按照天嵌官方的《linux移植之step by step》手册上的方法，做linux2.6.30.4触摸屏驱动程序的移植没有成功，经过一番摸索发现是2.6.30.4没有合适的ADC驱动，所以就着手自己做ADC和触摸屏驱动的移植，下面是我解决问题的详细过程：
1.找到天嵌给的linux2.6.30.4的源码，进入drivers/char 目录，把ADC驱动程序的源码抠出来，注意还有那个ADC驱动程序要调用的头文件，我的是直接把头文件加到ADC驱动程序的源码里面，下面是加入头文件修改后的ADC驱动程序的源代码（我把他命名为my_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>
#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_ */
#undef DEBUG
//#define DEBUG
#ifdef DEBUG
#define DPRINTK(x...) {printk("EmbedSky_adc: " x);}
#else
#define DPRINTK(x...) (void)(0)
#endif
#define DEVICE_NAME "adc"
#define ch_0 0
#define ch_1 1
#define ch_2 2
#define ch_3 3
static void __iomem *base_addr;
typedef struct
{
wait_queue_head_t wait;
int channel;
int prescale;
}ADC_DEV;
DECLARE_MUTEX(ADC_LOCK);
static int ADC_enable = 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)
int iSaveADCTSC=0;
static int tq2440_adc_ioctl(
struct inode *inode,
struct file *file,
unsigned int cmd,
unsigned long arg)
{
if (arg > 4)
{
return -EINVAL;
}
switch(cmd)
{
case ch_0:
adcdev.channel=0;
return 0;
case ch_1:
adcdev.channel=1;
return 0;
case ch_2:
adcdev.channel=2;
return 0;
case ch_3:
adcdev.channel=3;
return 0;
default:
return -EINVAL;
}
}
static ssize_t tq2440_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)
{
ADC_enable = 1;
START_ADC_AIN(adcdev.channel, adcdev.prescale);
iSaveADCTSC=ADCTSC;
ADCTSC=ADCTSC&(~0x1<<2);
ADCCON|=0x01;
while(ADCCON&0x1);
while(!ADCCON&(0x1<<15));
adc_data = ADCDAT0 & 0x3ff;
ADCTSC=iSaveADCTSC;
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));
ADC_enable = 0;
up(&ADC_LOCK);
len = sprintf(str, "%d\n", value);
if (count >= len)
{
int r = copy_to_user(buffer, str, len);
return r ? r : len;
}
else
{
return -1;
}
}
else
{
return -1;
//value = -1;
}
}
static int tq2440_adc_open(struct inode *inode, struct file *filp)
{
init_waitqueue_head(&(adcdev.wait));
adcdev.channel=2;
adcdev.prescale=0xff;
DPRINTK( "ADC opened\n");
return 0;
}
static int tq2440_adc_release(struct inode *inode, struct file *filp)
{
DPRINTK( "ADC closed\n");
return 0;
}
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.open = tq2440_adc_open,
.ioctl = tq2440_adc_ioctl,
.read = tq2440_adc_read,
.release = tq2440_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);
ADCTSC = 0;
ret = misc_register(&misc);
printk (DEVICE_NAME" initialized\n");
return ret;
}
static void __exit dev_exit(void)
{
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");
上述程序的源码以后再作分析。
2.进入2.6.30.4源码目录：drivers/input/touchscreen ,把触摸屏驱动程序的源码抠出来（我把他命名为my_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>
#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 *tq2440ts_name = "TQ2440 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 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;
