datasheet

Tiny210触摸屏之一线触摸屏驱动

2018-10-12来源: eefocus关键字:Tiny210  触摸屏  线触摸屏驱动

1wire_ts.c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/clk.h"

#include "linux/miscdevice.h"

#include "linux/platform_device.h"

#include "linux/timer.h"

#include "linux/param.h"

#include "linux/poll.h"

#include "linux/proc_fs.h"

#include "linux/gpio.h"

#include "linux/cdev.h"

#include "linux/sched.h"

#include "linux/interrupt.h"

#include "linux/irq.h"

#include "linux/err.h"

#include "linux/io.h"

#include "asm/system.h"

#include "asm/leds.h"

#include "asm/mach-types.h"

#include "asm/irq.h"

#include "asm/mach/time.h"

#include "asm/io.h"

#include "asm/irq.h"

#include "asm/uaccess.h"

#include "mach/map.h"

#include "mach/regs-irq.h"

#include "mach/regs-clock.h"

#include "mach/regs-gpio.h"

#include "plat/regs-timer.h"     

#include "plat/gpio-cfg.h"

#include "plat/clock.h"

#include "plat/cpu.h"

static DECLARE_WAIT_QUEUE_HEAD(ts_waitq);

#define MHZ (1000*1000)

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

#define TOUCH_DEVICE_NAME    "tiny_ts"

#define SAMPLE_BPS 9600

#define SLOW_LOOP_FEQ 25

#define FAST_LOOP_FEQ 60

#define REQ_TS   0x40U

#define REQ_INFO 0x60U

enum {

    IDLE,

    START,

    REQUEST,

    WAITING,

    RESPONSE,

    STOPING,

} one_wire_status = IDLE;

struct timer_regs {

    unsigned long tcfg0;

    unsigned long tcfg1;

    unsigned long tcon;

    unsigned long reserved1[9];

    unsigned long tcntb3;

    unsigned long tcmpb3;

    unsigned long tcnto3;

    unsigned long reserved2[2];

    unsigned long tint_cstat;    

};

static struct timer_regs *timer_regs;

static unsigned long *gph1con;

static unsigned long *gph1dat;

static int ts_ready;

static unsigned ts_status;

static unsigned lcd_type, firmware_ver;

static unsigned total_received, total_error;

static unsigned last_req, last_res;

static unsigned long TCNT_FOR_SAMPLE_BIT;

static volatile unsigned int io_bit_count;

static volatile unsigned int io_data;

static volatile unsigned char one_wire_request;

static int exitting;

static struct timer_list ts_timer;

static inline void notify_ts_data(unsigned x, unsigned y, unsigned down)

{

    if (!down && !(ts_status &(1U << 31))) {

        // up repeat, give it up

        return;

    }

    ts_status = ((x << 16) | (y)) | (down << 31);

    ts_ready = 1;

    wake_up_interruptible(&ts_waitq);

}

static ssize_t ts_read(struct file *filp, char *buffer, size_t count, loff_t *ppos)

{

    unsigned long err;

    if (!ts_ready) {

        if (filp->f_flags & O_NONBLOCK)

            return -EAGAIN;

        else

            wait_event_interruptible(ts_waitq, ts_ready);

    }

    ts_ready = 0;

    if (count < sizeof ts_status) {

        return -EINVAL;

    } else {

        count = sizeof ts_status;

    }

    err = copy_to_user((void *)buffer, (const void *)(&ts_status), sizeof ts_status);

    return err ? -EFAULT : sizeof ts_status;

}

static unsigned int ts_poll( struct file *file, struct poll_table_struct *wait)

{

    unsigned int mask = 0;

    poll_wait(file, &ts_waitq, wait);

    if (ts_ready)

        mask |= POLLIN | POLLRDNORM;

    return mask;

}

static struct file_operations ts_fops = {

    owner:        THIS_MODULE,

    read:           ts_read,    

    poll:            ts_poll,

};

static struct miscdevice ts_misc = {

    .minor        = 181,

    .name         = TOUCH_DEVICE_NAME,

    .fops           = &ts_fops,

};

static inline void notify_info_data(unsigned char _lcd_type,unsigned char ver_year, 

                                                         unsigned char week)

{

    if (_lcd_type != 0xFF) {

        lcd_type = _lcd_type;

        firmware_ver = ver_year * 100 + week;

    }

}

static inline void set_pin_value(int v)

{

    if (v) {

        *gph1dat |= 1<<2;

    } else {

        *gph1dat &= ~(1<<2);

    }

}

static inline int get_pin_value(void)

{

    if(*gph1dat & (1<<2))

        return 1;

    else

        return 0;

