2022年linux驱动程序设计方案实例.docx

《2022年linux驱动程序设计方案实例.docx》由会员分享，可在线阅读，更多相关《2022年linux驱动程序设计方案实例.docx（22页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、精品学习资源封面欢迎下载精品学习资源作者： PanHongliang仅供个人学习AT91SAM9G20 驱动程序设计开发环境： Vmware + ubuntu10.04硬件平台： AT91SAM9G20欢迎下载精品学习资源Linux 版本： linux2.6.27一： led 驱动说明：由于设计的开发板上没有led 灯，便通过 PC0 来演示，通过示波器来观看引脚端的电平变化；1.驱动程序： my_led.c#include #include #include #include #include #include #include #define MY_LED_MAJOR250/定义主设备号#

2、define LED_ON0#define LED_OFF 1 struct global_devstruct cdev cdev； ；/定义设备结构体struct global_dev *global_devp ；/定义一个指向设备结构体的指针static int my_led_openstruct inode *inode, struct file *filpfilp-private_data = global_devp ；return 0；static int my_led_releasestruct inode *inode, struct file *filereturn 0；sta

3、tic int my_led_ioctlstruct inode *inode, struct file *filp, unsigned int cmd, unsigned long dataswitchcmdcase LED_ON:at91_set_gpio_valueA T91_PIN_PC0, 0 ；/将 PC0 引脚置低break；case LED_OFF:at91_set_gpio_valueA T91_PIN_PC0, 1 ；/将 PC1 引脚置高break；欢迎下载精品学习资源default:printkno valid cmd input.n；break；欢迎下载精品学习资源r

4、eturn 0；struct file_operations my_led_ctl_ops =欢迎下载精品学习资源.owner = THIS_MODULE,.open = my_led_open,.release = my_led_release,.ioctl = my_led_ioctl, ；/* 初始化设备结构体 */static void my_led_setupstruct global_dev *dev, int indexint err ；int devno = MKDEVMY_LED_MAJOR, index；cdev_init&dev-cdev, &my_led_ctl_ops

5、；dev-cdev.owner = THIS_MODULE；dev-cdev.ops = &my_led_ctl_ops ；err = cdev_add&dev-cdev, devno, 1 ；iferrprintkadd my led setup failed.n；static int my_led_initvoidint ret ；dev_t devno = MKDEVMY_LED_MAJOR, 0； / 创建设备号printkmy first driver-led.n；at91_set_GPIO_periphA T91_PIN_PC0, 1 ；at91_set_gpio_outputA

6、T91_PIN_PC0, 1 ；/对 PC0 引脚的初始化ret = register_chrdev_regiondevno, 1, my_led；/申请设备号if ret cdev ；/删除设备kfreeglobal_devp ；/释放内存unregister_chrdev_regionMKDEVMY_LED_MAJOR, 0, 1；/释放设备号MODULE_LICENSEMYGPL；MODULE_AUTHORFANY；module_initmy_led_init； /注册设备module_exitmy_led_cleanup ；/卸载设备2:如何将驱动驱动程序编译成模块在 drivers

7、目录下新建 led 目录，并在该目录下添加 Kconfig ，欢迎下载精品学习资源Makefile 文件；Kconfig ：Menu My driver support ConfigTrisate led driver. HelpLed driverEndmenu:Makefile ：Obj-$CONFIG_MY_LED+= my_led.o修改 linux/drivers 目录下的 Kconfig ， Makefile 文件Kconfig:Source drivers/led/Kconfig Makefile:Obj-y+= my_led/修改体系结构目录 arch/arm 目录下的 Kco

8、nfig 文件，否就在配置菜单中将无法看到 led 的配置选项；（假如是在 drivers 目录下新建一文件夹，并在其中添加驱动程序，必需相应的体系结构目录下添加配置选项）；Kconfig:Source driver/led/Kconfig3.测试程序： my_led_test.c#include #include #include #include #include #define DEVICE_NAME /dev/my_led #define LED_ON0#define LED_OFF1int mainvoidint fd ；int ret ；int i ；printfmy_led_dr

