linux驱动的异步通知（kill_fasync,fasync）---- 驱动程序向应用程序发送信号 应用程序

其他 2018-07-12 16:15:59 阅读次数: 0

应用程序

  1. #include <sys/types.h>
  2. #include <sys/stat.h>
  3. #include <fcntl.h>
  4. #include <stdio.h>
  5. #include <poll.h>
  6. #include <signal.h>
  7. #include <sys/types.h>
  8. #include <unistd.h>
  9. #include <fcntl.h>
  12. /* fifthdrvtest
  13. */
  14. int fd;
  16. //信号处理函数
  17. void my_signal_fun(int signum)
  18. {
  19. unsigned char key_val;
  20. read(fd, &key_val, 1);
  21. printf( "key_val: 0x%x\n", key_val);
  22. }
  24. int main(int argc, char **argv)
  25. {
  26. unsigned char key_val;
  27. int ret;
  28. int Oflags;
  30. //在应用程序中捕捉SIGIO信号（由驱动程序发送）
  31. signal(SIGIO, my_signal_fun);
  33. fd = open( "/dev/buttons", O_RDWR);
  34. if (fd < 0)
  35. {
  36. printf( "can't open!\n");
  37. }
  39. //将当前进程PID设置为fd文件所对应驱动程序将要发送SIGIO,SIGUSR信号进程PID
  40. fcntl(fd, F_SETOWN, getpid());
  42. //获取fd的打开方式
  43. Oflags = fcntl(fd, F_GETFL);
  45. //将fd的打开方式设置为FASYNC --- 即 支持异步通知
  46. //该行代码执行会触发 驱动程序中 file_operations->fasync 函数 ------fasync函数调用fasync_helper初始化一个fasync_struct结构体，该结构体描述了将要发送信号的进程PID (fasync_struct->fa_file->f_owner->pid)
  47. fcntl(fd, F_SETFL, Oflags | FASYNC);
  50. while ( 1)
  51. {
  52. sleep( 1000);
  53. }
  55. return 0;
  56. }


