Messages in this thread | | | From | Luis de Oliveira <> | Subject | RE: [PATCH v4 3/5] i2c: designware: Add slave definitions | Date | Tue, 13 Dec 2016 10:50:44 +0000 |
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The controller for i2c-designware cannot be slave/master at the same time and it has to be enabled knowing beforehand if we want it to be slave or master by something outside of the controller itself.
I as looking and I see the use of this I2C_OWN_SLAVE_ADDRESS with the "linux,slave-24c02" slave interface but I am not seeing how it will help me identify a selected i2c-designware block as a "slave" device before instantiation. I'm sorry if I'm not understanding properly. I use the "linux,slave-24c02" to instantiate the i2c-designware as a slave with an address so I can do write/read operations, it is how I tested it.
Luis
-----Original Message----- From: Rob Herring [mailto:robh@kernel.org] Sent: Monday, December 12, 2016 23:16 To: Luis de Oliveira <Luis.Oliveira@synopsys.com> Cc: wsa@the-dreams.de; mark.rutland@arm.com; jarkko.nikula@linux.intel.com; andriy.shevchenko@linux.intel.com; mika.westerberg@linux.intel.com; linux-i2c@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Ramiro.Oliveira@synopsys.com; Joao.Pinto@synopsys.com; CARLOS.PALMINHA@synopsys.com Subject: Re: [PATCH v4 3/5] i2c: designware: Add slave definitions
On Mon, Dec 12, 2016 at 12:35 PM, Luis de Oliveira <Luis.Oliveira@synopsys.com> wrote: > Hi all,
Please don't top post.
> > The slave address could be set by the I2C slave backend so I can't use it to setup the controller. > A boolean property was my initial approach then Andy and Wolfram Sang suggested the use of compatible strings and later It was suggested to use a property to select mode but I can do it again if it's the best way. > Can you please tell me where should it be documented?
bindings/i2c/i2c.txt.
Actually, looking at this some more, we already have a way to describe the controller being a slave device with the I2C_OWN_SLAVE_ADDRESS flag in the reg property. We should just need a helper to read reg property of each child and check for the bit set.
Rob
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