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Re: [PATCH v2 0/4] hw/i2c: Adds pca954x i2c mux switch device
From: |
Corey Minyard |
Subject: |
Re: [PATCH v2 0/4] hw/i2c: Adds pca954x i2c mux switch device |
Date: |
Fri, 9 Apr 2021 13:31:14 -0500 |
On Fri, Apr 09, 2021 at 09:25:41AM -0700, Patrick Venture wrote:
> The i2c mux device pca954x implements two devices:
> - the pca9546 and pca9548.
>
> v2:
> - the core i2c bus now calls a match method on each i2c child, which
> by default will only check for a match against itself.
> - the pca954x device overrides the i2c device match method to search
> the children for each of its buses that are active.
> - the pca954x device now owns an i2c bus for each channel, allowing
> the normal device model to attach devices to the channels.
I like this design. Avoiding hacking into the bus code is a bonus.
Can these devices really have multiple channels enabled at the same
time? That seems strange, but I guess that could be useful.
I'm not sure if you need to add a vmstate structure for this. In
general most new devices have them; if it's ever included on an x86
system (or a system with vmstate transfer capability, probably more than
x86) that will become an issue. I'm not sure what the expectations are,
though.
-corey
>
> Patrick Venture (4):
> hw/i2c: name I2CNode list in I2CBus
> hw/i2c: add match method for device search
> hw/i2c: move search to i2c_scan_bus method
> hw/i2c: add pca954x i2c-mux switch
>
> MAINTAINERS | 6 +
> hw/i2c/Kconfig | 4 +
> hw/i2c/core.c | 55 ++++--
> hw/i2c/i2c_mux_pca954x.c | 290 +++++++++++++++++++++++++++++++
> hw/i2c/meson.build | 1 +
> hw/i2c/trace-events | 5 +
> include/hw/i2c/i2c.h | 16 +-
> include/hw/i2c/i2c_mux_pca954x.h | 19 ++
> 8 files changed, 382 insertions(+), 14 deletions(-)
> create mode 100644 hw/i2c/i2c_mux_pca954x.c
> create mode 100644 include/hw/i2c/i2c_mux_pca954x.h
>
> --
> 2.31.1.295.g9ea45b61b8-goog
>
Re: [PATCH v2 0/4] hw/i2c: Adds pca954x i2c mux switch device,
Corey Minyard <=