}

// CRC

static const unsigned char crc8_tab[] = {

0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15,

0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,

0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,

0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,

0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5,

0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,

0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85,

0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,

0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,

0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,

0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2,

0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,

0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32,

0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,

0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,

0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,

0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C,

0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,

0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,

0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,

0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,

0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,

0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C,

0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,

0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B,

0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,

0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,

0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,

0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB,

0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,

0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB,

0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3,

};

#define crc8_init(crc) ((crc) = 0XACU)

#define crc8(crc, v) ( (crc) = crc8_tab[(crc) ^(v)])

// once a session complete

static void one_wire_session_complete(unsigned char req, unsigned int res)

{

    unsigned char crc;

    const unsigned char *p = (const unsigned char*)&res;

    total_received ++;

    last_res = res;

    crc8_init(crc);

    crc8(crc, p[3]);

    crc8(crc, p[2]);

    crc8(crc, p[1]);

    if (crc != p[0]) {

        // CRC dismatch

        if (total_received > 100) {

            total_error++;

        }

        return;

    }

    switch(req) {

        case REQ_TS:

            {

                unsigned short x,y;

                unsigned pressed;

                x =  ((p[3] >>   4U) << 8U) + p[2];

                y =  ((p[3] &  0xFU) << 8U) + p[1];

                pressed = (x != 0xFFFU) && (y != 0xFFFU); 

                notify_ts_data(x, y, pressed);

            }

            break;

        case REQ_INFO:

            notify_info_data(p[3], p[2], p[1]);

            break;

        default:

            break;

    }

}

// one-wire protocol core

static int init_timer3_for_ts(void)

{

    struct clk *clk;

    unsigned long pclk;

    unsigned long prescaler;

    unsigned long prescale1_value;

    // 获得时钟,并使能时钟 

    clk = clk_get(NULL, "timers");

    if (IS_ERR(clk)) {

        printk("ERROR to get PCLK\n");

        return -EIO;

    }

    clk_enable(clk);

    pclk = clk_get_rate(clk);

    printk("Timer3 clock source : %ld.ld Mhz\n", PRINT_MHZ(pclk));

    // 获得定时器的预定标器的值,目的是为了不修改该值,因为定时器2,3,4共享它 

    prescaler = timer_regs->tcfg0;

    prescale1_value = (prescaler >> 8) & 0xFF;

    // calc the TCNT_FOR_SAMPLE_BIT, that is one of the goal

    TCNT_FOR_SAMPLE_BIT = pclk / (prescale1_value + 1) / SAMPLE_BPS - 1;

    // 定时器3的分频系数为1 

    timer_regs->tcfg1 &= (0xf<<12); 

    printk("TCNT_FOR_SAMPLE_BIT = %d\n", TCNT_FOR_SAMPLE_BIT);

    return 0;

}

static inline void stop_timer_for_1wire(void)

{

    timer_regs->tcon &= ~(1<<16);    // 停止定时器3 

}

static irqreturn_t timer_for_1wire_interrupt(int irq, void *dev_id)

{

    timer_regs->tint_cstat |= 0x100; // 清中断 

  

    io_bit_count--;

    switch(one_wire_status) 

    {

      case START:

          if (io_bit_count == 0) {

              io_bit_count = 16;

              one_wire_status = REQUEST;

          }

          break;

  

      case REQUEST:

          // Send a bit

          set_pin_value(io_data & (1U << 31));

          io_data <<= 1;

          if (io_bit_count == 0) {

              io_bit_count = 2;

              one_wire_status = WAITING;

          }

          break;

          

      case WAITING:

          if (io_bit_count == 0) {

              io_bit_count = 32;

              one_wire_status = RESPONSE;

          }

          if (io_bit_count == 1) {

              *gph1con &= ~(1<<8);// 设置为输入 

              set_pin_value(1);

          }

          break;

          

      case RESPONSE:

          // Get a bit

          io_data = (io_data << 1) | get_pin_value();

          if (io_bit_count == 0) {

              io_bit_count = 2;

              one_wire_status = STOPING;

              set_pin_value(1);

              *gph1con |= 1<<8;// 设置为输出 

              one_wire_session_complete(one_wire_request, io_data);

          }

          break;

  

      case STOPING:

          if (io_bit_count == 0) {

              one_wire_status = IDLE;

              stop_timer_for_1wire();

          }

          break;

          

      default:

          stop_timer_for_1wire();

    }

    return IRQ_HANDLED;

}

static struct irqaction timer_for_1wire_irq = {

    .name     = "1-wire Timer Tick",

    .flags      = IRQF_DISABLED | IRQF_IRQPOLL,

    .handler = timer_for_1wire_interrupt,

    .dev_id   = &timer_for_1wire_irq,

};

static void start_one_wire_session(unsigned char req)

