一个基于linux2.6内核下S3C2410触摸屏驱动

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

//* Purpose:this is a s3c2410 touch screen drive

//*

//* Author: alvin.zhang

//*

//* Date: 2008/04/06

//*

//* Revision: 2009/01/12

//*

//* Description : the code about s3c2410 touch screen , you can reference it in your code

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

#include <linux/platform_device.h>

//#include <linux/config.h>

#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 <asm/io.h>

#include <asm/irq.h>

#include <asm/arch/regs-adc.h>

#include <asm/arch/regs-gpio.h>

#include <asm/arch/s3c2410_ts.h>

#include <asm/arch/regs-clock.h>

#include <linux/clk.h>

/* 定义版本*/

#define S3C2410TSVERSION 0x0101

/*IT4INT(1) 为UP_INT WAIT4INT(0)为 DOWN_INT*/

#define WAIT4INT(x) (((x)<<8) | S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | S3C2410_ADCTSC_XY_PST(3))

/* 设置触摸屏的模式为AUTOPST */

#define AUTOPST (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST(0))

#define DEBUG_LVL KERN_DEBUG

#define DEBUG 1

MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>");

MODULE_DESCRIPTION("s3c2410 touchscreen driver");

MODULE_LICENSE("GPL");

/*

* Definitions & global arrays.

*/

static char *s3c2410ts_name = "s3c2410 TouchScreen";

/*

* Per-touchscreen data.

*/

struct s3c2410ts {

/*修改前

struct input_dev dev;

*/

/*add by alvin*/

struct input_dev *dev;

/*add by alvin*/

long xp;

long yp;

int count;

/*驱动内取样的频率定义在oversampling_shift 作法是取樣

(1<<oversampling_shift) 次，然後取平均值當作最後抓到的座標。 */

int shift;

char phys[32];

};

static struct s3c2410ts ts;

static void __iomem *base_addr;

/* 配置GPIO PIN*/

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);

}

/*

* touch_timer_fire这个函数主要实现以下功能：

* 1、stylus down的时候，在中断函数stylus_updown里面被调用，

* 此时缓存区没有数据，ts.count为0，所以只是简单的设

* 置ad转换的模式，然后开启ad转换。

* 2、但ADC中断函数stylus_action把缓冲区填满的时候，作为中

断后半段函数稍后被调用，此时ts.count为4，算出其平

均值后，交给事件处理层(Event Handler)处理，主要是填写

缓冲，然后唤醒等待输入数据的进程。

* 3、stylus抬起，等到缓冲区填满后(可能会包含一些无用的数据)被调用，

* 这时候判断出stylus up，报告stylus up事件，重新等待stylus down。

*/

static void touch_timer_fire(unsigned long data)

{

unsigned long data0;

unsigned long data1;

int updown;

data0 = readl(base_addr+S3C2410_ADCDAT0);

data1 = readl(base_addr+S3C2410_ADCDAT1);

updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT1_UPDOWN));

if (updown) {//注意updown变量只在stylus_updown中更新

if (ts.count != 0) {/*<功能2>*/

ts.xp >>= ts.shift;

ts.yp >>= ts.shift;

#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG

{

struct timeval tv;

do_gettimeofday(&tv);

printk(DEBUG_LVL "T: %06d, X: %03ld, Y: %03ld/n", (int)tv.tv_usec, ts.xp, ts.yp);

printk(KERN_INFO "T: %06d, X: %03ld, Y: %03ld/n", (int)tv.tv_usec, ts.xp, ts.yp);

}

#endif

/* 报告x、y的绝对坐标值 */

input_report_abs(ts.dev/*&ts.dev*/, ABS_X, ts.xp);

input_report_abs(ts.dev/*&ts.dev*/, ABS_Y, ts.yp);

/* 报告按键事件，键值为1(代表触摸屏对应的按键被按下) */

input_report_key(ts.dev/*&ts.dev*/, BTN_TOUCH, 1);

/* 报告触摸屏的状态，1表明触摸屏被按下 */

input_report_abs(ts.dev/*&ts.dev*/, ABS_PRESSURE, 1);

/* 等待接收方受到数据后回复确认，用于同步 */

input_sync(ts.dev/*&ts.dev*/);

}

/*<功能1>*/

ts.xp = 0;

ts.yp = 0;

ts.count = 0;

