1、驱动源代码
#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/platform_device.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/arch/regs-adc.h>
#include <asm/arch/regs-gpio.h>
/* For ts.dev.id.version */
#define S3C2410TSVERSION 0x0101
#define WAIT4INT(x) (((x)<<8) | \
S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
S3C2410_ADCTSC_XY_PST(3)) //设置等待中断模式
#define AUTOPST (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST(0)) //设置X,Y自动转换
static char *s3c2410ts_name = "s3c2410 TouchScreen";
static struct input_dev *dev;
static long xp;
static long yp;
static int count;
static int OwnADC = 0;
static void __iomem *base_addr;
static inline void s3c2410_ts_connect(void) //配置管脚的功能
{
s3c2410_gpio_cfgpin(S3C2410_GPG12, S3C2410_GPG12_XMON);
s3c2410_gpio_cfgpin(S3C2410_GPG13, S3C2410_GPG13_nXPON);
s3c2410_gpio_cfgpin(S3C2410_GPG14, S3C2410_GPG14_YMON);
s3c2410_gpio_cfgpin(S3C2410_GPG15, S3C2410_GPG15_nYPON);
}
static void touch_timer_fire(unsigned long data)
{
unsigned long data0;
unsigned long data1;
int updown;
data0 = ioread32(base_addr+S3C2410_ADCDAT0);
data1 = ioread32(base_addr+S3C2410_ADCDAT1);
updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));
if (updown) {
if (count != 0) {/*转换四次后进行事件汇报*/
long tmp;
tmp = xp;
xp = yp;
yp = tmp;
/* 求平均值 */
xp >>= 2;
yp >>= 2;
/* 报告x、y的绝对坐标值 */
input_report_abs(dev, ABS_X, xp);
input_report_abs(dev, ABS_Y, yp);
/* 报告按键事件,键值为1(代表触摸屏对应的按键被按下) */
input_report_key(dev, BTN_TOUCH, 1);
/* 报告触摸屏的状态,1表明触摸屏被按下 */
input_report_abs(dev, ABS_PRESSURE, 1);
/* 同步 */
input_sync(dev);
}
xp = 0;
yp = 0;
count = 0;
/*自动X/Y轴坐标转换模式的设置,自动地进行X轴和Y轴的转换操作,随后产生相应的INT_ADC中断通知转换完毕*/
iowrite32(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);
/*如果还没有启动ADC或者ADC转换四次完毕后则启动ADC*/
iowrite32(ioread32(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);
} else {
count = 0;
/* 如果触摸笔是弹起状态,则提出报告,并让触摸屏处于等待触摸的阶段 */
/* 报告按键事件,键值为0(代表触摸屏对应的按键被释放) */
input_report_key(dev, BTN_TOUCH, 0);
/* 报告触摸屏的状态,0表明触摸屏未被按下 */
input_report_abs(dev, ABS_PRESSURE, 0);
/*同步 */
input_sync(dev);
/* 设置触摸屏为等待中断模式,等待触摸笔按下 */
iowrite32(WAIT4INT(0), base_addr+S3C2410_ADCTSC);
if (OwnADC) {
OwnADC = 0;
}
}
}
static struct timer_list touch_timer =
TIMER_INITIALIZER(touch_timer_fire, 0, 0);
/*当触摸按下时,产生INT_TC中断,会进入到stylus_updown中断处理函数*/
static irqreturn_t stylus_updown(int irq, void *dev_id)
{
unsigned long data0;
unsigned long data1;
int updown;
OwnADC = 1;
data0 = ioread32(base_addr+S3C2410_ADCDAT0);//读数据寄存器
data1 = ioread32(base_addr+S3C2410_ADCDAT1);
updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));
/*判断目前触摸笔的状态
updown = 1 触摸笔按下;
updown = 0 触摸笔弹起;
*/
if (updown) {
touch_timer_fire(0); /*这是一个定时器函数,当然在这里只是作为普通函数调用,用来启动ADC*/
} else {
OwnADC = 0;
}
return IRQ_HANDLED;
}
/*INT_ADC 中断处理函数*/
static irqreturn_t stylus_action(int irq, void *dev_id)
{
unsigned long data0;
unsigned long data1;
if (OwnADC) {
data0 = ioread32(base_addr+S3C2410_ADCDAT0); //读取转换的数据
data1 = ioread32(base_addr+S3C2410_ADCDAT1);
xp += data0 & S3C2410_ADCDAT0_XPDATA_MASK;
yp += data1 & S3C2410_ADCDAT1_YPDATA_MASK;
count++;
if (count < (1<<2)) { /*如果小于四次重新启动ADC转换*/
iowrite32(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);
iowrite32(ioread32(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);
} else {
