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Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected with SPI

From Sean Young <sean@mess.org>
Newsgroups linux.kernel
Subject Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected with SPI
Date 2016-07-01 11:50 +0200
Message-ID <rQ3fc-4Yz-25@gated-at.bofh.it> (permalink)
References <rQ29s-4m1-43@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Fri, Jul 01, 2016 at 05:33:42PM +0900, Andi Shyti wrote:
> The ir-spi is a simple device driver which supports the
> connection between an IR LED and the MOSI line of an SPI device.
> 
> The driver, indeed, uses the SPI framework to stream the raw data
> provided by userspace through a character device. The chardev is
> handled by the LIRC framework and its functionality basically
> provides:
> 
>  - raw write: data to be sent to the SPI and then streamed to the
>    MOSI line;
>  - set frequency: sets the frequency whith which the data should
>    be sent;
>  - set length: sets the data length. This information is
>    optional, if the length is set, then userspace should send raw
>    data only with that length; while if the length is set to '0',
>    then the driver will figure out himself the length of the data
>    based on the length of the data written on the character
>    device.
>    The latter is not recommended, though, as the driver, at
>    any write, allocates and deallocates a buffer where the data
>    from userspace are stored.
> 
> The driver provides three feedback commands:
> 
>  - get length: reads the length set and (as mentioned), if the
>    length is '0' it will be calculated at any write
>  - get frequency: the driver reports the frequency. If userpace
>    doesn't set the frequency, the driver will use a default value
>    of 38000Hz.

This interface is not compatible with other lirc devices; there is no
way of determining whether this is a regular lirc device or this new
flavour you've invented.

Also I don't see what justifies this new interface. This can be 
implemented in rc-core in less lines of code and it will be entirely 
compatible with existing user-space.


Sean

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Thread

[PATCH] [media] rc: ir-spi: add support for IR LEDs connected with SPI Andi Shyti <andi.shyti@samsung.com> - 2016-07-01 10:40 +0200
  Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected  with SPI Sean Young <sean@mess.org> - 2016-07-01 11:50 +0200
    Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected with  SPI Andi Shyti <andi.shyti@samsung.com> - 2016-07-01 14:40 +0200
      Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected  with SPI Sean Young <sean@mess.org> - 2016-07-01 15:30 +0200
        Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected  with SPI Andi Shyti <andi@etezian.org> - 2016-07-01 16:10 +0200
  Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected  with SPI kbuild test robot <lkp@intel.com> - 2016-07-02 07:00 +0200
  Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected  with SPI Rob Herring <robh@kernel.org> - 2016-07-05 16:30 +0200
    Re: [PATCH] [media] rc: ir-spi: add support for IR LEDs connected  with SPI Andi Shyti <andi@etezian.org> - 2016-07-05 17:10 +0200

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