From: Wolfram Sang <wsa@the-dreams.de>
To: Luca Ceresoli <luca@lucaceresoli.net>
Cc: linux-media@vger.kernel.org, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Kieran Bingham <kieran.bingham@ideasonboard.com>,
Jacopo Mondi <jacopo@jmondi.org>,
Vladimir Zapolskiy <vz@mleia.com>, Peter Rosin <peda@axentia.se>
Subject: Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support
Date: Mon, 2 Sep 2019 22:42:08 +0200 [thread overview]
Message-ID: <20190902204208.GA7253@kunai> (raw)
In-Reply-To: <20190723203723.11730-3-luca@lucaceresoli.net>
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Hi Luca,
> + * Topology:
> + *
> + * Slave X @ 0x10
> + * .-----. |
> + * .-----. | |---+---- B
> + * | CPU |--A--| ATR |
> + * `-----' | |---+---- C
> + * `-----' |
> + * Slave Y @ 0x10
> + *
> + * Alias table:
> + *
> + * Client Alias
> + * -------------
> + * X 0x20
> + * Y 0x30
Great that you already provided docs for this driver!
One huge drawback for me is the attach/detach callbacks. One year ago, I
removed a similar callback from the I2C core ("[PATCH 0/2] i2c: remove
deprecated attach_adapter callback") because some drivers did a lot of
crazy things there. It took years to remove all that.
What I could imagine here: the adapter (B and C each in the picture
above) gets a flag like NEEDS_ATR before registering to the core. The
flag means all clients on that bus will have their address translated.
The core will figure out a free alias when a device is registered. We
can then have an ATR specific callback with the original and translated
address as arguments, so one can setup the HW as needed.
Do you think that would work? Jacopo, does that meet GMSL as well?
Regards,
Wolfram
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next prev parent reply other threads:[~2019-09-02 20:42 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 20:37 [RFC,v2 0/6] TI camera serdes and I2C address translation Luca Ceresoli
2019-07-23 20:37 ` [RFC,v2 1/6] i2c: core: let adapters be notified of client attach/detach Luca Ceresoli
2019-07-23 20:37 ` [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support Luca Ceresoli
2019-09-01 14:31 ` jacopo mondi
2019-09-03 7:31 ` Luca Ceresoli
2019-09-03 7:37 ` Wolfram Sang
2019-09-04 8:09 ` Peter Rosin
2019-09-08 19:40 ` Luca Ceresoli
2019-09-10 18:46 ` Wolfram Sang
2019-09-08 20:45 ` Vladimir Zapolskiy
2019-09-09 4:56 ` Vladimir Zapolskiy
2019-09-10 17:40 ` Luca Ceresoli
2019-09-09 7:22 ` Wolfram Sang
2019-09-09 15:10 ` Vladimir Zapolskiy
2019-09-09 17:48 ` Luca Ceresoli
2019-09-10 17:16 ` Wolfram Sang
2019-09-02 20:42 ` Wolfram Sang [this message]
2019-09-03 8:48 ` Luca Ceresoli
2019-09-03 9:06 ` Wolfram Sang
2019-07-23 20:37 ` [RFC,v2 3/6] media: dt-bindings: add DS90UB954-Q1 video deserializer Luca Ceresoli
2019-08-13 15:44 ` Rob Herring
2019-08-19 22:41 ` Luca Ceresoli
2019-08-20 15:44 ` Rob Herring
2019-08-21 21:50 ` Luca Ceresoli
2019-09-02 20:48 ` Wolfram Sang
2019-09-03 9:09 ` Luca Ceresoli
2019-09-03 9:34 ` Wolfram Sang
2019-09-03 11:03 ` Luca Ceresoli
2019-09-03 14:16 ` Wolfram Sang
2019-09-10 9:43 ` Sakari Ailus
2019-09-10 15:02 ` Luca Ceresoli
2019-07-23 20:37 ` [RFC,v2 4/6] media: dt-bindings: add DS90UB953-Q1 video serializer Luca Ceresoli
2019-07-23 20:37 ` [RFC,v2 5/6] media: ds90ub954: new driver for TI DS90UB954-Q1 video deserializer Luca Ceresoli
2019-07-23 20:37 ` [RFC,v2 6/6] media: ds90ub953: new driver for TI DS90UB953-Q1 video serializer Luca Ceresoli
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