9、iver test.n ；fd = openDEVICE_NAME, O_RDONLY ；iffd = -1printfopen device %s error.n, DEVICE_NAME；fori = 0 ； i 50 ； i+欢迎下载精品学习资源ioctlfd, LED_OFF ；sleep1；ioctlfd, LED_ON ；sleep1；ret = closefd ；printfret = %dn, ret ；printfclose my_led_driver.n；return 0；将测试程序编译成目标平台的可执行文件，并下载到开发板GCC=/home/zzq/9G20/arm-20

10、07q1/bin/arm-none-linux-gnueabi-gcc # 交叉编译器的路径My_led_test:my_led_test.c$GCC -o my_led_test my_led_test.c clean:rm -f my_led_test学习总结：熟识驱动程序的架构，如何将驱动程序添加到内核即如何写测试程序；二：按键驱动设计1. 硬件部分： PC4 接按键；2. 驱动程序：#include #include #include #include #include #include #include #include #include #include #include #inc

11、lude #include #include #include #include #include #include #define BUTTON_MAJOR245#define DEVICE_NAME/dev/button static volatile int ev_press = 0 ；static struct cdev button_cdev；static void button_do_taskletunsigned long n ；欢迎下载精品学习资源DECLARE_TASKLETbutton_tasklet, button_do_tasklet, 0；/定义 tasklet 并与

12、处理函数关联起来static DECLARE_WAIT_QUEUE_HEADbutton_waitq；/ 静态的初始化一个等待队列struct button_irq_desc int irq ；int irq_type ；int pin ；int number；char *name； ；staticstructbutton_irq_descbutton_irq1=A T91_PIN_PB22,AT91_AIC_SRCTYPE_LOW,AT91_PIN_PB22, 0, KEY0 ；static int key_values1=0；/中断处理底半部static void button_do_ta

13、skletunsigned long nwake_up_interruptible&button_waitq；/唤醒队列printkbutton press.n ；/中断处理顶半部static irqreturn_t button_interruptint irq, void *dev_id, struct pt_regs *regsint up ；static int press_down；up = gpio_get_valuebutton_irq0.pin ；printkirqn ；/* 按键消抖 */ifuppress_down = 1； /当按键没有按下 ,置标志位为 1. if.up

14、 & press_down = 1 press_down = 0； / 当按键按下 ,置标志位为 0. ev_press = 1；at91_set_gpio_valuebutton_irq0.pin, 1 ；key_valuesbutton_irq0.number = .up ；tasklet_schedule&button_tasklet ；return IRQ_RETV ALIRQ_HANDLED；static int button_openstruct inode *inode, struct file *filpreturn 0；static int button_releasestr

15、uct inode *inode, struct file *filpreturn 0；static int button_readstruct file *filp, charuser *buff, size_t count, loff_t *offpint ret ；if.ev_press /当按键没有按下时，读进程挂起，知道按键按下；wait_event_interruptiblebutton_waitq, ev_press ；ev_press = 0；ret = copy_to_userbuff, const void *key_values, minsizeofkey_values,

16、 count；欢迎下载精品学习资源memsetvoiduser *key_values, 0, sizeofkey_values ；return ret . -EFAULT:minsizeofkey_values, count ；static struct file_operations button_fops = .owner = THIS_MODULE,.open = button_open,.release = button_release,.read = button_read, ；static int irq_initvoidint err ；at91_set_gpio_inputb

17、utton_irq0.pin, 1 ；at91_set_deglitchbutton_irq0.pin, 1 ；/ 将 PC0 设置为中断功能set_irq_typebutton_irq0.irq, button_irq0.irq_type；/设置中断类型at91_set_gpio_valuebutton_irq0.pin, 1 ；err = request_irq button_irq0.irq, button_interrupt, IRQF_DISABLED, button_irq0.name, void *&button_irq0；/申请中断欢迎下载精品学习资源if err disabl

18、e_irqbutton_irq0.irq ；free_irqbutton_irq0.irq, void *&button_irq0；return -EBUSY ；欢迎下载精品学习资源return 0；static intinit button_initvoidint ret, err ；ret = register_chrdev_regionMKDEVBUTTON_MAJOR, 0, 1, DEVICE_NAME；ifret 0 printkbutton init failed with %dn, ret；return ret ；cdev_init&button_cdev, &button_f

