#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 <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 "s3c2440_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;
DECLARE_MUTEX(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;
#define ADCCON (*(volatile unsigned long *)(base_addr + S3C2410_ADCCON)) //ADC control
#define ADCTSC (*(volatile unsigned long *)(base_addr + S3C2410_ADCTSC)) //ADC touch screen control
#define ADCDLY (*(volatile unsigned long *)(base_addr + S3C2410_ADCDLY)) //ADC start or Interval Delay
#define ADCDAT0 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT0)) //ADC conversion data 0
#define ADCDAT1 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT1)) //ADC conversion data 1
#define ADCUPDN (*(volatile unsigned long *)(base_addr + 0x14)) //Stylus Up/Down interrupt status
#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; sprintf(str,"%5d", adc_data); copy_to_user(buffer, (char *)&adc_data, sizeof(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");
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