/* 设置触摸屏的模式为AUTOPST */

writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);

/* 启动ADC转换 */

writel(readl(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);

} else {/*<功能3>*/

ts.count = 0;

input_report_key(ts.dev/*&ts.dev*/, BTN_TOUCH, 0);

input_report_abs(ts.dev/*&ts.dev*/, ABS_PRESSURE, 0);

input_sync(ts.dev/*&ts.dev*/);

writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC);

}

}

/*这里初始化定时器,并把中断处理函数指向touch_timer_fire*/

static struct timer_list touch_timer = TIMER_INITIALIZER(touch_timer_fire, 0, 0);

static irqreturn_t stylus_updown(int irq, void *dev_id, struct pt_regs *regs)

{

unsigned long data0;

unsigned long data1;

int updown;

/********************************debug************************************/

printk(KERN_INFO "You touch the screen/n");

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

data0 = readl(base_addr+S3C2410_ADCDAT0);

data1 = readl(base_addr+S3C2410_ADCDAT1);

/*更新stylus状态寄变量updown：

1 = down

0 = up */

updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT1_UPDOWN));

/* TODO we should never get an interrupt with updown set while

* the timer is running, but maybe we ought to verify that the

* timer isn't running anyways. */

if (updown)

touch_timer_fire(0);

return IRQ_HANDLED;

}

/*ADC中断服务程序*/

static irqreturn_t stylus_action(int irq, void *dev_id, struct pt_regs *regs)

{

unsigned long data0;

unsigned long data1;

data0 = readl(base_addr+S3C2410_ADCDAT0);

data1 = readl(base_addr+S3C2410_ADCDAT1);

ts.xp += data0 & S3C2410_ADCDAT0_XPDATA_MASK;

ts.yp += data1 & S3C2410_ADCDAT1_YPDATA_MASK;

ts.count++;

if (ts.count < (1<<ts.shift)) {/* 缓冲区未满，再次激活ADC转换 */

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 {/* 缓冲区满，激活下半部处理程序touch_timer_fire，处理接收数据 */

mod_timer(&touch_timer, jiffies+1);//修改定时器的expire

writel(WAIT4INT(1), base_addr+S3C2410_ADCTSC);//等待提笔中断

}

return IRQ_HANDLED;

}

static struct clk *adc_clock;

/*

* The functions for inserting/removing us as a module.

*/

static int __init s3c2410ts_probe(struct device *dev)

{

struct s3c2410_ts_mach_info *info;

/*s3c2410_ts_mach_info这个结构需要我们去填充，里面存放的是触摸屏需要的一些配置参数，见下面的附录部分*/

info = ( struct s3c2410_ts_mach_info *)dev->platform_data;

if (!info)

{

printk(KERN_ERR "Hm... too bad : no platform data for ts/n");

return -EINVAL;

}

#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG

printk(DEBUG_LVL "Entering s3c2410ts_init/n");

#endif

adc_clock = clk_get(NULL, "adc");//可以获得adc时钟

if (!adc_clock) {

printk(KERN_ERR "failed to get adc clock source/n");

return -ENOENT;

}

//clk_use(adc_clock);//这个在高版本下已经不需要了

clk_enable(adc_clock);// 使能时钟

#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG

printk(DEBUG_LVL "got and enabled clock/n");

#endif

base_addr=ioremap(S3C2410_PA_ADC,0x20);//映射触摸屏的控制寄存器

if (base_addr == NULL) {

printk(KERN_ERR "Failed to remap register block/n");

return -ENOMEM;

}

/* Configure GPIOs */

s3c2410_ts_connect();

/* Set the prscvl*/

if ((info->presc&0xff) > 0)

writel(S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(info->presc&0xFF),/

base_addr+S3C2410_ADCCON);

else

writel(0,base_addr+S3C2410_ADCCON);

/* Initialise the adcdly registers */

if ((info->delay&0xffff) > 0)

writel(info->delay & 0xffff, base_addr+S3C2410_ADCDLY);

writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC);

/* Initialise input stuff */

memset(&ts, 0, sizeof(struct s3c2410ts));

