Re: [PATCH 15/17] v4l: add RF tuner channel bandwidth control

[Antti Palosaari <crope@iki.fi>]

On 03.02.2014 11:08, Hans Verkuil wrote:
> Hi Antti,
>
> On 02/01/2014 03:24 PM, Antti Palosaari wrote:
>> Modern silicon RF tuners has one or more adjustable filters on
>> signal path, in order to filter noise from desired radio channel.
>>
>> Add channel bandwidth control to tell the driver which is radio
>> channel width we want receive. Filters could be then adjusted by
>> the driver or hardware, using RF frequency and channel bandwidth
>> as a base of filter calculations.
>>
>> On automatic mode (normal mode), bandwidth is calculated from sampling
>> rate or tuning info got from userspace. That new control gives
>> possibility to set manual mode and let user have more control for
>> filters.
>>
>> Cc: Hans Verkuil <hverkuil@xs4all.nl>
>> Signed-off-by: Antti Palosaari <crope@iki.fi>
>> ---
>>   drivers/media/v4l2-core/v4l2-ctrls.c | 4 ++++
>>   include/uapi/linux/v4l2-controls.h   | 2 ++
>>   2 files changed, 6 insertions(+)
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
>> index d201f61..e44722b 100644
>> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
>> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
>> @@ -865,6 +865,8 @@ const char *v4l2_ctrl_get_name(u32 id)
>>   	case V4L2_CID_MIXER_GAIN:		return "Mixer Gain";
>>   	case V4L2_CID_IF_GAIN_AUTO:		return "IF Gain, Auto";
>>   	case V4L2_CID_IF_GAIN:			return "IF Gain";
>> +	case V4L2_CID_BANDWIDTH_AUTO:		return "Channel Bandwidth, Auto";
>> +	case V4L2_CID_BANDWIDTH:		return "Channel Bandwidth";
>>   	default:
>>   		return NULL;
>>   	}
>> @@ -917,6 +919,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>>   	case V4L2_CID_LNA_GAIN_AUTO:
>>   	case V4L2_CID_MIXER_GAIN_AUTO:
>>   	case V4L2_CID_IF_GAIN_AUTO:
>> +	case V4L2_CID_BANDWIDTH_AUTO:
>>   		*type = V4L2_CTRL_TYPE_BOOLEAN;
>>   		*min = 0;
>>   		*max = *step = 1;
>> @@ -1078,6 +1081,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>>   	case V4L2_CID_LNA_GAIN:
>>   	case V4L2_CID_MIXER_GAIN:
>>   	case V4L2_CID_IF_GAIN:
>> +	case V4L2_CID_BANDWIDTH:
>
> Booleans never have the slider flag set (they are represented as a checkbox, so a slider
> makes no sense).
>
>>   		*flags |= V4L2_CTRL_FLAG_SLIDER;

These are two different controls, as it is controls groups with auto 
mode (boolean) and value (slider).

regards
Antti

>>   		break;
>>   	case V4L2_CID_PAN_RELATIVE:
>> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
>> index 076fa34..3cf68a6 100644
>> --- a/include/uapi/linux/v4l2-controls.h
>> +++ b/include/uapi/linux/v4l2-controls.h
>> @@ -905,5 +905,7 @@ enum v4l2_deemphasis {
>>   #define V4L2_CID_MIXER_GAIN			(V4L2_CID_RF_TUNER_CLASS_BASE + 4)
>>   #define V4L2_CID_IF_GAIN_AUTO			(V4L2_CID_RF_TUNER_CLASS_BASE + 5)
>>   #define V4L2_CID_IF_GAIN			(V4L2_CID_RF_TUNER_CLASS_BASE + 6)
>> +#define V4L2_CID_BANDWIDTH_AUTO			(V4L2_CID_RF_TUNER_CLASS_BASE + 7)
>> +#define V4L2_CID_BANDWIDTH			(V4L2_CID_RF_TUNER_CLASS_BASE + 8)
>>
>>   #endif
>>


-- 
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