s3c2410-adc.rar_s3c2410_s3c2410 adc

/* * s3c2410-adc.c * * S3C2410 ADC * exclusive with s3c2410-ts.c * * Author: SeonKon Choi <bushi@mizi.com> * Date : $Date: 2003/01/20 14:24:49 $ * * $Revision: 1.1.2.6 $ * 2004-6-14 add a device by threewater<threewater@up-tech.com> Fri Dec 03 2002 SeonKon Choi <bushi@mizi.com> - initial * * 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/config.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/irq.h> #include <linux/delay.h> #include <asm/hardware.h> #include <asm/semaphore.h> #include <asm/uaccess.h> #include "s3c2410-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 "s3c2410-adc" #define ADCRAW_MINOR 1 static int adcMajor = 0; typedef struct { struct semaphore lock; wait_queue_head_t wait; int channel; int prescale; }ADC_DEV; static ADC_DEV adcdev; #define START_ADC_AIN(ch, prescale) \ do{ \ ADCCON = PRESCALE_EN | PRSCVL(prescale) | ADC_INPUT((ch)) ; \ ADCCON |= ADC_START; \ }while(0) static void adcdone_int_handler(int irq, void *dev_id, struct pt_regs *reg) { wake_up(&adcdev.wait); } static ssize_t s3c2410_adc_write(struct file *file, const char *buffer, size_t count, loff_t * ppos) { int data; if(count!=sizeof(data)){ //error input data size DPRINTK("the size of input data must be %d\n", sizeof(data)); return 0; } copy_from_user(&data, buffer, count); adcdev.channel=ADC_WRITE_GETCH(data); adcdev.prescale=ADC_WRITE_GETPRE(data); DPRINTK("set adc channel=%d, prescale=0x%x\n", adcdev.channel, adcdev.prescale); return count; } static ssize_t s3c2410_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos) { int ret = 0; if (down_interruptible(&adcdev.lock)) return -ERESTARTSYS; START_ADC_AIN(adcdev.channel, adcdev.prescale); interruptible_sleep_on(&adcdev.wait); ret = ADCDAT0; ret &= 0x3ff; DPRINTK("AIN[%d] = 0x%04x, %d\n", adcdev.channel, ret, ADCCON & 0x80 ? 1:0); copy_to_user(buffer, (char *)&ret, sizeof(ret)); up(&adcdev.lock); return sizeof(ret); } static int s3c2410_adc_open(struct inode *inode, struct file *filp) { init_MUTEX(&adcdev.lock); init_waitqueue_head(&(adcdev.wait)); adcdev.channel=0; adcdev.prescale=0xff; MOD_INC_USE_COUNT; DPRINTK( "adc opened\n"); return 0; } static int s3c2410_adc_release(struct inode *inode, struct file *filp) { MOD_DEC_USE_COUNT; DPRINTK( "adc closed\n"); return 0; } static struct file_operations s3c2410_fops = { owner: THIS_MODULE, open: s3c2410_adc_open, read: s3c2410_adc_read, write: s3c2410_adc_write, release: s3c2410_adc_release, }; #ifdef CONFIG_DEVFS_FS static devfs_handle_t devfs_adc_dir, devfs_adcraw; #endif int __init s3c2410_adc_init(void) { int ret; /* normal ADC */ ADCTSC = 0; //XP_PST(NOP_MODE); ret = request_irq(IRQ_ADC_DONE, adcdone_int_handler, SA_INTERRUPT, DEVICE_NAME, NULL); if (ret) { return ret; } ret = register_chrdev(0, DEVICE_NAME, &s3c2410_fops); if (ret < 0) { printk(DEVICE_NAME " can't get major number\n"); return ret; } adcMajor=ret; #ifdef CONFIG_DEVFS_FS devfs_adc_dir = devfs_mk_dir(NULL, "adc", NULL); devfs_adcraw = devfs_register(devfs_adc_dir, "0raw", DEVFS_FL_DEFAULT, adcMajor, ADCRAW_MINOR, S_IFCHR | S_IRUSR | S_IWUSR, &s3c2410_fops, NULL); #endif printk (DEVICE_NAME"\tinitialized\n"); return 0; } module_init(s3c2410_adc_init); #ifdef MODULE void __exit s3c2410_adc_exit(void) { #ifdef CONFIG_DEVFS_FS devfs_unregister(devfs_adcraw); devfs_unregister(devfs_adc_dir); #endif unregister_chrdev(adcMajor, DEVICE_NAME); free_irq(IRQ_ADC_DONE, NULL); } module_exit(s3c2410_adc_exit); MODULE_LICENSE("GPL"); #endif