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接 续：linux设备驱动篇之LED驱动（一)
原文声明：
PC 平 台：ubuntu12.10
开 发 板 ：tq2440fl2440
内核版本：linux-3.0
作 者：fulinux
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一、内核3.0的LED设备驱动程序：
/********************************************************************************** Copyright: (C) 2011 Guo Wenxue<guowenxue@gmail.com>* All rights reserved.** Filename: s3c_led.c* Description: This is the common LED driver runs on S3C24XX.* * Version: 1.0.0(10/27/2011~)* Author: Guo Wenxue <guowenxue@gmail.com>* ChangeLog: 1, Release initial version on "10/27/2011 11:39:10 AM"* ********************************************************************************/#include "s3c_driver.h"
#define DRV_AUTHOR "Guo Wenxue <guowenxue@gmail.com>"#define DRV_DESC "S3C24XX LED driver"
/* Driver version*/#define DRV_MAJOR_VER 1#define DRV_MINOR_VER 0#define DRV_REVER_VER 0
#define DEV_NAME DEV_LED_NAME
//#define DEV_MAJOR DEV_LED_MAJOR#ifndef DEV_MAJOR#define DEV_MAJOR 0 /* dynamic major by default */ #endif
#define TIMER_TIMEOUT 40
static int debug = DISABLE;static int dev_major = DEV_MAJOR;static int dev_minor = 0;
/* ============================ Platform Device part ===============================*//* LED hardware informtation structure*/struct s3c_led_info{ unsigned char num; /* The LED number */ unsigned int gpio; /* Which GPIO the LED used */ unsigned char active_level; /* The GPIO pin level(HIGHLEVEL or LOWLEVEL) to turn on or off */ unsigned char status; /* Current LED status: OFF/ON */ unsigned char blink; /* Blink or not */};
/* The LED platform device private data structure */struct s3c_led_platform_data{ struct s3c_led_info *leds; int nleds;};
/* LED hardware informtation data*/static struct s3c_led_info s3c_leds[] = { [0] = { .num = 1, .gpio = S3C2410_GPB(5), .active_level = LOWLEVEL, .status = OFF, .blink = ENABLE, }, [1] = { .num = 2, .gpio = S3C2410_GPB(6), .active_level = LOWLEVEL, .status = OFF, .blink = DISABLE, }, [2] = { .num = 3, .gpio = S3C2410_GPB(8), .active_level = LOWLEVEL, .status = OFF, .blink = DISABLE, }, [3] = { .num = 4, .gpio = S3C2410_GPB(10), .active_level = LOWLEVEL, .status = OFF, .blink = ENABLE, },};
/* The LED platform device private data */static struct s3c_led_platform_data s3c_led_data = { .leds = s3c_leds, .nleds = ARRAY_SIZE(s3c_leds),};
struct led_device{ struct s3c_led_platform_data *data; struct cdev cdev; struct class *dev_class; struct timer_list blink_timer;} led_device;
static void platform_led_release(struct device * dev){ int i; struct s3c_led_platform_data *pdata = dev->platform_data;
dbg_print("%s():%d\n", __FUNCTION__,__LINE__);
/* Turn all LED off */ for(i=0; i<pdata->nleds; i++) { s3c2410_gpio_setpin(pdata->leds[i].gpio, ~pdata->leds[i].active_level); }}
static struct platform_device s3c_led_device = { .name = "s3c_led", .id = 1, .dev = { .platform_data = &s3c_led_data, .release = platform_led_release, },};
/* ===================== led device driver part ===========================*/
void led_timer_handler(unsigned long data){ int i; struct s3c_led_platform_data *pdata = (struct s3c_led_platform_data *)data;
for(i=0; i<pdata->nleds; i++) { if(ON == pdata->leds[i].status) { s3c2410_gpio_setpin(pdata->leds[i].gpio, pdata->leds[i].active_level); } else { s3c2410_gpio_setpin(pdata->leds[i].gpio, ~pdata->leds[i].active_level); }
if(ENABLE == pdata->leds[i].blink ) /* LED should blink */ { /* Switch status between 0 and 1 to turn LED ON or off */ pdata->leds[i].status = pdata->leds[i].status ^ 0x01; }
mod_timer(&(led_device.blink_timer), jiffies + TIMER_TIMEOUT); }}
static int led_open(struct inode *inode, struct file *file){ struct led_device *pdev ; struct s3c_led_platform_data *pdata;
pdev = container_of(inode->i_cdev,struct led_device, cdev); pdata = pdev->data;
file->private_data = pdata;
return 0;}
static int led_release(struct inode *inode, struct file *file){ return 0;}
static void print_led_help(void){ printk("Follow is the ioctl() command for LED driver:\n"); printk("Enable Driver debug command: %u\n", SET_DRV_DEBUG); printk("Get Driver verion command : %u\n", GET_DRV_VER); printk("Turn LED on command : %u\n", LED_ON); printk("Turn LED off command : %u\n", LED_OFF); printk("Turn LED blink command : %u\n", LED_BLINK);}
/* compatible with kernel version >=2.6.38*/static long led_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ struct s3c_led_platform_data *pdata = file->private_data;
