N32905 adc字符设备驱动

#include <linux/errno.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/input.h> #include <linux/init.h> #include <linux/serio.h> #include <linux/delay.h> #include <linux/clk.h> #include <linux/wait.h> #include <linux/sched.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/uaccess.h> #include <linux/cdev.h> #include <linux/miscdevice.h> #include <mach/hardware.h> #include <mach/irqs.h> #include <mach/w55fa93_reg.h> #include <linux/input.h> #include <linux/clk.h> #define DEVICE_NAME "adc" #define outp32(addr, value) writel(value, addr) #define inp32(addr) readl(addr) static void __iomem *base_addr; #define ADC_INPUT(x) ((x) << 9) #define SET_NORMAL_AIN2_WI do{\ outl( (ADC_CON_ADC_EN | ADC_CONV | ADC_INT | (2<<9)), \ REG_ADC_CON);\ }while(0) #define SET_NORMAL_AIN2_WI_WR \ while( (inl(REG_ADC_CON) & ADC_INT) != ADC_INT ) #define SET_NORMAL_AIN0_WI do{\ outl( (ADC_CON_ADC_EN | ADC_CONV | ADC_INT | (0<<9)), \ REG_ADC_CON);\ }while(0) #define SET_NORMAL_AIN0_WI_WR \ while( (inl(REG_ADC_CON) & ADC_INT) != ADC_INT ) static ssize_t w55fa93_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos) { unsigned int adc_data = -1; SET_NORMAL_AIN2_WI; SET_NORMAL_AIN2_WI_WR; adc_data = inl(REG_ADC_XDATA); // printk("adc_data=%d\n", adc_data); if (adc_data != -1) { copy_to_user(buffer, &adc_data, sizeof(adc_data)); } return 0; } static int w55fa93_adc_open(struct inode *inode, struct file *filp) { printk( "adc opened\n"); outp32(REG_APBIPRST, inp32(REG_APBIPRST) | ADCRST); outp32(REG_APBIPRST, inp32(REG_APBIPRST) & ~ADCRST); return 0; } static int w55fa93_adc_release(struct inode *inode, struct file *filp) { printk( "adc closed\n"); return 0; } static struct file_operations dev_fops = { owner: THIS_MODULE, open: w55fa93_adc_open, read: w55fa93_adc_read, release: w55fa93_adc_release, }; static struct miscdevice misc = { .minor = MISC_DYNAMIC_MINOR, .name = DEVICE_NAME, .fops = &dev_fops, }; static int __init dev_init(void) { int ret; struct clk *clk; base_addr=ioremap(W55FA93_PA_ADC, 0x20); if (base_addr == NULL) { printk(KERN_ERR "Failed to remap register block\n"); return -ENOMEM; } printk("base_addr:0x%lx\n", (unsigned long)base_addr); clk = clk_get(NULL, "ADC"); clk_enable(clk); ret = misc_register(&misc); printk (DEVICE_NAME"\tinitialized\n"); return ret; } static void __exit dev_exit(void) { struct clk *clk; clk = clk_get(NULL, "ADC"); clk_disable(clk); iounmap(base_addr); printk (DEVICE_NAME"\texit!\n"); misc_deregister(&misc); } module_init(dev_init); module_exit(dev_exit); MODULE_AUTHOR("zpzyf"); MODULE_DESCRIPTION("w55fa93 adc char driver"); MODULE_LICENSE("GPL");