1.LCD屏触摸芯片
zt2083。
2.中断唤醒管脚
define ZT2083_IRQ_PIN GPIO_58
3.触摸芯片通信地址
LCD触摸屏使用的芯片为zt2083，I2C的默认通信地址为：0x48.
4.触摸驱动代码分析
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/miscdevice.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/workqueue.h>
#include <linux/poll.h>
#include "ls1x_board_int.h"
#include "gpio.h"
#define ZT2083_DEV_NAME "zt2083"
#define ZT2083_IRQ_PIN GPIO_58
#define ZT2083_INIT 0xc8
#define ZT2083_INIT2 0xcc
#define ZT2083_Z1_EN 0xa0
#define ZT2083_Z2_EN 0xa0
#define ZT2083_X_EN 0x80
#define ZT2083_Y_EN 0x90
#define ZT2083_PWRDOWN 0x8c
#define ZT2083_ADDR 0x90
#define TS_POLL_DELAY 6
#define TS_POLL_PERIOD 30
#define ZT2083_12BIT 1
#define MAX_12BIT 2047
struct ts_event {
unsigned int x;
unsigned int y;
unsigned int z1, z2;
};
struct zt2083_data {
struct input_dev *input;
char phys[32];
struct delayed_work work;
struct i2c_client *client;
bool pendown;
int irq;
};
static struct i2c_client *zt2083_adcclient = NULL;
static int _i2c_read_byte(unsigned char addr,unsigned char *data,unsigned long num)
{
int err = 0;
struct i2c_client *client = zt2083_adcclient;
struct i2c_msg msg;
msg.addr = addr;
msg.len = num;
msg.buf = data;
msg.flags = I2C_M_RD;
if((err = i2c_transfer(client->adapter,&msg,1))!=1){
printk(KERN_ERR "msg failed!!!\n");
return 0;
}
return err;
}
static int _i2c_write_byte(unsigned char addr,unsigned char *data,unsigned long num)
{
int err = 0;
struct i2c_client *client = zt2083_adcclient;
struct i2c_msg msg;
msg.addr = addr;
msg.len = num;
msg.buf = data;
msg.flags = 0;
if((err = i2c_transfer(client->adapter,&msg,1)) != 1){
printk(KERN_ERR "msg failed!!!\n");
return 0;
}
return err;
}
static int zt2083_get_xypos(void)
{
#if 1
int err=0,ret=0;
unsigned char data[2]={0};
err = _i2c_read_byte(ZT2083_ADDR,data,2);
if(!err)
printk(KERN_ERR "zt2083 get data failed!!!\n");
ret=data[0];
return ((data[1]>>4) | ret<<4);
#endif
}
static int zt2083_set_cmd(unsigned char cmd)
{
#if 1
int err=0;
unsigned char data[1]={0};
data[0]=cmd;
err = _i2c_write_byte(ZT2083_ADDR,(unsigned char*)data,1);
if(!err)
printk(KERN_ERR "zt2083 write reg failed!!!\n");
return err;
#endif
}
static void zt2083_get_values(struct ts_event *tc)
{
zt2083_set_cmd(ZT2083_X_EN);
//zt2083_set_cmd(0xcc);
zt2083_set_cmd(0xc0);
udelay(4);
tc->x = zt2083_get_xypos();
zt2083_set_cmd(ZT2083_Y_EN);
//zt2083_set_cmd(0xdc);
zt2083_set_cmd(0xd0);
udelay(4);
tc->y = zt2083_get_xypos();
zt2083_set_cmd(ZT2083_Z1_EN);
//zt2083_set_cmd(0xec);
zt2083_set_cmd(0xe0);
udelay(4);
tc->z1 = zt2083_get_xypos();
zt2083_set_cmd(ZT2083_Z2_EN);
//zt2083_set_cmd(0xfc);
zt2083_set_cmd(0xf0);
udelay(4);
tc->z2 = zt2083_get_xypos();
//zt2083_set_cmd(ZT2083_INIT2);
return ;
}
static unsigned int zt2083_calc_pressure(struct zt2083_data *ts, struct ts_event *tc)
{
u32 rt = 0;
if (tc->x == MAX_12BIT)
tc->x = 0;
if (likely(tc->x && tc->z1)) {
rt = tc->z2 - tc->z1;
rt *= tc->x;
//rt *= tsc->x_plate_ohms;
rt *= 600;
rt /= tc->z1;
rt = (rt + 2047) >> 12;
}
return rt;
}
static void en_inter(unsigned int irq)
{
(*(volatile unsigned long *)0xbfd01094) |= 1<<(irq - 64 - 32);
enable_irq(irq);
}
void ts_work_handler(struct work_struct *work)
{
unsigned int rt=0;
struct ts_event tc;
struct zt2083_data *ts = container_of(to_delayed_work(work), struct zt2083_data, work);
zt2083_get_values(&tc);
rt = zt2083_calc_pressure(ts,&tc);
if(rt){
input_report_key(ts->input, BTN_TOUCH, 1);
input_report_abs(ts->input, ABS_PRESSURE,1); /*X-Y swap*/
input_report_abs(ts->input, ABS_X, tc.x); /*X-Y swap*/
input_report_abs(ts->input, ABS_Y, tc.y);
input_sync(ts->input);
printk( "%s:x==%d,y==%d,rt====%d\n",__func__,tc.x,tc.y,rt);
ts->pendown = true;
}
else if(ts->pendown){
input_report_key(ts->input, BTN_TOUCH, 0);
input_report_abs(ts->input, ABS_PRESSURE,0); /*X-Y swap*/
input_sync(ts->input);
ts->pendown = false;
}
//printk("ts->pendown = %d\n", ts->pendown);
if(ts->pendown)
