mini2440 adc驱动--linux-3.10.59

/* linux/drivers/char/mini2440_adc.c *Copyright (c) 2013 Feng Guoqing * * mini2440 ADC Driver * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file COPYING in the main directory of this archive for * more details. **/#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 <mach/regs-clock.h> #include <plat/regs-timer.h> #include <plat/regs-adc.h> #include <mach/regs-gpio.h> #include <linux/cdev.h> #include <linux/miscdevice.h> #include "s3c24xx-adc.h" #undef DEBUG //#define DEBUG #ifdef DEBUG #define DPRINTK(x...) {printk(__FUNCTION__"(%d): ",__LINE__);printk(##x);} #else #define DPRINTK(x...) (void)(0) #endif #define DEVICE_NAME  "adc" static void __iomem *base_addr; typedef struct {     wait_queue_head_t wait;     int channel;     int prescale; }ADC_DEV; DEFINE_SEMAPHORE(ADC_LOCK); static int OwnADC = 0; static ADC_DEV adcdev; static volatile int ev_adc = 0; static int adc_data; static struct clk  *adc_clock; //ADC control #define ADCCON       (*(volatile unsigned long *)(base_addr + S3C2410_ADCCON))//ADC  touch  screen control#define ADCTSC (*(volatile unsigned long *)(base_addr + S3C2410_ADCTSC))//ADC  start  or  Interval Delay #define ADCDLY (*(volatile unsigned long *)(base_addr + S3C2410_ADCDLY))//ADC  conversion data 0#define ADCDAT0      (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT0))//ADC  conversion data 1#define ADCDAT1      (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT1))//Stylus Up/Down interrupt status #define ADCUPDN (*(volatile unsigned long *)(base_addr + 0x14))#define PRESCALE_DIS (0 << 14)#define PRESCALE_EN (1 << 14)#define PRSCVL(x) ((x) << 6)#define ADC_INPUT(x) ((x) << 3)#define ADC_START (1 << 0)#define ADC_ENDCVT (1 << 15)#define START_ADC_AIN(ch, prescale) \do{ \    ADCCON = PRESCALE_EN | PRSCVL(prescale) | ADC_INPUT((ch)) ; \    ADCCON |= ADC_START; \}while(0)static irqreturn_t adcdone_int_handler(int irq, void *dev_id){     if (OwnADC) {         adc_data = ADCDAT0 & 0x3ff;         ev_adc = 1;         wake_up_interruptible(&adcdev.wait);     }     return IRQ_HANDLED; } static ssize_t s3c2410_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos) {     char str[20];     int value;     size_t len;     if (down_trylock(&ADC_LOCK) == 0) {         OwnADC = 1;         START_ADC_AIN(adcdev.channel, adcdev.prescale);         wait_event_interruptible(adcdev.wait, ev_adc);        ev_adc = 0;         DPRINTK("AIN[%d] = 0x%04x, %d\n", adcdev.channel, adc_data, ADCCON & 0x80 ? 1:0);         value = adc_data;        OwnADC = 0;         up(&ADC_LOCK);     } else {         value = -1;     }        len = sprintf(str, "%d\n", value);     if (count >= len) {         int r = copy_to_user(buffer, str, len);         return r ? r : len;     } else {         return -EINVAL;     } } static int s3c2410_adc_open(struct inode *inode, struct file *filp) {     init_waitqueue_head(&(adcdev.wait));     adcdev.channel=0;     adcdev.prescale=0xff;     DPRINTK( "adc opened\n");     return 0; } static int s3c2410_adc_release(struct inode *inode, struct file *filp) {     DPRINTK( "adc closed\n");     return 0; }static struct file_operations dev_fops = {     owner: THIS_MODULE,     open: s3c2410_adc_open,     read:s3c2410_adc_read,     release: s3c2410_adc_release, };static struct miscdevice misc = {     .minor = MISC_DYNAMIC_MINOR,     .name = DEVICE_NAME,     .fops = &dev_fops, }; static int __init dev_init(void) {     int ret;     base_addr=ioremap(S3C2410_PA_ADC,0x20);     if (base_addr == NULL) {         printk(KERN_ERR "Failed to remap register block\n");         return -ENOMEM;     }         adc_clock = clk_get(NULL, "adc");    if (!adc_clock) {         printk(KERN_ERR "failed to get adc clock source\n");         return -ENOENT;     }         clk_enable(adc_clock);     /* normal ADC */     ADCTSC = 0;     ret = request_irq(IRQ_ADC, adcdone_int_handler, IRQF_SHARED, DEVICE_NAME, &adcdev);     if (ret) {         iounmap(base_addr);         return ret;     }        ret = misc_register(&misc);     printk (DEVICE_NAME"\tinitialized\n");     return ret; }static void __exit dev_exit(void) {     free_irq(IRQ_ADC, &adcdev);     iounmap(base_addr);     if (adc_clock) {         clk_disable(adc_clock);        clk_put(adc_clock);        adc_clock = NULL;    }     misc_deregister(&misc);} EXPORT_SYMBOL(ADC_LOCK);module_init(dev_init); module_exit(dev_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("FriendlyARM Inc.");

s3c24xx-adc.h

<pre name="code" class="plain">#ifndef _S3C2410_ADC_H_ #define _S3C2410_ADC_H_ #define ADC_WRITE(ch, prescale) ((ch)<<16|(prescale)) #define ADC_WRITE_GETCH(data) (((data)>>16)&0x7) #define ADC_WRITE_GETPRE(data) ((data)&0xff) #endif /* _S3C2410_ADC_H_ */