LED驅動程式相關標頭檔案簡單介紹
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- 《常識》
- ¥應用程式----->系統核心----->裝置驅動----->硬體裝置
- ¥裝置驅動既是系統核心的下屬,又是硬體裝置的老大。
- ¥在inux系統中用一個檔案來代表一個裝置。這個檔案就叫裝置檔案。裝置驅動的責任是將應用程式對裝置檔案
- 的開啟、讀、寫、定位等操作轉化為對硬體裝置的開啟、讀、寫、定位等操作。而對於任何硬體裝置,應用程式
- 只需利用這些基本操作就可以完全控制它!
- ¥編寫linux裝置驅動需要的知識結構:
- 1、40%的設計模式相關知識。設計模式是系統核心限定的,做別人的下屬就得按照別人的規矩辦事。
- 2、30%的核心工作原理相關知識。核心是你領導,領會領導意圖才能把事情辦好。
- 3、30%的硬體相關知識。控制好硬體是你的的本質工作,你得把你的小弟管理好.
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 《常識》 ¥應用程式----->系統核心----->裝置驅動----->硬體裝置 ¥裝置驅動既是系統核心的下屬,又是硬體裝置的老大。 ¥在inux系統中用一個檔案來代表一個裝置。這個檔案就叫裝置檔案。裝置驅動的責任是將應用程式對裝置檔案 的開啟、讀、寫、定位等操作轉化為對硬體裝置的開啟、讀、寫、定位等操作。而對於任何硬體裝置,應用程式 只需利用這些基本操作就可以完全控制它! ¥編寫linux裝置驅動需要的知識結構: 1、40%的設計模式相關知識。設計模式是系統核心限定的,做別人的下屬就得按照別人的規矩辦事。 2、30%的核心工作原理相關知識。核心是你領導,領會領導意圖才能把事情辦好。 3、30%的硬體相關知識。控制好硬體是你的的本質工作,你得把你的小弟管理好. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
在解讀OK6410官方提供的LED驅動程式原始碼的過程中,發現很多沒見過的巨集和函式。例如S3C64XX_GPM(0)、S3C64XX_GPM_OUTPUT(0)、__raw_writel(tmp,S3C64XX_GPMPUD)、__raw_writel(tmp,S3C64XX_GPMCON)等。而這些都包含在一些標頭檔案裡面。另一方面,我們自己動手編寫LED的驅動程式也必須知道相關的標頭檔案有哪些,對我們有哪些用。因此,我覺得在自己動手編寫LED驅動程式之前對相關標頭檔案進行簡單的分析是非常有必要的。以下是我自己結合原始碼分析得出的一些結論,如有不正確的地方,希望能夠得到指正。
OK6410官方提供的LED驅動程式原始碼:
[cpp] view plain copy print?- #include <linux/module.h>
- #include <linux/kernel.h>
- #include <linux/fs.h>
- #include <linux/init.h>
- #include <linux/miscdevice.h>
- #include <linux/delay.h>
- #include <linux/device.h>
- #include <linux/cdev.h>
- #include <asm/irq.h>
- #include <mach/gpio.h>
- #include <plat/regs-gpio.h>
- #include <plat/gpio-cfg.h>
- #include <mach/hardware.h>
- #include <linux/io.h>
- #define DEVICE_NAME "leds"
- #define LED_MAJOR 231
- static unsigned long led_table [] = {
- S3C64XX_GPM(0),
- S3C64XX_GPM(1),
- S3C64XX_GPM(2),
- S3C64XX_GPM(3),
- };
- static unsigned int led_cfg_table [] = {
- S3C64XX_GPM_OUTPUT(0),
- S3C64XX_GPM_OUTPUT(1),
- S3C64XX_GPM_OUTPUT(2),
- S3C64XX_GPM_OUTPUT(3),
- };
- staticint s3c6410_leds_ioctl(
- struct inode *inode,
- struct file *file,
- unsigned int cmd,
- unsigned long arg)
- {
- unsigned long tmp;
- switch(cmd) {
- case 0:
- case 1:
- if (arg > 4) {
- return -EINVAL;
- }
- tmp = __raw_readl(S3C64XX_GPMDAT);
- if(cmd)
- tmp &= (~(1<<arg));
- else
- tmp |= (1<<arg);
- __raw_writel(tmp,S3C64XX_GPMDAT);
- // gpio_set_value(led_table[arg], !cmd);
- return 0;
- default:
- return -EINVAL;
- }
- }
- staticstruct file_operations s3c6410_leds_fops = {
- .owner = THIS_MODULE,
- .ioctl = s3c6410_leds_ioctl,
- };
- staticstruct cdev cdev_leds;
- structclass * my_class;
- staticint __init s3c6410_leds_init(void)
- {
- int ret;
- unsigned long tmp;
- int i;
- dev_t devno;
- printk(KERN_NOTICE "enter s3c6410_leds_init\n");
- devno = MKDEV(LED_MAJOR,0);
- ret = register_chrdev_region(devno,1,DEVICE_NAME);
- ret = 0;
- if(ret<0)
- {
- printk(KERN_NOTICE "can not register led device");
- return ret;
- }
- cdev_init(&cdev_leds,&s3c6410_leds_fops);
- cdev_leds.owner = THIS_MODULE;
- ret =cdev_add(&cdev_leds,devno,1);
- if(ret)
- {
- printk(KERN_NOTICE "can not add leds device");
- return ret;
- }