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 tq2440ts_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;
}
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 = tq2440ts_name;
dev->id.bustype = BUS_RS232;
dev->id.vendor = 0xDEAD;
dev->id.product = 0xBEEF;
dev->id.version = S3C2410TSVERSION;
if (request_irq(IRQ_ADC, stylus_action, IRQF_SHARED|IRQF_SAMPLE_RANDOM, tq2440ts_name, dev))
{
printk(KERN_ERR "tq2440_ts.c: Could not allocate ts IRQ_ADC !\n");
iounmap(base_addr);
return -EIO;
}
if (request_irq(IRQ_TC, stylus_updown, IRQF_SAMPLE_RANDOM, tq2440ts_name, dev))
{
printk(KERN_ERR "tq2440_ts.c: Could not allocate ts IRQ_ADC !\n");
iounmap(base_addr);
return -EIO;
}
printk(KERN_INFO "%s successfully loaded\n", tq2440ts_name);
input_register_device(dev);
return 0;
}
static void __exit tq2440ts_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(tq2440ts_init);
module_exit(tq2440ts_exit);
源码暂时不作分析。
3.个人建议自己先把上述源码都交叉编译成内核模块，至于怎么交叉编译成内核模块，这里就不再赘述了，在编译模块的过程中可以检查驱动程序的错误与否，不然你要是直接抠出来就放进内核源码里面，要是等下你编译内核的时候出错，这个就比较麻烦和耗时间了，好了，如果编译内核模块的这个过程中驱动程序源码没有什么问题的话，接下来你就可以放心大胆地将my_adc.c和my_ts.c放进内核源码中，并且修改相应的kconfig和Makefile文件了，具体步骤如下：
3.1 把my_adc.c放入内核源码drivers/char 这个目录下，并且修改这个目录下的kconfig和Makefile文件：
在kconfig里面把config TQ2440_ADC的代码改成下面所示的代码：
config MY_ADC bool "My ADC driver for TQ2440" depends on ARCH_S3C2440 default y if ARCH_S3C2440 help My ADC driver for TQ2440.
在Makefile里面把obj-$(CONFIG_TQ2440_ADC) += EmbedSky_adc.o 改成下面所示的代码：
obj-$(CONFIG_MY_ADC) += my_adc.o
3.2 把my_ts.c放入内核源码drivers/input/touchscreen下，并修改这个目录下的kconfig和Makefile文件：
在kconfig里面把原来的config TOUCHSCREEN_TQ2440的代码修改成如下所示的代码：
config TOUCHSCREEN_MY2440 tristate " MY2440 TouchScreen input driver" depends on ARCH_S3C2410 && INPUT && INPUT_TOUCHSCREEN && MY_ADC help Say Y here if you have the MY2440 TouchScreen. and depends on MY_ADC If unsure, say N. To compile this driver as a module, choose M here: the module will be called my_ts.
在Makefile里面把原来的obj-$(CONFIG_TOUCHSCREEN_TQ2440) += tq2440_ts.o 修改成下面所示的代码：
obj-$(CONFIG_TOUCHSCREEN_MY2440) += my_ts.o
4.至此修改linux内核源码的工作就结束了，接下来我们来配置和编译内核：
进入修改后的源码目录linux2.6.30.4下，找到config_EmbedSky_W43（我的显示屏是4.3寸的），然后输入指令:cp config_EmbedSky_W43 .config ，再然后输入指令：make menuconfig ,接着会弹出内核配置的图形界面，具体操作如下：
4.1 进入Device Drivers--> Character devices 把 My ADC driver for TQ2440 这个选项选上，如下图所示：
4.2 进入 Device Drivers --->Input device support ---> Touchscreens --->MY2440 TouchScreen input driver 这个选项选上，如下图所示：
4.3 最后回到 Linux Kernel Configuration ，选择 Save an Alternate Configuration File ，保存你刚才所做的所有设置。
5.好了，到此内核源码的修改和内核的配置工作你都完成了，接下来你就可以编译内核了，输入指令：make 然后就开始编译内核了，等到结束后，找到zImage.bin这个文件便是我们编译好的内核镜像文件，然后把这个内核烧写进开发板，你会发现触摸屏就奇迹般地能够用了，至此TQ2440触摸屏驱动程序的移植就结束了。
时间： 2024-10-25 01:04:42