/*如果超过四次,启动1个时间滴答的定时器,停止ADC,然后调用定时器处理函数touch_timer_fire进行数据上报*/
mod_timer(&touch_timer, jiffies+1); //启动1个时间滴答的定时器
iowrite32(WAIT4INT(1), base_addr+S3C2410_ADCTSC);//等待按下
}
}
return IRQ_HANDLED;
}
static struct clk *adc_clock;
static int __init s3c2410ts_init(void)
{
struct input_dev *input_dev; //输入设备的指针
/*获取时钟,触摸屏是挂载在APB BUS上的外围设备,需要时钟控制,见数据手册第7章*/
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); //使能触摸屏时钟
/*I/O内存是不能直接进行访问的,必须对其进行映射 */
base_addr=ioremap(S3C2410_PA_ADC,0x20);//映射:把物理地址映射为虚拟地址
if (base_addr == NULL) {
printk(KERN_ERR "Failed to remap register block\n");
return -ENOMEM;
}
/* Configure GPIOs */
s3c2410_ts_connect(); /*GPIO 设置*/
/*使能预分频和设置分频系数*/
iowrite32(S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(0xFF),\
base_addr+S3C2410_ADCCON);
/*设置ADC延时,在等待中断模式下表示产生INT_TC的间隔时间,ADC转换周期等待定时器*/
iowrite32(0xffff, base_addr+S3C2410_ADCDLY);
/*ADCTSC = 0xd3 ,将触摸屏置为等待中断模式,等待触摸屏被按下产生INT_TC中断*/
iowrite32(WAIT4INT(0), base_addr+S3C2410_ADCTSC);
/* 以下配置2.6内核划分出来的输入设备 */
/* Initialise input stuff */
input_dev = input_allocate_device();
if (!input_dev) {
printk(KERN_ERR "Unable to allocate the input device !!\n");
return -ENOMEM;
}
dev = input_dev;
/*
evbit字段用来定义该输入设备可以支持的(产生和响应)的事件的类型,
触摸屏设置为支持同步(EN_SYN)、按键(EN_KEY)、绝对坐标(EV_ABS)事件
*/
dev->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
/* 设置所支持的按键(键值),触摸屏可以看成只有一个按键的设备 */
dev->keybit[BITS_TO_LONGS(BTN_TOUCH)] = BIT(BTN_TOUCH);
/* 设置绝对坐标x的最小最大值(0-0x3FF) */
input_set_abs_params(dev, ABS_X, 0, 0x3FF, 0, 0);
/* 设置绝对坐标y的最小最大值(0-0x3FF) */
input_set_abs_params(dev, ABS_Y, 0, 0x3FF, 0, 0);
input_set_abs_params(dev, ABS_PRESSURE, 0, 1, 0, 0);
dev->name = s3c2410ts_name;
dev->id.bustype = BUS_RS232;
dev->id.vendor = 0xDEAD;
dev->id.product = 0xBEEF;
dev->id.version = S3C2410TSVERSION;
/*INT_TC, INT_ADC中断注册,问题:两种中断的产生时机?哪种中断会先产生?*/
/* Get irqs */
if (request_irq(IRQ_ADC, stylus_action, IRQF_SHARED|IRQF_SAMPLE_RANDOM,
"s3c2410_action", dev)) {
printk(KERN_ERR "s3c2410_ts.c: Could not allocate ts IRQ_ADC !\n");
iounmap(base_addr);
return -EIO;
}
if (request_irq(IRQ_TC, stylus_updown, IRQF_SAMPLE_RANDOM,
"s3c2410_action", dev)) {
printk(KERN_ERR "s3c2410_ts.c: Could not allocate ts IRQ_TC !\n");
iounmap(base_addr);
return -EIO;
}
printk(KERN_INFO "%s successfully loaded\n", s3c2410ts_name);
/* All went ok, so register to the input system */
/*注册输入设备*/
input_register_device(dev);
return 0;
}
static void __exit s3c2410ts_exit(void)
{
disable_irq(IRQ_ADC); //禁止中断
disable_irq(IRQ_TC);
free_irq(IRQ_TC,dev); //注销中断
free_irq(IRQ_ADC,dev);
if (adc_clock) {
clk_disable(adc_clock);
clk_put(adc_clock); //关闭触摸屏的时钟
adc_clock = NULL;
}
input_unregister_device(dev);//注销输入设备
iounmap(base_addr); //解除映射
}
module_init(s3c2410ts_init);
module_exit(s3c2410ts_exit);
2、应用程序
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <errno.h>
#include <linux/input.h>
int main(void)
{
int ts_fd;
int ts_value,i=0,count;
struct input_event ev_ts;
ts_fd = open("/dev/event1", O_RDWR);
if (ts_fd < 0) {
perror("open device ts");
exit(1);
}
for (;;) {
count = read(ts_fd,&ev_ts,sizeof(struct input_event));
for(i=0; i<(int)count/sizeof(struct input_event); i++)
if(EV_ABS==ev_ts.type)
{ if(ABS_X == ev_ts.code)
printf(" x = %d\n", ev_ts.value);
if(ABS_Y == ev_ts.code)
printf(" y = %d\n", ev_ts.value);
}
}
close(ts_fd);
return 0;
}