2018年10月12日 | Tiny210触摸屏之触摸屏控制器驱动

tiny_ts.c驱动源码：

#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/plat-s3c24xx/ts.h"

#include "asm/arch/regs-adc.h"

#include "asm/arch/regs-gpio.h"

#define MHZ (1000*1000)

#define PRINT_MHZ(m)             ((m) / MHZ), ((m / 1000) % 1000)

struct tiny_ts_regs {

    unsigned long tsadccon1;

    unsigned long tscon1;

    unsigned long tsdly1;

    unsigned long tsdatx1;

    unsigned long tsdaty1;

    unsigned long tspenstat1;

    unsigned long clrintadc1;

    unsigned long reserved;

    unsigned long clrintpen1;

};

static struct input_dev *tiny_ts_dev;

static volatile struct tiny_ts_regs *tiny_ts_regs;

static unsigned long *tsadccon0;

static struct timer_list ts_timer;

static void enter_wait_pen_down_mode(void)

{

    tiny_ts_regs->tscon1 = 0xd3;

}

static void enter_wait_pen_up_mode(void)

{

    tiny_ts_regs->tscon1 = 0x1d3;

}

static void enter_measure_xy_mode(void)

{

    tiny_ts_regs->tscon1 = (1<<3)|(1<<2);

}

static void start_adc(void)

{

    tiny_ts_regs->tsadccon1 |= (1<<0);

}

static int tiny_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 tiny_ts_timer_function(unsigned long data)

{

    if (tiny_ts_regs->tsdatx1 & (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();

    }

}

static irqreturn_t pen_down_up_irq(int irq, void *dev_id)

{

    if (tiny_ts_regs->tsdatx1 & (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 = tiny_ts_regs->tsdatx1;

    adcdat1 = tiny_ts_regs->tsdaty1;

    if (tiny_ts_regs->tsdatx1 & (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 (tiny_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);

                input_sync(s3c_ts_dev);

            }

            cnt = 0;

            enter_wait_pen_up_mode();

            // 启动定时器处理长按/滑动的情况 

            mod_timer(&ts_timer, jiffies + HZ/100);

        }

        else

        {

            enter_measure_xy_mode();

            start_adc();

        }        

    }

    return IRQ_HANDLED;

}

static int s3c_ts_init(void)

{

    struct clk* clk;

    // 1. 分配一个input_dev结构体 

    tiny_ts_dev = input_allocate_device();

    // 2. 设置 

    // 2.1 能产生哪类事件 

    set_bit(EV_KEY, tiny_ts_dev->evbit);

    set_bit(EV_ABS, tiny_ts_dev->evbit);

    // 2.2 能产生这类事件里的哪些事件 

    set_bit(BTN_TOUCH, tiny_ts_dev->keybit);

    input_set_abs_params(tiny_ts_dev, ABS_X, 0, 0x3FF, 0, 0);

    input_set_abs_params(tiny_ts_dev, ABS_Y, 0, 0x3FF, 0, 0);

    input_set_abs_params(tiny_ts_dev, ABS_PRESSURE, 0, 1, 0, 0);

    // 3. 注册 

    input_register_device(tiny_ts_dev);

    // 4. 硬件相关的操作 

    // 4.1 使能时钟(CLKCON[15]) 

    clk = clk_get(NULL, "adc");

    if (!clk || IS_ERR(clk)) {

        printk(KERN_INFO "failed to get adc clock source\n");

    }

    clk_enable(clk);

    printk("Tiny_TS clock got enabled :: %ld.ld Mhz\n", PRINT_MHZ(clk_get_rate(tiny_clk)));

    // 4.2 设置S3C2440的ADC/TS寄存器 

    tsadccon0 =  ioremap(0xE1700000, 4);

    tiny_ts_regs = ioremap(0xE1701000, sizeof(struct tiny_ts_regs));

    // s5pv210有触摸屏接口0，1

    // Tiny210开发板向外提供接口1

    // 所以这里选择接口1

    tsadccon0 |= 1<<17;

    // bit[14]  : 1-A/D converter prescaler enable

    // bit[13:6]: A/D converter prescaler value,

    //            65, ADCCLK=PCLKP/(65+1)=66.7MHz/(65+1)=1MHz

    // bit[2]: 默认为1，即Standby mode，我们要设置为0，正常模式

    // bit[0]: A/D conversion starts by enable. 先设为0

    tiny_ts_regs->tsadccon1 &= ~(1<<2);

    tiny_ts_regs->tsadccon1 |= (1<<14)|(65<<6);

    request_irq(IRQ_TC, pen_down_up_irq, IRQF_SAMPLE_RANDOM, "ts_pen", NULL);

    request_irq(IRQ_ADC, adc_irq, IRQF_SAMPLE_RANDOM, "adc", NULL);

    // 优化措施1: 

    // 设置ADCDLY为最大值, 这使得电压稳定后再发出IRQ_TC中断

    tiny_ts_regs->tsdaty1 = 0xffff;

    // 优化措施5: 使用定时器处理长按,滑动的情况 

    init_timer(&ts_timer);

    ts_timer.function = tiny_ts_timer_function;

    add_timer(&ts_timer);

    enter_wait_pen_down_mode();

    return 0;

}

static void s3c_ts_exit(void)

{

    free_irq(IRQ_TC, NULL);

    free_irq(IRQ_ADC, NULL);

    iounmap(tiny_ts_regs);

    iounmap(tsadccon0);

    input_unregister_device(tiny_ts_dev);

    input_free_device(tiny_ts_dev);

    del_timer(&ts_timer);

}

module_init(s3c_ts_init);

module_exit(s3c_ts_exit);

MODULE_LICENSE("GPL");

===================================================================

测试以及tslib-1.4.tar.gz安装编译方法参考：“触摸屏驱动程序（输入子系统）”