{

    unsigned long flags;

    if (one_wire_status != IDLE) {

        return;

    }

    one_wire_status = START;

    set_pin_value(1);

    *gph1con |= 1<<8; // 设置为输出 

    //  IDLE to START 

    {

        unsigned char crc;

        crc8_init(crc);

        crc8(crc, req);

        io_data = (req << 8) + crc;

        io_data <<= 16;

    }

    last_req = (io_data >> 16);

    one_wire_request = req;

    io_bit_count = 1;

    *gph1con |= 1<<8; // 设置为输出 

    timer_regs->tcntb3 = TCNT_FOR_SAMPLE_BIT;

    // 不手动装载,不电平反转,不自动装载 

    timer_regs->tcon &=~(0xF << 16); 

    timer_regs->tcon |= 1<<17;      // 手动转载数据 

    local_irq_save(flags);

    timer_regs->tcon |= 1<<16;      // 开启定时器3,并开启自动装载 

    timer_regs->tcon |= 1<<19;

    timer_regs->tcon &= ~(1<<17);// 关闭手动装载 

    set_pin_value(0);

    local_irq_restore(flags);

}

void one_wire_timer_proc(unsigned long v)

{

    unsigned char req;

    if (exitting) {

        return;

    }

    // 设置查询周期为20ms,并启动内核定时器 

    ts_timer.expires = jiffies + HZ / 50;

    add_timer(&ts_timer);

    if (lcd_type == 0) {

        req = REQ_INFO;

    } 

    else {

        req = REQ_TS;

    }

    start_one_wire_session(req);

}

static int read_proc(char *buf, char **start, off_t offset, int count, int *eof, void *data)

{

    int len;

    len = sprintf(buf, "%u %u %u %u X X\n",

                          lcd_type, firmware_ver, total_received, total_error, last_req, last_res);

    *eof = 1;

    return len;

}

static int dev_init(void)

{

    int ret;

    ret = misc_register(&ts_misc);

    if (ret == 0) {

        create_proc_read_entry("driver/one-wire-info", 0, NULL, read_proc, NULL);

        printk (TOUCH_DEVICE_NAME"\tinitialized\n");

    }

    

    timer_regs = ioremap(0xE2500000, sizeof(struct timer_regs));

    gph1con = ioremap(0xE0200C20, 8);

    gph1dat = gph1con + 1;

    // 设置GPH1_2为输出,并输出1 

    *gph1con |= 1<<8;

    *gph1dat |= 1<<2;

    setup_irq(IRQ_TIMER3, &timer_for_1wire_irq);

    init_timer3_for_ts();

    // 初始化内核的定时器 

    init_timer(&ts_timer);

    ts_timer.function = one_wire_timer_proc;

    one_wire_timer_proc(0);

    // 使能定时器3中断,清中断 

    timer_regs->tint_cstat |= 0x108; 

    return ret;

}

static void dev_exit(void)

{

    exitting = 1;

    remove_proc_entry("driver/one-wire-info", NULL);

    misc_deregister(&ts_misc);

    del_timer_sync(&ts_timer);

    free_irq(IRQ_TIMER3, &timer_for_1wire_irq);

    iounmap(timer_regs);

    iounmap(gph1con);

}

module_init(dev_init);

module_exit(dev_exit);

MODULE_LICENSE("GPL");

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

一线触摸屏介绍:

杂项设备:(由于在移植一线触摸屏驱动的时候,会用到杂项设备,下面分析下它的框架)

分析\drivers\char\misc.c的实现过程:

static const struct file_operations misc_fops = { //分配设置一个file_operations结构体

   .owner = THIS_MODULE,

   .open  = misc_open,

};

static int __init misc_init(void) //入口函数

{

    misc_class = class_create(THIS_MODULE, "misc");    //创建类

    if (register_chrdev(MISC_MAJOR,"misc",&misc_fops)) //注册一个主设备号为10的字符设备

}

subsys_initcall(misc_init); //申明misc_init()函数到子系统初始化集

问:从上面的分析过程可以发现,该子系统初始化程序完全符号写一般的字符驱动程序的步骤,那么应用程序是怎么对通过misc_register()注册的设备进行相应的读,写等操作的呢?

答:过程如下:

app:  open() 应用程序使用open函数

------------------------------------------------------------------------------------------------------------------

kernel:(内核最终会调用到misc.c中的file_operations结构体中的open函数)

问:当看上面的file_operations结构体的时候,发现里面只有一个open函数?那是怎么来实现一系列的其他的操作的呢(读,写...)?

