i2c 设备的 linux 驱动程序——两个字节读取

Question

我正在尝试为 I2C 设备编写一个 Linux 驱动程序，该设备似乎与典型设备略有不同。具体来说，我需要连续读取两个字节，而不在中间发送停止位，如下所示：

[S] [Slave Addr | 0] [A] [Reg Addr 1] [A] [Sr] [Slave Addr | 1] [Data Byte 1] [NA]  
[Sr][Slave Addr | 0] [A] [Reg Addr 2] [A] [Sr] [Slave Addr | 1] [Data Byte 2] [NA] [P]

我已经研究了几种执行此操作的方法，包括 i2c_transfer()、i2c_master_send() 和 i2c_master_recv()，但我'我不确定他们是否会支持这些。有没有什么方法可以直接使用这些函数来做到这一点，而不是非常痛苦？到目前为止我发现的文档对此事还没有完全清楚。

编辑#1：添加符号键以使其可读。感谢 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/i2c/i2c-protocol

 Key to symbols
==============

S     (1 bit) : Start bit
P     (1 bit) : Stop bit
Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0.
A, NA (1 bit) : Accept and reverse accept bit. 
Addr  (7 bits): I2C 7 bit address. Note that this can be expanded as usual to 
                get a 10 bit I2C address.
Comm  (8 bits): Command byte, a data byte which often selects a register on
                the device.
Data  (8 bits): A plain data byte. Sometimes, I write DataLow, DataHigh
            for 16 bit data.
Count (8 bits): A data byte containing the length of a block operation.
[..]: Data sent by I2C device, as opposed to data sent by the host adapter.

Answer 1

在同一读/写操作中，字节之间不发送停止位。 i2c_master_recv 可能就是您所需要的。