06.输入系统：第10课第20节_输入系统_多点触摸_电容屏驱动程序

上小节我们讲解了android多点触摸屏驱动程序的理论框架，该小节我们开始编写代码，把多点触摸屏驱动的框架编写完成。下面是单点触摸屏（电阻屏），与多点触摸屏（电容屏的一个对比）：

我们主要以讲解android系统为目的，所以驱动部分就不再进行讲解，下面是SDK\kernel\drivers\input\touchscreen\gslx680.c

 /*
 * drivers/input/touchscreen/gslX680.c
 *
 * Copyright (c) 2012 Shanghai Basewin
 *	Guan Yuwei<[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */



#include <linux/module.h>
#include <linux/delay.h>
#include <linux/hrtimer.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/async.h>
#include <linux/irq.h>
#include <linux/workqueue.h>
#include <linux/proc_fs.h>
#include <linux/input/mt.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include "tp_suspend.h"

#include "gslx680.h"

extern unsigned char root_config[32];
static int REPORT_DATA_ANDROID_4_0 = 1;
static int is_linux = 0;  //为了程序的方便移植。分为了linux与安卓我们只需要关注linux即可
static int MAX_FINGERS = 10;
static int MAX_CONTACTS = 10;

//#define GSL_DEBUG
//#define GSL_MONITOR
//#define HAVE_TOUCH_KEY
//#define SLEEP_CLEAR_POINT
//#define FILTER_POINT
#ifdef FILTER_POINT
#define FILTER_MAX	9
#endif

#define GSLX680_I2C_NAME 	"gslX680"
#define GSLX680_I2C_ADDR 	0x40
#define IRQ_PORT		PB_PIO_IRQ(CFG_IO_TOUCH_PENDOWN_DETECT)//IRQ_EINT(8)

#define GSL_DATA_REG		0x80
#define GSL_STATUS_REG		0xe0
#define GSL_PAGE_REG		0xf0
#define PRESS_MAX    		255

#define DMA_TRANS_LEN		0x20
#ifdef GSL_MONITOR
static struct delayed_work gsl_monitor_work;
static struct workqueue_struct *gsl_monitor_workqueue = NULL;
static u8 int_1st[4] = {0};
static u8 int_2nd[4] = {0};
static char dac_counter = 0;
static char b0_counter = 0;
static char bc_counter = 0;
static char i2c_lock_flag = 0;
#endif
static struct gsl_ts *gts;
static struct i2c_client *gsl_client = NULL;

#ifdef HAVE_TOUCH_KEY
static u16 key = 0;
static int key_state_flag = 0;
struct key_data {
	u16 key;
	u16 x_min;
	u16 x_max;
	u16 y_min;
	u16 y_max;
};

const u16 key_array[]={
                                      KEY_BACK,
                                      KEY_HOME,
                                      KEY_MENU,
                                      KEY_SEARCH,
                                     };
#define MAX_KEY_NUM     (sizeof(key_array)/sizeof(key_array[0]))

struct key_data gsl_key_data[MAX_KEY_NUM] = {
	{KEY_BACK, 2048, 2048, 2048, 2048},
	{KEY_HOME, 2048, 2048, 2048, 2048},
	{KEY_MENU, 2048, 2048, 2048, 2048},
	{KEY_SEARCH, 2048, 2048, 2048, 2048},
};
#endif

struct gsl_ts_data {
	u8 x_index;
	u8 y_index;
	u8 z_index;
	u8 id_index;
	u8 touch_index;
	u8 data_reg;
	u8 status_reg;
	u8 data_size;
	u8 touch_bytes;
	u8 update_data;
	u8 touch_meta_data;
	u8 finger_size;
};

/*触摸屏数据结构体*/
static struct gsl_ts_data devices[] = {
	{
		.x_index = 6,
		.y_index = 4,
		.z_index = 5,
		.id_index = 7,
		.data_reg = GSL_DATA_REG,
		.status_reg = GSL_STATUS_REG,
		.update_data = 0x4,
		.touch_bytes = 4,
		.touch_meta_data = 4,
		.finger_size = 70,
	},
};

struct gsl_ts {
	struct i2c_client *client;
	struct input_dev *input;
	struct work_struct work;
	struct workqueue_struct *wq;
	struct gsl_ts_data *dd;
	u8 *touch_data;
	u8 device_id;
	int irq;
	int irq_pin;
	int rst_pin;
	int rst_val;
	struct work_struct	resume_work;
};

#ifdef GSL_DEBUG
#define print_info(fmt, args...)   \
        do{                              \
                printk(fmt, ##args);     \
        }while(0)
#else
#define print_info(fmt, args...)
#endif


static u32 id_sign[10+1] = {0};
static u8 id_state_flag[10+1] = {0};
static u8 id_state_old_flag[10+1] = {0};
static u16 x_old[10+1] = {0};
static u16 y_old[10+1] = {0};
static u16 x_new = 0;
static u16 y_new = 0;

static int gslX680_init(void)
{
	/* shutdown pin */
	gpio_request(gts->rst_pin, "reset-gpio");
	mdelay(5);
	if (gpio_is_valid(gts->rst_pin)) {
		gpio_set_value(gts->rst_pin,0);
	}
	mdelay(50);
	if (gpio_is_valid(gts->rst_pin)) {
		gpio_set_value(gts->rst_pin,1);
	}
	mdelay(5);