19、ops ；button_cdev.owner = THIS_MODULE ；button_cdev.ops = &button_fops ；err = cdev_add&button_cdev, MKDEVBUTTON_MAJOR, 0, 1；if err0 printkkey add failedn ；return err；irq_init ；printkkey driver add success.n ；return 0；static voidexit button_exitvoidcdev_del&button_cdev ；unregister_chrdev_regionMKDEVBUT

20、TON_MAJOR, 0, 1；disable_irqbutton_irq0.irq ；free_irqbutton_irq0.irq, void *&button_irq0；printkunregister key driver.n；欢迎下载精品学习资源module_initbutton_init ；module_exitbutton_exit ；MODULE_AUTHORfany；MODULE_DESCRIPTIONAtmel9g20 key Driver；MODULE_LICENSEGPL；3. 测试程序：#include #include #include #include #incl

21、ude #include #define DEVICE_NAME /dev/button int mainvoidint fd,i ；int ret ；int key_value1 ；printfkey test.n ；fd = openDEVICE_NAME, O_RDWR；iffd 0欢迎下载精品学习资源else while1 printfopen device %s error.n, DEVICE_NAME；printfopen device success.n ；ret = readfd, key_value, 1 ；if .ret 欢迎下载精品学习资源elseprintfbutton

22、 not press.n ；printfbutton press.n ；欢迎下载精品学习资源printfkey_value %dn, key_value ；closefd；printfclose key driver.n；return 0；4. 学习总结：在 linux 设备驱动程序中，中断处理程序通常分为两部分：上半部和下半部；上半部处理比较紧急的的硬件操作，比如简洁的读取寄存器中的状态并清除中断标志后，进行登记中断的工作；剩下的工作就由下半部来实现；对堵塞与非堵塞进程的懂得，堵塞：在执行设备操作时，如不能欢迎下载精品学习资源猎取设备资源就挂起，直到中意可操作的条件后再进行操作；非堵塞操作：

23、在执行设备操作时，如不能猎取设备资源就马上返回； 三：总线驱动AT91SAM9G20 储备器映射图 截取部分 ，片选 4 接外设，利用总线对外设进行拜望；但是在 linux 驱动，不能对物理地址进行操作，可通过内存拜望的机制实现对物理地址的拜望；将一段物理地址空间映射到虚拟地 址空间中，然后对虚拟地址的操作即是对物理地址的操作；3.1 ：总线驱动#include #include #include #include #include #include #include #include #include #include #include #include #include #include

24、#include #include atmel9g20_liu.h struct gr_liu_info void iomem *virtbase ；void iomem *regbase；struct resource *res；u32 flags； ；static struct gr_liu_info liu_info ；static struct cdev atmel9g20_liu_cdev ；unsigned short liu_readunsigned addraddr &= A TMEL9G20_LIU_MASK；addr = addr 1 ；欢迎下载精品学习资源addr +=

25、unsigned longliu_info.regbase ；printkread the virtual addr is 0x%xn, addr ；return readwaddr & 0xff ； /读 IO 内存；EXPORT_SYMBOLliu_read；int liu_writeunsigned addr, unsigned valaddr &= A TMEL9G20_LIU_MASK；addr = addr num_resources .= 1 ret = -ENODEV ；goto err1；/IO 内存的申请liu_info.res=request_mem_regionpdev

26、-resource0.start,pdev-resource0.end-pdev-resource0.start + 1, 9g20-liu ；if .liu_info.res printkliu: cant get request mem region ；ret = -ENOMEM ；goto err1；/IO 内存的映射欢迎下载精品学习资源1；liu_info.regbase = ioremappdev-resource0.start, pdev-resource0.end - pdev-resource0.start +printkrequest virtual addr liu_inf

