基于设备树的TQ2440触摸屏驱动移植

平台

开发板：tq2440

内核：Linux-4.9

u-boot：u-boot-2015.04

 

概述

之前移植了LCD驱动，下面继续移植触摸屏驱动，然后将tslib也移植上去。

正文

一、移植触摸屏驱动

为了简单起见我们对TQ2440自带的触摸屏驱动进行改写，改成设备树的形式。

1、设备树

触摸屏使用了两个中断，如下：

这两个中断是子中断，隶属于主中断INT_ADC:

关于寄存器，参考芯片手册的第16章，知道了上面的信息，我们就可以得到如下的设备树节点（可以参考博文基于设备树的TQ2440的中断（1））：

tq2440ts@ {
compatible = "tq2440,ts";
reg = <0x58000000 0x100>;
reg-names = "adc_ts_physical";
interrupts = <   >, <   >;
interrupt-names = "int_ts", "int_adc_s";
clocks = <&clocks PCLK_ADC>;
clock-names = "adc";
}; 

2、驱动

对应的触摸屏驱动是drivers/input/touchscreen/tq2440_ts.c

这部分我已经上传到github上面了，可以使用下面的命令下载：

git clone git@github.com:pengdonglin137/linux-4.9.git -b tq2440_dt 

代码如下：

 /*************************************

 NAME:tq2440_ts.c
 COPYRIGHT:www.embedsky.net

  *************************************/
 #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 <linux/of_device.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <asm/io.h>
 #include <asm/irq.h>

 #include <plat/regs-adc.h>
 #include <mach/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())

 #define AUTOPST         (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
     S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST())

 static char *tq2440ts_name = "TQ2440 TouchScreen";

 static    struct input_dev *idev;
 static    long xp;
 static    long yp;
 static    int count;

 static void __iomem *base_addr;

 static void touch_timer_fire(unsigned long data)
 {
     u32 data0;
     u32 data1;
     int updown;

     data0 = readl(base_addr+S3C2410_ADCDAT0);
     data1 = readl(base_addr+S3C2410_ADCDAT1);

     updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));

     if (updown) {
         if (count != ) {
             long tmp;

             tmp = xp;
             xp = yp;
             yp = tmp;

             xp >>= ;
             yp >>= ;

             input_report_abs(idev, ABS_X, xp);
             input_report_abs(idev, ABS_Y, yp);

             input_report_key(idev, BTN_TOUCH, );
             input_report_abs(idev, ABS_PRESSURE, );
             input_sync(idev);
         }

         xp = ;
         yp = ;
         count = ;

         writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);
         writel(readl(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);
     } else {
         count = ;

         input_report_key(idev, BTN_TOUCH, );
         input_report_abs(idev, ABS_PRESSURE, );
         input_sync(idev);

         writel(WAIT4INT(), base_addr+S3C2410_ADCTSC);
     }
 }

 static struct timer_list touch_timer =
 TIMER_INITIALIZER(touch_timer_fire, , );

 static irqreturn_t stylus_updown(int irq, void *dev_id)
 {
     u32 data0;
     u32 data1;
     int updown;

     data0 = readl(base_addr+S3C2410_ADCDAT0);
     data1 = readl(base_addr+S3C2410_ADCDAT1);

     updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));

     if (updown)
         touch_timer_fire();

     return IRQ_HANDLED;
 }

 static irqreturn_t stylus_action(int irq, void *dev_id)
 {
     u32 data0;
     u32 data1;

     data0 = readl(base_addr+S3C2410_ADCDAT0);
     data1 = readl(base_addr+S3C2410_ADCDAT1);

     xp += data0 & S3C2410_ADCDAT0_XPDATA_MASK;
     yp += data1 & S3C2410_ADCDAT1_YPDATA_MASK;
     count++;

     if (count < (<<)) {
         writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);
         writel(readl(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);
     } else {
         mod_timer(&touch_timer, jiffies+);
         writel(WAIT4INT(), base_addr+S3C2410_ADCTSC);
     }

     return IRQ_HANDLED;
 }

 static int tq2440ts_probe(struct platform_device *pdev)
 {
     struct device *dev = &pdev->dev;
     struct device_node *node = dev->of_node;
     struct clk    *adc_clock;
     struct resource *tsmem, *irq;
     struct input_dev *input_dev;
     int ret;

     if (!node) {
         dev_dbg(dev, "of_node is NULL\n");
         return -EINVAL;
     }

     adc_clock = devm_clk_get(dev, "adc");
     dev_dbg(dev, "adc_clock: %p\n", adc_clock);
     if (IS_ERR(adc_clock)) {
         dev_err(dev, "cannot get clock\n");
         return -ENOENT;
     }
     clk_prepare(adc_clock);
     clk_enable(adc_clock);

     dev_dbg(dev, "get mem\n");
     tsmem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "adc_ts_physical");
     if (!tsmem) {
         dev_dbg(dev, "get mem resource failed.\n");
         ret = -EINVAL;
         goto err;
     }

     base_addr = devm_ioremap_resource(dev, tsmem);
     if (IS_ERR(base_addr)) {
         dev_dbg(dev, "ioremap failed.\n");
         ret = PTR_ERR(base_addr);
         goto err;
     }

     writel(S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(0xFF),base_addr+S3C2410_ADCCON);
     writel(0xffff,  base_addr+S3C2410_ADCDLY);
     writel(WAIT4INT(), base_addr+S3C2410_ADCTSC);

     input_dev = devm_input_allocate_device(dev);
     if (!input_dev) {
         dev_dbg(dev, "ioremap failed.\n");
         ret = -ENOMEM;
         goto err;
     }

     idev = input_dev;
     idev->evbit[] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);

