ARM+LINUX移植攻略（十七）Linux驱动移植之触摸屏

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努力成为linux kernel hacker的人李万鹏原创作品，为梦而战。转载请标明出处

http://blog.csdn.net/woshixingaaa/archive/2011/05/23/6439839.aspx

第一步移植触摸屏驱动：

1.准备源码：

s3c24xx-adc.h

#ifndef _S3C2410_ADC_H_#define _S3C2410_ADC_H_#define ADC_WRITE(ch, prescale)    ((ch)<<16|(prescale))#define ADC_WRITE_GETCH(data)    (((data)>>16)&0x7)#define ADC_WRITE_GETPRE(data)    ((data)&0xff)#endif /* _S3C2410_ADC_H_ */

TE2440II_adc.c

#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 <asm/io.h>#include <asm/irq.h>#include <asm/uaccess.h>#include <mach/regs-clock.h>#include <plat/regs-timer.h>     #include <plat/regs-adc.h>#include <mach/regs-gpio.h>#include <linux/cdev.h>#include <linux/miscdevice.h>#include "s3c24xx-adc.h"#undef DEBUG//#define DEBUG#ifdef DEBUG#define DPRINTK(x...) {printk(__FUNCTION__"(%d): ",__LINE__);printk(##x);}#else#define DPRINTK(x...) (void)(0)#endif#define DEVICE_NAME    "adc"static void __iomem *base_addr;typedef struct {    wait_queue_head_t wait;    int channel;    int prescale;}ADC_DEV;DECLARE_MUTEX(ADC_LOCK);static int OwnADC = 0;static ADC_DEV adcdev;static volatile int ev_adc = 0;static int adc_data;static struct clk    *adc_clock;#define ADCCON (*(volatile unsigned long *)(base_addr + S3C2410_ADCCON))    //ADC control#define ADCTSC (*(volatile unsigned long *)(base_addr + S3C2410_ADCTSC))    //ADC touch screen control#define ADCDLY (*(volatile unsigned long *)(base_addr + S3C2410_ADCDLY))    //ADC start or Interval Delay#define ADCDAT0 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT0))    //ADC conversion data 0#define ADCDAT1 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT1))    //ADC conversion data 1#define ADCUPDN (*(volatile unsigned long *)(base_addr + 0x14))    //Stylus Up/Down interrupt status#define PRESCALE_DIS (0 << 14)#define PRESCALE_EN (1 << 14)#define PRSCVL(x) ((x) << 6)#define ADC_INPUT(x) ((x) << 3)#define ADC_START (1 << 0)#define ADC_ENDCVT (1 << 15)#define START_ADC_AIN(ch, prescale) \    do{ \        ADCCON = PRESCALE_EN | PRSCVL(prescale) | ADC_INPUT((ch)) ; \        ADCCON |= ADC_START; \    }while(0)static irqreturn_t adcdone_int_handler(int irq, void *dev_id){    if (OwnADC) {        adc_data = ADCDAT0 & 0x3ff;        ev_adc = 1;        wake_up_interruptible(&adcdev.wait);    }    return IRQ_HANDLED;}static ssize_t s3c2410_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos){    char str[20];    int value;    size_t len;    if (down_trylock(&ADC_LOCK) == 0) {        OwnADC = 1;        START_ADC_AIN(adcdev.channel, adcdev.prescale);        wait_event_interruptible(adcdev.wait, ev_adc);        ev_adc = 0;        DPRINTK("AIN[%d] = 0x%04x, %d\n", adcdev.channel, adc_data, ADCCON & 0x80 ? 1:0);        value = adc_data;        sprintf(str,"%5d", adc_data);        copy_to_user(buffer, (char *)&adc_data, sizeof(adc_data));        OwnADC = 0;        up(&ADC_LOCK);    } else {        value = -1;    }    len = sprintf(str, "%d\n", value);    if (count >= len) {        int r = copy_to_user(buffer, str, len);        return r ? r : len;    } else {        return -EINVAL;    }}static int s3c2410_adc_open(struct inode *inode, struct file *filp){    init_waitqueue_head(&(adcdev.wait));    adcdev.channel=0;    adcdev.prescale=0xff;    DPRINTK( "adc opened\n");    return 0;}static int s3c2410_adc_release(struct inode *inode, struct file *filp){    DPRINTK( "adc closed\n");    return 0;}static struct file_operations dev_fops = {    owner:    THIS_MODULE,    open:    s3c2410_adc_open,    read:    s3c2410_adc_read,        release:    s3c2410_adc_release,};static struct miscdevice misc = {    .minor = MISC_DYNAMIC_MINOR,    .name = DEVICE_NAME,    .fops = &dev_fops,};static int __init dev_init(void){    int ret;    base_addr=ioremap(S3C2410_PA_ADC,0x20);    if (base_addr == NULL) {        printk(KERN_ERR "Failed to remap register block\n");        return -ENOMEM;    }    adc_clock = clk_get(NULL, "adc");    if (!adc_clock) {        printk(KERN_ERR "failed to get adc clock source\n");        return -ENOENT;    }    clk_enable(adc_clock);        /* normal ADC */    ADCTSC = 0;    ret = request_irq(IRQ_ADC, adcdone_int_handler, IRQF_SHARED, DEVICE_NAME, &adcdev);    if (ret) {        iounmap(base_addr);        return ret;    }    ret = misc_register(&misc);    printk (DEVICE_NAME"\tinitialized\n");    return ret;}static void __exit dev_exit(void){    free_irq(IRQ_ADC, &adcdev);    iounmap(base_addr);    if (adc_clock) {        clk_disable(adc_clock);        clk_put(adc_clock);        adc_clock = NULL;    }    misc_deregister(&misc);}EXPORT_SYMBOL(ADC_LOCK);module_init(dev_init);module_exit(dev_exit);MODULE_LICENSE("GPL");

