On 2016-09-13 22:37, vadimp@xxxxxxxxxxxx wrote: > From: Vadim Pasternak <vadimp@xxxxxxxxxxxx> > > This driver allows I2C routing controlled through CPLD select registers on > a wide range of Mellanox systems (CPLD Lattice device). > MUX selection is provided by digital and analog HW. Analog part is not > under SW control. > Digital part is under CPLD control (channel selection/de-selection). > > Connectivity schema. > i2c-mlxcpld Digital Analog > driver > *--------* * -> mux1 (virt bus2) -> mux ->| > | I2CLPC | i2c physical * -> mux2 (virt bus3) -> mux ->| > | bridge | bus 1 *---------* | > | logic |---------------------> * mux reg * | > | in CPLD| *---------* | > *--------* i2c-mux-mlxpcld ^ * -> muxn (virt busn) -> mux ->| > | driver | | > | *---------------* | Devices > | * CPLD (i2c bus)* select | > | * registers for *--------* > | * mux selection * deselect > | *---------------* > | | > <--------> <-----------> > i2c cntrl Board cntrl reg > reg space space (mux select, > IO, LED, WD, info) Hmm, I'm wondering about the above schematics, which seems a bit overly complex. I mean, it's not relevant to this driver how the I2CLPC bridge logic in the CPLD is controlled. Particularly so since it does not need to be a this particular i2c adapter that is muxed. But what I'm really wondering is if this mux can mux same other bus than is used to control the mux. I.e. is it possible to do something like this: .---. .-------------. | | | |-- i2c2 -- | l |-- i2c0 --| mlxcpld mux | | i | | |-- i2c3 -- | n | '-------------' | u | | | x |-- i2c1 ---------' | | '---' Or is it always as below, with the mux being controlled from the same i2c bus it muxes? .---. .-------------. | l | | |-- i2c1 -- | i |-- i2c0 --+--| mlxcpld mux | | n | | | |-- i2c2 -- | u | | '-------------' | x | | | '---' '---------' Cheers, Peter -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
