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Subject: Re: How to define an I2C-to-SPI bridge device ?
From: =?ISO-8859-1?Q?Andr=E9?= Schwarz <andre.schwarz@matrix-vision.de>
To: Anton Vorontsov <cbouatmailru@gmail.com>
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Date: Mon, 06 Sep 2010 16:37:52 +0200
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Anton,

looks like I should have looked at include/spi/spi.h earlier :

/*
 * INTERFACES between SPI master-side drivers and SPI infrastructure.
 * (There's no SPI slave support for Linux yet...)
 */

...this is what I've been looking for.


thanks for your help and sorry for the noise.


Regards,
André





On Mon, 2010-09-06 at 13:40 +0200, Andre Schwarz wrote:
> Anton,
> 
> > we're about to get new MPC8377 based hardware with various peripherals.
> >> There are two I2C-to-SPI bridge devices (NXP SC18IS602) and I'm not sure
> >> how to define a proper dts...
> >>
> >> Of course it's an easy thing creating 2 child nodes on the CPU's I2C
> >> device - but how can I represent the created SPI bus ?
> > Um.. the same as the other SPI buses? I.e.
> >
> > i2c-controller {  /* SOC I2C controller */
> > 	spi-controller {  /* The I2C-to-SPI bridge */
> > 		spi-device@0 {
> > 		};
> > 		spi-device@1 {
> > 		};
> > 	};
> > };
> >
> ok , thanks - looks straight forward.
> Is this any more than plain definition, i.e. will this trigger any I2C 
> or SPI device registration/linking ?
> >> Is the (possibly) required driver (of_sc18is60x_spi ?) supposed to be an
> >> I2C slave or an SPI host driver ?
> > It should be an I2C driver that registers an SPI master (i.e.
> > calls spi_alloc_master() and spi_register_master()).
> hmm - ok. Will have to do it manually then ...
> 
> I still wonder how to make the driver arch-generic *and* of-capable.
> Do we need a generic I2C slave driver that can be probed along with an 
> "of glue driver" or should the of-binding be part of a single device 
> driver ?
> 
> Sorry for the dumb questions - looks like I expected a little too much 
> functionality already existing.
> 
> 
> Regards,
> André
> 




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