ARM+LINUX移植攻略（十七）Linux驱动移植之触摸屏
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; 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 = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS); dev->keybit = 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：
http://hi.csdn.net/attachment/201105/23/0_1306137766tNY4.gif
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