- my_class = class_create(THIS_MODULE,"my_class");
- if(IS_ERR(my_class))
- {
- printk("Err: Failed in creating class\n");
- return -1;
- }
- device_create(my_class,NULL,MKDEV(LED_MAJOR,0),NULL,DEVICE_NAME);
- //gpm0-3 pull up
- tmp = __raw_readl(S3C64XX_GPMPUD);
- tmp &= (~0xFF);
- tmp |= 0xaa;
- __raw_writel(tmp,S3C64XX_GPMPUD);
- //gpm0-3 output mode
- tmp = __raw_readl(S3C64XX_GPMCON);
- tmp &= (~0xFFFF);
- tmp |= 0x1111;
- __raw_writel(tmp,S3C64XX_GPMCON);
- //gpm0-3 output 0
- tmp = __raw_readl(S3C64XX_GPMDAT);
- tmp |= 0x10;
- __raw_writel(tmp,S3C64XX_GPMDAT);
- //printk("S3C64XX_GPMCON is %x\n",__raw_readl(S3C64XX_GPMCON));
- //printk("S3C64XX_GPMDAT is %x\n",__raw_readl(S3C64XX_GPMDAT));
- //printk("S3C64XX_GPMPUD is %x\n",__raw_readl(S3C64XX_GPMPUD));
- printk(DEVICE_NAME " initialized\n");
- return 0;
- }
- staticvoid __exit s3c6410_leds_exit(void)
- {
- cdev_del(&cdev_leds);
- unregister_chrdev_region(MKDEV(LED_MAJOR,0),1);
- printk(KERN_NOTICE "s3c2440_leds_exit\n");
- }
- module_init(s3c6410_leds_init);
- module_exit(s3c6410_leds_exit);
- MODULE_LICENSE("GPL");
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <asm/irq.h>
#include <mach/gpio.h>
#include <plat/regs-gpio.h>
#include <plat/gpio-cfg.h>
#include <mach/hardware.h>
#include <linux/io.h>
#define DEVICE_NAME "leds"
#define LED_MAJOR 231
static unsigned long led_table [] = {
S3C64XX_GPM(0),
S3C64XX_GPM(1),
S3C64XX_GPM(2),
S3C64XX_GPM(3),
};
static unsigned int led_cfg_table [] = {
S3C64XX_GPM_OUTPUT(0),
S3C64XX_GPM_OUTPUT(1),
S3C64XX_GPM_OUTPUT(2),
S3C64XX_GPM_OUTPUT(3),
};
static int s3c6410_leds_ioctl(
struct inode *inode,
struct file *file,
unsigned int cmd,
unsigned long arg)
{
unsigned long tmp;
switch(cmd) {
case 0:
case 1:
if (arg > 4) {
return -EINVAL;
}
tmp = __raw_readl(S3C64XX_GPMDAT);
if(cmd)
tmp &= (~(1<<arg));
else
tmp |= (1<<arg);
__raw_writel(tmp,S3C64XX_GPMDAT);
// gpio_set_value(led_table[arg], !cmd);
return 0;
default:
return -EINVAL;
}
}
static struct file_operations s3c6410_leds_fops = {
.owner = THIS_MODULE,
.ioctl = s3c6410_leds_ioctl,
};
static struct cdev cdev_leds;
struct class * my_class;
static int __init s3c6410_leds_init(void)
{
int ret;
unsigned long tmp;
int i;
dev_t devno;
printk(KERN_NOTICE "enter s3c6410_leds_init\n");
devno = MKDEV(LED_MAJOR,0);
ret = register_chrdev_region(devno,1,DEVICE_NAME);
ret = 0;
if(ret<0)
{
printk(KERN_NOTICE "can not register led device");
return ret;
}
cdev_init(&cdev_leds,&s3c6410_leds_fops);
cdev_leds.owner = THIS_MODULE;
ret =cdev_add(&cdev_leds,devno,1);
if(ret)
{
printk(KERN_NOTICE "can not add leds device");
return ret;
}
my_class = class_create(THIS_MODULE,"my_class");
if(IS_ERR(my_class))
{
printk("Err: Failed in creating class\n");
return -1;
}
device_create(my_class,NULL,MKDEV(LED_MAJOR,0),NULL,DEVICE_NAME);
//gpm0-3 pull up
tmp = __raw_readl(S3C64XX_GPMPUD);
tmp &= (~0xFF);
tmp |= 0xaa;
__raw_writel(tmp,S3C64XX_GPMPUD);
//gpm0-3 output mode
tmp = __raw_readl(S3C64XX_GPMCON);
tmp &= (~0xFFFF);
tmp |= 0x1111;
__raw_writel(tmp,S3C64XX_GPMCON);
//gpm0-3 output 0
