基於Tiny210v2的Linux-3.9.6內核驅動移植

tiny210v2上有4個led，可以通過gpio直接控制，今天嘗試最簡單的led驅動移植，主要通過對比友善給的linux-3.0.8來進行移植。

第一步：

查得對應GPIO為GPJ_0---GPJ_3;

在drivers/char/ 下新建smdkv210_led.c

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/delay.h>

#include <mach/gpio.h>
#include <mach/regs-gpio.h>
#include <plat/gpio-cfg.h>

#define DEVICE_NAME "leds"

static int led_gpios[] = {
S5PV210_GPJ2(0),
S5PV210_GPJ2(1),
S5PV210_GPJ2(2),
S5PV210_GPJ2(3),
};

#defineLED_NUM ARRAY_SIZE(led_gpios)

static long smdkv210_leds_ioctl(struct file *filp, unsigned intcmd,
unsignedlong arg)
{
switch(cmd){
case0:
case1:
if (arg> LED_NUM) {
return-EINVAL;
}

gpio_set_value(led_gpios[arg], !cmd);
//printk(DEVICE_NAME": %d %d\n", arg, cmd);
break;

default:
return-EINVAL;
}

return0;
}

static struct file_operations smdkv210_led_dev_fops = {
.owner =THIS_MODULE,
.unlocked_ioctl = smdkv210_leds_ioctl,
};

static struct miscdevice smdkv210_led_dev = {
.minor =MISC_DYNAMIC_MINOR,
.name =DEVICE_NAME,
.fops =&smdkv210_led_dev_fops,
};

static int __init smdkv210_led_dev_init(void) {
intret;
int i;

for (i = 0;i < LED_NUM; i++) {
ret =gpio_request(led_gpios[i], "LED");
if (ret){
printk("%s:request GPIO %d for LED failed, ret = %d\n", DEVICE_NAME,
led_gpios[i], ret);
returnret;
}

s3c_gpio_cfgpin(led_gpios[i], S3C_GPIO_OUTPUT);
gpio_set_value(led_gpios[i], 1);
}

ret =misc_register(&smdkv210_led_dev);

printk(DEVICE_NAME"\tinitialized\n");

returnret;
}

static void __exit smdkv210_led_dev_exit(void) {
int i;

for (i = 0;i < LED_NUM; i++) {
gpio_free(led_gpios[i]);
}

misc_deregister(&smdkv210_led_dev);
}

module_init(smdkv210_led_dev_init);
module_exit(smdkv210_led_dev_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");

修改該目錄下的Kconfig文件
添加：
config SMDKV210_LEDS
tristate"LED Support for FriendlyARM Mini210 GPIO LEDs"
depends onMACH_SMDKV210
defaulty
help
This option enables support for LEDs connectedto GPIO lines
on tiny210v2 boards.
修改該目錄下的Makefile文件
添加：
obj-$(CONFIG_SMDKV210_LEDS) += smdkv210_leds.o
修改arch/arm/mach-s5pv210/include/mach/gpio.h
添加：
#definegpio_get_value __gpio_get_value
#definegpio_set_value __gpio_set_value
#definegpio_cansleep __gpio_cansleep
#definegpio_to_irq __gpio_to_irq
#include <asm-generic/gpio.h>

#include <plat/gpio-cfg.h>
保存make,led驅動就編譯到內核了。

友善的測試程序：

#include<stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
int main(int argc, char **argv)
{
int on;
int led_no;
int fd;

if (argc != 3 || sscanf(argv[1], "%d", &led_no) !=1 || sscanf(argv[2],"%d", &on) != 1 ||
on < 0 || on > 1 || led_no< 0 || led_no > 3) {
fprintf(stderr, "Usage: leds led_no 0|1\n");
exit(1);
}

fd = open("/dev/leds0", 0);
if (fd < 0) {
fd = open("/dev/leds", 0);
}
if (fd < 0) {
perror("open device leds");
exit(1);
}

ioctl(fd, on, led_no);

close(fd);
return 0;
}