	/* config interrupt pin */
	
	return 0;
}

static int gslX680_shutdown_low(void)
{
	if (gpio_is_valid(gts->rst_pin)) {
		gpio_set_value(gts->rst_pin,0);
	}
	return 0;
}

static int gslX680_shutdown_high(void)
{
	if (gpio_is_valid(gts->rst_pin)) {
		gpio_set_value(gts->rst_pin,1);
	}
	return 0;
}

static inline u16 join_bytes(u8 a, u8 b)
{
	u16 ab = 0;
	ab = ab | a;
	ab = ab << 8 | b;
	return ab;
}

#if 0
static u32 gsl_read_interface(struct i2c_client *client, u8 reg, u8 *buf, u32 num)
{
	struct i2c_msg xfer_msg[2];

	xfer_msg[0].addr = client->addr;
	xfer_msg[0].len = 1;
	xfer_msg[0].flags = client->flags & I2C_M_TEN;
	xfer_msg[0].buf = &reg;

	xfer_msg[1].addr = client->addr;
	xfer_msg[1].len = num;
	xfer_msg[1].flags |= I2C_M_RD;
	xfer_msg[1].buf = buf;

	if (reg < 0x80) {
		i2c_transfer(client->adapter, xfer_msg, ARRAY_SIZE(xfer_msg));
		msleep(5);
	}

	return i2c_transfer(client->adapter, xfer_msg, ARRAY_SIZE(xfer_msg)) == ARRAY_SIZE(xfer_msg) ? 0 : -EFAULT;
}
#endif

static u32 gsl_write_interface(struct i2c_client *client, const u8 reg, u8 *buf, u32 num)
{
	struct i2c_msg xfer_msg[1];

	buf[0] = reg;

	xfer_msg[0].addr = client->addr;
	xfer_msg[0].len = num + 1;
	xfer_msg[0].flags = client->flags & I2C_M_TEN;
	xfer_msg[0].buf = buf;

	return i2c_transfer(client->adapter, xfer_msg, 1) == 1 ? 0 : -EFAULT;
}

static int gsl_ts_write(struct i2c_client *client, u8 addr, u8 *pdata, int datalen)
{
	int ret = 0;
	u8 tmp_buf[128];
	unsigned int bytelen = 0;
	if (datalen > 125)
	{
		printk("%s too big datalen = %d!\n", __func__, datalen);
		return -1;
	}

	tmp_buf[0] = addr;
	bytelen++;

	if (datalen != 0 && pdata != NULL)
	{
		memcpy(&tmp_buf[bytelen], pdata, datalen);
		bytelen += datalen;
	}

	ret = i2c_master_send(client, tmp_buf, bytelen);
	return ret;
}

int gsl_ts_readbyte(struct i2c_client *client, u8 addr, u8 *pdata)
{
	int ret = 0;
	ret = gsl_ts_write(client, addr, NULL, 0);
	if (ret < 0)
	{
		printk("%s set data address fail!\n", __func__);
		return ret;
	}

	return i2c_master_recv(client, pdata, 1);
}

static int gsl_ts_read(struct i2c_client *client, u8 addr, u8 *pdata, unsigned int datalen)
{
	int ret = 0;
	int i = 0;

	if (datalen > 126)
	{
		printk("%s too big datalen = %d!\n", __func__, datalen);
		return -1;
	}
	for(i=0; i<datalen; i++){
		ret = gsl_ts_readbyte(client, addr+i, pdata+i);
		if(ret < 0)
			return ret;
	}
	return ret;
}

static __inline__ void fw2buf(u8 *buf, const u32 *fw)
{
	u32 *u32_buf = (int *)buf;
	*u32_buf = *fw;
}

static void gsl_load_fw(struct i2c_client *client)
{
	u8 buf[DMA_TRANS_LEN*4 + 1] = {0};
	u8 send_flag = 1;
	u8 *cur = buf + 1;
	u32 source_line = 0;
	u32 source_len;
	struct fw_data *ptr_fw;

	//printk("=============gsl_load_fw start==============\n");

	ptr_fw = GSLX680_FW;
	source_len = ARRAY_SIZE(GSLX680_FW);

	for (source_line = 0; source_line < source_len; source_line++)
	{
		/* init page trans, set the page val */
		if (GSL_PAGE_REG == ptr_fw[source_line].offset)
		{
			fw2buf(cur, &ptr_fw[source_line].val);
			gsl_write_interface(client, GSL_PAGE_REG, buf, 4);
			send_flag = 1;
		}
		else
		{
			if (1 == send_flag % (DMA_TRANS_LEN < 0x20 ? DMA_TRANS_LEN : 0x20))
	    			buf[0] = (u8)ptr_fw[source_line].offset;

			fw2buf(cur, &ptr_fw[source_line].val);
			cur += 4;

			if (0 == send_flag % (DMA_TRANS_LEN < 0x20 ? DMA_TRANS_LEN : 0x20))
			{
	    			gsl_write_interface(client, buf[0], buf, cur - buf - 1);
	    			cur = buf + 1;
			}

			send_flag++;
		}
	}

	printk("=============gsl_load_fw end==============\n");

