#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <asm/arch/regs-gpio.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
#define DEVICE_NAME "leds"
#define LED_MAJOR 231
#define IOCTL_LED_ON 0
#define IOCTL_LED_OFF 1
static unsigned long led_table [] = {
S3C2410_GPF7,
S3C2410_GPF6,
S3C2410_GPF5,
S3C2410_GPF4,
};
static unsigned int led_cfg_table [] = {
S3C2410_GPF7_OUTP,
S3C2410_GPF6_OUTP,
S3C2410_GPF5_OUTP,
S3C2410_GPF4_OUTP,
};
#undef NDEBUG
#define NDEBUG
#undef PDEBUG
#define VERBOSE
#ifdef NDEBUG
#ifdef __KERNEL__
#ifdef VERBOSE
#define PDEBUG(fmt, args...) printk( KERN_ERR "%s:%d " fmt, __FILE__, __LINE__, ## args)
#else
#define PDEBUG(fmt, args...) printk( KERN_ERR "kdebug: " fmt, ## args)
#endif
#else
#define PDEBUG(fmt, args...) fprintf(stderr, "%s:%d " fmt, __FILE__, __LINE__, ## args)
#endif
#else
#define PDEBUG(fmt, args...) do {} while(0)
#endif
static int s3c24xx_leds_open(struct inode *inode, struct file *file)
{
int i;
for (i = 0; i < 4; i++) {
// 設定GPIO引腳的功能：本驅動中LED所涉及的GPIO引腳設為輸出功能
s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);
// 關閉内部上拉
s3c2410_gpio_pullup(led_table[i], 1);
}
return 0;
}
static int s3c24xx_leds_ioctl(
struct inode *inode,
struct file *file,
unsigned int cmd,
unsigned long arg)
{
if (arg > 4) {
return -EINVAL;
}
switch(cmd) {
case IOCTL_LED_ON:
// 設定指定引腳的輸出電平為0V
s3c2410_gpio_setpin(led_table[arg], 0);
return 0;
case IOCTL_LED_OFF:
// 設定指定引腳的輸出電平為3.3V
s3c2410_gpio_setpin(led_table[arg], 1);
return 0;
default:
return -EINVAL;
}
}
static inline void s3c24xx_leds_proc_usage(char *exename)
{
printk(KERN_ERR "Usage:\n");
printk(KERN_ERR "echo \"<led_no> <on/off>\" > /proc/%s\n", exename);
printk(KERN_ERR "led_no = 1, 2, 3 or 4\n");
}
static ssize_t s3c24xx_leds_proc_write (struct file *file,
const char __user *buffer, size_t count, loff_t *offset)
{
char *buf, *tok, **tokptrs;
char *whitespace = " ,\t\r\n"; //空格和","分隔
int ret = -EINVAL, leds_state, leds_no = -1, ntoks;
int i = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (count == 0)
return 0;
if (!(buf = kmalloc(count + 1, GFP_KERNEL)))
return -ENOMEM;
if (copy_from_user((void *)buf, buffer, count)) {
ret = -EFAULT;
goto out0;
}
buf[count] = '\0';
PDEBUG("s3c24xx_leds: buf= %s\n", buf);
if (!(tokptrs = (char **)get_zeroed_page(GFP_KERNEL))) {
ret = -ENOMEM;
goto out1;
}
ret = -EINVAL;
ntoks = 0;
do {
buf = buf + strspn(buf, whitespace);
tok = strsep(&buf, whitespace);
if (*tok == '\0') {
if (ntoks == 0) {
goto out1;
} else
break;
}
PDEBUG("in do_while loop%d buf=%s, tok=%s\n",ntoks, buf, tok);
if (ntoks == (PAGE_SIZE / sizeof(char **)))
goto out1;
tokptrs[ntoks++] = tok;
} while(buf);
PDEBUG("s3c24xx_leds: ntoks= %d, buf2= %s\n", ntoks, buf);