答:可以猜测出,一定是在这个open函数里面做了一些设置,然后在新的设置里面来进行相关的操作。

static int misc_open(struct inode * inode, struct file * file)

{

    int minor = iminor(inode); //获得次设备号

    list_for_each_entry(c, &misc_list, list) { //从misc_list链表中取出每一项(即miscdevice结构体)

        if (c->minor == minor) { //通过次设备号进行匹配

            new_fops = fops_get(c->fops); //如果次设备号一样,则获得该项的file_operations结构体成员        

        }

    }

    if (!new_fops) { //如果上述操作,获得file_operations结构体没有成功,则再次获取

        list_for_each_entry(c, &misc_list, list) {...}

    }

    

    file->f_op = new_fops; //重新初始化struct file结构中的成员f_op,让它指向新的file_operations!

    if (file->f_op->open) { //如果新获得的file_operations结构体有open函数

        err=file->f_op->open(inode,file); //则调用他的open函数

    }

}

问:从分析以上open函数时,发现会从misc_list链表中取出某一项来获取一个miscdevice结构体,进而获取他的成员fops(即新的file_operations结构体),从而构建出了一个新的file_operations结构体,那么上述misc_list链表是由谁来设置的呢?即链表中的成员miscdevice结构体又由谁来传入呢?

答:收索最终发现,它在misc_register函数中被设置:

int misc_register(struct miscdevice * misc)

{

misc->this_device = device_create(misc_class, misc->parent, dev, misc, "%s", misc->name); //建设备节点

    list_add(&misc->list, &misc_list); //将传入的参数miscdevice结构体放入misc_list链表

}

Tiny210的硬件原理:

问:Tiny210一线触摸屏到底是什么?

答:友善的人自以为傲的核心技术,设计了一个一线精准触摸电路,并集成到LCD 的驱动板上,它采用触摸屏控制芯片ADS7843(或者相类似),配合一个ATC的单片机(该单片机里面固话了程序),构成一个独立的四线电阻触摸屏采集电路,最后通过一个普通的GPIO口把处理过的数据发送出去,在开发板上与之相连的是GPH1_2,实现单总线通信,这就是一线的来源。

说白了,就是ATC单片机通过SPI和ADS7843通信,控制ADS7843去读写触摸屏的数据,然后将数据存在单片机里面的RAM中,然后再通过单片机的一个GPIO发给ARM。

问:能够自己写出一线触摸的驱动吗?

答:能使肯定的,但是有些烦躁:

(1).在开发板的原理图上面,与GPH1_2相连接的LCD管脚上面用的net为"PWM",让人误以为是用PWM来通信(当然不可能,PWM是输出,无法读入数据);

(2).上面说了,触摸屏的数据会经单片机处理后,然后通过一个IO管脚发个ARM,但是该IO发出的数据的格式是什么样子的呢(即时序,几秒代表1,几秒代表0),由于友善把其视为核心技术,他们不向外提供固话在单片机中的程序(这个我能理解),但是他们也不提供IO发出的数据的时序。但是大家可以去阅读他们提供的内核里面的触摸屏驱动,然后反推出时序是怎么样的。但是,我没有去弄了,我只是移植了。

最后说说,友善的一线触摸驱动是怎么写的,它在入口函数中注册了一个内核定时器,用于查询方式去读取IO上面的"一帧"数据,然后再启用一个定时器3去解码这些数据,具体怎么解码,请大家参考我移植好了的驱动,然后攻破它吧。写出文档,记得共享到群共享去,发扬互学互助的精神!!!

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

tslib编译使用_测试一线触摸屏:

tslib-one-wire.tar.bz2已经上传自同文件夹中,这是一个已经打过补丁,支持一线触摸屏测试的tslib

编译:

tar xjvf tslib-one-wire.tar.bz2

cd tslib-1.0.0

./autogen.sh

mkdir tmp

echo "ac_cv_func_malloc_0_nonnull=yes" >arm-linux.cache

./configure --host=arm-linux --cache-file=arm-linux.cache --prefix=$(pwd)/tmp

make

make install

修改ts.conf

echo "module_raw one_wire_ts_input" > ts.conf.bck

cat $PWD/tmp/etc/ts.conf >>ts.conf.bck

mv ts.conf.bck $PWD/tmp/etc/ts.conf

安装到开发板:

cd tmp

cp * -rfd /nfsroot

-----------------------------------------------------------------------------

    注意:以上操作都是在PC上面执行

----------------------------------------------------------------------------

export TSLIB_CALIBFILE=/etc/pointercal

export TSLIB_CONFFILE=/etc/ts.conf

export TSLIB_PLUGINDIR=/lib/ts

export TSLIB_CONSOLEDEVICE=none

export TSLIB_FBDEVICE=/dev/fb0

export TSLIB_TSDEVICE=/dev/tiny_ts

ts_calibrate


关键字:Tiny210  触摸屏  线触摸屏驱动

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