gslx680.c触摸屏驱动

转：http://blog.csdn.net/zgkxzx/article/details/56980769

前言

gslx680电容触摸屏是一种目前Android嵌入式设备中比较常用的触摸屏类型。这里我们以Exynos4412为Android bsp平台，移植一款gslx680电容触摸屏。
关于电容触摸屏的原理，这里不进行讲解，不明白的，可以参照一下博客：http://blog.csdn.net/xubin341719/article/details/7820492
这里只从实际工程出发，讲解移植过程。谢谢~~

一、具体操作配置

1.添加GSLX68X到内核的Kconfig配置

路径：xxx/kernel/drivers/input/touchscreen/Kconfig

2.编写Makefile文件

路径：xxx/kernel/drivers/input/touchscreen/Makefile

3.在触摸屏驱动目录xxx/kernel/drivers/input/touchscreen/文件夹下，添加一下文件：

gslx680.c
gslx680.h
gsl_point_id
查看附件

注意：gsl_point_id是一个Linux库文件

4.因为TP采用的是I2C总线驱动，还要在linux/arch/arm/mach-exynos/mach-smdk4x12.c文件中添加

这里的IIC地址一定要与程序上面一致，并且和设备的吻合

二、程序分析

1.定义地址和参数

#define GSLX680_I2C_NAME "gslX680"        //IIC的设备名#define GSLX680_I2C_ADDR 0x40             //IIC 设备的地址#define IRQ_PORT        IRQ_EINT(7)     //TP的中断引脚#define GSL_DATA_REG    0x80            //IIC 设备具体功能寄存器的地址 这个是数据寄存器#define GSL_STATUS_REG  0xe0            //状态寄存器#define GSL_PAGE_REG    0xf0#define PRESS_MAX 255            //手指按下的最大值#define MAX_FINGERS 10             //支持的最大手指数#define MAX_CONTACTS 10             //支持的最大关联#define DMA_TRANS_LEN   0x20           //DMA传输的最大长度
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2.设备的驱动初始化函数

首先，在加载驱动后，Linux系统通过module_init(gsl_ts_init);进行设备的初始化

static int __init gsl_ts_init(void){    int ret;    if(strcasecmp(tp_name, "gslx680") == 0)    {        printk("Initial gslx680 Touch Driver\n");    }    else    {        return 0;    }    print_info("==gsl_ts_init==\n");    ret = i2c_add_driver(&gsl_ts_driver);    print_info("ret=%d\n",ret);    return ret;}
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主要是通过i2c_add_driver(&gsl_ts_driver)将

static struct i2c_driver gsl_ts_driver = {    .driver = {    .name = GSLX680_I2C_NAME,    .owner = THIS_MODULE,},#ifndef CONFIG_HAS_EARLYSUSPEND    .suspend    = gsl_ts_suspend,    .resume = gsl_ts_resume,#endif    .probe  = gsl_ts_probe,    .remove = __devexit_p(gsl_ts_remove),    .id_table   = gsl_ts_id,};
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挂载到IIC总线

3.设备的探针函数

设备的探测函数，退出函数、设备的ID等等都注册上去。
在设备工作时，首先是探测函数

static int __devinit gsl_ts_probe(struct i2c_client *client,                                  const struct i2c_device_id *id){    struct gsl_ts *ts;    int rc;    print_info("GSLX680 Enter %s\n", __func__);    if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {        dev_err(&client->dev, "I2C functionality not supported\n");        return -ENODEV;    }    ts = kzalloc(sizeof(*ts), GFP_KERNEL);    if (!ts)        return -ENOMEM;    print_info("==kzalloc success=\n");    ts->client = client;    i2c_set_clientdata(client, ts);    ts->device_id = id->driver_data;    rc = gslX680_ts_init(client, ts); //初始化gls1680    if (rc < 0) {        dev_err(&client->dev, "GSLX680 init failed\n");        goto error_mutex_destroy;    }    gsl_client = client;    gslX680_init();    /初始化gls1680相关的IO端口    init_chip(ts->client);    check_mem_data(ts->client);    rc= request_irq(client->irq, gsl_ts_irq, IRQF_TRIGGER_RISING, client->name, ts); //中断请求 ，注册终端，上升沿触发 gsl_ts_irq 回调函数    if (rc < 0) {        print_info( "gsl_probe: request irq failed\n");        goto error_req_irq_fail;    }    /* create debug attribute */    //rc = device_create_file(&ts->input->dev, &dev_attr_debug_enable);#ifdef CONFIG_HAS_EARLYSUSPEND    ts->early_suspend.level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN + 1;    //ts->early_suspend.level = EARLY_SUSPEND_LEVEL_DISABLE_FB + 1;    ts->early_suspend.suspend = gsl_ts_early_suspend;    ts->early_suspend.resume = gsl_ts_late_resume;    register_early_suspend(&ts->early_suspend);#endif#ifdef GSL_MONITOR    print_info( "gsl_ts_probe () : queue gsl_monitor_workqueue\n");    INIT_DELAYED_WORK(&gsl_monitor_work, gsl_monitor_worker);    gsl_monitor_workqueue = create_singlethread_workqueue("gsl_monitor_workqueue");    queue_delayed_work(gsl_monitor_workqueue, &gsl_monitor_work, 1000);#endif    print_info("[GSLX680] End %s\n", __func__);    return 0;    //exit_set_irq_mode:error_req_irq_fail:    free_irq(ts->irq, ts);error_mutex_destroy:    input_free_device(ts->input);    kfree(ts);    return rc;}
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4.设备初始化

