Linux下GT9147/GT9271多点触摸驱动

xiaotaotao · 发表于 2020-8-6 10:59:27

本帖最后由 xiaotaotao 于 2020-8-6 11:01 编辑

正点原子10寸LCD触摸屏使用了GT9271作为触摸IC、而4.3寸LCD触摸（分为800*480、480*272两款）屏则使用了GT9147作为触摸IC。
这两款触摸IC在Linux下实现多点触摸不太好处理，主要原因在于GT9147/GT9271没有硬件检测每个触摸点的按下和抬起状态，
因此在上报数据的时候不好处理；像FT5426这类触摸IC，它能够检测到触摸点的按下与松开等状态，通过读取寄存器就可以知道。
虽然说GT9147/GT9271没有硬件检测每个触摸点的按下和抬起状态，但也不是不能实现多点触摸，只是比较麻烦一点，现给出笔者
的一份驱动代码，大家可以参考一下：

/***************************************************************
Copyright © ALIENTEK Co., Ltd. 1998-2029. All rights reserved.
文件名 : gt9xx.c
作者 : 邓涛
版本 : V1.0
描述 : GOODiX GT9147/GT9271触摸屏驱动程序
其他 : 无
论坛 : www.openedv.com
日志 : 初版V1.0 2020/7/26 邓涛创建
***************************************************************/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/input/mt.h>
#include <linux/of_gpio.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of_device.h>
/* 寄存器定义 */
#define GOODIX_REG_COMMAND 0x8040
#define GOODIX_REG_CFG_DATA 0x8047
#define GOODIX_REG_CFG_CSM 0x80FF
#define GOODIX_REG_ID 0x8140
#define GOODIX_READ_COOR_ADDR 0x814E
/*
*GT9271配置参数表
*第一个字节为版本号,必须保证新的版本号大于等于GT9147内部
*flash原有版本号,才会更新配置.
*/
static u8 gt9271_cfg_data[]=
{
0x41,0x00,0x05,0x20,0x03,0x0A,0x3d,0x20,0x01,0x0A,
0x28,0x0F,0x6E,0x5A,0x03,0x05,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x18,0x1A,0x1E,0x14,0x8F,0x2F,0xAA,
0x26,0x24,0x0C,0x08,0x00,0x00,0x00,0x81,0x03,0x2D,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x1A,0x3C,0x94,0xC5,0x02,0x07,0x00,0x00,0x04,
0x9E,0x1C,0x00,0x89,0x21,0x00,0x77,0x27,0x00,0x68,
0x2E,0x00,0x5B,0x37,0x00,0x5B,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x19,0x18,0x17,0x16,0x15,0x14,0x11,0x10,
0x0F,0x0E,0x0D,0x0C,0x09,0x08,0x07,0x06,0x05,0x04,
0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x02,0x04,0x06,0x07,0x08,0x0A,0x0C,
0x0D,0x0F,0x10,0x11,0x12,0x13,0x14,0x19,0x1B,0x1C,
0x1E,0x1F,0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,
0x28,0x29,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x5D,0x01,
};
/*
*GT9147配置参数表
*第一个字节为版本号,必须保证新的版本号大于等于GT9147内部
*flash原有版本号,才会更新配置.