}

static int test_i2c(struct i2c_client *client)
{
	u8 buf;

	buf = 0x12;
	if(gsl_ts_write(client, 0xf0, &buf, 1) < 0)
		return -1;

	buf = 0x00;
	if(gsl_ts_read(client, 0xf0, &buf, 1) < 0)
		return -1;

	if(buf == 0x12)
		return 0;
	return -1;
}

static void startup_chip(struct i2c_client *client) //启动设备开始工作
{
	u8 tmp = 0x00;

#ifdef GSL_NOID_VERSION
	gsl_DataInit(gsl_config_data_id);
#endif
	gsl_ts_write(client, 0xe0, &tmp, 1);
	//msleep(10);
}

static void reset_chip(struct i2c_client *client)  //设备复位操作
{
	u8 tmp = 0x88;
	u8 buf[4] = {0x00};

	gsl_ts_write(client, 0xe0, &tmp, sizeof(tmp));
	msleep(20);
	tmp = 0x04;
	gsl_ts_write(client, 0xe4, &tmp, sizeof(tmp));
	msleep(10);
	gsl_ts_write(client, 0xbc, buf, sizeof(buf));
	msleep(10);
}

static void clr_reg(struct i2c_client *client)
{
	u8 write_buf[4]	= {0};

	write_buf[0] = 0x88;
	gsl_ts_write(client, 0xe0, &write_buf[0], 1);
	//msleep(20);
	write_buf[0] = 0x03;
	gsl_ts_write(client, 0x80, &write_buf[0], 1);
	//msleep(5);
	write_buf[0] = 0x04;
	gsl_ts_write(client, 0xe4, &write_buf[0], 1);
	//msleep(5);
	write_buf[0] = 0x00;
	gsl_ts_write(client, 0xe0, &write_buf[0], 1);
	//msleep(20);
}

static int init_chip(struct i2c_client *client)
{
	int rc;
	
	/*复位操作一次*/
	gslX680_shutdown_low();	
	msleep(20); 	
	gslX680_shutdown_high();	
	msleep(20); 

	/*检测I2C设备，即触摸屏设备*/
	rc = test_i2c(client);
	if(rc < 0)
		return -1;

	//芯片初始具体化工作，对寄存器的配置可以查看芯片文档
	clr_reg(client);
	reset_chip(client);
	gsl_load_fw(client);
	startup_chip(client);
	reset_chip(client);
	startup_chip(client);
	return 0;
}

#if 0
static void check_mem_data(struct i2c_client *client)
{
	u8 read_buf[4]  = {0};

	//msleep(30);

	gsl_ts_read(client,0xb0, read_buf, sizeof(read_buf));


	if (read_buf[3] != 0x5a || read_buf[2] != 0x5a || read_buf[1] != 0x5a || read_buf[0] != 0x5a)
	{
		printk("#########check mem read 0xb0 = %x %x %x %x #########\n", read_buf[3], read_buf[2], read_buf[1], read_buf[0]);
		init_chip(client);
	}
}
#endif

#ifdef FILTER_POINT
static void filter_point(u16 x, u16 y , u8 id)
{
	u16 x_err =0;
	u16 y_err =0;
	u16 filter_step_x = 0, filter_step_y = 0;

	id_sign[id] = id_sign[id] + 1;
	if(id_sign[id] == 1)
	{
		x_old[id] = x;
		y_old[id] = y;
	}

	x_err = x > x_old[id] ? (x -x_old[id]) : (x_old[id] - x);
	y_err = y > y_old[id] ? (y -y_old[id]) : (y_old[id] - y);

	if( (x_err > FILTER_MAX && y_err > FILTER_MAX/3) || (x_err > FILTER_MAX/3 && y_err > FILTER_MAX) )
	{
		filter_step_x = x_err;
		filter_step_y = y_err;
	}
	else
	{
		if(x_err > FILTER_MAX)
			filter_step_x = x_err;
		if(y_err> FILTER_MAX)
			filter_step_y = y_err;
	}

	if(x_err <= 2*FILTER_MAX && y_err <= 2*FILTER_MAX)
	{
		filter_step_x >>= 2;
		filter_step_y >>= 2;
	}
	else if(x_err <= 3*FILTER_MAX && y_err <= 3*FILTER_MAX)
	{
		filter_step_x >>= 1;
		filter_step_y >>= 1;
	}
	else if(x_err <= 4*FILTER_MAX && y_err <= 4*FILTER_MAX)
	{
		filter_step_x = filter_step_x*3/4;
		filter_step_y = filter_step_y*3/4;
	}

	x_new = x > x_old[id] ? (x_old[id] + filter_step_x) : (x_old[id] - filter_step_x);
	y_new = y > y_old[id] ? (y_old[id] + filter_step_y) : (y_old[id] - filter_step_y);

