Linux驱动学习—IIC总线之FT5X06触摸驱动实验

1、实现触摸坐标值上报

流程图：

设备树如下：

触摸设备对应的设备树节点是：

读取坐标的寄存器：

#include <linux/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/input.h>
#include <linux/wprkqueue.h>

#define DEVICE_MODE 0x00
#define ID_G_MODE   0Xa4

int irq;
static struct device_node *ft5x06_device_node;
static struct input_dev *ft5x06_dev;

static struct i2c_client *ft5x06_client;

static const struct i2c_device_id ft5x06_id_ts[] = {
    {"xxx",0},
};

static const struct of_device_id ft5x06_id[]  = {
    {.compatible = "edt,edt-ft5306", 0},
    {.compatible = "edt,edt-ft5x06", 0},
    {.compatible = "edt,edt-ft5406", 0},
};

static int ft5x06_read_reg(u8 reg_addr);
static void ft5x06_write_reg(u8 reg_addr, u8 data, u8 len);

static void ft5x06_func(struct work_struct *work);

DECLARE_WORK(ft5x06_work, ft5x06_func);

static void ft5x06_read_reg(u8 reg_addr)
{
    u8 data;
    struct i2c_msg msgs[] {
        //第一个数据包，写
        [0] = {
            .addr  = ft5x06_client->addr,
            .flags = 0,
            .len = sizeof(reg_addr),
            .buf = &reg_addr,
        },
        //第二个数据包，读
        [1] = {
            .addr  = ft5x06_client->addr,
            .flags = 0,
            .len =  sizeof(data),
            .buf = &data,
        },
    };
    i2c_transfer(ft5x06_client->adapter, msgs, 2);
    return data;
}

static void ft5x06_write_reg(u8 reg_addr, u8 data, u8 len)
{
    u8 buff[256];
    struct i2c_msg msgs[] = {
        [0] = {
            .addr  = ft5x06_client->addr,
            .flags = 0,
            .len = len+1,
            .buf = buff,
        }
    };
    buff[0] = reg_addr;
    memcpy(&buff[1], &data, len);
    i2c_transfer(ft5x06_client->adapter, msgs, 1);
}

static void ft5x06_func(struct work_struct *work)
{
    int TOUCH1_XH,TOUCH1_XL,x;
    int TOUCH1_YH,TOUCH1_YL,y;
    int TD_STATUS;
    
    //读取 TOUCH1_XH 的值
    TOUCH1_XH = ft5x06_read_reg(0x03);
    //读取 TOUCH1_XL 的值
    TOUCH1_XL = ft5x06_read_reg(0x04);
    //获取x的坐标值
    x = ( (TOUCH1_XH << 8) | TOUCH1_XL ) & 0x0fff;
    
    //读取 TOUCH1_YH 的值
    TOUCH1_YH = ft5x06_read_reg(0x05);
    //读取 TOUCH1_YL 的值
    TOUCH1_YL = ft5x06_read_reg(0x06);
    //获取y的坐标值
    y = ( (TOUCH1_YH << 8) | TOUCH1_YH ) & 0x0fff;
    
    //获取寄存器TD_STATUS的值
    TD_STATUS = ft5x06_read_reg(0x02);
    TD_STATUS = TD_STATUS & 0xf;
    if (TD_STATUS == 0) {//判断有没有手指按下，如果有的化就上报按下去的事件
        input_report_key(ft5x06_dev, BTN_TOUCH, 0);
        input_sync(ft5x06_dev);
    } else {
        input_report_key(ft5x06_dev, BTN_TOUCH, 1);
        input_report_key(ft5x06_dev, ABS_X, x);
        input_report_key(ft5x06_dev, ABS_Y, y);
        input_sync(ft5x06_dev);
    }
}

static irqreturn_t ft5x06_handler(int irq, void *args)
{
    printk("This is ft5x06_handler\n");
    schedule_work(&ft5x06_work);
    return IRQ_HANDLED;
}

int ft5x06_probe(struct i2c_client *i2c_client, const struct i2c_device_id *id)
{
    int ret;
    int ft5x05_irq_gpio;
    int ft5x05_reset_gpio;
    
    printk("This is ft5x06_probe\n");
    ft5x06_client = client;//因为我们再别的函数里面用到这个client，所以我们要把他复制出来。

    //获得触摸芯片的节点
    ft5x06_device_node = of_find_node_by_path("/soc/aips-bus@02100000/i2c@021a4000/edt-ft5");
    if(NULL == ft5x06_device_node)
    {
        printk("of_find_node_by_path is error\n");
        return -1;
    }
    printk("ft5x06_device_node is %s\n", ft5x06_device_node->name);
    