/* 以下配置2.6内核划分出来的输入设备 */

/* 修改前

init_input_dev(&ts.dev);//这是低版本linux函数,新版本中已经被取替

ts.dev.evbit[0] = ts.dev.evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);

ts.dev.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);

input_set_abs_params(&ts.dev, ABS_X, 0, 0x3FF, 0, 0);

input_set_abs_params(&ts.dev, ABS_Y, 0, 0x3FF, 0, 0);

input_set_abs_params(&ts.dev, ABS_PRESSURE, 0, 1, 0, 0);

sprintf(ts.phys, "ts0");

ts.dev.private = &ts;

ts.dev.name = s3c2410ts_name;

ts.dev.phys = ts.phys;

ts.dev.id.bustype = BUS_RS232;

ts.dev.id.vendor = 0xDEAD;

ts.dev.id.product = 0xBEEF;

ts.dev.id.version = S3C2410TSVERSION;

*/

/*add by alvin*/

// int err;

if (ts.dev) {

return -ENODEV; /* already initialized */

}

ts.dev = input_allocate_device();

if (!ts.dev)

return -ENOMEM;

/* evbit字段用来定义该输入设备可以支持的（产生和响应）的事件的类型，

在此触摸屏设置为支持同步(EN_SYN)、按键(EN_KEY)、绝对坐标(EV_ABS)事件*/

ts.dev->evbit[0] = ts.dev->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);

/* 设置所支持的按键(键值)，触摸屏可以看成只有一个按键的设备 */

ts.dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);

/* 设置绝对坐标x和y的最小最大值，在这是0-0x3FF */

input_set_abs_params(ts.dev, ABS_X, 0, 320/*0x3FF*/, 0, 0);

input_set_abs_params(ts.dev, ABS_Y, 0, 240/*0x3FF*/, 0, 0);

input_set_abs_params(ts.dev, ABS_PRESSURE, 0, 1, 0, 0);

sprintf(ts.phys, "ts0");

ts.dev->private = &ts;

ts.dev->name = s3c2410ts_name;

ts.dev->phys = ts.phys;

ts.dev->id.bustype = BUS_RS232;

ts.dev->id.vendor = 0xDEAD;

ts.dev->id.product = 0xBEEF;

ts.dev->id.version = S3C2410TSVERSION;

/*add by alvin*/

ts.shift = info->oversampling_shift;

/* 这个比较重要，配置输入数据的缓存区大小，

在这里oversampling_shift设为2，也就是缓存区的大小为4(1<<2) */

/* Get irqs */

/* ADC转换中断，转换结束后触发 */

if (request_irq(IRQ_ADC, stylus_action, SA_SAMPLE_RANDOM,

"s3c2410_action", ts.dev/*&ts.dev*/)) {

printk(KERN_ERR "s3c2410_ts.c: Could not allocate ts IRQ_ADC !/n");

iounmap(base_addr);

return -EIO;

}

/* 触摸屏的中断,按下或提笔触发*/

if (request_irq(IRQ_TC, stylus_updown, SA_SAMPLE_RANDOM,

"s3c2410_action", ts.dev/*&ts.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(ts.dev/*&ts.dev*/);

return 0;

}

static int s3c2410ts_remove(struct device *dev)

{

disable_irq(IRQ_ADC);

disable_irq(IRQ_TC);

free_irq(IRQ_TC,ts.dev/*&ts.dev*/);

free_irq(IRQ_ADC,ts.dev/*&ts.dev*/);

if (adc_clock) {

clk_disable(adc_clock);

// clk_unuse(adc_clock);

clk_put(adc_clock);

adc_clock = NULL;

}

input_unregister_device(ts.dev/*&ts.dev*/);

iounmap(base_addr);

return 0;

}

static struct device_driver s3c2410ts_driver = {

.name = "s3c2410-ts",

.bus = &platform_bus_type,

.probe = s3c2410ts_probe,

.remove = s3c2410ts_remove,

};

int __init s3c2410ts_init(void)

{

return driver_register(&s3c2410ts_driver);

}

void __exit s3c2410ts_exit(void)

{

driver_unregister(&s3c2410ts_driver);

}

module_init(s3c2410ts_init);

module_exit(s3c2410ts_exit);

/*

mach-smdk2410.c中

static struct s3c2410_ts_mach_info s3c2410_ts_cfg __initdata = {

.delay = 10000,

.presc = 49,

.oversampling_shift = 2,

};

在devs.c中定义

struct platform_device s3c_device_ts = {

.name = "s3c2410-ts",

.id = -1,

.dev = {

.platform_data = &s3c2410ts_info,

}

};

*/