tmp = __raw_readl(S3C64XX_GPMDAT);
tmp |= 0x10;
__raw_writel(tmp,S3C64XX_GPMDAT);
//printk("S3C64XX_GPMCON is %x\n",__raw_readl(S3C64XX_GPMCON));
//printk("S3C64XX_GPMDAT is %x\n",__raw_readl(S3C64XX_GPMDAT));
//printk("S3C64XX_GPMPUD is %x\n",__raw_readl(S3C64XX_GPMPUD));
printk(DEVICE_NAME " initialized\n");
return 0;
}
static void __exit s3c6410_leds_exit(void)
{
cdev_del(&cdev_leds);
unregister_chrdev_region(MKDEV(LED_MAJOR,0),1);
printk(KERN_NOTICE "s3c2440_leds_exit\n");
}
module_init(s3c6410_leds_init);
module_exit(s3c6410_leds_exit);
MODULE_LICENSE("GPL");
一、模組相關標頭檔案:
1、#include <Linux/module.h>:在編寫任何模組都需要包含此標頭檔案。該標頭檔案自動包含了 <linux/version.h>標頭檔案,該標頭檔案包含了巨集MODULE_LICENSE("GPL")的定義。
2、#include <linux/init.h>:此標頭檔案也是必須的,module_init()與module_exit()巨集就是定義在它裡面的。而且正是這個標頭檔案定義了初始化函式加__init和推出函式加__exit的作用(static int __init s3c6410_leds_init(void)和static void __exit s3c6410_leds_exit(void))
3、#include <linux/kernel.h>:此標頭檔案也是常用標頭檔案,如果需要使用printk函式,則必須包含此標頭檔案。另外該標頭檔案還包含了<types.h>標頭檔案,而這個標頭檔案定義許多常用的資料型別,其中就包括裝置號型別dev_t。如下:
- #ifndef _LINUX_TYPES_H
- #define _LINUX_TYPES_H
- #ifdef __KERNEL__
- #define DECLARE_BITMAP(name,bits) \
- unsigned long name[BITS_TO_LONGS(bits)]
- #endif
- #include <linux/posix_types.h>
- #include <asm/types.h>
- #ifndef __KERNEL_STRICT_NAMES
- typedef __u32 __kernel_dev_t;
- typedef __kernel_fd_set fd_set;
- typedef __kernel_dev_t dev_t;
- typedef __kernel_ino_t ino_t;
- typedef __kernel_mode_t mode_t;
- typedef __kernel_nlink_t nlink_t;
- typedef __kernel_off_t off_t;
- typedef __kernel_pid_t pid_t;
- typedef __kernel_daddr_t daddr_t;
- typedef __kernel_key_t key_t;
- typedef __kernel_suseconds_t suseconds_t;
- typedef __kernel_timer_t timer_t;
- typedef __kernel_clockid_t clockid_t;
- typedef __kernel_mqd_t mqd_t;
- #ifdef __KERNEL__
- typedef _Bool bool;
- typedef __kernel_uid32_t uid_t;
- typedef __kernel_gid32_t gid_t;
- typedef __kernel_uid16_t uid16_t;
- typedef __kernel_gid16_t gid16_t;
- typedef unsigned longuintptr_t;
- #ifdef CONFIG_UID16
- /* This is defined by include/asm-{arch}/posix_types.h */
- typedef __kernel_old_uid_t old_uid_t;
- typedef __kernel_old_gid_t old_gid_t;
- #endif /* CONFIG_UID16 */
- /* libc5 includes this file to define uid_t, thus uid_t can never change
- * when it is included by non-kernel code
- */
- #else
- typedef __kernel_uid_t uid_t;
- typedef __kernel_gid_t gid_t;
- #endif /* __KERNEL__ */
- #if defined(__GNUC__)
- typedef __kernel_loff_t loff_t;
- #endif
- /*
- * The following typedefs are also protected by individual ifdefs for
- * historical reasons:
- */
- #ifndef _SIZE_T
- #define _SIZE_T
- typedef __kernel_size_t size_t;
- #endif
- #ifndef _SSIZE_T
- #define _SSIZE_T
- typedef __kernel_ssize_t ssize_t;
- #endif
- #ifndef _PTRDIFF_T
- #define _PTRDIFF_T
- typedef __kernel_ptrdiff_t ptrdiff_t;
- #endif
- #ifndef _TIME_T
- #define _TIME_T
- typedef __kernel_time_t time_t;
- #endif
- #ifndef _CLOCK_T
- #define _CLOCK_T
- typedef __kernel_clock_t clock_t;
- #endif
- #ifndef _CADDR_T
- #define _CADDR_T
- typedef __kernel_caddr_t caddr_t;
- #endif