驱动程序

  1. #include <linux/module.h>
  2. #include <linux/kernel.h>
  3. #include <linux/fs.h>
  4. #include <linux/init.h>
  5. #include <linux/delay.h>
  6. #include <linux/irq.h>
  7. #include <asm/uaccess.h>
  8. #include <asm/irq.h>
  9. #include <asm/io.h>
  10. #include <asm/arch/regs-gpio.h>
  11. #include <asm/hardware.h>
  12. #include <linux/poll.h>
  15. static struct class *fifthdrv_class;
  16. static struct class_device *fifthdrv_class_dev;
  18. //volatile unsigned long *gpfcon;
  19. //volatile unsigned long *gpfdat;
  21. static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
  23. /* 中断事件标志, 中断服务程序将它置1，fifth_drv_read将它清0 */
  24. static volatile int ev_press = 0;
  26. static struct fasync_struct *button_async;
  29. struct pin_desc{
  30. unsigned int pin;
  31. unsigned int key_val;
  32. };
  35. /* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */
  36. /* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */
  37. static unsigned char key_val;
  39. /*
  40. * K1,K2,K3,K4对应GPG0，GPG3，GPG5，GPG6
  41. */
  43. struct pin_desc pins_desc[4] = {
  44. {S3C2410_GPG0, 0x01},
  45. {S3C2410_GPG3, 0x02},
  46. {S3C2410_GPG5, 0x03},
  47. {S3C2410_GPG6, 0x04},
  48. };
  51. /*
  52. * 确定按键值
  53. */
  54. static irqreturn_t buttons_irq(int irq, void *dev_id)
  55. {
  56. struct pin_desc * pindesc = (struct pin_desc *)dev_id;
  57. unsigned int pinval;
  59. pinval = s3c2410_gpio_getpin(pindesc->pin);
  61. if (pinval)
  62. {
  63. /* 松开 */
  64. key_val = 0x80 | pindesc->key_val;
  65. }
  66. else
  67. {
  68. /* 按下 */
  69. key_val = pindesc->key_val;
  70. }
  72. ev_press = 1; /* 表示中断发生了 */
  73. wake_up_interruptible(&button_waitq); /* 唤醒休眠的进程 */
  75. //发送信号SIGIO信号给fasync_struct 结构体所描述的PID，触发应用程序的SIGIO信号处理函数
  76. kill_fasync (&button_async, SIGIO, POLL_IN);
  78. return IRQ_RETVAL(IRQ_HANDLED);
  79. }
  81. static int fifth_drv_open(struct inode *inode, struct file *file)
  82. {
  83. /* GPG0，GPG3，GPG5，GPG6为中断引脚: EINT8,EINT11,EINT13,EINT14 */
  84. request_irq(IRQ_EINT8, buttons_irq, IRQT_BOTHEDGE, "K1", &pins_desc[ 0]);
  85. request_irq(IRQ_EINT11, buttons_irq, IRQT_BOTHEDGE, "K2", &pins_desc[ 1]);
  86. request_irq(IRQ_EINT13, buttons_irq, IRQT_BOTHEDGE, "K3", &pins_desc[ 2]);
  87. request_irq(IRQ_EINT14, buttons_irq, IRQT_BOTHEDGE, "K4", &pins_desc[ 3]);
  89. return 0;
  90. }
  92. ssize_t fifth_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
  93. {
  94. if (size != 1)
  95. return -EINVAL;
  97. /* 如果没有按键动作, 休眠 */
  98. wait_event_interruptible(button_waitq, ev_press);
  100. /* 如果有按键动作, 返回键值 */
  101. copy_to_user(buf, &key_val, 1);
  102. ev_press = 0;
  104. return 1;
  105. }
  108. int fifth_drv_close(struct inode *inode, struct file *file)
  109. {
  110. free_irq(IRQ_EINT8, &pins_desc[ 0]);
  111. free_irq(IRQ_EINT11, &pins_desc[ 1]);
  112. free_irq(IRQ_EINT13, &pins_desc[ 2]);
  113. free_irq(IRQ_EINT14, &pins_desc[ 3]);
  114. return 0;
  115. }
  117. static unsigned fifth_drv_poll(struct file *file, poll_table *wait)
  118. {
  119. unsigned int mask = 0;
  120. poll_wait(file, &button_waitq, wait); // 不会立即休眠
  122. if (ev_press)
  123. mask |= POLLIN | POLLRDNORM;
  125. return mask;
  126. }
  128. static int fifth_drv_fasync (int fd, struct file *filp, int on)
  129. {
  130. printk( "driver: fifth_drv_fasync\n");
  131. //初始化/释放 fasync_struct 结构体 (fasync_struct->fa_file->f_owner->pid)
  132. return fasync_helper (fd, filp, on, &button_async);
  133. }
  136. static struct file_operations sencod_drv_fops = {
  137. .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
  138. .open = fifth_drv_open,
  139. .read = fifth_drv_read,
  140. .release = fifth_drv_close,
  141. .poll = fifth_drv_poll,
  142. .fasync = fifth_drv_fasync,
  143. };
  146. int major;
  147. static int fifth_drv_init(void)
  148. {
  149. major = register_chrdev( 0, "fifth_drv", &sencod_drv_fops);
  151. fifthdrv_class = class_create(THIS_MODULE, "fifth_drv");
  153. fifthdrv_class_dev = class_device_create(fifthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */
  155. // gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
  156. // gpfdat = gpfcon + 1;
  158. return 0;
  159. }
  161. static void fifth_drv_exit(void)
  162. {
  163. unregister_chrdev(major, "fifth_drv");
  164. class_device_unregister(fifthdrv_class_dev);
  165. class_destroy(fifthdrv_class);
  166. // iounmap(gpfcon);
  167. return 0;
  168. }
  171. module_init(fifth_drv_init);
  173. module_exit(fifth_drv_exit);
  175. MODULE_LICENSE( "GPL");