     __set_bit(EV_SYN, idev->evbit);
     __set_bit(EV_KEY, idev->evbit);
     __set_bit(EV_ABS, idev->evbit);
     __set_bit(BTN_TOUCH, idev->keybit);

     input_set_abs_params(idev, ABS_X, , 0x3FF, , );
     input_set_abs_params(idev, ABS_Y, , 0x3FF, , );
     input_set_abs_params(idev, ABS_PRESSURE, , , , );

     idev->name = tq2440ts_name;
     idev->id.bustype = BUS_RS232;
     idev->id.vendor = 0xDEAD;
     idev->id.product = 0xBEEF;
     idev->id.version = S3C2410TSVERSION;

     irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "int_ts");
     if (!irq) {
         dev_err(dev, "get irq resource int_ts failed.\n");
         ret = -EINVAL;
         goto err;
     }
     ret = devm_request_irq(dev, irq->start, stylus_updown, IRQF_ONESHOT, "int_ts", NULL);
     if (ret < ){
         dev_err(dev, "request irq tsirq %d failed.\n", irq->start);
         goto err;
     }

     irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "int_adc_s");
     if (!irq) {
         dev_err(dev, "get irq resource int_adc_s failed.\n");
         ret = -EINVAL;
         goto err;
     }
     ret = devm_request_irq(dev, irq->start, stylus_action, IRQF_ONESHOT, "int_adc_s", NULL);
     if (ret < ) {
         dev_err(dev, "request irq adcirq %d failed.\n", irq->start);
         goto err;
     }

     dev_info(dev, "%s successfully loaded\n", tq2440ts_name);
     input_register_device(idev);

     return ;
 err:
     clk_disable(adc_clock);
     return ret;
 }

 static const struct of_device_id tq2440ts_match[] = {
     { .compatible = "tq2440,ts", .data = (void *) },
     {},
 };

 static struct platform_driver tq2440ts_driver = {
     .probe        = tq2440ts_probe,
     .driver        = {
         .name    = "tq2440ts",
         .of_match_table = of_match_ptr(tq2440ts_match),
     },
 };

 static int __init tq2440ts_init(void)
 {
     return platform_driver_register(&tq2440ts_driver);
 }

 static void __exit tq2440ts_exit(void)
 {
     platform_driver_unregister(&tq2440ts_driver);
 }

 module_init(tq2440ts_init);
 module_exit(tq2440ts_exit);

 MODULE_LICENSE("GPL");

3、测试

查看中断信息：

[root@tq2440 ]# cat /proc/interrupts
           CPU0
  :          s3c-eint    Edge      eth0
  :                 s3c    Edge      s3c2410-rtc tick
 :            s3c   Edge      samsung_time_irq
 :                 s3c   Edge      4d000000.fb
 :                 s3c   Edge      ohci_hcd:usb1
 :                 s3c   Edge      .i2c
 :                 s3c   Edge      s3c2410-rtc alarm
 :          s3c-level   Level     .serial
 :        s3c-level   Level     .serial
 :          s3c-level   Edge      int_ts
 :        s3c-level   Edge      int_adc_s
 :            s3c-level   Edge      .watchdog
Err:          

使用hexdump /dev/input/event0:

[root@tq2440 ]# hexdump /dev/input/event0
 cb74 386e bc0b 000b
 cb74 386e bc0b 000b   01e4
 cb74 386e bc0b 000b  014a
 cb74 386e bc0b 000b
 cb74 386e bc0b 000b
 cb74 386e 0a4e 000c   01dc
 cb74 386e 0a4e 000c   01fa
 cb74 386e 0a4e 000c
 cb74 386e 585a 000c  014a
 cb74 386e 585a 000c    

二、移植tslib

参考：

http://www.latelee.org/embedded-linux/porting-linux-tslib.html

http://www.it165.net/embed/html/201409/2656.html

登陆http://www.tslib.org/下载最新的版本：

https://github.com/kergoth/tslib/releases/download/1.10/tslib-1.10.tar.xz

或者tslib-1.10.tar.gz

编译安装：

#!/bin/bash

./autogen.sh

mkdir install

./configure  \
--prefix="`pwd`/install" \
--host=arm-linux  \
ac_cv_func_malloc_0_nonnull=yes

make
make install

安装完成后，可以看到：

$ls install
bin/  etc/  include/  lib/  share/

将这些文件拷贝到开发板上面，然后修改板子上面的/etc/profile文件，添加如下内容：

echo "Set Env for Tslib"
export TSLIB_ROOT=/
export TSLIB_TSDEVICE=/dev/input/event0
export TSLIB_CONFFILE=$TSLIB_ROOT/etc/ts.conf
export TSLIB_PLUGINDIR=$TSLIB_ROOT/lib/ts
export TSLIB_CALIBFILE=/etc/pointercal
export TSLIB_CONSOLEDEVICE=none
export TSLIB_FBDEVICE=/dev/fb0
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$TSLIB_ROOT/lib

修改完成后，重新启动开发板。

三、测试

运行ts_calibrate生成校准数据

[root@tq2440 ]# ts_calibrate
xres = , yres =
Took  samples...
Top left : X =   Y =
Took  samples...
Top right : X =   Y =
Took  samples...
Bot right : X =   Y =
Took  samples...
Bot left : X =   Y =
Took  samples...
Center : X =   Y =
582.617065 -0.602301 -0.108929
-72.806641 0.023253 0.396149
Calibration constants:  - - -    

运行ts_test测试：

[root@tq2440 ]# ts_test
946785862.424089:
946785862.444036:
946785865.264038:
946785865.284058:
946785865.519036:
946785865.539107:
946785865.559054:
946785865.829038:              

完。