switch (cmd) { case SET_DRV_DEBUG: dbg_print("%s driver debug now.\n", DISABLE == arg ? "Disable" : "Enable"); debug = (0==arg) ? DISABLE : ENABLE; break; case GET_DRV_VER: print_version(DRV_VERSION); return DRV_VERSION;
case LED_OFF: if(pdata->nleds <= arg) { printk("LED%ld doesn’t exist\n", arg); return -ENOTTY; } pdata->leds[arg].status = OFF; pdata->leds[arg].blink = DISABLE; break;
case LED_ON: if(pdata->nleds <= arg) { printk("LED%ld doesn’t exist\n", arg); return -ENOTTY; } pdata->leds[arg].status = ON; pdata->leds[arg].blink = DISABLE; break;
case LED_BLINK: if(pdata->nleds <= arg) { printk("LED%ld doesn’t exist\n", arg); return -ENOTTY; } pdata->leds[arg].blink = ENABLE; pdata->leds[arg].status = ON; break;
default: dbg_print("%s driver don’t support ioctl command=%d\n", DEV_NAME, cmd); print_led_help(); return -EINVAL;
} return 0;}
static struct file_operations led_fops = { .owner = THIS_MODULE, .open = led_open, .release = led_release, .unlocked_ioctl = led_ioctl, /* compatible with kernel version >=2.6.38*/};
static int s3c_led_probe(struct platform_device *dev){ struct s3c_led_platform_data *pdata = dev->dev.platform_data; int result = 0; int i; dev_t devno;
/* Initialize the LED status */ for(i=0; i<pdata->nleds; i++) { s3c2410_gpio_cfgpin(pdata->leds[i].gpio, S3C2410_GPIO_OUTPUT); if(ON == pdata->leds[i].status) { s3c2410_gpio_setpin(pdata->leds[i].gpio, pdata->leds[i].active_level); } else { s3c2410_gpio_setpin(pdata->leds[i].gpio, ~pdata->leds[i].active_level); } }
/* 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 structure and register cdev*/ memset(&led_device, 0, sizeof(led_device)); led_device.data = dev->dev.platform_data; cdev_init (&(led_device.cdev), &led_fops); led_device.cdev.owner = THIS_MODULE;
result = cdev_add (&(led_device.cdev), devno , 1); if (result) { printk (KERN_NOTICE "error %d add %s device", result, DEV_NAME); goto ERROR; }
led_device.dev_class = class_create(THIS_MODULE, DEV_NAME); if(IS_ERR(led_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(led_device.dev_class, NULL, devno, NULL, DEV_NAME);#else device_create (led_device.dev_class, NULL, devno, DEV_NAME);#endif
/* Initial the LED blink timer */ init_timer(&(led_device.blink_timer)); led_device.blink_timer.function = led_timer_handler; led_device.blink_timer.data = (unsigned long)pdata; led_device.blink_timer.expires = jiffies + TIMER_TIMEOUT; add_timer(&(led_device.blink_timer));
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(&(led_device.cdev));
unregister_chrdev_region(devno, 1); return result;
}
static int s3c_led_remove(struct platform_device *dev){ dev_t devno = MKDEV(dev_major, dev_minor);
del_timer(&(led_device.blink_timer));
cdev_del(&(led_device.cdev)); device_destroy(led_device.dev_class, devno); class_destroy(led_device.dev_class);
unregister_chrdev_region(devno, 1); printk("S3C %s driver removed\n", DEV_NAME);
return 0;}
static struct platform_driver s3c_led_driver = { .probe = s3c_led_probe, .remove = s3c_led_remove, .driver = { .name ="s3c_led", .owner = THIS_MODULE, },};
static int __init s3c_led_init(void){ int ret = 0;
ret = platform_device_register(&s3c_led_device); if(ret) { printk(KERN_ERR "%s:%d: Can’t register platform device %d\n", __FUNCTION__,__LINE__, ret); goto fail_reg_plat_dev; } dbg_print("Regist S3C LED Platform Device successfully.\n");
ret = platform_driver_register(&s3c_led_driver); if(ret) { printk(KERN_ERR "%s:%d: Can’t register platform driver %d\n", __FUNCTION__,__LINE__, ret); goto fail_reg_plat_drv; } dbg_print("Regist S3C LED Platform Driver successfully.\n"); return 0;
fail_reg_plat_drv: platform_driver_unregister(&s3c_led_driver);fail_reg_plat_dev: return ret;}
static void __init s3c_led_exit(void){ dbg_print("%s():%d remove LED platform drvier\n", __FUNCTION__,__LINE__); platform_driver_unregister(&s3c_led_driver); dbg_print("%s():%d remove LED platform device\n", __FUNCTION__,__LINE__); platform_device_unregister(&s3c_led_device);}
module_init(s3c_led_init);module_exit(s3c_led_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_led");
二、Makefile文件：
obj-m := plat_led.oKERNELDIR := ~/kernel/linux-3.0/ #这个地方填上你开发板所使用的内核路径（内核要make一下才奏效）PWD := $(shell pwd)modules: $(MAKE) -C $(KERNELDIR) M=$(PWD) modulesmodules_install: $(MAKE) -C $(KERNELDIR) M=$(PWD) modules_installclean: rm -rf *.o *~core .depend .*.cmd *.ko *.mod.c .tmp_versions *odule* $(TARGET)
三、下面是应用程序：