- /* bsd */
- typedef unsigned char u_char;
- typedef unsigned short u_short;
- typedef unsigned int u_int;
- typedef unsigned long u_long;
- /* sysv */
- typedef unsigned char unchar;
- typedef unsigned short ushort;
- typedef unsigned int uint;
- typedef unsigned long ulong;
- #ifndef __BIT_TYPES_DEFINED__
- #define __BIT_TYPES_DEFINED__
- typedef __u8 u_int8_t;
- typedef __s8 int8_t;
- typedef __u16 u_int16_t;
- typedef __s16 int16_t;
- typedef __u32 u_int32_t;
- typedef __s32 int32_t;
- #endif /* !(__BIT_TYPES_DEFINED__) */
- typedef __u8 uint8_t;
- typedef __u16 uint16_t;
- typedef __u32 uint32_t;
- #if defined(__GNUC__)
- typedef __u64 uint64_t;
- typedef __u64 u_int64_t;
- typedef __s64 int64_t;
- #endif
- /* this is a special 64bit data type that is 8-byte aligned */
- #define aligned_u64 __u64 __attribute__((aligned(8)))
- #define aligned_be64 __be64 __attribute__((aligned(8)))
- #define aligned_le64 __le64 __attribute__((aligned(8)))
- /**
- * The type used for indexing onto a disc or disc partition.
- *
- * Linux always considers sectors to be 512 bytes long independently
- * of the devices real block size.
- */
- #ifdef CONFIG_LBD
- typedef u64 sector_t;
- #else
- typedef unsigned long sector_t;
- #endif
- /*
- * The type of the inode's block count.
- */
- #ifdef CONFIG_LSF
- typedef u64 blkcnt_t;
- #else
- typedef unsigned long blkcnt_t;
- #endif
- /*
- * The type of an index into the pagecache. Use a #define so asm/types.h
- * can override it.
- */
- #ifndef pgoff_t
- #define pgoff_t unsigned long
- #endif
- #endif /* __KERNEL_STRICT_NAMES */
- /*
- * Below are truly Linux-specific types that should never collide with
- * any application/library that wants linux/types.h.
- */
- #ifdef __CHECKER__
- #define __bitwise__ __attribute__((bitwise))
- #else
- #define __bitwise__
- #endif
- #ifdef __CHECK_ENDIAN__
- #define __bitwise __bitwise__
- #else
- #define __bitwise
- #endif
- typedef __u16 __bitwise __le16;
- typedef __u16 __bitwise __be16;
- typedef __u32 __bitwise __le32;
- typedef __u32 __bitwise __be32;
- #if defined(__GNUC__)
- typedef __u64 __bitwise __le64;
- typedef __u64 __bitwise __be64;
- #endif
- typedef __u16 __bitwise __sum16;
- typedef __u32 __bitwise __wsum;
- #ifdef __KERNEL__
- typedef unsigned __bitwise__ gfp_t;
- typedef unsigned __bitwise__ fmode_t;
- #ifdef CONFIG_PHYS_ADDR_T_64BIT
- typedef u64 phys_addr_t;
- #else
- typedef u32 phys_addr_t;
- #endif
- typedef phys_addr_t resource_size_t;
- struct ustat {
- __kernel_daddr_t f_tfree;
- __kernel_ino_t f_tinode;
- char f_fname[6];
- char f_fpack[6];
- };
- #endif /* __KERNEL__ */
- #endif /* _LINUX_TYPES_H */
#ifndef _LINUX_TYPES_H
#define _LINUX_TYPES_H
#ifdef __KERNEL__
#define DECLARE_BITMAP(name,bits) \
unsigned long name[BITS_TO_LONGS(bits)]
#endif
#include <linux/posix_types.h>
#include <asm/types.h>
#ifndef __KERNEL_STRICT_NAMES
typedef __u32 __kernel_dev_t;
typedef __kernel_fd_set fd_set;
typedef __kernel_dev_t dev_t;
typedef __kernel_ino_t ino_t;
typedef __kernel_mode_t mode_t;
typedef __kernel_nlink_t nlink_t;