static int gslX680_ts_init(struct i2c_client *client, struct gsl_ts *ts){    struct input_dev *input_device;    int i, rc = 0;    printk("[GSLX680] Enter %s\n", __func__);    ts->dd = &devices[ts->device_id];    if (ts->device_id == 0) {        ts->dd->data_size = MAX_FINGERS * ts->dd->touch_bytes + ts->dd->touch_meta_data;        ts->dd->touch_index = 0;    }    printk("ts->dd->data_size is %d\n", ts->dd->data_size);    ts->touch_data = kzalloc(ts->dd->data_size, GFP_KERNEL);    if (!ts->touch_data) {        pr_err("%s: Unable to allocate memory\n", __func__);        return -ENOMEM;    }    input_device = input_allocate_device(); //申请输入子系统设备    if (!input_device) {        rc = -ENOMEM;        goto error_alloc_dev;    }    ts->input = input_device;    input_device->name = GSLX680_I2C_NAME;    input_device->id.bustype = BUS_I2C;    input_device->dev.parent = &client->dev;    input_set_drvdata(input_device, ts);    /*set_bit()告诉input输入子系统支持哪些事件，哪些按键    */    set_bit(ABS_MT_POSITION_X, input_device->absbit);//设置接触面的中心点X坐标    set_bit(ABS_MT_POSITION_Y, input_device->absbit);//设置接触面的中心点Y坐标    set_bit(ABS_MT_TOUCH_MAJOR, input_device->absbit);//设置触摸方向    set_bit(ABS_MT_WIDTH_MAJOR, input_device->absbit);//设置手指触摸接触面积大小    set_bit(ABS_PRESSURE, input_device->absbit);//设置压力    set_bit(BTN_TOUCH, input_device->keybit);//按键触摸    set_bit(EV_ABS, input_device->evbit);//绝对位移    set_bit(EV_KEY, input_device->evbit);//按键类型    set_bit(EV_SYN,input_device->evbit);//同步    __set_bit(INPUT_PROP_DIRECT, input_device->propbit);    input_mt_init_slots(input_device, (MAX_CONTACTS + 1));//设置子系统的参数上报    input_set_abs_params(input_device,ABS_MT_POSITION_X, 0, SCREEN_MAX_X, 0, 0);    input_set_abs_params(input_device,ABS_MT_POSITION_Y, 0, SCREEN_MAX_Y, 0, 0);    input_set_abs_params(input_device,ABS_MT_TOUCH_MAJOR, 0, PRESS_MAX, 0, 0);    input_set_abs_params(input_device,ABS_MT_WIDTH_MAJOR, 0, 200, 0, 0);    input_set_abs_params(input_device, ABS_MT_TRACKING_ID, 0, 5, 0, 0);    input_set_abs_params(input_device,ABS_PRESSURE, 0, PRESS_MAX, 0 , 0);    input_set_abs_params(input_device, ABS_MT_PRESSURE, 0, PRESS_MAX, 0, 0);#ifdef HAVE_TOUCH_KEY    input_device->evbit[0] = BIT_MASK(EV_KEY);//input_device->evbit[0] = BIT_MASK(EV_SYN) | BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);    for (i = 0; i < MAX_KEY_NUM; i++)        set_bit(key_array[i], input_device->keybit);#endif//中断设置    client->irq = IRQ_PORT;    ts->irq = client->irq;//创建单线程的工作队列    ts->wq = create_singlethread_workqueue("kworkqueue_ts");    if (!ts->wq) {        dev_err(&client->dev, "Could not create workqueue\n");        goto error_wq_create;    }//工作队列的挂起    flush_workqueue(ts->wq);//初始化工作队列，对应的处理函数为gslX680_ts_worker    INIT_WORK(&ts->work, gslX680_ts_worker);//注册输入设备子系统    rc = input_register_device(input_device);    if (rc)        goto error_unreg_device;    return 0;error_unreg_device:    destroy_workqueue(ts->wq);error_wq_create:    input_free_device(input_device);error_alloc_dev:    kfree(ts->touch_data);    return rc;}
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5.IO的初始化

