)pdev->status);
while(--i)
{
disable_irq(pdata->buttons[i].nIRQ);
free_irq(pdata->buttons[i].nIRQ, (void *)i);
}
ERROR:
kfree(pdev->timers);
return result;
}
static int button_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
struct button_device *pdev = file->private_data;
struct s3c_button_platform_data *pdata;
int i, ret;
unsigned int status = 0;
pdata = pdev->data;
dbg_print("ev_press: %d\n", pdev->ev_press);
if(!pdev->ev_press)
{
if(file->f_flags & O_NONBLOCK)
{
dbg_print("read() without block mode.\n");
return -EAGAIN;
}
else
{
/* Read() will be blocked here */
dbg_print("read() blocked here now.\n");
wait_event_interruptible(pdev->waitq, pdev->ev_press);
}
}
pdev->ev_press = 0;
for(i=0; i<pdata->nbuttons; i++)
{
dbg_print("button[%d] status=%d\n", i, pdev->status[i]);
status |= (pdev->status[i]<<i);
}
ret = copy_to_user(buf, (void *)&status, min(sizeof(status), count));
return ret ? -EFAULT : min(sizeof(status), count);
}
static unsigned int button_poll(struct file *file, poll_table * wait)
{
struct button_device *pdev = file->private_data;
unsigned int mask = 0;
poll_wait(file, &(pdev->waitq), wait);
if(pdev->ev_press)
{
mask |= POLLIN | POLLRDNORM; /* The data aviable */
}
return mask;
}
static int button_release(struct inode *inode, struct file *file)
{
int i;
struct button_device *pdev = file->private_data;
struct s3c_button_platform_data *pdata;
pdata = pdev->data;
for(i=0; i<pdata->nbuttons; i++)
{
disable_irq(pdata->buttons[i].nIRQ);
free_irq(pdata->buttons[i].nIRQ, (void *)i);
del_timer(&(pdev->timers[i]));
}
kfree(pdev->timers);
kfree((unsigned char *)pdev->status);
return 0;
}
static struct file_operations button_fops = {
.owner = THIS_MODULE,
.open = button_open,
.read = button_read,
.poll = button_poll,
.release = button_release,
};
static int s3c_button_probe(struct platform_device *dev)
{
int result = 0;
dev_t devno;
/* Alloc the device for driver */
if (0 != dev_major)
{
devno = MKDEV(dev_major, dev_minor);
result = register_chrdev_region(devno, 1, DEV_NAME);
}
else
{
result = alloc_chrdev_region(&devno, dev_minor, 1, DEV_NAME);
dev_major = MAJOR(devno);
}
/* Alloc for device major failure */
if (result < 0)
{
printk("%s driver can't get major %d\n", DEV_NAME, dev_major);
return result;
}
/* Initialize button_device structure and register cdev*/
memset(&button_device, 0, sizeof(button_device));
button_device.data = dev->dev.platform_data;
cdev_init (&(button_device.cdev), &button_fops);
button_device.cdev.owner = THIS_MODULE;
result = cdev_add (&(button_device.cdev), devno , 1);
if (result)
{
printk (KERN_NOTICE "error %d add %s device", result, DEV_NAME);
goto ERROR;
}
button_device.dev_class = class_create(THIS_MODULE, DEV_NAME);
if(IS_ERR(button_device.dev_class))
{
printk("%s driver create class failture\n",DEV_NAME);
result = -ENOMEM;
goto ERROR;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
device_create(button_device.dev_class, NULL, devno, NULL, DEV_NAME);
#else
device_create (button_device.dev_class, NULL, devno, DEV_NAME);
#endif
printk("S3C %s driver version %d.%d.%d initiliazed.\n", DEV_NAME, DRV_MAJOR_VER, DRV_MINOR_VER, DRV_REVER_VER);
return 0;
ERROR:
printk("S3C %s driver version %d.%d.%d install failure.\n", DEV_NAME, DRV_MAJOR_VER, DRV_MINOR_VER, DRV_REVER_VER);
cdev_del(&(button_device.cdev));
unregister_chrdev_region(devno, 1);
return result;
}
static int s3c_button_remove(struct platform_device *dev)
{
dev_t devno = MKDEV(dev_major, dev_minor);
cdev_del(&(button_device.cdev));
device_destroy(button_device.dev_class, devno);
class_destroy(button_device.dev_class);