typedef __kernel_off_t off_t;
typedef __kernel_pid_t pid_t;
typedef __kernel_daddr_t daddr_t;
typedef __kernel_key_t key_t;
typedef __kernel_suseconds_t suseconds_t;
typedef __kernel_timer_t timer_t;
typedef __kernel_clockid_t clockid_t;
typedef __kernel_mqd_t mqd_t;
#ifdef __KERNEL__
typedef _Bool bool;
typedef __kernel_uid32_t uid_t;
typedef __kernel_gid32_t gid_t;
typedef __kernel_uid16_t uid16_t;
typedef __kernel_gid16_t gid16_t;
typedef unsigned long uintptr_t;
#ifdef CONFIG_UID16
/* This is defined by include/asm-{arch}/posix_types.h */
typedef __kernel_old_uid_t old_uid_t;
typedef __kernel_old_gid_t old_gid_t;
#endif /* CONFIG_UID16 */
/* libc5 includes this file to define uid_t, thus uid_t can never change
* when it is included by non-kernel code
*/
#else
typedef __kernel_uid_t uid_t;
typedef __kernel_gid_t gid_t;
#endif /* __KERNEL__ */
#if defined(__GNUC__)
typedef __kernel_loff_t loff_t;
#endif
/*
* The following typedefs are also protected by individual ifdefs for
* historical reasons:
*/
#ifndef _SIZE_T
#define _SIZE_T
typedef __kernel_size_t size_t;
#endif
#ifndef _SSIZE_T
#define _SSIZE_T
typedef __kernel_ssize_t ssize_t;
#endif
#ifndef _PTRDIFF_T
#define _PTRDIFF_T
typedef __kernel_ptrdiff_t ptrdiff_t;
#endif
#ifndef _TIME_T
#define _TIME_T
typedef __kernel_time_t time_t;
#endif
#ifndef _CLOCK_T
#define _CLOCK_T
typedef __kernel_clock_t clock_t;
#endif
#ifndef _CADDR_T
#define _CADDR_T
typedef __kernel_caddr_t caddr_t;
#endif
/* bsd */
typedef unsigned char u_char;
typedef unsigned short u_short;
typedef unsigned int u_int;
typedef unsigned long u_long;
/* sysv */
typedef unsigned char unchar;
typedef unsigned short ushort;
typedef unsigned int uint;
typedef unsigned long ulong;
#ifndef __BIT_TYPES_DEFINED__
#define __BIT_TYPES_DEFINED__
typedef __u8 u_int8_t;
typedef __s8 int8_t;
typedef __u16 u_int16_t;
typedef __s16 int16_t;
typedef __u32 u_int32_t;
typedef __s32 int32_t;
#endif /* !(__BIT_TYPES_DEFINED__) */
typedef __u8 uint8_t;
typedef __u16 uint16_t;
typedef __u32 uint32_t;
#if defined(__GNUC__)
typedef __u64 uint64_t;
typedef __u64 u_int64_t;
typedef __s64 int64_t;
#endif
/* this is a special 64bit data type that is 8-byte aligned */
#define aligned_u64 __u64 __attribute__((aligned(8)))
#define aligned_be64 __be64 __attribute__((aligned(8)))
#define aligned_le64 __le64 __attribute__((aligned(8)))
/**
* The type used for indexing onto a disc or disc partition.
*
* Linux always considers sectors to be 512 bytes long independently
* of the devices real block size.
*/
#ifdef CONFIG_LBD
typedef u64 sector_t;
#else
typedef unsigned long sector_t;
#endif
/*
* The type of the inode's block count.
*/
#ifdef CONFIG_LSF
typedef u64 blkcnt_t;
#else
typedef unsigned long blkcnt_t;
#endif
/*
* The type of an index into the pagecache. Use a #define so asm/types.h
* can override it.
*/
#ifndef pgoff_t
#define pgoff_t unsigned long
#endif
#endif /* __KERNEL_STRICT_NAMES */
/*
* Below are truly Linux-specific types that should never collide with
* any application/library that wants linux/types.h.