27、o.regbase=0x%xn,unsigned intliu_info.regbase；if liu_info.regbase = NULL printkliu: cant get ioremap memn ；ret = -ENOMEM ；goto err2；欢迎下载精品学习资源dev_set_drvdata&pdev-dev, &liu_info；printkLIU probe done.n；return 0；err2:release_mem_regionpdev-resource0.start, pdev-resource0.end - pdev-resource0.start + 1

28、；err1:return ret ；static int liu_removestruct platform_device *pdev欢迎下载精品学习资源释放内存struct gr_liu_info *fi ；fi = pdev-dev.driver_data ；iounmapfi-regbase ；/解除映射，release_mem_regionpdev-resource0.start, pdev-resource0.end - pdev-resource0.start + 1；/fi-flags = 0x0 ；return 0；欢迎下载精品学习资源static struct platfor

29、m_driver liu_driver = .probe = liu_probe,.remove = liu_remove,.driver = .name = 9g20-liu,.owner = THIS_MODULE, ；/设置 SMC 寄存器static void cs4_initvoid欢迎下载精品学习资源at91_sys_writeAT91_MA TRIX_EBICSA,at91_sys_readAT91_MATRIX_EBICSA| AT91_MA TRIX_CS4A_SMC ；/* Configure SMC CS4 */ at91_sys_writeAT91_SMC_SETUP4

30、,AT91_SMC_NWESETUP_2 | AT91_SMC_NCS_WRSETUP_2 | AT91_SMC_NRDSETUP_2 | AT91_SMC_NCS_RDSETUP_2；at91_sys_writeAT91_SMC_PULSE4,AT91_SMC_NWEPULSE_12 | AT91_SMC_NCS_WRPULSE_10 | AT91_SMC_NRDPULSE_12 | AT91_SMC_NCS_RDPULSE_10；at91_sys_writeAT91_SMC_CYCLE4,AT91_SMC_NWECYCLE_16 | AT91_SMC_NRDCYCLE_16；at91_sy

31、s_writeAT91_SMC_MODE4,AT91_SMC_READMODE | AT91_SMC_WRITEMODE | AT91_SMC_DBW_16 | AT91_SMC_EXNWMODE_DISABLE | AT91_SMC_TDF_3；at91_sys_writeAT91_PMC_PCER, 1 A T91SAM9260_ID_PIOC ；/* Enable CS4 */at91_set_A_periphA T91_PIN_PC8, 1 ；printk*at91sam9g20ek_ebibus_cs4_init*n；static intinit atmel9g20_liu_init

32、voidint ret,err ；ret = register_chrdev_regionMKDEVLIU_MAJOR, 0, 1, /dev/liu；if ret 0 printkLIU init_module failed with %dn, ret；return ret ；cdev_init&atmel9g20_liu_cdev, &atmel9g20_liu_fops；atmel9g20_liu_cdev.owner = THIS_MODULE；atmel9g20_liu_cdev.ops = &atmel9g20_liu_fops ；err = cdev_add&atmel9g20_

33、liu_cdev, MKDEVLIU_MAJOR, 0, 1；if err0 printkliu add failedn ；return err；cs4_init ；return platform_driver_register&liu_driver；/注册平台设备；static voidexit atmel9g20_liu_cleanupvoidprintkatmel 9g20 liu exitn；cdev_del&atmel9g20_liu_cdev ；unregister_chrdev_regionMKDEVLIU_MAJOR, 0, 1；platform_driver_unregist

34、er&liu_driver；module_initatmel9g20_liu_init ；module_exitatmel9g20_liu_cleanup ；MODULE_AUTHORfany；MODULE_DESCRIPTIONAtmel9g20 liu Driver；MODULE_LICENSEGPL；并在/arch/arm/mach-at91/board-sam9g20ek.c 中初始化欢迎下载精品学习资源#define GR_LIU_BASE 0x50000000 #define GR_LIU_SIZE 0x1000static struct resource gr_liu_resource = .start= GR_LIU_BASE,.end= GR_LIU_BASE + GR_LIU_SIZE - 1,.flags= IORESOURCE_MEM, ；static struct platform_device grd_liu = .name= 9g20-liu,.id= -1,.dev= .platform_data= NULL,.resource =