驱动框架不再累述，百度很多
代码如下
#include <linux/kernel.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/i2c.h>#include <linux/err.h>#include <linux/regmap.h>#include <linux/slab.h>#include <linux/fs.h>#include <asm/uaccess.h>static int major;static struct class *class;static struct i2c_client *iic_client;static int read_reg(const struct i2c_client *client, unsigned int *buf , unsigned char address){ struct i2c_msg msg[2]; int ret; unsigned char date1[2]; msg[0].addr = client->addr; msg[0].buf = &address; msg[0].len = 1; msg[0].flags = 0; msg[1].addr = client->addr; msg[1].buf = date1; msg[1].len = 2; msg[1].flags = I2C_M_RD; ret = i2c_transfer(client->adapter, msg, 2); if (ret > 0) { printk(KERN_INFO “date1 : %d date1 :%d\n”,date1[0],date1[1]); *buf = (date1[0] << 8) | (date1[1]); return 1; } else return -EIO;}static struct file_operations iic_fops = { .owner = THIS_MODULE,};static int iic_probe(struct i2c_client *client,const struct i2c_device_id *id){ int ret; unsigned int data = 0; iic_client = client; printk(KERN_INFO “%s %s %d\n”, FILE, FUNCTION, LINE); major = register_chrdev(0, “iic”, &iic_fops); class = class_create(THIS_MODULE, “iic”); device_create(class, NULL, MKDEV(major, 0), NULL, “iic”); ret = read_reg(iic_client,&data,0xff); printk(KERN_INFO “Device ID 0x%x\n”,data); return 0;}static int iic_remove(struct i2c_client *client){ printk(KERN_INFO “%s %s %d\n”, FILE, FUNCTION, LINE); device_destroy(class, MKDEV(major, 0)); class_destroy(class); unregister_chrdev(major, “iic”); return 0;}static const struct i2c_device_id iic_id_table = { { “iic_test”, 0 }, {}};static const struct of_device_id of_alc_match = { { .compatible = “alc5651” }, { }};static struct i2c_driver iic_driver = { .driver = { .name = “rt5651_iic”, .owner = THIS_MODULE, .of_match_table = of_alc_match, }, .probe = iic_probe, .remove = iic_remove, .id_table = iic_id_table,};static int iic_drv_init(void){ printk(KERN_INFO “%s %s %d\n”, FILE, FUNCTION, LINE); i2c_add_driver(&iic_driver); return 0;}static void iic_drv_exit(void){ i2c_del_driver(&iic_driver);}module_init(iic_drv_init);module_exit(iic_drv_exit);MODULE_LICENSE(“GPL”);
makefile文件
#!/bin/bash
obj-m += iic.o
obj-m += iic_dts.o
#obj-m += iic_test.o
obj-m += iic_dev.o
KDIR := /rk3399/source/g3399-v7-1-2-20180529/kernel
PWD ?= $(shell pwd)
all:
make -C $(KDIR) M=$(PWD) modules
clean:
rm -rf *.o *.ko
dts文件中新增内容：
&i2c1 { status = “okay”; i2c-scl-rising-time-ns = <300>; i2c-scl-falling-time-ns = <15>; rt5651: rt5651@1a { #sound-dai-cells = <0>; compatible = “realtek,rt5651”; reg = <0x1a>; clocks = <&cru SCLK_I2S_8CH_OUT>; clock-names = “mclk”; pinctrl-names = “default”; pinctrl-0 = <&i2s_8ch_mclk>; spk-con-gpio = <&gpio0 11 GPIO_ACTIVE_HIGH>; }; alc5651: alc5651@1a{ //新增的内容 status = “okay”; compatible = “alc5651”; reg = <0x1a>;//iic设备地址，不可忽略，必须写对 };};
一样，还是贴一下结果，注意，这里的模块里面没有iic_dev.ko，只有iic_dts.ko这个模块被加载
g3399:/storage/0000-0000 # lsLOST.DIR cmd_test iic_dev.ko test.ko System Volume Information iic.ko iic_dts.ko test_char.ko g3399:/storage/0000-0000 # insmod iic_dts.ko [ 449.444537] /rk3399/source/g3399-v7-1-2-20180529/test_code/iic/iic_dts.c iic_drv_init 96[ 449.452793] /rk3399/source/g3399-v7-1-2-20180529/test_code/iic/iic_dts.c iic_probe 55[ 449.456078] dag3399:/storage/0000-0000 # te1 : 98 date1 :129[ 449.456099] Device ID 0x6281g3399:/storage/0000-0000 # g3399:/storage/0000-0000 # g3399:/storage/0000-0000 # g3399:/storage/0000-0000 # lsmodModule Size Used byiic_dts 4050 0 g3399:/storage/0000-0000 #