/********************************************************************************** Copyright: (C) 2013 fulinux<fulinux@sina.com>* All rights reserved.** Filename: test_led.c* Description: This file is used to test plat_led.ko* * Version: 1.0.0(04/15/2013~)* Author: fulinux <fulinux@sina.com>* ChangeLog: 1, Release initial version on "04/15/2013 04:41:24 PM"* ********************************************************************************/#include "plat_ioctl.h"#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <sys/ioctl.h>
void main(void){ int fd; fd = open("/dev/led", O_RDWR); ioctl(fd,LED_ON,0); ioctl(fd,LED_ON,1); ioctl(fd,LED_ON,2); ioctl(fd,LED_BLINK,3); close(fd);}
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下面这个是另一个测试plat_led.ko的应用程序，这次不同的是它是可以通过命令的形式来控制led
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/********************************************************************************** Copyright: (C) 2013 fulinux<fulinux@sina.com>* All rights reserved.** Filename: test_cmd.c* Description: This file is used to test plat_led.ko* * Version: 1.0.0(04/15/2013~)* Author: fulinux <fulinux@sina.com>* ChangeLog: 1, Release initial version on "04/15/2013 04:41:24 PM"* ********************************************************************************/
#include <getopt.h>#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <errno.h>#include <sys/ioctl.h>
#include "plat_ioctl.h"
void usage(char *name);int do_ioctl(char *dev_name, int cmd, int arg);
/********************************************************************************* Description:* Input Args:* Output Args:* Return Value:********************************************************************************/int main (int argc, char **argv){ int opt = 0; static struct option long_options[] = { {"ioctl", required_argument, NULL, ‘i’}, {NULL, 0, NULL, 0} };
while((opt = getopt_long(argc, argv, "i:", long_options,NULL)) != -1 ) { switch(opt) { case ‘i’: if(5 != argc ) { printf(" argc != 5"); } else { do_ioctl(argv[2], atoi(argv[3]), atoi(argv[4])); } return 0; default: break; } } return 0;} /* —– End of main() —– */
int do_ioctl(char *dev_name, int cmd, int arg){ int fd = -1; int retval;
if(((fd = open(dev_name, O_RDWR)) < 0)) { printf("Open device \&;%s\&; failure: %s\n", dev_name, strerror(errno)); return -1; } retval = ioctl(fd, cmd, arg); printf("ioctl(%s, %d, %d) return %d", dev_name, cmd, arg, retval);
close(fd); return retval;}
下面是在开发板上执行命令的图片。
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下面试命令形式的又一升级
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/********************************************************************************** Copyright: (C) 2013 fulinux<fulinux@sina.com>* All rights reserved.** Filename: led_cmd.c* Description: This file * * Version: 1.0.0(04/17/2013~)* Author: fulinux <fulinux@sina.com>* ChangeLog: 1, Release initial version on "04/17/2013 12:17:28 PM"* ********************************************************************************/
#include <getopt.h>#include <stdio.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <errno.h>#include <sys/ioctl.h>
#include "plat_ioctl.h"
void usage(char *name);int do_ioctl(char *dev_name, char cmd, int arg);
/********************************************************************************* Description:* Input Args:* Output Args:* Return Value:********************************************************************************/int main (int argc, char **argv){ int opt = 0; static struct option long_options[] = { {"ioctl", required_argument, NULL, ‘i’}, {NULL, 0, NULL, 0} };
while((opt = getopt_long(argc, argv, "i:", long_options,NULL)) != -1 ) { switch(opt) { case ‘i’: if(5 != argc ) { printf(" argc != 5"); } else+ led_cmd.c { do_ioctl(argv[2], *argv[3], atoi(argv[4])); } return 0; default: break; } } return 0;} /* —– End of main() —– */
int do_ioctl(char *dev_name, char cmd, int arg){ int fd = -1; int i; int retval;
if(((fd = open(dev_name, O_RDWR)) < 0)) { printf("Open device \&;%s\&; failure: %s\n", dev_name, strerror(errno)); return -1; } switch(cmd) { case ‘n’: case ‘N’: retval = ioctl(fd, LED_ON, arg); break; case ‘o’: case ‘O’: retval = ioctl(fd, LED_OFF, arg); break; case ‘b’: retval = ioctl(fd, LED_BLINK, arg); break; case ‘a’: arg = 0; for(i=0;i<4;i++) { retval = ioctl(fd, LED_BLINK, i); sleep(1); } i = 0; break; default: break; } //printf("ioctl(%s, %c, %d) return %d", dev_name, cmd, arg, retval);
close(fd); return retval;}
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