unregister_chrdev_region(devno, 1);
printk("S3C %s driver removed\n", DEV_NAME);
return 0;
}
/*===================== Platform Device and driver regist part ===========================*/
static struct platform_driver s3c_button_driver = {
.probe = s3c_button_probe,
.remove = s3c_button_remove,
.driver = {
.name = "s3c_kbd",
.owner = THIS_MODULE,
},
};
static int __init s3c_button_init(void)
{
int ret = 0;
ret = platform_device_register(&s3c_button_device);
if(ret)
{
printk(KERN_ERR "%s: Can't register platform device %d\n", __FUNCTION__, ret);
goto fail_reg_plat_dev;
}
dbg_print("Regist S3C %s Device successfully.\n", DEV_NAME);
ret = platform_driver_register(&s3c_button_driver);
if(ret)
{
printk(KERN_ERR "%s: Can't register platform driver %d\n", __FUNCTION__, ret);
goto fail_reg_plat_drv;
}
dbg_print("Regist S3C %s Driver successfully.\n", DEV_NAME);
return 0;
fail_reg_plat_drv:
platform_driver_unregister(&s3c_button_driver);
fail_reg_plat_dev:
return ret;
}
static void s3c_button_exit(void)
{
platform_driver_unregister(&s3c_button_driver);
dbg_print("S3C %s platform device removed.\n", DEV_NAME);
platform_device_unregister(&s3c_button_device);
dbg_print("S3C %s platform driver removed.\n", DEV_NAME);
}
module_init(s3c_button_init);
module_exit(s3c_button_exit);
module_param(debug, int, S_IRUGO);
module_param(dev_major, int, S_IRUGO);
module_param(dev_minor, int, S_IRUGO);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:S3C24XX_button");
vim plat_ioctl.h 头文件
17 #ifndef __PLAT_IOCTL_H
18 #define __PLAT_IOCTL_H
19
20 #include <asm/ioctl.h>
21
22 /*===========================================================================
23 * Common ioctl command definition
24 *===========================================================================*/
25
26 #define PLATDRV_MAGIC 0x60
27
28 /*===========================================================================
29 * ioctl command for all the drivers 0x01~0x0F
30 *===========================================================================*/
31
32 /*args is enable or disable*/
33 #define SET_DRV_DEBUG _IO (PLATDRV_MAGIC, 0x01)
1 /*********************************************************************************
2 * Copyright(c) 2011, Guo Wenxue <guowenxue@gmail.com>
3 * All ringhts reserved.
4 *
5 * Filename: s3c_ioctl.h
6 * Description: ioctl() cmd argument definition here
7 *
8 * ChangLog:
9 * 1, Version: 1.0.0
10 * Date: 2011-08-10
11 * Author: guowenxue <guowenxue@gmail.com>
12 * Descrtipion: Initial first version
13 *
14 *
15 ********************************************************************************/
16
17 #ifndef __PLAT_IOCTL_H
18 #define __PLAT_IOCTL_H
19
20 #include <asm/ioctl.h>
21
22 /*===========================================================================
23 * Common ioctl command definition
24 *===========================================================================*/
25
26 #define PLATDRV_MAGIC 0x60
27
28 /*===========================================================================
29 * ioctl command for all the drivers 0x01~0x0F
30 *===========================================================================*/
31
32 /*args is enable or disable*/
33 #define SET_DRV_DEBUG _IO (PLATDRV_MAGIC, 0x01)
plat_ioctl.h
34 #define GET_DRV_VER _IO (PLATDRV_MAGIC, 0x02)
35
36 /*===========================================================================
37 * ioctl command for few ioctl() cmd driver 0x10~0x2F
38 *===========================================================================*/
39
40 /* LED driver */