*/
static u8 gt9147_cfg_data[]=
{
0x41,0x20,0x03,0xE0,0x01,0x05,0x0d,0x00,0x01,0x08,
0x28,0x05,0x50,0x32,0x03,0x05,0x00,0x00,0xff,0xff,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x89,0x28,0x0a,
0x17,0x15,0x31,0x0d,0x00,0x00,0x02,0x9b,0x03,0x25,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x32,0x00,0x00,
0x00,0x0f,0x94,0x94,0xc5,0x02,0x07,0x00,0x00,0x04,
0x8d,0x13,0x00,0x5c,0x1e,0x00,0x3c,0x30,0x00,0x29,
0x4c,0x00,0x1e,0x78,0x00,0x1e,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x08,0x0a,0x0c,0x0e,0x10,0x12,0x14,0x16,
0x18,0x1a,0x00,0x00,0x00,0x00,0x1f,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0x00,0x02,0x04,0x05,0x06,0x08,0x0a,0x0c,
0x0e,0x1d,0x1e,0x1f,0x20,0x22,0x24,0x28,0x29,0xff,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,
};
/* 自定义结构体,用于描述goodix触摸屏设备 */
struct goodix_gt9xx_dev {
struct i2c_client *client;
struct input_dev *input;
int max_support_points; //支持的最大触摸点数
int abs_x_max; //X轴最大值
int abs_y_max; //Y轴最大值
int reset_gpio;
int irq_gpio;
};
/* goodix触摸IC信息 */
struct goodix_i2c_chip_data {
int max_support_points; //支持的最大触摸点数
int abs_x_max; //X轴最大值
int abs_y_max; //Y轴最大值
int (*chip_cfg)(struct goodix_gt9xx_dev *); //配置函数
};
static int goodix_gt9xx_ts_write(struct goodix_gt9xx_dev *gt9xx,
u16 addr, u8 *buf, u16 len)
{
struct i2c_client *client = gt9xx->client;
struct i2c_msg msg;
u8 send_buf[190] = {0}; //gt9147/gt9271最大配置长度+4
int ret;
send_buf[0] = addr >> 8;
send_buf[1] = addr & 0xFF;
memcpy(&send_buf[2], buf, len);
msg.flags = 0; //i2c写
msg.addr = client->addr;
msg.buf = send_buf;
msg.len = len + 2;
ret = i2c_transfer(client->adapter, &msg, 1);
if (1 == ret)
return 0;
else {
dev_err(&client->dev, "%s: write error, addr=0x%x len=%d.\n",
__func__, addr, len);
return -1;
}
}
static int goodix_gt9xx_ts_read(struct goodix_gt9xx_dev *gt9xx,
u16 addr, u8 *buf, u16 len)
{
struct i2c_client *client = gt9xx->client;
struct i2c_msg msg[2];
u8 send_buf[2];
int ret;
send_buf[0] = addr >> 8;
send_buf[1] = addr & 0xFF;
msg[0].flags = 0; // i2c写
msg[0].addr = client->addr;
msg[0].buf = send_buf;
msg[0].len = 2; // 2个字节
msg[1].flags = I2C_M_RD; //i2c读
msg[1].addr = client->addr;
msg[1].buf = buf;
msg[1].len = len;
ret = i2c_transfer(client->adapter, msg, 2);
if (2 == ret)
return 0;
else {
dev_err(&client->dev, "%s: read error, addr=0x%x len=%d.\n",
__func__, addr, len);
return -1;
}
}
static int goodix_gt9147_cfg(struct goodix_gt9xx_dev *gt9xx)
{
struct i2c_client *client = gt9xx->client;
u8 buf[5] = {0};
int i;
/* 读取Chip ID */
goodix_gt9xx_ts_read(gt9xx, GOODIX_REG_ID, buf, 4);
dev_info(&client->dev, "Chip ID: %s\n", buf);
/* 软件复位 */
buf[0] = 0x2;
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_COMMAND, buf, 1);
/* 设置写入版本号以及分辨率 */
goodix_gt9xx_ts_read(gt9xx, GOODIX_REG_CFG_DATA, buf, 1);
gt9147_cfg_data[0] = buf[0]; //写入版本号等于IC原有版本号
gt9147_cfg_data[1] = gt9xx->abs_x_max & 0xFF;
gt9147_cfg_data[2] = (gt9xx->abs_x_max & 0xFF00) >> 8;
gt9147_cfg_data[3] = gt9xx->abs_y_max & 0xFF;
gt9147_cfg_data[4] = (gt9xx->abs_y_max & 0xFF00) >> 8;