schedule_delayed_work(&ts->work,msecs_to_jiffies(TS_POLL_PERIOD));
else{
en_inter(ts->irq);
printk("*****touch screen finish*****\n");
//ls1b_gpio_unmask_intr(ZT2083_IRQ_PIN);
}
}
static irqreturn_t ts_interrupt(int irq,void *handle)
{
printk("\t\n*****Touch screen start*****\n");
struct zt2083_data *ts = (struct zt2083_data *)handle;
disable_irq_nosync(irq);
schedule_delayed_work(&ts->work,msecs_to_jiffies(TS_POLL_DELAY));
return IRQ_HANDLED;
}
/*
* Initialization function
*/
static int zt2083_init_client(struct i2c_client *client)
{
return 0;
}
static int key_open(struct inode *inode,struct file *file)
{
return 0;
}
static int key_close(struct inode *inode,struct file *file)
{
return 0;
}
static int key_read(struct file *filp,char __user *buff,size_t count,loff_t *offp)
{
return 0;
}
static struct file_operations key_fops = {
.open = key_open,
.release = key_close,
.read = key_read,
};
static struct miscdevice key_dev = {
.minor = 189,
.name = ZT2083_DEV_NAME,
.fops = &key_fops,
};
static int __devinit zt2083_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err, ret;
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
struct zt2083_data *ts;
struct input_dev *input;
printk(KERN_INFO "----zt2083_probe----\n");
if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
dev_err(&adapter->dev, "doesn't support full I2C\n");
err = -EIO;
goto exit;
}
if (!(ts = kzalloc(sizeof(*ts), GFP_KERNEL))) {
dev_err(&adapter->dev, "failed to alloc memory\n");
err = -ENOMEM;
goto exit;
}
ts->client = client;
i2c_set_clientdata(client, ts);
/*send cmd init*/
if(!zt2083_adcclient){
printk(KERN_ERR "zt2083_detect!!!!!!\n");
zt2083_adcclient = client;
}
/* Initialize the zt2083 chip */
err = zt2083_init_client(client);
if (err)
goto exit_kfree;
err = misc_register(&key_dev);
if(err < 0 )
{
printk(ZT2083_DEV_NAME"\tmisc_register error\n");
goto exit;
}
input = input_allocate_device();
if (!input)
{
err = -ENOMEM;
goto exit;
}
ts->input=input;
ts->irq=ls1b_gpio_to_irq(ZT2083_IRQ_PIN);
input->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
set_bit(BTN_TOUCH, input->keybit);
input_set_abs_params(input, ABS_X, 0, 1024, 5, 0);
input_set_abs_params(input, ABS_Y, 0, 768, 5, 0);
input_set_abs_params(input, ABS_PRESSURE, 0, 1, 0, 0);
input->name = "ZT2083";
input->id.bustype = BUS_HOST;
err = input_register_device(input);
if (err) {
printk(KERN_ERR "Unable to register zt2083 ts input device\n");
goto exit;
}
INIT_DELAYED_WORK(&ts->work,ts_work_handler);
ls1b_gpio_set_interupt(ZT2083_IRQ_PIN);
ls1b_gpio_set_irq_type(ZT2083_IRQ_PIN,LS1B_EDGE_FALL);
ret |= request_irq(ts->irq,ts_interrupt,IRQF_DISABLED,ZT2083_DEV_NAME,ts);
printk(ZT2083_DEV_NAME"\tinitialized\n");
return 0;
exit_kfree:
kfree(ts);
exit:
return err;
}
static int __devexit zt2083_remove(struct i2c_client *client)
{
int err;
struct zt2083_data *ts = i2c_get_clientdata(client);
if(client == zt2083_adcclient)
zt2083_adcclient = NULL;
err = misc_deregister(&key_dev);
if(err < 0 )
{
printk(ZT2083_DEV_NAME"\tmisc_register error\n");
goto exit;
}
input_unregister_device(ts->input);
i2c_set_clientdata(client, NULL);
kfree(ts);
return 0;
exit:
return err;
}
static const struct i2c_device_id zt2083_id[] = {
{ "zt2083", 0 },
{ }
};
static struct i2c_driver zt2083_driver={
.driver = {
.name = "zt2083",
.owner = THIS_MODULE,
},
.probe = zt2083_probe,
.remove = __devexit_p(zt2083_remove),
.id_table = zt2083_id,
};
static int __init zt2083_init(void)
{
printk("\t\n*****zt2083_init*****\n");
return i2c_add_driver(&zt2083_driver);
}
static int __exit zt2083_exit(void)
{
int ret=0;
i2c_del_driver(&zt2083_driver);
ret = misc_deregister(&key_dev);
if(ret < 0 )
{
printk(ZT2083_DEV_NAME "cml: GPI misc_deregister error\n");
return ret;
}
return 0;
}
late_initcall(zt2083_init);
module_exit(zt2083_exit);
MODULE_AUTHOR("ZHAOKAI <zhaokai@loongson.cn>");
MODULE_DESCRIPTION("LS1B zt2083 touchscreen driver");
MODULE_LICENSE("GPL");
5触摸实验截图
6触摸芯片实现原理图
谢谢分享。