41 #define LED_OFF _IO (PLATDRV_MAGIC, 0x18)
42 #define LED_ON _IO (PLATDRV_MAGIC, 0x19)
43 #define LED_BLINK _IO (PLATDRV_MAGIC, 0x1A)
44 #define ADC_SET_CHANNEL _IO (PLATDRV_MAGIC, 0x1B)
45
46 /*===========================================================================
47 * ioctl command for GPRS driver 0x30~0x4F
48 *===========================================================================*/
49 #define GPRS_POWERDOWN _IO (PLATDRV_MAGIC, 0x30)
50 #define GPRS_POWERON _IO (PLATDRV_MAGIC, 0x31)
51 #define GPRS_RESET _IO (PLATDRV_MAGIC, 0x32)
52 #define GPRS_POWERMON _IO (PLATDRV_MAGIC, 0x33)
53 #define GPRS_CHK_SIMDOOR _IO (PLATDRV_MAGIC, 0x36)
54 #define GPRS_SET_DTR _IO (PLATDRV_MAGIC, 0x37)
55 #define GPRS_SET_RTS _IO (PLATDRV_MAGIC, 0x38)
56 #define GPRS_GET_RING _IO (PLATDRV_MAGIC, 0x39)
57 #define SET_PWUP_TIME _IO (PLATDRV_MAGIC, 0x3A)
58 #define SET_PWDOWN_TIME _IO (PLATDRV_MAGIC, 0x3B)
59 #define SET_RESET_TIME _IO (PLATDRV_MAGIC, 0x3C)
60 #define GPRS_CHK_MODEL _IO (PLATDRV_MAGIC, 0x3E)
61
62 /*===========================================================================
63 * ioctl command for EEPROM driver 0x50~0x5F
64 *===========================================================================*/
65 #define LL_POWEROFF _IO (PLATDRV_MAGIC, 0x50)
66 #define LL_POWERON _IO (PLATDRV_MAGIC, 0x51)
67 #define LL_STOP _IO (PLATDRV_MAGIC, 0x52)
68 #define LL_START _IO (PLATDRV_MAGIC, 0x53)
69 #define LL_READ _IO (PLATDRV_MAGIC, 0x54)
70 #define LL_WRITE _IO (PLATDRV_MAGIC, 0x55)
71 #define LL_DATALOW _IO (PLATDRV_MAGIC, 0x56)
72 #define LL_ACKNAK _IO (PLATDRV_MAGIC, 0x57)
73
74
75 #endif /* __PLAT_IOCTL_H */
s3c_driver.h
#ifndef __S3C_DRIVER_H
#define __S3C_DRIVER_H
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kref.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/string.h>
#include <linux/bcd.h>
#include <linux/miscdevice.h>
#include <linux/poll.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/proc_fs.h>
#include <linux/rtc.h>
#include <linux/spinlock.h>
#include <linux/usb.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <linux/syscalls.h> /* For sys_access*/
#include <linux/platform_device.h>
#include <linux/unistd.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/irq.h>
#include <mach/regs-gpio.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
#include <mach/hardware.h>
#include <mach/gpio.h>
#include <asm/irq.h>
#else
#include <asm-arm/irq.h>
#include <asm/arch/gpio.h>
#include <asm/arch/hardware.h>
#endif
#include "plat_ioctl.h"
/* ===========================================================================
* S3C24XX device driver common macro definition
*===========================================================================*/
#define ENPULLUP 1
#define DISPULLUP 0
#define HIGHLEVEL 1
#define LOWLEVEL 0
#define INPUT 1
#define OUTPUT 0
#define OFF 0
#define ON 1
#define ENABLE 1
#define DISABLE 0
#define TRUE 1
#define FALSE 0
/* ===========================================================================
* S3C24XX device driver name and Major number define
*===========================================================================*/
#define DEV_LED_NAME "led"
#define DEV_LED_MAJOR 203
#define DEV_BUTTON_NAME "button"
#define DEV_BUTTON_MAJOR "211"
#define DEV_ADC_NAME "adc"
#define DEV_ADC_MAJOR "212"
/* ***** Bit Operate Define *****/
#define SET_BIT(data, i) ((data) |= (1 << (i))) /* Set the bit "i" in "data" to 1 */
#define CLR_BIT(data, i) ((data) &= ~(1 << (i))) /* Clear the bit "i" in "data" to 0 */
#define NOT_BIT(data, i) ((data) ^= (1 << (i))) /* Inverse the bit "i" in "data" */