/* 计算校验和 */
buf[0] = 0;
buf[1] = 1;
for(i = 0; i < sizeof(gt9147_cfg_data); i++)
buf[0] += gt9147_cfg_data[i];
buf[0] = (~buf[0]) + 1;
/* 配置寄存器 */
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_CFG_DATA,
gt9147_cfg_data, sizeof(gt9147_cfg_data));
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_CFG_CSM, buf, 2); // 写入校验和,更新配置
/* 结束软件复位,回到读坐标模式 */
msleep(1);
buf[0] = 0x0;
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_COMMAND, buf, 1);
goodix_gt9xx_ts_write(gt9xx, GOODIX_READ_COOR_ADDR, buf, 1);
return 0;
}
static int goodix_gt9271_cfg(struct goodix_gt9xx_dev *gt9xx)
{
struct i2c_client *client = gt9xx->client;
u8 buf[5] = {0};
int i;
/* 读取Chip ID */
goodix_gt9xx_ts_read(gt9xx, GOODIX_REG_ID, buf, 4);
dev_info(&client->dev, "Chip ID: %s\n", buf);
/* 软件复位 */
buf[0] = 0x2;
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_COMMAND, buf, 1);
/* 读取配置文件版本号 */
goodix_gt9xx_ts_read(gt9xx, GOODIX_REG_CFG_DATA, buf, 1);
gt9271_cfg_data[0] = buf[0]; //写入版本号等于IC原有版本号
gt9271_cfg_data[1] = gt9xx->abs_x_max & 0xFF;
gt9271_cfg_data[2] = (gt9xx->abs_x_max & 0xFF00) >> 8;
gt9271_cfg_data[3] = gt9xx->abs_y_max & 0xFF;
gt9271_cfg_data[4] = (gt9xx->abs_y_max & 0xFF00) >> 8;
/* 计算校验和 */
buf[0] = 0;
buf[1] = 1;
for(i = 0; i < sizeof(gt9271_cfg_data) - 2; i++)
buf[0] += gt9271_cfg_data[i];
buf[0] = (~buf[0]) + 1;
/* 配置寄存器 */
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_CFG_DATA,
gt9271_cfg_data, sizeof(gt9271_cfg_data));
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_CFG_CSM, buf, 2); // 写入校验和,更新配置
/* 结束软件复位,回到读坐标模式 */
msleep(1);
buf[0] = 0x0;
goodix_gt9xx_ts_write(gt9xx, GOODIX_REG_COMMAND, buf, 1);
goodix_gt9xx_ts_write(gt9xx, GOODIX_READ_COOR_ADDR, buf, 1);
return 0;
}
static int goodix_gt9xx_ts_reset(struct goodix_gt9xx_dev *gt9xx)
{
struct i2c_client *client = gt9xx->client;
int ret;
/* 从设备树中获取复位管脚和中断管脚 */
gt9xx->reset_gpio = of_get_named_gpio(client->dev.of_node, "reset-gpio", 0);
if (!gpio_is_valid(gt9xx->reset_gpio)) {
dev_err(&client->dev, "Failed to get ts reset gpio\n");
return gt9xx->reset_gpio;
}
gt9xx->irq_gpio = of_get_named_gpio(client->dev.of_node, "interrupt-gpio", 0);
if (!gpio_is_valid(gt9xx->irq_gpio)) {
dev_err(&client->dev, "Failed to get ts interrupt gpio\n");
return gt9xx->irq_gpio;
}
/* 申请使用管脚 */
ret = devm_gpio_request_one(&client->dev, gt9xx->reset_gpio,
GPIOF_OUT_INIT_HIGH, "gt9xx reset PIN");
if (ret < 0)
return ret;
ret = devm_gpio_request_one(&client->dev, gt9xx->irq_gpio,
GPIOF_OUT_INIT_HIGH, "gt9xx interrupt PIN");
if (ret < 0)
return ret;
/*
*硬件复位开始
*这里严格按照官方参考手册提供的复位时序
*/
msleep(5);
/* begin select I2C slave addr */
gpio_set_value_cansleep(gt9xx->reset_gpio, 0);
msleep(20); /* T2: > 10ms */
/* HIGH: 0x28/0x29, LOW: 0xBA/0xBB */
gpio_set_value_cansleep(gt9xx->irq_gpio, client->addr == 0x14);
usleep_range(200, 1000); /* T3: > 100us */
gpio_set_value_cansleep(gt9xx->reset_gpio, 1);
msleep(10); /* T4: > 5ms */
/* end select I2C slave addr */
gpio_direction_input(gt9xx->reset_gpio);