    //获得中断引脚的GPIO标号
    ft5x05_irq_gpio = of_get_named_gpio(ft5x06_device_node, "irq-gpios", 0);
    if (ft5x05_irq_gpio < 0) {
        printk("of_get_named_gpio IS ERROR\n ");
        return -2;
    }
    
    //获得复位引脚的GPIO标号
    ft5x05_reset_gpio = of_get_named_gpio(ft5x06_device_node, "reset-gpios", 0);
    if (ft5x05_reset_gpio < 0) {
        printk("of_get_named_gpio IS ERROR\n ");
        return -3;
    } 
    
    printk("ft5x05_irq_gpio is %d\n ",ft5x05_irq_gpio);
    printk("ft5x05_reset_gpio is %d\n ",ft5x05_reset_gpio);
    
    
    //申请中断引脚
    gpio_free(ft5x05_irq_gpio);
    ret = gpio_request(ft5x05_irq_gpio, "irq_gpio");
    if (ret < 0) {
        printk("gpio_request IS ERROR\n ");
        return -4;
    } 
    
    //申请复位引脚
    gpio_free(ft5x05_reset_gpio);
    ret = gpio_request(ft5x05_reset_gpio, "reset_gpio");
    if (ret < 0) {
        printk("gpio_request IS ERROR\n ");
        return -5;
    } 
    
    //把中断引脚设置为输入
    gpio_direction_input(ft5x05_irq_gpio);
    
    //设置复位引脚的方向为输出，先输出低电平，然后输出高电平，停止复位
    gpio_direction_output(ft5x05_reset_gpio, 0);
    msleep(5);
    gpio_set_value(ft5x05_reset_gpio, 1);
    
    //获得中断号
    irq = gpio_to_irq(ft5x05_irq_gpio);
    //申请中断
    ret = request_irq(irq, ft5x06_handler, IRQ_TYPE_EDGE_FALLING|IRQF_ONSHOT, "ft5x06_irq", NULL);
    if (ret < 0) {
        printk("request_irq IS ERROR\n ");
        goto error_request_irq;;
    } 
    
    //设置工作模式为正常模式
    ft5x06_write_reg(DEVICE_MODE, 0, 1);
    ft5x06_write_reg(ID_G_MODE, 1, 1);
    ft5x06_dev = input_allocate_device();
    ft5x06_dev->name = "ft5x06_input_test";
    
    __set_bit(EV_KEY, ft5x06_dev->evbit);//支持按键事件
    __set_bit(EV_ABS, ft5x06_dev->evbit);//支持绝对坐标事件
    __set_bit(BIN_TOUCH, ft5x06_dev->keybit);//支持按键检测
    __set_bit(ABS_X, ft5x06_dev->absbit);//支持X坐标
    __set_bit(ABS_Y, ft5x06_dev->absbit);//支持Y坐标
    //__set_bit(ABS_PRESSURE, ft5x06_dev->keybit);//支持压力检测
    
    input_set_abs_params(ft5x06_dev, ABS_X, 0, 1024, 0, 0);//设置X坐标值的范围
    input_set_abs_params(ft5x06_dev, ABS_Y, 0, 600, 0, 0);//设置y坐标值的范围
    //input_set_abs_params(ft5x06_dev, ABS_PRESSURE, 0, 255, 0, 0);//设置压力值的范围
    ret = input_register_device(ft5x06_dev);
    if (ret < 0) {
        printk("request_irq IS ERROR\n ");
        goto error_input_register);
    } 
    
    return 0;
    
error_request_irq:
    free_irq(irq, NULL);
    return ret;
error_input_register:   
    free_irq(irq, NULL);
    input_unregister_device(ft5x06_dev);
    input_free_device(ft5x06_dev);
    return ret;
}

int ft5x06_remove(struct i2c_client *i2c_client)
{
    return 0;
}
static struct i2c_driver ft5x06_driver = {
    .driver = {
        .owner = YHIS_MODULE,
        .name = "ft5x06_test",
        .of_match_table = ft5x06_id,
    },
    .probe = ft5x06_probe,
    .remove = ft5x06_remove,
    .id_table = ft5x06_pid_ts
};

static int ft5x06_driver_init(void)
{
    int ret;
    ret = i2c_add_driver(&ft5x06_driver);
    if (ret < 0) {
        printk("i2c_add_driver is error\n");
        return ret;
    }
    printk("This is ft5x06_driver_init\n");
    return 0;
}

static void ft5x06_driver_exit(void)
{
    free_irq(irq, NULL);
    input_unregister_device(ft5x06_dev);
    input_free_device(ft5x06_dev);
    i2c_del_driver(&ft5x06_driver);
    printk("This is ft5x06_driver_exit\n");
}
module_init(ft5x06_driver_init);
module_exit(ft5x06_driver_exit);
MODULE_LICENSE("GPL");

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