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Subject: Re: [Xen-devel][PATCH 1/1] cameraif: add ABI for para-virtual camera
From: Oleksandr Andrushchenko <andr2000@gmail.com>
To: Juergen Gross <jgross@suse.com>, xen-devel@lists.xenproject.org,
        konrad.wilk@oracle.com, boris.ostrovsky@oracle.com,
        mchehab@kernel.org, linux-media@vger.kernel.org,
        sakari.ailus@linux.intel.com, koji.matsuoka.xm@renesas.com
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
References: <20180731093142.3828-1-andr2000@gmail.com>
 <20180731093142.3828-2-andr2000@gmail.com>
 <99cd131d-85ae-bbfb-61ef-fdc0401727f6@suse.com>
 <5505e5af-5b64-b317-a0d8-09c11317926f@gmail.com>
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Date: Mon, 3 Sep 2018 13:16:36 +0300
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On 08/21/2018 08:54 AM, Oleksandr Andrushchenko wrote:
> On 08/14/2018 11:30 AM, Juergen Gross wrote:
>> On 31/07/18 11:31, Oleksandr Andrushchenko wrote:
>>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>>>
>>> This is the ABI for the two halves of a para-virtualized
>>> camera driver which extends Xen's reach multimedia capabilities even
>>> farther enabling it for video conferencing, In-Vehicle Infotainment,
>>> high definition maps etc.
>>>
>>> The initial goal is to support most needed functionality with the
>>> final idea to make it possible to extend the protocol if need be:
>>>
>>> 1. Provide means for base virtual device configuration:
>>>   - pixel formats
>>>   - resolutions
>>>   - frame rates
>>> 2. Support basic camera controls:
>>>   - contrast
>>>   - brightness
>>>   - hue
>>>   - saturation
>>> 3. Support streaming control
>>> 4. Support zero-copying use-cases
>>>
>>> Signed-off-by: Oleksandr Andrushchenko 
>>> <oleksandr_andrushchenko@epam.com>
>> Some style issues below...
> Will fix all the below, thank you!
>
> I would like to draw some attention of the Linux/V4L community to this
> protocol as the plan is that once it is accepted for Xen we plan to
> upstream a Linux camera front-end kernel driver which will be based
> on this work and will be a V4L2 device driver (this is why I have sent
> this patch not only to Xen, but to the corresponding Linux mailing list
> as well)
ping
>
>>> ---
>>>   xen/include/public/io/cameraif.h | 981 
>>> +++++++++++++++++++++++++++++++
>>>   1 file changed, 981 insertions(+)
>>>   create mode 100644 xen/include/public/io/cameraif.h
>>>
>>> diff --git a/xen/include/public/io/cameraif.h 
>>> b/xen/include/public/io/cameraif.h
>>> new file mode 100644
>>> index 000000000000..bdc6a1262fcf
>>> --- /dev/null
>>> +++ b/xen/include/public/io/cameraif.h
>>> +struct xencamera_config {
>>> +    uint32_t pixel_format;
>>> +    uint32_t width;
>>> +    uint32_t height;
>>> +    uint32_t frame_rate_nom;
>>> +    uint32_t frame_rate_denom;
>>> +    uint8_t num_bufs;
>> Add explicit padding?
>>
>>> +};
>>> +struct xencamera_req {
>>> +    uint16_t id;
>>> +    uint8_t operation;
>>> +    uint8_t reserved[5];
>>> +    union {
>>> +        struct xencamera_config config;
>>> +        struct xencamera_buf_create_req buf_create;
>>> +    struct xencamera_buf_destroy_req buf_destroy;
>>> +    struct xencamera_set_ctrl_req set_ctrl;
>> No tabs, please.
>>
>>> +        uint8_t reserved[56];
>>> +    } req;
>>> +};
>>> +
>>> +struct xencamera_resp {
>>> +    uint16_t id;
>>> +    uint8_t operation;
>>> +    uint8_t reserved;
>>> +    int32_t status;
>>> +    union {
>>> +        struct xencamera_config config;
>>> +        struct xencamera_buf_details_resp buf_details;
>>> +    struct xencamera_get_ctrl_details_resp ctrl_details;
>> Tab again.
>>
>>> +        uint8_t reserved1[56];
>>> +    } resp;
>>> +};
>>
>> Juergen
> Thank you,
> Oleksandr