/* 中断管脚拉低 */
gpio_set_value_cansleep(gt9xx->irq_gpio, 0);
msleep(50); /* T5: 50ms */
/* 将中断引脚设置为输入模式 */
gpio_direction_input(gt9xx->irq_gpio);
return 0;
}
static int goodix_gt9xx_ts_get_points(struct goodix_gt9xx_dev *gt9xx, u8 *buf)
{
u8 state = 0;
int touch_num = 0;
int ret;
ret = goodix_gt9xx_ts_read(gt9xx, GOODIX_READ_COOR_ADDR, &state, 1);
if (ret)
return ret;
if ((state & 0x80) == 0) // 判断数据是否准备好
return -1;
touch_num = state & 0x0F; // 获取触摸点数
if (touch_num > gt9xx->max_support_points) {
touch_num = -1;
goto out;
}
if (touch_num) {
/* 读取触摸点坐标数据，从0x814F寄存器开始读取
* 其中每一个触摸点使用8个寄存器来描述
* 以第一个触摸点为例，各寄存器描述信息如下：
* 0x814F: 触摸点id
* 0x8150: 触摸点X轴坐标低位字节
* 0x8151: 触摸点X轴坐标高位字节
* 0x8152: 触摸点Y轴坐标低位字节
* 0x8153: 触摸点Y轴坐标高位字节
* 0x8154~0x8155: 触摸点的大小信息，我们不需要
* 0x8156: 保留
*/
ret = goodix_gt9xx_ts_read(gt9xx, GOODIX_READ_COOR_ADDR + 1,
buf, 8 * touch_num);
if (ret)
touch_num = -1;
}
out:
state = 0x0;
goodix_gt9xx_ts_write(gt9xx, GOODIX_READ_COOR_ADDR, &state, 1); //清buffer
return touch_num;
}
static irqreturn_t goodix_gt9xx_ts_isr(int irq, void *dev_id)
{
struct goodix_gt9xx_dev *gt9xx = dev_id;
static int pre_touch = 0; //上一次触摸点数
static int pre_ids[10] = {0}; //上一次触摸点的id
int cur_touch = 0; //当前触摸点数
int cur_ids[10] = {0}; //当前触摸点的id
u8 rdbuf[8 * 10] = {0}; //gt9147最大支持10点触摸
int i, x, y, id;
/* 读取触摸点坐标信息 */
cur_touch = goodix_gt9xx_ts_get_points(gt9xx, rdbuf);
if (cur_touch < 0)
goto out;
/* 上报触摸屏按下相关事件 */
for (i = 0; i < cur_touch; i++) {
u8 *buf = &rdbuf[i * 8];
id = buf[0];
x = (buf[2] << 8) | buf[1];
y = (buf[4] << 8) | buf[3];
input_mt_slot(gt9xx->input, id);
input_mt_report_slot_state(gt9xx->input, MT_TOOL_FINGER, true);
input_report_abs(gt9xx->input, ABS_MT_POSITION_X, x);
input_report_abs(gt9xx->input, ABS_MT_POSITION_Y, y);
cur_ids[i] = id;
}
/* 上报触摸屏松开相关事件 */
for (i = 0; i < pre_touch; i++) {
int j;
for (j = 0; j < cur_touch; j++) {
if (pre_ids[i] == cur_ids[j])
break;
}
if (j == cur_touch) { //表示当前触摸点中不存在这个pre_ids[i]id,表示它已经松开了
input_mt_slot(gt9xx->input, pre_ids[i]);
input_mt_report_slot_state(gt9xx->input, MT_TOOL_FINGER, false);
}
}
input_mt_report_pointer_emulation(gt9xx->input, true);
input_sync(gt9xx->input);
for (i = 0; i < cur_touch; i++)
pre_ids[i] = cur_ids[i];
pre_touch = cur_touch;
out:
return IRQ_HANDLED;
}
static int goodix_gt9xx_ts_irq(struct goodix_gt9xx_dev *gt9xx)
{
struct i2c_client *client = gt9xx->client;
int ret;
/* 注册中断服务函数 */
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, goodix_gt9xx_ts_isr, IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
client->name, gt9xx);
if (ret) {
dev_err(&client->dev, "Failed to request touchscreen IRQ.\n");
return ret;
}
return 0;
}
static int goodix_gt9xx_ts_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct goodix_gt9xx_dev *gt9xx;
const struct goodix_i2c_chip_data *chip_data;
struct input_dev *input;
int ret;
/* 实例化一个struct goodix_gt9xx_dev对象 */
gt9xx = devm_kzalloc(&client->dev, sizeof(struct goodix_gt9xx_dev), GFP_KERNEL);
if (!gt9xx) {