  1. #include <sys/types.h>
  2. #include <sys/stat.h>
  3. #include <fcntl.h>
  4. #include <stdio.h>
  5. #include <poll.h>
  6. #include <signal.h>
  7. #include <sys/types.h>
  8. #include <unistd.h>
  9. #include <fcntl.h>
  12. /* fifthdrvtest
  13. */
  14. int fd;
  16. //信号处理函数
  17. void my_signal_fun(int signum)
  18. {
  19. unsigned char key_val;
  20. read(fd, &key_val, 1);
  21. printf( "key_val: 0x%x\n", key_val);
  22. }
  24. int main(int argc, char **argv)
  25. {
  26. unsigned char key_val;
  27. int ret;
  28. int Oflags;
  30. //在应用程序中捕捉SIGIO信号（由驱动程序发送）
  31. signal(SIGIO, my_signal_fun);
  33. fd = open( "/dev/buttons", O_RDWR);
  34. if (fd < 0)
  35. {
  36. printf( "can't open!\n");
  37. }
  39. //将当前进程PID设置为fd文件所对应驱动程序将要发送SIGIO,SIGUSR信号进程PID
  40. fcntl(fd, F_SETOWN, getpid());
  42. //获取fd的打开方式
  43. Oflags = fcntl(fd, F_GETFL);
  45. //将fd的打开方式设置为FASYNC --- 即 支持异步通知
  46. //该行代码执行会触发 驱动程序中 file_operations->fasync 函数 ------fasync函数调用fasync_helper初始化一个fasync_struct结构体，该结构体描述了将要发送信号的进程PID (fasync_struct->fa_file->f_owner->pid)
  47. fcntl(fd, F_SETFL, Oflags | FASYNC);
  50. while ( 1)
  51. {
  52. sleep( 1000);
  53. }
  55. return 0;
  56. }


驱动程序

  1. #include <linux/module.h>
  2. #include <linux/kernel.h>
  3. #include <linux/fs.h>
  4. #include <linux/init.h>
  5. #include <linux/delay.h>
  6. #include <linux/irq.h>
  7. #include <asm/uaccess.h>
  8. #include <asm/irq.h>
  9. #include <asm/io.h>
  10. #include <asm/arch/regs-gpio.h>
  11. #include <asm/hardware.h>
  12. #include <linux/poll.h>
  15. static struct class *fifthdrv_class;
  16. static struct class_device *fifthdrv_class_dev;
  18. //volatile unsigned long *gpfcon;
  19. //volatile unsigned long *gpfdat;
  21. static DECLARE_WAIT_QUEUE_HEAD(button_waitq);
  23. /* 中断事件标志, 中断服务程序将它置1，fifth_drv_read将它清0 */
  24. static volatile int ev_press = 0;
  26. static struct fasync_struct *button_async;
  29. struct pin_desc{
  30. unsigned int pin;
  31. unsigned int key_val;
  32. };
  35. /* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */
  36. /* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */
  37. static unsigned char key_val;
  39. /*
  40. * K1,K2,K3,K4对应GPG0，GPG3，GPG5，GPG6
  41. */
  43. struct pin_desc pins_desc[4] = {
  44. {S3C2410_GPG0, 0x01},
  45. {S3C2410_GPG3, 0x02},
  46. {S3C2410_GPG5, 0x03},
  47. {S3C2410_GPG6, 0x04},
  48. };
  51. /*
  52. * 确定按键值
  53. */
  54. static irqreturn_t buttons_irq(int irq, void *dev_id)
  55. {
  56. struct pin_desc * pindesc = (struct pin_desc *)dev_id;
  57. unsigned int pinval;
  59. pinval = s3c2410_gpio_getpin(pindesc->pin);
  61. if (pinval)
  62. {
  63. /* 松开 */
  64. key_val = 0x80 | pindesc->key_val;
  65. }
  66. else
  67. {
  68. /* 按下 */
  69. key_val = pindesc->key_val;
  70. }
  72. ev_press = 1; /* 表示中断发生了 */
  73. wake_up_interruptible(&button_waitq); /* 唤醒休眠的进程 */
  75. //发送信号SIGIO信号给fasync_struct 结构体所描述的PID，触发应用程序的SIGIO信号处理函数
  76. kill_fasync (&button_async, SIGIO, POLL_IN);
  78. return IRQ_RETVAL(IRQ_HANDLED);
  79. }
  81. static int fifth_drv_open(struct inode *inode, struct file *file)
  82. {
  83. /* GPG0，GPG3，GPG5，GPG6为中断引脚: EINT8,EINT11,EINT13,EINT14 */
  84. request_irq(IRQ_EINT8, buttons_irq, IRQT_BOTHEDGE, "K1", &pins_desc[ 0]);
  85. request_irq(IRQ_EINT11, buttons_irq, IRQT_BOTHEDGE, "K2", &pins_desc[ 1]);
  86. request_irq(IRQ_EINT13, buttons_irq, IRQT_BOTHEDGE, "K3", &pins_desc[ 2]);
  87. request_irq(IRQ_EINT14, buttons_irq, IRQT_BOTHEDGE, "K4", &pins_desc[ 3]);
  89. return 0;
  90. }
  92. ssize_t fifth_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
  93. {
  94. if (size != 1)
  95. return -EINVAL;
  97. /* 如果没有按键动作, 休眠 */
  98. wait_event_interruptible(button_waitq, ev_press);
  100. /* 如果有按键动作, 返回键值 */
  101. copy_to_user(buf, &key_val, 1);
  102. ev_press = 0;
  104. return 1;
  105. }
  108. int fifth_drv_close(struct inode *inode, struct file *file)
  109. {
  110. free_irq(IRQ_EINT8, &pins_desc[ 0]);
  111. free_irq(IRQ_EINT11, &pins_desc[ 1]);
  112. free_irq(IRQ_EINT13, &pins_desc[ 2]);
  113. free_irq(IRQ_EINT14, &pins_desc[ 3]);
  114. return 0;
  115. }
  117. static unsigned fifth_drv_poll(struct file *file, poll_table *wait)
  118. {
  119. unsigned int mask = 0;
  120. poll_wait(file, &button_waitq, wait); // 不会立即休眠
  122. if (ev_press)
  123. mask |= POLLIN | POLLRDNORM;
  125. return mask;
  126. }
  128. static int fifth_drv_fasync (int fd, struct file *filp, int on)
  129. {
  130. printk( "driver: fifth_drv_fasync\n");
  131. //初始化/释放 fasync_struct 结构体 (fasync_struct->fa_file->f_owner->pid)
  132. return fasync_helper (fd, filp, on, &button_async);
  133. }
  136. static struct file_operations sencod_drv_fops = {
  137. .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
  138. .open = fifth_drv_open,
  139. .read = fifth_drv_read,
  140. .release = fifth_drv_close,
  141. .poll = fifth_drv_poll,
  142. .fasync = fifth_drv_fasync,
  143. };
  146. int major;
  147. static int fifth_drv_init(void)
  148. {
  149. major = register_chrdev( 0, "fifth_drv", &sencod_drv_fops);
  151. fifthdrv_class = class_create(THIS_MODULE, "fifth_drv");
  153. fifthdrv_class_dev = class_device_create(fifthdrv_class, NULL, MKDEV(major, 0), NULL, "buttons"); /* /dev/buttons */
  155. // gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
  156. // gpfdat = gpfcon + 1;
  158. return 0;
  159. }
  161. static void fifth_drv_exit(void)
  162. {
  163. unregister_chrdev(major, "fifth_drv");
  164. class_device_unregister(fifthdrv_class_dev);
  165. class_destroy(fifthdrv_class);
  166. // iounmap(gpfcon);
  167. return 0;
  168. }
  171. module_init(fifth_drv_init);
  173. module_exit(fifth_drv_exit);
  175. MODULE_LICENSE( "GPL");