static int gslX680_init(void){    /* shutdown pin */    gpio_request_one(EXYNOS4_GPX0(6), GPIOF_OUT_INIT_HIGH, "GPX0");    s3c_gpio_setpull(EXYNOS4_GPX0(6),S3C_GPIO_PULL_UP);    s3c_gpio_cfgpin(EXYNOS4_GPX0(6), S3C_GPIO_OUTPUT);    gpio_set_value(EXYNOS4_GPX0(6), 1);    mdelay(50);    gpio_set_value(EXYNOS4_GPX0(6), 0);    /* config interrupt pin */    s5p_register_gpio_interrupt(EXYNOS4_GPX0(7));//    s3c_gpio_cfgpin(EXYNOS4_GPX0(7), S3C_GPIO_SFN(0xf));//引脚配置，输入    s3c_gpio_setpull(EXYNOS4_GPX0(7), S3C_GPIO_PULL_UP);//上拉    irq_set_irq_type(EXYNOS4_GPX0(7), IRQ_TYPE_EDGE_RISING);//上升沿触发终端    return 0;}
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6.触摸屏终端回调函数

看看中断回调函数,中断回调函数相当于中断的上半部，主要是做一些简单工作，复制事情交给中断下半部实现，也就是开启的工作队列线程。

static irqreturn_t gsl_ts_irq(int irq, void *dev_id){    struct gsl_ts *ts = dev_id;    print_info("========gslX680 Interrupt=========\n");    disable_irq_nosync(ts->irq);//关闭中断    if (!work_pending(&ts->work)) {        queue_work(ts->wq, &ts->work);//将工作线程再次加入工作队列    }    return IRQ_HANDLED;}
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这里我们看看中断下半部核心处理部分，包括数据采集与上报子系统等等