	x_old[id] = x_new;
	y_old[id] = y_new;
}
#else
	
/*上报坐标数据*/
static void record_point(u16 x, u16 y , u8 id)
{
	u16 x_err =0;
	u16 y_err =0;

	id_sign[id]=id_sign[id]+1;

	if(id_sign[id]==1){
		x_old[id]=x;
		y_old[id]=y;
	}

	x = (x_old[id] + x)/2;
	y = (y_old[id] + y)/2;

	if(x>x_old[id]){
		x_err=x -x_old[id];
	}
	else{
		x_err=x_old[id]-x;
	}

	if(y>y_old[id]){
		y_err=y -y_old[id];
	}
	else{
		y_err=y_old[id]-y;
	}

	if( (x_err > 3 && y_err > 1) || (x_err > 1 && y_err > 3) ){
		x_new = x;     x_old[id] = x;
		y_new = y;     y_old[id] = y;
	}
	else{
		if(x_err > 3){
			x_new = x;     x_old[id] = x;
		}
		else
			x_new = x_old[id];
		if(y_err> 3){
			y_new = y;     y_old[id] = y;
		}
		else
			y_new = y_old[id];
	}

	if(id_sign[id]==1){
		x_new= x_old[id];
		y_new= y_old[id];
	}

}
#endif

#ifdef HAVE_TOUCH_KEY
/*上报按键数据*/
static void report_key(struct gsl_ts *ts, u16 x, u16 y)
{
	u16 i = 0;

	for(i = 0; i < MAX_KEY_NUM; i++)
	{
		if((gsl_key_data[i].x_min < x) && (x < gsl_key_data[i].x_max)&&(gsl_key_data[i].y_min < y) && (y < gsl_key_data[i].y_max))
		{
			key = gsl_key_data[i].key;
			input_report_key(ts->input, key, 1);
			input_sync(ts->input);
			key_state_flag = 1;
			break;
		}
	}
}
#endif

/*上报位移数据*/
static void report_data(struct gsl_ts *ts, u16 x, u16 y, u8 pressure, u8 id)
{
	swap(x, y);

	if(x > SCREEN_MAX_X || y > SCREEN_MAX_Y)
	{
	#ifdef HAVE_TOUCH_KEY
		report_key(ts,x,y);
	#endif
		return;
	}
	if(is_linux > 0)
	{
		input_report_abs(ts->input, ABS_X, x); 
	 	input_report_abs(ts->input, ABS_Y, y); //设置触摸屏支持上报绝对位移事件y轴
		if(pressure != 0)
			input_report_key(ts->input, BTN_TOUCH, 1);
		else
			input_report_key(ts->input, BTN_TOUCH, 0);
		input_sync(ts->input);
	}
	else
	{
		input_report_abs(ts->input, ABS_MT_PRESSURE, id);
		input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, 1);
		input_report_abs(ts->input, ABS_MT_POSITION_X, x);
		input_report_abs(ts->input, ABS_MT_POSITION_Y, y);
		input_mt_sync(ts->input);
	}
}


/*获取数据并且上报数据*/
static void gslX680_ts_worker(struct work_struct *work)
{
	struct gsl_ts *ts = container_of(work, struct gsl_ts,work);
	int rc, i;
	u8 id, touches;
	u16 x, y;

#ifdef GSL_NOID_VERSION
	u32 tmp1;
	u8 buf[4] = {0};
	struct gsl_touch_info cinfo;
	memset(&cinfo, 0, sizeof(struct gsl_touch_info));  //对结构体清零操作
#endif

	print_info("=====gslX680_ts_worker=====\n");

#ifdef GSL_MONITOR
	if(i2c_lock_flag != 0)  //判断I2C是否上锁，
		goto i2c_lock_schedule;   //如果上锁使能中断跳出该函数
	else
		i2c_lock_flag = 1;   //没有上锁则上锁
#endif

	rc = gsl_ts_read(ts->client, 0x80, &ts->touch_data[0], 4);
	if (rc < 0)
	{
		dev_err(&ts->client->dev, "read failed\n");
		goto schedule;
	}
	touches = ts->touch_data[ts->dd->touch_index];  //获取上报几个触摸点的数据

	//获取数据，最多获取九个点的数据
	if(touches > 0)
		gsl_ts_read(ts->client, 0x84, &ts->touch_data[4], 4);
	if(touches > 1)
		gsl_ts_read(ts->client, 0x88, &ts->touch_data[8], 4);
	if(touches > 2)
		gsl_ts_read(ts->client, 0x8c, &ts->touch_data[12], 4);
	if(touches > 3)
		gsl_ts_read(ts->client, 0x90, &ts->touch_data[16], 4);
	if(touches > 4)
		gsl_ts_read(ts->client, 0x94, &ts->touch_data[20], 4);
	if(touches > 5)
		gsl_ts_read(ts->client, 0x98, &ts->touch_data[24], 4);
	if(touches > 6)
		gsl_ts_read(ts->client, 0x9c, &ts->touch_data[28], 4);
	if(touches > 7)
		gsl_ts_read(ts->client, 0xa0, &ts->touch_data[32], 4);
	if(touches > 8)
		gsl_ts_read(ts->client, 0xa4, &ts->touch_data[36], 4);
	if(touches > 9)
		gsl_ts_read(ts->client, 0xa8, &ts->touch_data[40], 4);

