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Subject: Re: [PATCH 06/13] media: i2c: Switch control to
 V4L2_CID_ANALOGUE_GAIN
To:     Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc:     Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Ezequiel Garcia <ezequiel@collabora.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Yang Li <yang.lee@linux.alibaba.com>,
        "open list:MEDIA INPUT INFRASTRUCTURE (V4L/DVB)" 
        <linux-media@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        Yong Zhi <yong.zhi@intel.com>,
        Bingbu Cao <bingbu.cao@intel.com>,
        Tianshu Qiu <tian.shu.qiu@intel.com>,
        Colin Ian King <colin.king@canonical.com>,
        laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com
References: <20210722203407.3588046-1-djrscally@gmail.com>
 <20210722203407.3588046-7-djrscally@gmail.com> <YPp2X71VoMV4O+io@aptenodytes>
From:   Daniel Scally <djrscally@gmail.com>
Message-ID: <b7a32257-45ce-517f-ece1-63a27f768dc6@gmail.com>
Date:   Fri, 23 Jul 2021 13:00:40 +0100
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Hi Paul

On 23/07/2021 08:57, Paul Kocialkowski wrote:
> Hi,
>
> On Thu 22 Jul 21, 21:34, Daniel Scally wrote:
>> The V4L2_CID_GAIN control for this driver configures registers that
>> the datasheet specifies as analogue gain. Switch the control's ID
>> to V4L2_CID_ANALOGUE_GAIN.
> I had some doubts about this when writing the driver because it's called
> "AEC gain" but it seems that you're right. The datasheet also defines
> 0x350a and 0x350b as digital gain (which are unused by the driver).
>
> This is:
> Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>


Thanks - yeah it took me a while to be sure too. Particularly confusing
because it's called "AEC gain" in a section headed "Manual exposure /
gain compensation"...they do like to make the datasheets clear as mud
sometimes.

>
> Cheers,
>
> Paul
>
>> Signed-off-by: Daniel Scally <djrscally@gmail.com>
>> ---
>>  drivers/media/i2c/ov8865.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/media/i2c/ov8865.c b/drivers/media/i2c/ov8865.c
>> index c012f5cb11ab..09558a3342dd 100644
>> --- a/drivers/media/i2c/ov8865.c
>> +++ b/drivers/media/i2c/ov8865.c
>> @@ -2137,7 +2137,7 @@ static int ov8865_exposure_configure(struct ov8865_sensor *sensor, u32 exposure)
>>  
>>  /* Gain */
>>  
>> -static int ov8865_gain_configure(struct ov8865_sensor *sensor, u32 gain)
>> +static int ov8865_analog_gain_configure(struct ov8865_sensor *sensor, u32 gain)
>>  {
>>  	int ret;
>>  
>> @@ -2447,8 +2447,8 @@ static int ov8865_s_ctrl(struct v4l2_ctrl *ctrl)
>>  		if (ret)
>>  			return ret;
>>  		break;
>> -	case V4L2_CID_GAIN:
>> -		ret = ov8865_gain_configure(sensor, ctrl->val);
>> +	case V4L2_CID_ANALOGUE_GAIN:
>> +		ret = ov8865_analog_gain_configure(sensor, ctrl->val);
>>  		if (ret)
>>  			return ret;
>>  		break;
>> @@ -2493,7 +2493,7 @@ static int ov8865_ctrls_init(struct ov8865_sensor *sensor)
>>  
>>  	/* Gain */
>>  
>> -	v4l2_ctrl_new_std(handler, ops, V4L2_CID_GAIN, 128, 8191, 128, 128);
>> +	v4l2_ctrl_new_std(handler, ops, V4L2_CID_ANALOGUE_GAIN, 128, 8191, 128, 128);
>>  
>>  	/* White Balance */
>>  
>> -- 
>> 2.25.1
>>