Proposal spi.h

Proposal spi.h

[Maris]

* extend spi_device struct element 'mode' to u16 (currently u8, fully  
utilized as of 2.6.3x)
* chip_select to s16 (until now also u8)

Background:
Chip select size change: allow specification of SPI-device  
hardware-related spi control per device-specific (native) or gpio-based  
control.
mode size change: obligatory... A mode bit could also be assigned a  
selection bit: chip_select interpreted as native SSEL-index or as  
gpio-index (instead of negative value for chip_select).

Chip select differentiation bottom line: Naming of the device. I'm not  
sure how to establish this. spidev0.x are normally assigned for chip  
selects driven by the SPI peripheral hardware. GPIO-based: spidev0.gpioxx?

-Rob

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Re: Proposal spi.h

[Maris]

> ------------------------------
>
> Message: 2
> Date: Wed, 10 Feb 2010 08:36:27 +0100
> From: Maris <maris.rob-rHNaxI9ti4Y@public.gmane.org>
> Subject: [spi-devel-general] Proposal spi.h
> To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
> Message-ID: <op.u7wh21l67fwl0e-iGVHgWvKxCYNKJm4j5fLFA@public.gmane.org>
> Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes
>
> * extend spi_device struct element 'mode' to u16 (currently u8, fully
> utilized as of 2.6.3x)
> * chip_select to s16 (until now also u8)

I forgot to mention whzy signed: negative values for gpio-indices,  
positive as usual for SSEL lines.

-Rob

>
> Background:
> Chip select size change: allow specification of SPI-device
> hardware-related spi control per device-specific (native) or gpio-based
> control.
> mode size change: obligatory... A mode bit could also be assigned a
> selection bit: chip_select interpreted as native SSEL-index or as
> gpio-index (instead of negative value for chip_select).
>
> Chip select differentiation bottom line: Naming of the device. I'm not
> sure how to establish this. spidev0.x are normally assigned for chip
> selects driven by the SPI peripheral hardware. GPIO-based:  
> spidev0.gpioxx?
>
> -Rob
>
>

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SOLARIS 10 is the OS for Data Centers - provides features such as DTrace,
Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW
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