	print_info("-----touches: %d -----\n", touches);
#ifdef GSL_NOID_VERSION
	cinfo.finger_num = touches;
	print_info("tp-gsl  finger_num = %d\n",cinfo.finger_num);
	for(i = 0; i < (touches < MAX_CONTACTS ? touches : MAX_CONTACTS); i ++)
	{
		cinfo.x[i] = join_bytes( ( ts->touch_data[ts->dd->x_index  + 4 * i + 1] & 0xf),
				ts->touch_data[ts->dd->x_index + 4 * i]);
		cinfo.y[i] = join_bytes(ts->touch_data[ts->dd->y_index + 4 * i + 1],
				ts->touch_data[ts->dd->y_index + 4 * i ]);
		cinfo.id[i] = ((ts->touch_data[ts->dd->x_index  + 4 * i + 1] & 0xf0)>>4);
		print_info("tp-gsl  before: x[%d] = %d, y[%d] = %d, id[%d] = %d \n",i,cinfo.x[i],i,cinfo.y[i],i,cinfo.id[i]);
	}
	cinfo.finger_num=(ts->touch_data[3]<<24)|(ts->touch_data[2]<<16)
		|(ts->touch_data[1]<<8)|(ts->touch_data[0]);
	gsl_alg_id_main(&cinfo);
	tmp1=gsl_mask_tiaoping();
	print_info("[tp-gsl] tmp1=%x\n",tmp1);
	if(tmp1>0&&tmp1<0xffffffff)
	{
		buf[0]=0xa;buf[1]=0;buf[2]=0;buf[3]=0;
		gsl_ts_write(ts->client,0xf0,buf,4);
		buf[0]=(u8)(tmp1 & 0xff);
		buf[1]=(u8)((tmp1>>8) & 0xff);
		buf[2]=(u8)((tmp1>>16) & 0xff);
		buf[3]=(u8)((tmp1>>24) & 0xff);
		print_info("tmp1=%08x,buf[0]=%02x,buf[1]=%02x,buf[2]=%02x,buf[3]=%02x\n",
			tmp1,buf[0],buf[1],buf[2],buf[3]);
		gsl_ts_write(ts->client,0x8,buf,4);
	}
	touches = cinfo.finger_num;
#endif
    
	/*对上报标号和上报状态清零*/
	for(i = 1; i <= MAX_CONTACTS; i ++)
	{
		if(touches == 0)
			id_sign[i] = 0;
		id_state_flag[i] = 0;
	}
	
	/*判断是是否为指尖触摸*/
	for(i= 0;i < (touches > MAX_FINGERS ? MAX_FINGERS : touches);i ++)
	{
	#ifdef GSL_NOID_VERSION
		id = cinfo.id[i];
		x =  cinfo.x[i];
		y =  cinfo.y[i];
	#else
		/*加载上报的数据*/
		x = join_bytes( ( ts->touch_data[ts->dd->x_index  + 4 * i + 1] & 0xf),
				ts->touch_data[ts->dd->x_index + 4 * i]);
		y = join_bytes(ts->touch_data[ts->dd->y_index + 4 * i + 1],
				ts->touch_data[ts->dd->y_index + 4 * i ]);
		id = ts->touch_data[ts->dd->id_index + 4 * i] >> 4;
	#endif

		if(1 <=id && id <= MAX_CONTACTS)
		{
		#ifdef FILTER_POINT
			filter_point(x, y ,id);  //进行数据过滤
		#else
			record_point(x, y , id);  //保存数据
		#endif
			report_data(ts, x_new, y_new, 10, id); //设置报表上报数据
			id_state_flag[id] = 1;
		}
	}
	for(i = 1; i <= MAX_CONTACTS; i ++)  //检测每个上报点是否设定完毕，并且上报数据
	{
		if( (0 == touches) || ((0 != id_state_old_flag[i]) && (0 == id_state_flag[i])) )
		{
			if(REPORT_DATA_ANDROID_4_0 > 0)
			{
				input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, 0);
				input_mt_sync(ts->input);
			}
			if(is_linux > 0)
			{
				report_data(ts, x_new, y_new, 0, i); 
			}
			id_sign[i]=0;
		}
		id_state_old_flag[i] = id_state_flag[i];
	}
	if(0 == touches)   //如果是指尖触摸
	{
		if(REPORT_DATA_ANDROID_4_0 > 0)
			input_mt_sync(ts->input);
	#ifdef HAVE_TOUCH_KEY
		if(key_state_flag)
		{
        		input_report_key(ts->input, key, 0);
			input_sync(ts->input);
			key_state_flag = 0;
		}
	#endif
	}
	input_sync(ts->input);  //同步上报时间

schedule:
#ifdef GSL_MONITOR
	i2c_lock_flag = 0;
i2c_lock_schedule:
#endif
	enable_irq(ts->irq);

