xref: /OK3568_Linux_fs/kernel/Documentation/ABI/testing/sysfs-bus-i2c-devices-pca954x (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunWhat:		/sys/bus/i2c/.../idle_state
2*4882a593SmuzhiyunDate:		January 2019
3*4882a593SmuzhiyunKernelVersion:	5.2
4*4882a593SmuzhiyunContact:	Robert Shearman <robert.shearman@att.com>
5*4882a593SmuzhiyunDescription:
6*4882a593Smuzhiyun		Value that exists only for mux devices that can be
7*4882a593Smuzhiyun		written to control the behaviour of the multiplexer on
8*4882a593Smuzhiyun		idle. Possible values:
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun		===========  ===============================================
11*4882a593Smuzhiyun		-2	     disconnect on idle, i.e. deselect the last used
12*4882a593Smuzhiyun			     channel, which is useful when there is a device
13*4882a593Smuzhiyun			     with an address that conflicts with another
14*4882a593Smuzhiyun			     device on another mux on the same parent bus.
15*4882a593Smuzhiyun		-1	     leave the mux as-is, which is the most optimal
16*4882a593Smuzhiyun			     setting in terms of I2C operations and is the
17*4882a593Smuzhiyun			     default mode.
18*4882a593Smuzhiyun		0..<nchans>  set the mux to a predetermined channel,
19*4882a593Smuzhiyun			     which is useful if there is one channel that is
20*4882a593Smuzhiyun			     used almost always, and you want to reduce the
21*4882a593Smuzhiyun			     latency for normal operations after rare
22*4882a593Smuzhiyun			     transactions on other channels
23*4882a593Smuzhiyun		===========  ===============================================
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