*/
#ifdef __CHECKER__
#define __bitwise__ __attribute__((bitwise))
#else
#define __bitwise__
#endif
#ifdef __CHECK_ENDIAN__
#define __bitwise __bitwise__
#else
#define __bitwise
#endif
typedef __u16 __bitwise __le16;
typedef __u16 __bitwise __be16;
typedef __u32 __bitwise __le32;
typedef __u32 __bitwise __be32;
#if defined(__GNUC__)
typedef __u64 __bitwise __le64;
typedef __u64 __bitwise __be64;
#endif
typedef __u16 __bitwise __sum16;
typedef __u32 __bitwise __wsum;
#ifdef __KERNEL__
typedef unsigned __bitwise__ gfp_t;
typedef unsigned __bitwise__ fmode_t;
#ifdef CONFIG_PHYS_ADDR_T_64BIT
typedef u64 phys_addr_t;
#else
typedef u32 phys_addr_t;
#endif
typedef phys_addr_t resource_size_t;
struct ustat {
__kernel_daddr_t f_tfree;
__kernel_ino_t f_tinode;
char f_fname[6];
char f_fpack[6];
};
#endif /* __KERNEL__ */
#endif /* _LINUX_TYPES_H */
二、字元裝置驅動相關標頭檔案:
1、#include <linux/fs.h>:該標頭檔案包含了常用的資料結構,當然也包括三種最重要的:struct file、struct file_operation、struct
inode。另外該標頭檔案還包含了<linux/ioctl.h>標頭檔案。
2、#include <linux/cdev.h>:該標頭檔案定義了struct cdev資料結構,也包含了字元裝置操作的相關函式:
- #ifndef _LINUX_CDEV_H
- #define _LINUX_CDEV_H
- #include <linux/kobject.h>
- #include <linux/kdev_t.h>
- #include <linux/list.h>
- struct file_operations;
- struct inode;
- struct module;
- struct cdev {
- struct kobject kobj;
- struct module *owner;
- conststruct file_operations *ops;
- struct list_head list;
- dev_t dev;
- unsigned int count;
- };
- void cdev_init(struct cdev *, conststruct file_operations *);
- struct cdev *cdev_alloc(void);
- void cdev_put(struct cdev *p);
- int cdev_add(struct cdev *, dev_t, unsigned);
- void cdev_del(struct cdev *);
- void cd_forget(struct inode *);
- externstruct backing_dev_info directly_mappable_cdev_bdi;
- #endif
#ifndef _LINUX_CDEV_H
#define _LINUX_CDEV_H
#include <linux/kobject.h>
#include <linux/kdev_t.h>
#include <linux/list.h>
struct file_operations;
struct inode;
struct module;
struct cdev {
struct kobject kobj;
struct module *owner;
const struct file_operations *ops;
struct list_head list;
dev_t dev;
unsigned int count;
};
void cdev_init(struct cdev *, const struct file_operations *);
struct cdev *cdev_alloc(void);
void cdev_put(struct cdev *p);
int cdev_add(struct cdev *, dev_t, unsigned);
void cdev_del(struct cdev *);
void cd_forget(struct inode *);
extern struct backing_dev_info directly_mappable_cdev_bdi;
#endif
3、<linux/device.h>:包含自動建立裝置檔案的相關函式的申明:原函式中-class_create(THIS_MODULE,"my_class")、device_create(my_class,NULL,MKDEV(LED_MAJOR,0),NULL,DEVICE_NAME)。
三、s3c64xx GPIO操作相關標頭檔案:
1、#include <mach/gpio.h>:此標頭檔案包含了對S3C64xx 各個GPIO的巨集定義,幷包含了各個埠的讀寫函式,如下:
- /* linux/arch/arm/mach-s3c6400/include/mach/gpio.h
- *
- * Copyright 2008 Openmoko, Inc.
- * Copyright 2008 Simtec Electronics
- * http://armlinux.simtec.co.uk/
- * Ben Dooks <[email protected]>
- *
- * S3C6400 - GPIO lib support
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
- #define gpio_get_value __gpio_get_value
- #define gpio_set_value __gpio_set_value
- #define gpio_cansleep __gpio_cansleep
- #define gpio_to_irq __gpio_to_irq
- /* GPIO bank sizes */
- #define S3C64XX_GPIO_A_NR (8)
- #define S3C64XX_GPIO_B_NR (7)
- #define S3C64XX_GPIO_C_NR (8)
- #define S3C64XX_GPIO_D_NR (5)
- #define S3C64XX_GPIO_E_NR (5)
- #define S3C64XX_GPIO_F_NR (16)
- #define S3C64XX_GPIO_G_NR (7)
- #define S3C64XX_GPIO_H_NR (10)
- #define S3C64XX_GPIO_I_NR (16)
- #define S3C64XX_GPIO_J_NR (12)
- #define S3C64XX_GPIO_K_NR (16)
- #define S3C64XX_GPIO_L_NR (15)
- #define S3C64XX_GPIO_M_NR (6)
- #define S3C64XX_GPIO_N_NR (16)
- #define S3C64XX_GPIO_O_NR (16)
- #define S3C64XX_GPIO_P_NR (15)
- #define S3C64XX_GPIO_Q_NR (9)
- /* GPIO bank numbes */
- /* CONFIG_S3C_GPIO_SPACE allows the user to select extra
- * space for debugging purposes so that any accidental
- * change from one gpio bank to another can be caught.