}

#ifdef GSL_MONITOR
/*该函数简单解释：一个监听器，一直监听触摸是否有问题，如果出现问题就通过设备初始化进行校准*/
static void gsl_monitor_worker(void)
{
	u8 write_buf[4] = {0}; 
	u8 read_buf[4]  = {0};
	char init_chip_flag = 0; 
	print_info("----------------gsl_monitor_worker-----------------\n");

	if(i2c_lock_flag != 0) 
		goto queue_monitor_work;
	else
		i2c_lock_flag = 1;

	gsl_ts_read(gsl_client, 0xb0, read_buf, 4); 
	

	if(read_buf[3] != 0x5a || read_buf[2] != 0x5a || read_buf[1] != 0x5a || read_buf[0] != 0x5a)
		b0_counter ++;
	else
		b0_counter = 0;

	if(b0_counter > 1)  
	{
		printk("======read 0xb0: %x %x %x %x ======\n",read_buf[3], read_buf[2], read_buf[1], read_buf[0]);
		init_chip_flag = 1;  
		b0_counter = 0;
		goto queue_monitor_init_chip;
	}

	gsl_ts_read(gsl_client, 0xb4, read_buf, 4);
	int_2nd[3] = int_1st[3];
	int_2nd[2] = int_1st[2];
	int_2nd[1] = int_1st[1];
	int_2nd[0] = int_1st[0];
	int_1st[3] = read_buf[3];
	int_1st[2] = read_buf[2];
	int_1st[1] = read_buf[1];
	int_1st[0] = read_buf[0];


	if(int_1st[3] == int_2nd[3] && int_1st[2] == int_2nd[2] &&int_1st[1] == int_2nd[1] && int_1st[0] == int_2nd[0])
	{
		printk("======int_1st: %x %x %x %x , int_2nd: %x %x %x %x ======\n",int_1st[3], int_1st[2], int_1st[1], int_1st[0], int_2nd[3], int_2nd[2],int_2nd[1],int_2nd[0]);
		init_chip_flag = 1;
		goto queue_monitor_init_chip;
	}

#if 1 //version 1.4.0 or later than 1.4.0 read 0xbc for esd checking
	gsl_ts_read(gsl_client, 0xbc, read_buf, 4);
	
	
	if(read_buf[3] != 0 || read_buf[2] != 0 || read_buf[1] != 0 || read_buf[0] != 0)
		bc_counter++;
	else
		bc_counter = 0;
	if(bc_counter > 1)
	{
		printk("======read 0xbc: %x %x %x %x======\n",read_buf[3], read_buf[2], read_buf[1], read_buf[0]);
		init_chip_flag = 1;
		bc_counter = 0;
	}
#else
	write_buf[3] = 0x01;
	write_buf[2] = 0xfe;
	write_buf[1] = 0x10;
	write_buf[0] = 0x00;
	gsl_ts_write(gsl_client, 0xf0, write_buf, 4);
	gsl_ts_read(gsl_client, 0x10, read_buf, 4);
	gsl_ts_read(gsl_client, 0x10, read_buf, 4);
	
  
	if(read_buf[3] < 10 && read_buf[2] < 10 && read_buf[1] < 10 && read_buf[0] < 10)
		dac_counter ++;
	else
		dac_counter = 0;

	if(dac_counter > 1)
	{
		printk("======read DAC1_0: %x %x %x %x ======\n",read_buf[3], read_buf[2], read_buf[1], read_buf[0]);
		init_chip_flag = 1;
		dac_counter = 0;
	}
#endif
queue_monitor_init_chip:
	if(init_chip_flag)  
		init_chip(gsl_client);

	i2c_lock_flag = 0;    

queue_monitor_work:  
	queue_delayed_work(gsl_monitor_workqueue, &gsl_monitor_work, 100);
}
#endif

static irqreturn_t gsl_ts_irq(int irq, void *dev_id)
{
	struct gsl_ts *ts = dev_id;

	disable_irq_nosync(ts->irq);  //禁用中断

	if (!work_pending(&ts->work))  //判断等待队列是否挂起
	{
		queue_work(ts->wq, &ts->work);  //调度任务
	}

	return IRQ_HANDLED;

}

static int gslX680_ts_init(struct i2c_client *client, struct gsl_ts *ts)
{
	struct input_dev *input_device;
	int rc = 0;

	printk("[GSLX680] Enter %s\n", __func__);

	//获取触摸屏结构体gsl_ts_data 
	ts->dd = &devices[ts->device_id];  

	//如果这是第一个触摸屏设备
	if (ts->device_id == 0) {
		ts->dd->data_size = MAX_FINGERS * ts->dd->touch_bytes + ts->dd->touch_meta_data; //获取触摸屏数据的大小
		ts->dd->touch_index = 0;  //设置该触摸屏的序列号为1
	}

	/*分配触摸数据空间大小*/
	ts->touch_data = kzalloc(ts->dd->data_size, GFP_KERNEL);
	if (!ts->touch_data) {
		pr_err("%s: Unable to allocate memory\n", __func__);
		return -ENOMEM;
	}

	input_device = input_allocate_device();
	if (!input_device) {
		rc = -ENOMEM;
		goto error_alloc_dev;
	}