dev_err(&client->dev, "Failed to allocate ts driver data.\n");
return -ENOMEM;
}
gt9xx->client = client;
/* 获取gt9147、gt9271不同IC对应的信息 */
chip_data = of_device_get_match_data(&client->dev);
gt9xx->max_support_points = chip_data->max_support_points;
gt9xx->abs_x_max = chip_data->abs_x_max;
gt9xx->abs_y_max = chip_data->abs_y_max;
/* 复位GT9xx触摸芯片 */
ret = goodix_gt9xx_ts_reset(gt9xx);
if (ret)
return ret;
msleep(5);
/* 初始化GT9xx */
ret = chip_data->chip_cfg(gt9xx);
if (ret)
return ret;
/* 申请、注册中断服务函数 */
ret = goodix_gt9xx_ts_irq(gt9xx);
if (ret)
return ret;
/* 注册input设备 */
input = devm_input_allocate_device(&client->dev);
if (!input) {
dev_err(&client->dev, "Failed to allocate input device.\n");
return -ENOMEM;
}
gt9xx->input = input;
input->name = "Goodix GT9xx TouchScreen";
input->id.bustype = BUS_I2C;
input_set_abs_params(input, ABS_MT_POSITION_X,
0, gt9xx->abs_x_max, 0, 0);
input_set_abs_params(input, ABS_MT_POSITION_Y,
0, gt9xx->abs_y_max, 0, 0);
ret = input_mt_init_slots(input, gt9xx->max_support_points,
INPUT_MT_DIRECT);
if (ret) {
dev_err(&client->dev, "Failed to init MT slots.\n");
return ret;
}
ret = input_register_device(input);
if (ret)
return ret;
i2c_set_clientdata(client, gt9xx);
return 0;
}
static int goodix_gt9xx_ts_remove(struct i2c_client *client)
{
struct goodix_gt9xx_dev *gt9xx = i2c_get_clientdata(client);
input_unregister_device(gt9xx->input);
return 0;
}
static const struct goodix_i2c_chip_data goodix_gt9147_data = {
.max_support_points = 5,
.abs_x_max = 800, //以4.3寸800*480屏幕为例
.abs_y_max = 480, //如果是4.3寸480*272,这里要改
.chip_cfg = goodix_gt9147_cfg,
};
static const struct goodix_i2c_chip_data goodix_gt9271_data = {
.max_support_points = 10,
.abs_x_max = 1280,
.abs_y_max = 800,
.chip_cfg = goodix_gt9271_cfg,
};
static const struct of_device_id goodix_gt9xx_of_match[] = {
{ .compatible = "goodix,gt9147", .data = &goodix_gt9147_data },
{ .compatible = "goodix,gt9271", .data = &goodix_gt9271_data },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, goodix_gt9xx_of_match);
static struct i2c_driver goodix_gt9xx_ts_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "goodix-gt9xx",
.of_match_table = of_match_ptr(goodix_gt9xx_of_match),
},
.probe = goodix_gt9xx_ts_probe,
.remove = goodix_gt9xx_ts_remove,
};
module_i2c_driver(goodix_gt9xx_ts_driver);
MODULE_AUTHOR("Deng Tao <773904075@qq.com>, ALIENTEK, Inc.");
MODULE_DESCRIPTION("Goodix gt9147/gt9271 I2C Touchscreen Driver");
MODULE_LICENSE("GPL");

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设备树配置：

gt9xx: ts@5d {
compatible = "goodix,gt9147";
//compatible = "goodix,gt9271";
status = "okay";
reg = <0x5d>;
interrupt-parent = <&gpio0>;
interrupts = <64 0>;
reset-gpio = <&gpio0 63 GPIO_ACTIVE_LOW>;
interrupt-gpio = <&gpio0 64 GPIO_ACTIVE_LOW>;
};

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如果你的触摸IC是GT9147那就将compatible属性设置为"goodix,gt9147"，如果是GT9271就将其设置为"goodix,gt9271"。
复位管脚、中断管脚大家根据实际情况修改。
需要注意的是正点原子4.3寸屏有两款，它们的分辨率不同，分别为800*480以及480*272，代码默认支持的是800*480，
如果要改成480*272则需要对驱动代码进行修改，修改位置如下：

驱动源码见附件。