static void gslX680_ts_worker(struct work_struct *work){    int rc, i,j;    u8 id, touches, read_buf[4] = {0};    u16 x, y;    struct gsl_ts *ts = container_of(work, struct gsl_ts,work);    print_info("=====gslX680_ts_worker=====\n");#ifdef GSL_MONITOR    if(i2c_lock_flag != 0)        goto i2c_lock_schedule;    else        i2c_lock_flag = 1;#endif#ifdef GSL_NOID_VERSION    u32 tmp1;    u8 buf[4] = {0};    struct gsl_touch_info cinfo = {0};#endif    rc = gsl_ts_read(ts->client, 0x80, ts->touch_data, ts->dd->data_size);//读取触摸屏的信息    if (rc < 0) {        dev_err(&ts->client->dev, "read failed\n");        goto schedule;    }    touches = ts->touch_data[ts->dd->touch_index];//触点数    print_info("-----touches: %d -----\n", touches);#ifdef GSL_NOID_VERSION    cinfo.finger_num = touches;    print_info("tp-gsl finger_num = %d\n",cinfo.finger_num);    for(i = 0; i < (touches < MAX_CONTACTS ? touches : MAX_CONTACTS); i ++) {        cinfo.x[i] = join_bytes( ( ts->touch_data[ts->dd->x_index + 4 * i + 1] & 0xf),                                 ts->touch_data[ts->dd->x_index + 4 * i]);        cinfo.y[i] = join_bytes(ts->touch_data[ts->dd->y_index + 4 * i + 1],                                ts->touch_data[ts->dd->y_index + 4 * i ]);        cinfo.id[i] = ((ts->touch_data[ts->dd->x_index + 4 * i + 1] & 0xf0)>>4);        print_info("tp-gsl before: x[%d] = %d, y[%d] = %d, id[%d] = %d \n",i,cinfo.x[i],i,cinfo.y[i],i,cinfo.id[i]);    }    cinfo.finger_num=(ts->touch_data[3]<<24)|(ts->touch_data[2]<<16)                     |(ts->touch_data[1]<<8)|(ts->touch_data[0]);    gsl_alg_id_main(&cinfo);    tmp1=gsl_mask_tiaoping();    print_info("[tp-gsl] tmp1=%x\n",tmp1);    if(tmp1>0&&tmp1<0xffffffff) {        buf[0]=0xa;        buf[1]=0;        buf[2]=0;        buf[3]=0;        gsl_ts_write(ts->client,0xf0,buf,4);        buf[0]=(u8)(tmp1 & 0xff);        buf[1]=(u8)((tmp1>>8) & 0xff);        buf[2]=(u8)((tmp1>>16) & 0xff);        buf[3]=(u8)((tmp1>>24) & 0xff);        print_info("tmp1=%08x,buf[0]=%02x,buf[1]=%02x,buf[2]=%02x,buf[3]=%02x\n",                   tmp1,buf[0],buf[1],buf[2],buf[3]);        gsl_ts_write(ts->client,0x8,buf,4);    }    touches = cinfo.finger_num;#endif    for(i = 1; i <= MAX_CONTACTS; i ++) {        if(touches == 0)            id_sign[i] = 0;        id_state_flag[i] = 0;    }    for(i= 0; i < (touches > MAX_FINGERS ? MAX_FINGERS : touches); i ++) {#ifdef GSL_NOID_VERSION        id = cinfo.id[i];        x = cinfo.x[i];        y = cinfo.y[i];#else        x = join_bytes( ( ts->touch_data[ts->dd->x_index + 4 * i + 1] & 0xf),                        ts->touch_data[ts->dd->x_index + 4 * i]);        y = join_bytes(ts->touch_data[ts->dd->y_index + 4 * i + 1],                       ts->touch_data[ts->dd->y_index + 4 * i ]);//id = ts->touch_data[ts->dd->id_index + 4 * i] >> 4;        id = ts->touch_data[ts->dd->id_index + 4 * i] >> 4;#endif        print_info("-->x = %d, y = %d,id = %d, max = %d,ts->dd->x_index = %d\n",x,y,id,MAX_CONTACTS,ts->dd->id_index);//id = touches;        if(1 <=id && id <= MAX_CONTACTS) {#ifdef FILTER_POINT            filter_point(x, y ,id);//滤波#else            record_point(x, y , id);//记录处理#endif            print_info("-->x_new = %d, y_new = %d\n",x_new,y_new);            report_data(ts, x_new, y_new, 10, id);  //上报数据            id_state_flag[id] = 1;        }    }    for(i = 1; i <= MAX_CONTACTS; i ++) {        if( (0 == touches) || ((0 != id_state_old_flag[i]) && (0 == id_state_flag[i])) ) {#ifdef REPORT_DATA_ANDROID_4_0            input_mt_slot(ts->input, i);            input_report_abs(ts->input, ABS_MT_TRACKING_ID, -1);            input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, false);#endif            id_sign[i]=0;        }        id_state_old_flag[i] = id_state_flag[i];    }    if(0 == touches) {#ifndef REPORT_DATA_ANDROID_4_0        input_mt_sync(ts->input);#endif#ifdef HAVE_TOUCH_KEY        if(key_state_flag) {            input_report_key(ts->input, key, 0);            input_sync(ts->input);            key_state_flag = 0;        }#endif    }    input_sync(ts->input);//同步更新schedule:#ifdef GSL_MONITOR    i2c_lock_flag = 0;i2c_lock_schedule:#endif    enable_irq(ts->irq);//再次开启中断}
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7. 上报输入子系统

static void report_data(struct gsl_ts *ts, u16 x, u16 y, u8 pressure, u8 id){    swap(x, y);//  print_info("#####id=%d,x=%d,y=%d######\n",id,x,y);    print_info("#####id=%d,x=%d,y=%d######\n",id,x,y);    if(x > SCREEN_MAX_X || y > SCREEN_MAX_Y) {#ifdef HAVE_TOUCH_KEY        report_key(ts,x,y);#endif        return;    }    input_mt_slot(ts->input, id);    input_report_abs(ts->input, ABS_MT_TRACKING_ID, id);    input_report_abs(ts->input, ABS_MT_POSITION_X, x);    input_report_abs(ts->input, ABS_MT_POSITION_Y, y);    input_report_abs(ts->input, ABS_MT_PRESSURE, pressure);    input_report_key(ts->input, BTN_TOUCH, 1);}
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至此，glax680电容触摸屏的驱动移植与分析完毕，希望能给大家带来一点点的帮助…
参考资料下载地址：http://download.csdn.net/detail/zgkxzx/9763694