	/*初始化input设备*/
	ts->input = input_device; 
	input_device->name = GSLX680_I2C_NAME;
	input_device->id.bustype = BUS_I2C;
	input_device->dev.parent = &client->dev;
	input_set_drvdata(input_device, ts);

	set_bit(EV_ABS, input_device->evbit);

//	__set_bit(INPUT_PROP_DIRECT, input_device->propbit);
//	input_mt_init_slots(input_device, (MAX_CONTACTS + 1));

	if(is_linux > 0)
	{
		set_bit(BTN_TOUCH, input_device->keybit);
	 	set_bit(EV_ABS, input_device->evbit);//设置触摸屏支持上报绝对位移类型
		set_bit(EV_KEY, input_device->evbit);//设置触摸屏支持上报绝对位移类型
		//设置触摸屏支持上报绝对位x值
		input_set_abs_params(input_device, ABS_X, 0, SCREEN_MAX_X, 0, 0);
		//设置触摸屏支持上报绝对位y值
		input_set_abs_params(input_device, ABS_Y, 0, SCREEN_MAX_Y, 0, 0);
	}
	else
	{
		input_set_abs_params(input_device,ABS_MT_POSITION_X, 0, SCREEN_MAX_X, 0, 0);
		input_set_abs_params(input_device,ABS_MT_POSITION_Y, 0, SCREEN_MAX_Y, 0, 0);
		input_set_abs_params(input_device,ABS_MT_TOUCH_MAJOR, 0, PRESS_MAX, 0, 0);
		input_set_abs_params(input_device, ABS_MT_PRESSURE, 0, 255, 0, 0);
	}
#ifdef HAVE_TOUCH_KEY  
	input_device->evbit[0] = BIT_MASK(EV_KEY);  //上报按键类型
	//input_device->evbit[0] = BIT_MASK(EV_SYN) | BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	for (i = 0; i < MAX_KEY_NUM; i++)
		set_bit(key_array[i], input_device->keybit);
#endif

//	client->irq = IRQ_PORT;
	ts->irq = client->irq;

	//创建一个工作队列
	ts->wq = create_singlethread_workqueue("kworkqueue_ts");  
	if (!ts->wq) {
		dev_err(&client->dev, "Could not create workqueue\n");
		goto error_wq_create;
	}
	
	//冲洗工作队列，即清理工作队列
	flush_workqueue(ts->wq);

	//往工作队列增加一个任务，该任务为执行gslX680_ts_worker函数
	INIT_WORK(&ts->work, gslX680_ts_worker);

	rc = input_register_device(input_device);  //注册input设备
	if (rc)
		goto error_unreg_device;

	return 0;

error_unreg_device:
	destroy_workqueue(ts->wq);
error_wq_create:
	input_free_device(input_device);
error_alloc_dev:
	kfree(ts->touch_data);
	return rc;
}

static void gs_ts_work_resume(struct work_struct *work)
{
    struct gsl_ts *ts = container_of(work, struct gsl_ts,resume_work);
	init_chip(ts->client);     //芯片初始化

#ifdef GSL_MONITOR
	printk( "gsl_ts_resume () : queue gsl_monitor_work\n");
	queue_work(gsl_monitor_workqueue, &gsl_monitor_work.work);  //调度监听任务
#endif
	enable_irq(ts->irq);   //使能中断
}

static int  gsl_ts_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct gsl_ts *ts;
	int rc;
	struct device_node *np = client->dev.of_node;
	enum of_gpio_flags rst_flags;
	unsigned long irq_flags;
	int ret = 0;

	//printk("GSLX680 Enter %s\n", __func__);
	/*检测触摸屏设备*/
	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(&client->dev, "I2C functionality not supported\n");
		return -ENODEV;
	}

	/*分配一个struct gsl_ts结构体，为了后续调用函数方便*/
	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;
	printk("==kzalloc success=\n");

	/*把client嵌入到gsl_ts结构体中*/
	ts->client = client;
	/*把gsl_ts嵌入到client结构体中*/
	i2c_set_clientdata(client, ts);
	ts->device_id = 0;

	/*从设备树获取触摸中断引脚*/
	ts->irq_pin = of_get_named_gpio_flags(np, "touch-gpio", 0, (enum of_gpio_flags *)&irq_flags);
	
	/*从设备树获取复位中断引脚*/
	ts->rst_pin = of_get_named_gpio_flags(np, "reset-gpio", 0, &rst_flags);
	
	/*检测复位引脚是否有效，如果有效申请一个GPIO口设定为设备树指定的电平*/
	if (gpio_is_valid(ts->rst_pin)) {
		ts->rst_val = (rst_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1;
		ret = devm_gpio_request_one(&client->dev, ts->rst_pin, (rst_flags & OF_GPIO_ACTIVE_LOW) ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, "goodix reset pin");
		if (ret != 0) {
			dev_err(&client->dev, "goodix gpio_request error\n");
			return -EIO;
		}
		gpio_direction_output(ts->rst_pin, 0);
		gpio_set_value(ts->rst_pin, 1);
		msleep(20);
	} else {
		dev_info(&client->dev, "reset pin invalid\n");
	}

	gts = ts;

