On 3/20/24 01:02, Andrew Lunn wrote:
Yes, after discussion with Vaishnav and trying to brainstorm some way to do the same thing with dt overlays, it seems that trying to use dt overlays will mean need to have completely separate implementation of mikroBUS for local ports and mikroBUS over greybus.Could you explain why please? Are greybus I2C bus masters different from physical I2C bus masters? Are greybus SPI bus masters different from physical SPI bus masters?
Well, they are virtual, so they are not declared in the device tree. I have linked the greybus i2c implementation. It basically allocates an i2c_adpater and then adds it using `i2c_add_adapter` method. This adapter can then be passed to say mikroBUS driver where it can be used as a normal i2c_adapter, and we can register the device to it.
Additionally, trying to put dt overlays in EEPROM would mean they will be incompatible with use in local ports and vice versa.I don't think you need to put the DT overlay in the EEPROM. All you need to do is translate the manifest into DT for those simple devices which can be described by the limited manifest format. For more complex devices, you use the ID to go find a DT fragment which describes the board, and skip the manifest to DT transformation. Andrew
I am not familiar enough to know if the device tree can work with virtual devices created by greybus subsystem.
Maybe the problem stems from the fact that mikroBUS does not have a physical controller (and my inability to explain the patch properly). However, the purpose of this patchset is to in fact provide a virtual mikroBUS controller to allow us to register a mikroBUS addon board described by board_info struct similar to how it is possible to create and register an i2c device on an i2c adapter using `i2c_new_client_device` or spi device using `spi_new_device`. The manifest is used to populate this board_info struct, but it will be possible to use something other than mikroBUS manifest if someone wants to. I can make the necessary adjustments by moving manifest support to its own config option.
Link: https://elixir.bootlin.com/linux/latest/source/drivers/staging/greybus/i2c.c#L230 Greybus i2c
Ayush Singh _______________________________________________ greybus-dev mailing list -- greybus-dev@xxxxxxxxxxxxxxxx To unsubscribe send an email to greybus-dev-leave@xxxxxxxxxxxxxxxx
|