先发出 Command Code(它一般表示芯片内部的寄存器地址),再发出 1 个字节的数据。 Functionality flag: I2C_FUNC_SMBUS_WRITE_WORD_DATA (9)SMBus Block Read I2C-tools 中的函数:i2c_smbus_read_block_data()。先发出 Command Code(它一般表示芯片内部的寄存器地址)
此协议只是I2C协议的具体实现,因而其中的command code字段也占用结构体i2c_msg中的buf字段,为buf[0] ,明确这点后就更容易理解i2cdetect的代码实现。 command code既可以表示某个寄存器偏移量,例如要访问slave device 的寄存器 0xa,则在向slave device 发送命令时,此处command code字段填写 0xa....
unsigned int data); /* a ioctl like command that can be used to perform specific functions * with the device. */ int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); struct device_driver driver; const struct i2c_device_id *id_table; /* Device detection callback f...
(Command)操作码 (Operands)写数据 (Write Data)读数据 (Read Data)NOPNo OperationFFN/AN/AN/A R...
cmd - command code byte - data byte. byte is an unsigned integer in the range 0 to 255. cb - completion callback Asynchronous SMBus write byte. The callback gets one argument (err). bus.writeByteSync(addr, cmd, byte) addr - I2C device address ...
U8X8_UNUSED void *arg_ptr) { switch(msg) { case U8X8_MSG_GPIO_AND_DELAY_INIT: break; case U8X8_MSG_DELAY_MILLI: delay_ms(arg_int); break; case U8X8_MSG_GPIO_I2C_CLOCK: break; case U8X8_MSG_GPIO_I2C_DATA: break; default: return 0; } return 1; // command processed successful...
This command is sent from a SMBus device acting as a master to the SMBus host acting as a slave. It is the same form as Write Word, with the command code replaced by the alerting device's address. [S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P] ...
0x80 KCM_CUSTOM_CODE 设置用户自定义功能寄存器 0x81 KCM_RD_INFO 读取模块信息寄存器 0x82 KCM_FW_UPGRADE 升级模块固件寄存器 0x83 KCM_RD_RAM 读取指定地址的RAM内容 0x86 KCM_MAX_DELAY 读取所有声道最大可用的延迟时间 0x87 KCM_DELAY_TIME 设置所有声道的延迟时间 0x88 KCM_PROGUCE_SIGNAL ...
在IIC子系统中,用struct i2c_client来描述一个具体的IIC设备(IIC从机)。73行,如果没有IIC设备的话就直接返回0,表示匹配不成功。 77行,用of的方式进行匹配,应该是设备树方面的,具体没了解过。 82行,如果驱动的id table存在则调用83行的i2c_match_id函数进行匹配: ...
I2C commands with a 7-bit device address of 0x55 (8 bits = 0xAA to read and 0xAB to write). Each standard command has an associated command code pair, as indicated in Table 12-1, Standard Commands. Each protocol has specific means to access the data at each command code. Data RAM ...