s3c2410_ts.c

#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 <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(3))#define AUTOPST     (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \         S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST(0))static char *s3c2410ts_name = "s3c2410 TouchScreen";static    struct input_dev *dev;static    long xp;static    long yp;static    int count;extern struct semaphore ADC_LOCK;static int OwnADC = 0;static void __iomem *base_addr;static inline void s3c2410_ts_connect(void){    s3c2410_gpio_cfgpin(S3C2410_GPG12, S3C2410_GPG12_XMON);    s3c2410_gpio_cfgpin(S3C2410_GPG13, S3C2410_GPG13_nXPON);    s3c2410_gpio_cfgpin(S3C2410_GPG14, S3C2410_GPG14_YMON);    s3c2410_gpio_cfgpin(S3C2410_GPG15, S3C2410_GPG15_nYPON);}static void touch_timer_fire(unsigned long data){      unsigned long data0;      unsigned long data1;    int updown;      data0 = ioread32(base_addr+S3C2410_ADCDAT0);      data1 = ioread32(base_addr+S3C2410_ADCDAT1);     updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));     if (updown) {         if (count != 0) {            long tmp;                                                                                                             tmp = xp;            xp = yp;            yp = tmp;                                                                                                             xp >>= 2;            yp >>= 2;#ifdef CONFIG_TOUCHSCREEN_MY2440_DEBUG            struct timeval tv;            do_gettimeofday(&tv);            printk(KERN_DEBUG "T: %06d, X: %03ld, Y: %03ld\n", (int)tv.tv_usec, xp, yp);#endif             input_report_abs(dev, ABS_X, xp);             input_report_abs(dev, ABS_Y, yp);             input_report_key(dev, BTN_TOUCH, 1);             input_report_abs(dev, ABS_PRESSURE, 1);             input_sync(dev);         }         xp = 0;         yp = 0;         count = 0;         iowrite32(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);         iowrite32(ioread32(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);     } else {         count = 0;         input_report_key(dev, BTN_TOUCH, 0);         input_report_abs(dev, ABS_PRESSURE, 0);         input_sync(dev);         iowrite32(WAIT4INT(0), base_addr+S3C2410_ADCTSC);        if (OwnADC) {            OwnADC = 0;            up(&ADC_LOCK);        }     }}static struct timer_list touch_timer =        TIMER_INITIALIZER(touch_timer_fire, 0, 0);static irqreturn_t stylus_updown(int irq, void *dev_id){    unsigned long data0;    unsigned long data1;    int updown;    if (down_trylock(&ADC_LOCK) == 0) {        OwnADC = 1;        data0 = ioread32(base_addr+S3C2410_ADCDAT0);        data1 = ioread32(base_addr+S3C2410_ADCDAT1);        updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));        if (updown) {            touch_timer_fire(0);        } else {            OwnADC = 0;            up(&ADC_LOCK);        }    }    return IRQ_HANDLED;}static irqreturn_t stylus_action(int irq, void *dev_id){    unsigned long data0;    unsigned long data1;    if (OwnADC) {        data0 = ioread32(base_addr+S3C2410_ADCDAT0);        data1 = ioread32(base_addr+S3C2410_ADCDAT1);        xp += data0 & S3C2410_ADCDAT0_XPDATA_MASK;        yp += data1 & S3C2410_ADCDAT1_YPDATA_MASK;        count++;     if (count < (1<<2)) {            iowrite32(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);            iowrite32(ioread32(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);        } else {            mod_timer(&touch_timer, jiffies+1);            iowrite32(WAIT4INT(1), base_addr+S3C2410_ADCTSC);        }    }    return IRQ_HANDLED;}static struct clk    *adc_clock;static int __init s3c2410ts_init(void){    struct input_dev *input_dev;    adc_clock = clk_get(NULL, "adc");    if (!adc_clock) {        printk(KERN_ERR "failed to get adc clock source\n");        return -ENOENT;    }    clk_enable(adc_clock);    base_addr=ioremap(S3C2410_PA_ADC,0x20);    if (base_addr == NULL) {        printk(KERN_ERR "Failed to remap register block\n");        return -ENOMEM;    }    /* Configure GPIOs */    s3c2410_ts_connect();    iowrite32(S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(0xFF),\         base_addr+S3C2410_ADCCON);    iowrite32(0xffff, base_addr+S3C2410_ADCDLY);    iowrite32(WAIT4INT(0), base_addr+S3C2410_ADCTSC);    /* Initialise input stuff */    input_dev = input_allocate_device();    if (!input_dev) {        printk(KERN_ERR "Unable to allocate the input device !!\n");        return -ENOMEM;    }    dev = input_dev;    dev->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);    dev->keybit[BITS_TO_LONGS(BTN_TOUCH)] = BIT(BTN_TOUCH);    input_set_abs_params(dev, ABS_X, 0, 0x3FF, 0, 0);    input_set_abs_params(dev, ABS_Y, 0, 0x3FF, 0, 0);    input_set_abs_params(dev, ABS_PRESSURE, 0, 1, 0, 0);    dev->name = s3c2410ts_name;    dev->id.bustype = BUS_RS232;    dev->id.vendor = 0xDEAD;    dev->id.product = 0xBEEF;    dev->id.version = S3C2410TSVERSION;    /* Get irqs */    if (request_irq(IRQ_ADC, stylus_action, IRQF_SHARED|IRQF_SAMPLE_RANDOM,        "s3c2410_action", dev)) {        printk(KERN_ERR "s3c2410_ts.c: Could not allocate ts IRQ_ADC !\n");        iounmap(base_addr);        return -EIO;    }    if (request_irq(IRQ_TC, stylus_updown, IRQF_SAMPLE_RANDOM,            "s3c2410_action", dev)) {        printk(KERN_ERR "s3c2410_ts.c: Could not allocate ts IRQ_TC !\n");        iounmap(base_addr);        return -EIO;    }    printk(KERN_INFO "%s successfully loaded\n", s3c2410ts_name);    /* All went ok, so register to the input system */    input_register_device(dev);    return 0;}static void __exit s3c2410ts_exit(void){    disable_irq(IRQ_ADC);    disable_irq(IRQ_TC);    free_irq(IRQ_TC,dev);    free_irq(IRQ_ADC,dev);    if (adc_clock) {        clk_disable(adc_clock);        clk_put(adc_clock);        adc_clock = NULL;    }    input_unregister_device(dev);    iounmap(base_addr);}module_init(s3c2410ts_init);module_exit(s3c2410ts_exit);