#define GET_BIT(data, i) ((data) >> (i) & 1) /* Get the value of bit "i" in "data" */
#define L_SHIFT(data, i) ((data) << (i)) /* Shift "data" left for "i" bit */
#define R_SHIFT(data, i) ((data) >> (i)) /* Shift "data" Right for "i" bit */
/* ===========================================================================
* S3C24XX device driver common function definition
*===========================================================================*/
#define SLEEP(x) {DECLARE_WAIT_QUEUE_HEAD (stSleep); if (10 > x) mdelay ((x * 1000)); \
else wait_event_interruptible_timeout (stSleep, 0, (x / 10));}
#define VERSION_CODE(a,b,c) ( ((a)<<16) + ((b)<<8) + (c))
#define DRV_VERSION VERSION_CODE(DRV_MAJOR_VER, DRV_MINOR_VER, DRV_REVER_VER)
#define MAJOR_VER(a) ((a)>>16&0xFF)
#define MINOR_VER(a) ((a)>>8&0xFF)
#define REVER_VER(a) ((a)&0xFF)
#define dbg_print(format,args...) if(DISABLE!=debug) \
{printk("[kernel] ");printk(format, ##args);}
static inline void print_version(int version)
{
#ifdef __KERNEL__
printk("%d.%d.%d\n", MAJOR_VER(version), MINOR_VER(version), REVER_VER(version));
#else
printf("%d.%d.%d\n", MAJOR_VER(version), MINOR_VER(version), REVER_VER(version));
#endif
}
#endif /* __S3C_DRIVER_H */
把Makefile,s3c_button.c,plat_ioctl.h,s3c_driver.h放在同一个文件夹中编译
make之后产生s3c_button.然后传到开发板,接下来再做按键驱动测试程序。
led_button.c(按键驱动测试代码)
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/fb.h>
#include <sys/mman.h>
#define KEY1 0x01
#define KEY2 0x02
#define KEY3 0x04
#define KEY4 0x08
#define PLATDRV_MAGIC 0x60
#define OFF _IO (PLATDRV_MAGIC,0x18)
#define ON _IO (PLATDRV_MAGIC,0X19)
#if 0
int fork_1()
{
int pid = 0;
pid = fork();
if(pid < 0)
{
printf("failed to fork!\n");
return 1;
}
if(pid > 0)
{
wait(NULL);
}
else
{
execl("/bin/cp", "cp", "dev/fb0", "qwe", NULL);
}
return 0;
}
int fork_2()
{
int pid = 0;
pid = fork();
if(pid < 0)
{
printf("failed to fork!\n");
return 1;
}
if(pid > 0)
{
wait(NULL);
}
else
{
execl("/bin/tftp","tftp", "-p", "-r", "qwe", "192.168.1.8", NULL);
}
return 0;
}
#endif
int main (int argc, char **argv)
{
int button_fd;
int led_fd;
int ret_button;
int current_button;
int i=1;
int j=1;
int x=1;
int y=1;
button_fd = open("/dev/button", 0);
if (button_fd < 0)
{
printf("open button failed.\n");
exit(1);
}
while (1)
{
ret_button = read(button_fd, ¤t_button, sizeof(4));
if (ret_button != sizeof(current_button))
{
printf("Read() button failed.\n");
}
else
{
if (current_button == KEY1)
{
led_fd = open("/dev/led0",O_RDWR,755);
switch (i%2)
{
case 0:
ioctl(led_fd, OFF, 0);
i++;
printf("Turn led0 OFF.\n");
break;
case 1:
ioctl(led_fd, ON, 0);
i++;
printf("Turn led0 ON.\n");
break;
}
}
else if (current_button == KEY2)
{
led_fd = open("/dev/led1",O_RDWR,755);
switch (j%2)
{
case 0:
ioctl(led_fd, OFF, 1);
j++;
printf("Turn led1 OFF.\n");
break;
case 1:
ioctl(led_fd, ON, 1);
j++;
printf("Turn led1 ON.\n");
break;
}
}
else if (current_button == KEY3)
{
led_fd = open("/dev/led2",O_RDWR,755);
switch (x%2)
{
case 0:
ioctl(led_fd, OFF, 2);
x++;
printf("Turn led2 OFF.\n");
break;
case 1:
ioctl(led_fd, ON, 2);
x++;
printf("Turn led2 ON.\n");
break;
}
}
else if (current_button == KEY4)
{
led_fd = open("/dev/led3",O_RDWR,755);
switch (y%2)
{
case 0:
ioctl(led_fd, OFF, 3);
y++;
printf("Turn led3 OFF.\n");
break;
case 1:
ioctl(led_fd, ON, 3);
y++;
printf("Turn led3 ON.\n");
break;
}
}
}
}
ioctl(led_fd,OFF);
close(led_fd);
close(button_fd);
return 0;
}
运用交叉编译器执行armgcc led_button.c -o led_button(其中armgcc是我定义的变量)
将生成的led_button可执行文件也传到开发板板上
按按键观看led的变化 测试就做完了!
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