	/*对触摸屏软件进行初始化工作：中断以及input设备*/
	rc = gslX680_ts_init(client, ts);
	if (rc < 0) {
		dev_err(&client->dev, "GSLX680 init failed\n");
		goto error_mutex_destroy;
	}
	gsl_client = client;

	/*复位一次触摸屏*/
	gslX680_init();
	
	/*芯片初始化*/
	if(init_chip(ts->client) < 0)
		return -1;

	//获取中断号，并且申请中断
	ts->irq=gpio_to_irq(ts->irq_pin);
	if (ts->irq)
	{
		rc=  request_irq(ts->irq, gsl_ts_irq, IRQF_TRIGGER_RISING, client->name, ts);
		if (rc != 0) {
			printk(KERN_ALERT "Cannot allocate ts INT!ERRNO:%d\n", ret);
			goto error_req_irq_fail;
		}
	}

	/* create debug attribute */
	//rc = device_create_file(&ts->input->dev, &dev_attr_debug_enable);
#ifdef GSL_MONITOR   //如果定义了监听
	printk( "gsl_ts_probe () : queue gsl_monitor_workqueue\n");

	//初始化一个延时监听队列
	INIT_DELAYED_WORK(&gsl_monitor_work, gsl_monitor_worker);
	
	//创建一个监听队列
	gsl_monitor_workqueue = create_singlethread_workqueue("gsl_monitor_workqueue");
	
	//1000个单位后执行监听函数
	queue_delayed_work(gsl_monitor_workqueue, &gsl_monitor_work, 1000);
#endif
	device_enable_async_suspend(&client->dev);  //
	
	INIT_WORK(&ts->resume_work, gs_ts_work_resume);  //

	printk("[GSLX680] End %s\n", __func__);

	return 0;

//exit_set_irq_mode:
error_req_irq_fail:
    free_irq(ts->irq, ts);

error_mutex_destroy:
	input_free_device(ts->input);
	kfree(ts);
	return rc;
}

static int  gsl_ts_remove(struct i2c_client *client)
{
	struct gsl_ts *ts = i2c_get_clientdata(client);
	printk("==gsl_ts_remove=\n");

#ifdef GSL_MONITOR
	cancel_delayed_work_sync(&gsl_monitor_work);
	destroy_workqueue(gsl_monitor_workqueue);
#endif

	device_init_wakeup(&client->dev, 0);
	cancel_work_sync(&ts->work);
	free_irq(ts->irq, ts);
	destroy_workqueue(ts->wq);
	input_unregister_device(ts->input);
	//device_remove_file(&ts->input->dev, &dev_attr_debug_enable);

	kfree(ts->touch_data);
	kfree(ts);

	gpio_free(gts->rst_pin);	//hdc 20150129

	return 0;
}

static const struct i2c_device_id gsl_ts_id[] = {
	{GSLX680_I2C_NAME, 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, gsl_ts_id);

static struct of_device_id goodix_ts_dt_ids[] = {
	{ .compatible = "gslX680" },
	{ }
};

static struct i2c_driver gsl_ts_driver = {
	.driver = {
		.name = GSLX680_I2C_NAME,
		.owner = THIS_MODULE,
		.of_match_table = of_match_ptr(goodix_ts_dt_ids),
	},
	.probe		= gsl_ts_probe,
	.remove		= gsl_ts_remove,
	.id_table	= gsl_ts_id,
};

static int __init gsl_ts_init(void)
{
	int ret;

	if(strcasecmp(root_config, "default") == 0)
	{
		printk("Initial gslx680 Touch Driver\n");
		REPORT_DATA_ANDROID_4_0 = 1;
		is_linux = 0;
		MAX_FINGERS = 10;
		MAX_CONTACTS = 10;
	}
	else
	{
		printk("Initial gslx680 linux Touch Driver\n");
		REPORT_DATA_ANDROID_4_0 = 0;
		is_linux = 1;
		MAX_FINGERS = 1;
		MAX_CONTACTS = 1;
	}

	ret = i2c_add_driver(&gsl_ts_driver);
	return ret;
}
static void __exit gsl_ts_exit(void)
{
	i2c_del_driver(&gsl_ts_driver);
	return;
}

module_init(gsl_ts_init);
module_exit(gsl_ts_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("GSLX680 touchscreen controller driver");
MODULE_AUTHOR("Guan Yuwei, [email protected]");
MODULE_ALIAS("platform:gsl_ts");

下面是驱动对应的设备树：

	gslX680:gslX680@40 {
        compatible = "gslX680";
		reg = <0x40>;
		screen_max_x = <1024>;
		screen_max_y = <600>;
		touch-gpio = <&gpio1 20 IRQ_TYPE_LEVEL_LOW>;
		reset-gpio = <&gpio0 13 GPIO_ACTIVE_HIGH>;
	};