Re: [PATCH 4/4] dvb_frontend: add routine for DTMB parameter validation

[Antti Palosaari <crope@iki.fi>]

On 09/11/2012 10:43 PM, Mauro Carvalho Chehab wrote:
> Em 16-08-2012 23:03, Antti Palosaari escreveu:
>> Common routine for use of dvb-core, demodulator and tuner for check
>> given DTMB parameters correctness.
>
> I won't repeat myself on the stuff I commented on patch 1/4.
>
> I dunno much about this standard, nor I have the specs, so, I'm
> assuming that you did the right checks here.

I am not 100% sure for bandwidth. When I did that driver I never got it 
working other than 8 MHz (used modulator allowed to set 5, 6, 7, 8). 
There is mentioned also 6 and 7 MHz in many places over the Net. 8 MHz 
is still surely the only real one and also I suspect it is the only one 
specified too. Like any other terrestrial modulation, hardware still 
could support more freely selectable configuration.

> In any case, as there's just one driver for this standard that doesn't work
> on "AUTO" mode, the only driver that could break here is your driver.

hd29l2 driver you mean is currently forced to AUTO mode and is abusing 
API DVB-T delivery system.

>>
>> Signed-off-by: Antti Palosaari <crope@iki.fi>
>> ---
>>   drivers/media/dvb-core/dvb_frontend.c | 97 +++++++++++++++++++++++++++++++++++
>>   drivers/media/dvb-core/dvb_frontend.h |  1 +
>>   2 files changed, 98 insertions(+)
>>
>> diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
>> index 6a19c87..7c3ba26 100644
>> --- a/drivers/media/dvb-core/dvb_frontend.c
>> +++ b/drivers/media/dvb-core/dvb_frontend.c
>> @@ -2813,6 +2813,103 @@ int dvb_validate_params_dvbc_annex_a(struct dvb_frontend *fe)
>>   }
>>   EXPORT_SYMBOL(dvb_validate_params_dvbc_annex_a);
>>
>> +int dvb_validate_params_dtmb(struct dvb_frontend *fe)
>> +{
>> +	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
>> +
>> +	dev_dbg(fe->dvb->device, "%s:\n", __func__);
>> +
>> +	switch (c->delivery_system) {
>> +	case SYS_DTMB:
>> +		break;
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: delivery_system=%d\n", __func__,
>> +				c->delivery_system);
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (c->frequency >= 470000000 && c->frequency <= 862000000) {
>> +		;
>> +	} else {
>> +		dev_dbg(fe->dvb->device, "%s: frequency=%d\n", __func__,
>> +				c->frequency);
>> +		return -EINVAL;
>> +	}
>> +
>> +	switch (c->bandwidth_hz) {
>> +	case 8000000:
>> +		break;
>
> Again, 0 should be accepted, as it means AUTO.

ok

>
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: bandwidth_hz=%d\n", __func__,
>> +				c->bandwidth_hz);
>> +		return -EINVAL;
>> +	}
>> +
>> +	switch (c->modulation) {
>> +	case QAM_AUTO:
>> +	case QPSK: /* QAM4 */
>> +	case QAM_16:
>> +	case QAM_32:
>> +	case QAM_64:
>> +	case QAM_4_NR:
>> +		break;
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: modulation=%d\n", __func__,
>> +				c->modulation);
>> +		return -EINVAL;
>> +	}
>> +
>> +	switch (c->transmission_mode) {
>> +	case TRANSMISSION_MODE_AUTO:
>> +	case TRANSMISSION_MODE_C1:
>> +	case TRANSMISSION_MODE_C3780:
>> +		break;
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: transmission_mode=%d\n", __func__,
>> +				c->transmission_mode);
>> +		return -EINVAL;
>> +	}
>> +
>> +	switch (c->guard_interval) {
>> +	case GUARD_INTERVAL_AUTO:
>> +	case GUARD_INTERVAL_PN420:
>> +	case GUARD_INTERVAL_PN595:
>> +	case GUARD_INTERVAL_PN945:
>> +		break;
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: guard_interval=%d\n", __func__,
>> +				c->guard_interval);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* inner coding LDPC */
>> +	switch (c->fec_inner) {
>> +	case FEC_AUTO:
>> +	case FEC_2_5: /* 0.4 */
>> +	case FEC_3_5: /* 0.6 */
>> +	case FEC_4_5: /* 0.8 */
>> +		break;
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: fec_inner=%d\n", __func__,
>> +				c->fec_inner);
>> +		return -EINVAL;
>> +	}
>> +
>> +	switch (c->interleaving) {
>> +	case INTERLEAVING_AUTO:
>> +	case INTERLEAVING_240:
>> +	case INTERLEAVING_720:
>> +		break;
>> +	default:
>> +		dev_dbg(fe->dvb->device, "%s: interleaving=%d\n", __func__,
>> +				c->interleaving);
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(dvb_validate_params_dtmb);
>> +
>>   int dvb_register_frontend(struct dvb_adapter* dvb,
>>   			  struct dvb_frontend* fe)
>>   {
>> diff --git a/drivers/media/dvb-core/dvb_frontend.h b/drivers/media/dvb-core/dvb_frontend.h
>> index e6e6fe1..9499039 100644
>> --- a/drivers/media/dvb-core/dvb_frontend.h
>> +++ b/drivers/media/dvb-core/dvb_frontend.h
>> @@ -428,5 +428,6 @@ extern s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime);
>>   extern int dvb_validate_params_dvbt(struct dvb_frontend *fe);
>>   extern int dvb_validate_params_dvbt2(struct dvb_frontend *fe);
>>   extern int dvb_validate_params_dvbc_annex_a(struct dvb_frontend *fe);
>> +extern int dvb_validate_params_dtmb(struct dvb_frontend *fe);
>>
>>   #endif
>>
>


-- 
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