- */
- #define S3C64XX_GPIO_NEXT(__gpio) \
- ((__gpio##_START) + (__gpio##_NR) + CONFIG_S3C_GPIO_SPACE + 1)
- enum s3c_gpio_number {
- S3C64XX_GPIO_A_START = 0,
- S3C64XX_GPIO_B_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_A),
- S3C64XX_GPIO_C_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_B),
- S3C64XX_GPIO_D_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_C),
- S3C64XX_GPIO_E_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_D),
- S3C64XX_GPIO_F_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_E),
- S3C64XX_GPIO_G_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_F),
- S3C64XX_GPIO_H_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_G),
- S3C64XX_GPIO_I_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_H),
- S3C64XX_GPIO_J_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_I),
- S3C64XX_GPIO_K_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_J),
- S3C64XX_GPIO_L_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_K),
- S3C64XX_GPIO_M_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_L),
- S3C64XX_GPIO_N_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_M),
- S3C64XX_GPIO_O_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_N),
- S3C64XX_GPIO_P_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_O),
- S3C64XX_GPIO_Q_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_P),
- };
- /* S3C64XX GPIO number definitions. */
- #define S3C64XX_GPA(_nr) (S3C64XX_GPIO_A_START + (_nr))
- #define S3C64XX_GPB(_nr) (S3C64XX_GPIO_B_START + (_nr))
- #define S3C64XX_GPC(_nr) (S3C64XX_GPIO_C_START + (_nr))
- #define S3C64XX_GPD(_nr) (S3C64XX_GPIO_D_START + (_nr))
- #define S3C64XX_GPE(_nr) (S3C64XX_GPIO_E_START + (_nr))
- #define S3C64XX_GPF(_nr) (S3C64XX_GPIO_F_START + (_nr))
- #define S3C64XX_GPG(_nr) (S3C64XX_GPIO_G_START + (_nr))
- #define S3C64XX_GPH(_nr) (S3C64XX_GPIO_H_START + (_nr))
- #define S3C64XX_GPI(_nr) (S3C64XX_GPIO_I_START + (_nr))
- #define S3C64XX_GPJ(_nr) (S3C64XX_GPIO_J_START + (_nr))
- #define S3C64XX_GPK(_nr) (S3C64XX_GPIO_K_START + (_nr))
- #define S3C64XX_GPL(_nr) (S3C64XX_GPIO_L_START + (_nr))
- #define S3C64XX_GPM(_nr) (S3C64XX_GPIO_M_START + (_nr))
- #define S3C64XX_GPN(_nr) (S3C64XX_GPIO_N_START + (_nr))
- #define S3C64XX_GPO(_nr) (S3C64XX_GPIO_O_START + (_nr))
- #define S3C64XX_GPP(_nr) (S3C64XX_GPIO_P_START + (_nr))
- #define S3C64XX_GPQ(_nr) (S3C64XX_GPIO_Q_START + (_nr))
- /* the end of the S3C64XX specific gpios */
- #define S3C64XX_GPIO_END (S3C64XX_GPQ(S3C64XX_GPIO_Q_NR) + 1)
- #define S3C_GPIO_END S3C64XX_GPIO_END
- /* define the number of gpios we need to the one after the GPQ() range */
- #define ARCH_NR_GPIOS (S3C64XX_GPQ(S3C64XX_GPIO_Q_NR) + 1)
- #include <asm-generic/gpio.h>
/* linux/arch/arm/mach-s3c6400/include/mach/gpio.h
*
* Copyright 2008 Openmoko, Inc.