if (ntoks <2)
goto out1;
leds_state = -1;
//The following two lines just for debug
i= strcmp(tokptrs[ntoks-1], "on");
PDEBUG("s3c24xx_leds states:%s,strcmp result=%d\n", tokptrs[ntoks-1],i);
if (strcmp(tokptrs[ntoks-1], "on")==0) {
leds_state = 1;
} else if (strcmp(tokptrs[ntoks-1], "off") == 0) {
leds_state = 0;
} else {
goto out1;
}
for (i = 0; i< ntoks-1; i++) {
leds_no = simple_strtoul(tokptrs[i], NULL, 0);
PDEBUG("operate led-%d\n", leds_no);
if(leds_no < 1 || leds_no >4) {
PDEBUG("Error leds number %d\n", leds_no);
s3c24xx_leds_proc_usage(DEVICE_NAME);
continue;
}
s3c2410_gpio_setpin(led_table[leds_no-1], 1-leds_state); // LED ON or OFF
ret = 0;
}
out1:
free_page((unsigned long)tokptrs);
out0:
kfree(buf);
if (ret == 0)
return count;
else {
s3c24xx_leds_proc_usage(DEVICE_NAME);
return ret;
}
}
static struct file_operations s3c24xx_leds_fops = {
.owner = THIS_MODULE,
.open = s3c24xx_leds_open,
.ioctl = s3c24xx_leds_ioctl,
};
static struct file_operations s3c24xx_leds_proc_ops = {
.owner = THIS_MODULE,
.write = s3c24xx_leds_proc_write,
};
static int __init s3c24xx_leds_init(void)
{
int ret;
struct proc_dir_entry *entry;
ret = register_chrdev(LED_MAJOR, DEVICE_NAME, &s3c24xx_leds_fops);
if (ret < 0) {
printk(DEVICE_NAME " can't register major number\n");
return ret;
}
entry = create_proc_entry(DEVICE_NAME, S_IFREG | S_IRUGO, NULL);
if (!entry)
return -ENOMEM;
entry->proc_fops = &s3c24xx_leds_proc_ops;
printk(DEVICE_NAME " initialized\n");
PDEBUG("LEDS INIT\n");
return 0;
}
static void __exit s3c24xx_leds_exit(void)
{
remove_proc_entry(DEVICE_NAME, NULL); //與create_proc_entry函數相反
unregister_chrdev(LED_MAJOR, DEVICE_NAME);
}
module_init(s3c24xx_leds_init);
module_exit(s3c24xx_leds_exit);
MODULE_AUTHOR("StephenYee, Shenzhen Office, Farsight Inc.,"); // 驅動程式的作者
MODULE_DESCRIPTION("S3C2410/S3C2440 LED Driver"); // 一些描述資訊
MODULE_LICENSE("GPL"); // 遵循的協定
應用程式：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#define IOCTL_LED_ON 0
#define IOCTL_LED_OFF 1
void usage(char *exename)
{
printf("Usage:\n");
printf(" %s <led_no> <on/off>\n", exename);
printf(" led_no = 1, 2, 3 or 4\n");
}
int main(int argc, char **argv)
{
unsigned int led_no;
int fd = -1;
if (argc != 3)
goto err;
fd = open("/dev/leds", 0); // 打開裝置
if (fd < 0) {
printf("Can't open /dev/leds\n");
return -1;
}
led_no = strtoul(argv[1], 0, 0) - 1; // 操作哪個LED？
if (led_no > 3)
goto err;
if (!strcmp(argv[2], "on")) {
ioctl(fd, IOCTL_LED_ON, led_no); // 點亮它
} else if (!strcmp(argv[2], "off")) {
ioctl(fd, IOCTL_LED_OFF, led_no); // 熄滅它
} else {
goto err;
}
close(fd);
return 0;
err:
if (fd > 0)
close(fd);
usage(argv[0]);
return -1;
}
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