adc.rar_adc linux2

#include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/errno.h> // error codes #include <linux/types.h> // size_t #include <linux/delay.h> // mdelay #include <linux/proc_fs.h> #include <asm/uaccess.h> // to copy to/from userspace #include <asm/hardware.h> #include <asm/arch-s3c2410/s3c2410.h> #include <asm-arm/arch-s3c2410/irqs.h> #include <linux/wait.h> #include <linux/signal.h> #include <linux/ioctl.h> #define adc_CTL_BASE io_p2v(0x58000000) //??? #define S3C2410_ADCCON (adc_CTL_BASE + 0x0) #define S3C2410_ADCDAT (adc_CTL_BASE + 0xC) #define PCLK 50700000 //??? #define ADC_FREQ 2500000 //??? #define START_ADC 0x0304 // the command of starting adc 数值任意 //#define MY_ADC_SIG 51 static int global; // recieve the value of adc //static int pid; // the pid of the user process //static int my_send_sig(void); // send signal to the user process struct unit { u32 *ADC_CON; u32 *ADC_DAT; }; static struct unit adc_unit = { .ADC_CON = (u32 *)S3C2410_ADCCON, .ADC_DAT = (u32 *)S3C2410_ADCDAT, }; //int send_sig(); // send signal to the user process /*static int my_send_sig(void) { siginfo_t info; struct task_struct * p; info.si_signo = MY_ADC_SIG; info.si_code = -1; info.si_int = 0x8; read_lock(&tasklist_lock); for_each_task(p) { if(p->pid == pid) { read_unlock(&tasklist_lock); goto find_ps; } } read_unlock(&tasklist_lock); printk("can not find process\n"); return -1; find_ps: send_sig_info(MY_ADC_SIG,&info,p); //printk("pid is : %d\n",pid); //printk("send adc-sig to user space!\n"); return 0; } */ static void adcdone_int_handler(int irq, void *dev_id, struct pt_regs *reg) { //printk("in adc int handler!\n"); global =( (int)*adc_unit.ADC_DAT & 0x3FF); //得到转换后的数据 //my_send_sig(); } ssize_t adc_open(struct inode * inode, struct file * file) { MOD_INC_USE_COUNT; file->private_data = &adc_unit; return 0; } ssize_t adc_release(struct inode * inode, struct file * file) { MOD_DEC_USE_COUNT; return 0; } ssize_t adc_read(struct file * file, char * buf, size_t count, loff_t * offset) { int ret; int temp; temp = global; ret = copy_to_user(buf, &temp, count); //把转换后的值送用户 if(ret!=0) { printk("The copy to user error!\n"); return -EFAULT; } return ret; } //adc_write()没用 ssize_t adc_write(struct file * file, const char * buf, size_t count, loff_t * offset) { int ret,temp; ret = copy_from_user(&temp,buf,count); if(ret!=0) { printk("The copy from user error!\n"); return -EFAULT; } //pid = temp; //printk("in adc-write, the pid is : %d\n",pid); return ret; } int adc_ioctl(struct inode * inode, struct file * filp,unsigned int cmd,unsigned long arg) { switch(cmd) { case START_ADC: *adc_unit.ADC_CON |= 0x1; break; //位0：置1，启动AD default: { printk("the ioctl error!\n"); break; } } return 0; } struct file_operations adc_Ctl_ops = { open: adc_open, read: adc_read, write: adc_write, ioctl: adc_ioctl, release: adc_release, }; static devfs_handle_t devfs_handle,devfs_adc_dir; static void __init init_hardware(struct unit *unit) { char preScaler = PCLK/ADC_FREQ - 1; //14: AD converter prescaler enable 1(enable) //6-13: AD converter prescaler value 取值1－255 //3-5: analog input channel select 010: AIN2 *unit->ADC_CON = (1<<14) | (preScaler<<6) | (1<<4); //有问题 ?? *unit->ADC_DAT = 0x0; } static int __init init_adc() { int res; printk("This is my Adc driver!\n"); devfs_register_chrdev(224, "adc", &adc_Ctl_ops); devfs_adc_dir = devfs_mk_dir(NULL, "adc", NULL); devfs_handle = devfs_register(devfs_adc_dir, "0", DEVFS_FL_DEFAULT, 224, 0,S_IFCHR | S_IRUSR | S_IWUSR,&adc_Ctl_ops, NULL); res = request_irq(IRQ_ADC_DONE, adcdone_int_handler, SA_INTERRUPT , "adc", NULL); if(res < 0) printk("The IRQ Wrong!\n"); init_hardware(&adc_unit); return res; } static void __exit clean_adc() { devfs_unregister_chrdev(224,"adc"); devfs_unregister(devfs_handle); devfs_unregister(devfs_adc_dir); free_irq(IRQ_ADC_DONE,NULL); } module_init(init_adc); module_exit(clean_adc); MODULE_DESCRIPTION("EduKitIII-2410 adc driver"); MODULE_AUTHOR("ssdut"); MODULE_LICENSE("GPL");