* Copyright 2008 Simtec Electronics
* http://armlinux.simtec.co.uk/
* Ben Dooks <[email protected]>
*
* S3C6400 - GPIO lib support
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define gpio_get_value __gpio_get_value
#define gpio_set_value __gpio_set_value
#define gpio_cansleep __gpio_cansleep
#define gpio_to_irq __gpio_to_irq
/* GPIO bank sizes */
#define S3C64XX_GPIO_A_NR (8)
#define S3C64XX_GPIO_B_NR (7)
#define S3C64XX_GPIO_C_NR (8)
#define S3C64XX_GPIO_D_NR (5)
#define S3C64XX_GPIO_E_NR (5)
#define S3C64XX_GPIO_F_NR (16)
#define S3C64XX_GPIO_G_NR (7)
#define S3C64XX_GPIO_H_NR (10)
#define S3C64XX_GPIO_I_NR (16)
#define S3C64XX_GPIO_J_NR (12)
#define S3C64XX_GPIO_K_NR (16)
#define S3C64XX_GPIO_L_NR (15)
#define S3C64XX_GPIO_M_NR (6)
#define S3C64XX_GPIO_N_NR (16)
#define S3C64XX_GPIO_O_NR (16)
#define S3C64XX_GPIO_P_NR (15)
#define S3C64XX_GPIO_Q_NR (9)
/* GPIO bank numbes */
/* CONFIG_S3C_GPIO_SPACE allows the user to select extra
* space for debugging purposes so that any accidental
* change from one gpio bank to another can be caught.
*/
#define S3C64XX_GPIO_NEXT(__gpio) \
((__gpio##_START) + (__gpio##_NR) + CONFIG_S3C_GPIO_SPACE + 1)
enum s3c_gpio_number {
S3C64XX_GPIO_A_START = 0,
S3C64XX_GPIO_B_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_A),
S3C64XX_GPIO_C_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_B),
S3C64XX_GPIO_D_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_C),
S3C64XX_GPIO_E_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_D),
S3C64XX_GPIO_F_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_E),
S3C64XX_GPIO_G_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_F),
S3C64XX_GPIO_H_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_G),
S3C64XX_GPIO_I_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_H),
S3C64XX_GPIO_J_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_I),
S3C64XX_GPIO_K_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_J),
S3C64XX_GPIO_L_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_K),
S3C64XX_GPIO_M_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_L),
S3C64XX_GPIO_N_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_M),
S3C64XX_GPIO_O_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_N),
S3C64XX_GPIO_P_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_O),
S3C64XX_GPIO_Q_START = S3C64XX_GPIO_NEXT(S3C64XX_GPIO_P),
};
/* S3C64XX GPIO number definitions. */
#define S3C64XX_GPA(_nr) (S3C64XX_GPIO_A_START + (_nr))
#define S3C64XX_GPB(_nr) (S3C64XX_GPIO_B_START + (_nr))
#define S3C64XX_GPC(_nr) (S3C64XX_GPIO_C_START + (_nr))
#define S3C64XX_GPD(_nr) (S3C64XX_GPIO_D_START + (_nr))
#define S3C64XX_GPE(_nr) (S3C64XX_GPIO_E_START + (_nr))
#define S3C64XX_GPF(_nr) (S3C64XX_GPIO_F_START + (_nr))
#define S3C64XX_GPG(_nr) (S3C64XX_GPIO_G_START + (_nr))
#define S3C64XX_GPH(_nr) (S3C64XX_GPIO_H_START + (_nr))
#define S3C64XX_GPI(_nr) (S3C64XX_GPIO_I_START + (_nr))
#define S3C64XX_GPJ(_nr) (S3C64XX_GPIO_J_START + (_nr))
#define S3C64XX_GPK(_nr) (S3C64XX_GPIO_K_START + (_nr))
#define S3C64XX_GPL(_nr) (S3C64XX_GPIO_L_START + (_nr))
#define S3C64XX_GPM(_nr) (S3C64XX_GPIO_M_START + (_nr))
#define S3C64XX_GPN(_nr) (S3C64XX_GPIO_N_START + (_nr))
#define S3C64XX_GPO(_nr) (S3C64XX_GPIO_O_START + (_nr))
#define S3C64XX_GPP(_nr) (S3C64XX_GPIO_P_START + (_nr))
#define S3C64XX_GPQ(_nr) (S3C64XX_GPIO_Q_START + (_nr))
/* the end of the S3C64XX specific gpios */
#define S3C64XX_GPIO_END (S3C64XX_GPQ(S3C64XX_GPIO_Q_NR) + 1)
#define S3C_GPIO_END S3C64XX_GPIO_END
/* define the number of gpios we need to the one after the GPQ() range */
#define ARCH_NR_GPIOS (S3C64XX_GPQ(S3C64XX_GPIO_Q_NR) + 1)
#include <asm-generic/gpio.h>
上面的標頭檔案包含了<asm-generic/gpio.h>標頭檔案,該標頭檔案包含了GPIO的資料讀寫函式,如下:
- #ifndef _ASM_GENERIC_GPIO_H
- #define _ASM_GENERIC_GPIO_H
- #include <linux/types.h>
- #include <linux/errno.h>
- #ifdef CONFIG_GPIOLIB
- #include <linux/compiler.h>
- /* Platforms may implement their GPIO interface with library code,