猜你喜欢

转载自blog.csdn.net/wlf_go/article/details/80924537
今日推荐
火速冲上 GitHub 热榜 —— 开源编程语言、框架哪有这么可爱？
北京人形机器人创新中心发布全球首个纯电驱拟人奔跑的全尺寸人形机器人“天工”
LFOSSA 源来如此公开课 | 掌握云原生未来：CNCF 认证全面攻略与备考秘籍
国产云输入法——仅华为无云端数据上传安全问题
开源日报 | 工业开源项目OGG 1.0；姐姐，你要和我一起配置火狐吗；苹果AI遥遥落后？Fedora 40
开放签电子签章：停止新增，优化体验，前进更进（五一假期前工作）
开源日报 | 中学生开源前端动画引擎；全球首个Llama3 8B中文版开源模型；联想电脑恐出局；Linus讽刺AI炒作
周排行
浏览器对同一域名进行请求的最大并发连接数
React Hook之自定义Hook
【转】MyBatis缓存机制
-Java-泛型
自动化测试常用脚本-发送邮件
LeetCode#859: Buddy Strings
java、Python处理字符串
第二篇の博客
Hadoop伪分布式环境安装
SQL Server进阶（十一）临时表、表变量
每日归档
更多
2024-04-27(56)
2024-04-26(39)
2024-04-25(22)
2024-04-24(36)
2024-04-23(26)
2024-04-22(39)
2024-04-21(0)
2024-04-20(6)
2024-04-19(5)
2024-04-18(0)

代码天地 © 2018 codetd.com

境外服务器   最新电视剧2022