#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/plat-s3c24xx/ts.h"
#include"asm/arch/regs-adc.h"
#include"asm/arch/regs-gpio.h"
struct s3c_ts_regs {
unsigned long adccon;
unsigned long adctsc;
unsigned long adcdly;
unsigned long adcdat0;
unsigned long adcdat1;
unsigned long adcupdn;
};
static struct input_dev *s3c_ts_dev;
static volatile struct s3c_ts_regs *s3c_ts_regs;
static struct timer_list ts_timer;
//等到触控笔按下模式
static void enter_wait_pen_down_mode(void)
{
s3c_ts_regs->adctsc = 0xd3;
}
//等到触控笔松开模式
static void enter_wait_pen_up_mode(void)
{
s3c_ts_regs->adctsc = 0x1d3;
}
//进入X/Y方向ADC同时转换模式
static void enter_measure_xy_mode(void)
{
s3c_ts_regs->adctsc = (1<3)|(1<2);
}
//启动ADC转换
static void start_adc(void)
{
s3c_ts_regs->adccon |= (1<0);
}
static int s3c_filter_ts(int x[], int y[])
{
#define ERR_LIMIT 10
int avr_x, avr_y;
int det_x, det_y;
avr_x = (x[0] + x[1])/2;
avr_y = (y[0] + y[1])/2;
det_x = (x[2] > avr_x) ? (x[2] - avr_x) : (avr_x - x[2]);
det_y = (y[2] > avr_y) ? (y[2] - avr_y) : (avr_y - y[2]);
if ((det_x > ERR_LIMIT) || (det_y > ERR_LIMIT))
return 0;
avr_x = (x[1] + x[2])/2;
avr_y = (y[1] + y[2])/2;
det_x = (x[3] > avr_x) ? (x[3] - avr_x) : (avr_x - x[3]);
det_y = (y[3] > avr_y) ? (y[3] - avr_y) : (avr_y - y[3]);
if ((det_x > ERR_LIMIT) || (det_y > ERR_LIMIT))
return 0;
return 1;
}
static void s3c_ts_timer_function(unsigned long data)
{
if (s3c_ts_regs->adcdat0 & (1<15))
{
// 已经松开
input_report_abs(s3c_ts_dev, ABS_PRESSURE, 0);
input_report_key(s3c_ts_dev, BTN_TOUCH, 0);
input_sync(s3c_ts_dev);
enter_wait_pen_down_mode();
}
else
{
// 测量X/Y坐标
enter_measure_xy_mode();
start_adc();
}
}
//触控笔按下、抬起中断服务函数
static irqreturn_t pen_down_up_irq(int irq, void *dev_id)
{
if (s3c_ts_regs->adcdat0 & (1<15))
{
//printk("pen up\n");
input_report_abs(s3c_ts_dev, ABS_PRESSURE, 0);
input_report_key(s3c_ts_dev, BTN_TOUCH, 0);
input_sync(s3c_ts_dev);
enter_wait_pen_down_mode();
}
else
{
//printk("pen down\n");
//enter_wait_pen_up_mode();
enter_measure_xy_mode();
start_adc();
}
return IRQ_HANDLED;
}
static irqreturn_t adc_irq(int irq, void *dev_id)
{
static int cnt = 0;
static int x[4], y[4];
int adcdat0, adcdat1;
// 优化措施2: 如果ADC完成时, 发现触摸笔已经松开, 则丢弃此次结果
adcdat0 = s3c_ts_regs->adcdat0;
adcdat1 = s3c_ts_regs->adcdat1;
if (s3c_ts_regs->adcdat0 & (1<15))
{
// 已经松开
cnt = 0;
input_report_abs(s3c_ts_dev, ABS_PRESSURE, 0);
input_report_key(s3c_ts_dev, BTN_TOUCH, 0);
input_sync(s3c_ts_dev);
enter_wait_pen_down_mode();
}
else
{
// printk("adc_irq cnt = %d, x = %d, y = %d\n", ++cnt, adcdat0 & 0x3ff, adcdat1 & 0x3ff);
// 优化措施3: 多次测量求平均值
x[cnt] = adcdat0 & 0x3ff;
y[cnt] = adcdat1 & 0x3ff;
++cnt;
if (cnt == 4)
{
// 优化措施4: 软件过滤
if (s3c_filter_ts(x, y))
{
//printk("x = %d, y = %d\n", (x[0]+x[1]+x[2]+x[3])/4, (y[0]+y[1]+y[2]+y[3])/4);
input_report_abs(s3c_ts_dev, ABS_X, (x[0]+x[1]+x[2]+x[3])/4);
input_report_abs(s3c_ts_dev, ABS_Y, (y[0]+y[1]+y[2]+y[3])/4);
input_report_abs(s3c_ts_dev, ABS_PRESSURE, 1);
input_report_key(s3c_ts_dev, BTN_TOUCH, 1);
