adc.rar_S3C2440 ADC_adc linux_linux adc examples_linux adc_s3c2

//ADC驱动程序： //10位转换，通道“0”最大转换频率2.5M,分频率预置为19,采用PCLK时钟50M #include <linux/kernel.h> #include <linux/config.h> #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/delay.h> #include <linux/devfs_fs_kernel.h> #include <asm/io.h> #include <asm/arch/hardware.h> #include <asm/arch-s3c2410/regs-adc.h> #define MAJOR_ID 109 #define DEV_NAME "adc" #define ADCCON 0x58000000 /*ADC控制寄存器地址*/ #define ADCDAT0 0x5800000c /*数据寄存器地址*/ static void *ADC_CON; /*定义一指针用作地址赋值用--虚拟地址映射*/ static void *ADC_DAT0; static int adc_open(struct inode * inode, struct file * file) { int ADC_MAX_FREQ=2500000; int PCLK=50000000; int ADC_PRSCVL,ADC_CMD; ADC_CON=ioremap(ADCCON,0x00000004); /*虚拟地址映射或者因为在宏里面地址链接断了要不然可以用(*(volitle unsigned *)S3C2410-ADCCON)*/ ADC_DAT0=ioremap(ADCDAT0,0x00000004); ADC_PRSCVL=(PCLK/ADC_MAX_FREQ)-1; ADC_CMD=((S3C2410_ADCCON_PRSCEN)|(S3C2410_ADCCON_PRSCVL(ADC_PRSCVL))|(S3C2410_ADCCON_SELMUX(0))|(S3C2410_ADCCON_STDBM)); writel(ADC_CMD,ADC_CON); mdelay(200); return 0; } static int adc_read(struct file * file, char __user * userbuf, size_t count, loff_t * off) { writel(0x01,ADC_CON); /*开始启动转换*/ if (readl(ADC_CON)&0x01); /*开始使能变为低电平?同时读取转换的数据,把数据读写到ADT1与DAT0中*/ if (readl(ADC_CON)&0x8000); /*AD转换结束?*/ *userbuf=readl(ADC_DAT0); return count; } static int adc_close(struct inode * inode, struct file * file) { writel(0x3cf4,ADC_CON); /*关ADC转换器*/ return 0; } static struct file_operations adc = { .open = adc_open, .read = adc_read, .release = adc_close, }; static int __init adc_init(void) { int result; result=register_chrdev(MAJOR_ID,DEV_NAME,&adc); if (result<0) {printk ("the drives registre is fail!!\n"); return result; } else {printk ("the drives registre is success!!\n"); devfs_mk_cdev(MKDEV(MAJOR_ID,0),S_IFCHR | S_IRUSR | S_IWUSR,"adc"); return result; } return 0; } static void __exit adc_exit(void) { unregister_chrdev(MAJOR_ID,DEV_NAME); devfs_remove(DEV_NAME); } module_init(adc_init); module_exit(adc_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("kang"); MODULE_DESCRIPTION("ADC");