2. 部署驱动源代码到内核中：

#cp -f s3c24xx-adc.h TE2440II_adc.c /linux-2.6.30.4/drivers/char/#cp -f s3c2410_ts.c /linux-2.6.30.4/drivers/input/touchscreen/

3. 将驱动模块添加到内核配置文件中

#gedit linux-2.6.30.4/drivers/char/Kconfig  //添加如下内容config TE2440II_ADC    bool "ADC device for TE2440II"    default y
#gedit linux-2.6.30.4/drivers/char/Makefile  //添加如下内容obj-$(CONFIG_TE2440II_ADC)  += TE2440II_adc.o
#gedit linux-2.6.30.4/drivers/input/touchscreen/Kconfig  //添加如下内容config TOUCHSCREEN_TE2440II    tristate "TE2440II touchscreens input driver"    default y config TOUCHSCREEN_TE2440II_DEBUG    boolean "TE2440II touchscreens input driver debug messages"    depends on TOUCHSCREEN_TE2440II    help        Select this if you want debug messages
#gedit linux-2.6.30.4/drivers/input/touchscreen/Makefile  //添加如下内容obj-$(CONFIG_TOUCHSCREEN_TE2440II) += s3c2410_ts.o
4. 修改内核配置选项

Device Drivers --->    Input device support --->        (320) Horizontal screen resolution         (240) Vertical screen resolution         

Touchscreens --->             <*> TE2440II touchscreens input driver (NEW)            

TE2440II touchscreens input driver debug messages     Character devices --->         

ADC device for TE2440II (NEW)
这里说一下，如果打开evbug，可以显示出type,code,value的值，而不只是乱码。
第二步：移植tslib。
1.安装工具：automake，autoconf，libtool。
2.编译：
./autogen.sh
./configure --host=arm-linux --prefix=/opt/tslib
make
make install
可能报错 “ts_test.c:(.text+0x200): undefined reference to `rpl_malloc'”，
原因是在 tslib-1.4/config.h 中有一行定义 “#define malloc rpl_malloc”，
直接注释掉这行定义即可，除非你自己实现了一个 malloc 版本。
3.
安装后， 主机 /opt/tslib 存在如下目录：
bin etc include lib
拷贝主机 /opt/tslib 目录至开发板 /opt/ 目录。
4.
在开发板运行触摸屏校正：
(1) 在运行触摸屏校正之前，需要设置一些环境变量，以下是我的开发板的 /etc/profile 文件的内容：
# Ash profile # vim: syntax=sh# No core files by defaultulimit -S -c 0 > /dev/null 2>&1USER="`id -un`"LOGNAME=$USERPS1='[\u@\h \W]\# 'PATH=$PATHHOSTNAME=`/bin/hostname`export USER LOGNAME PS1 PATHexport TSLIB_ROOT=/opt/tslibexport TSLIB_TSDEVICE=/dev/event0export TSLIB_CONFFILE=$TSLIB_ROOT/etc/ts.confexport TSLIB_PLUGINDIR=$TSLIB_ROOT/lib/tsexport TSLIB_CALIBFILE=/etc/pointercalexport TSLIB_CONSOLEDEVICE=noneexport TSLIB_FBDEVICE=/dev/fb0export TS_INFO_FILE=/sys/class/input/input0/ueventexport LD_LIBRARY_PATH=lib:/usr/lib:$TSLIB_ROOT/lib:$LD_LIBRARY_PATH
运行触摸屏校正：
# cd /opt/tslib/bin
# ./ts_calibrate
报错 “No raw modules loaded.”， 原因是缺省时，/opt/tslib/etc/ts.conf 中所有的 raw module 都注释掉了，打开第一项 “module_raw input” 即可 。ts.conf文件中的各个设置选项之前不能有空格，否则会出现：Segmentationfault错误。
秀一下效果：

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