[media] DVB: Query DVB frontend delivery capabilities

Currently, for any multi-standard frontend it is assumed that it just
 has a single standard capability. This is fine in some cases, but
 makes things hard when there are incompatible standards in conjuction.
 Eg: DVB-S can be seen as a subset of DVB-S2, but the same doesn't hold
 the same for DSS. This is not specific to any driver as it is, but a
 generic issue. This was handled correctly in the multiproto tree,
 while such functionality is missing from the v5 API update.

 http://www.linuxtv.org/pipermail/vdr/2008-November/018417.html

 Later on a FE_CAN_2G_MODULATION was added as a hack to workaround this
 issue in the v5 API, but that hack is incapable of addressing the
 issue, as it can be used to simply distinguish between DVB-S and
 DVB-S2 alone, or another X vs X2 modulation. If there are more systems,
 then you have a potential issue.

 An application needs to query the device capabilities before requesting
 any operation from the device.

Signed-off-by: Manu Abraham <abraham.manu@gmail.com>
Acked-by: Andreas Oberritter <obi@linuxtv.org>
Acked-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Manu Abraham 2011-11-13 18:47:44 -03:00 committed by Mauro Carvalho Chehab
parent e79c70e6e5
commit ba2780c796
3 changed files with 40 additions and 2 deletions

View File

@ -974,6 +974,8 @@ static struct dtv_cmds_h dtv_cmds[DTV_MAX_COMMAND + 1] = {
_DTV_CMD(DTV_GUARD_INTERVAL, 0, 0),
_DTV_CMD(DTV_TRANSMISSION_MODE, 0, 0),
_DTV_CMD(DTV_HIERARCHY, 0, 0),
_DTV_CMD(DTV_ENUM_DELSYS, 0, 0),
};
static void dtv_property_dump(struct dtv_property *tvp)
@ -1209,6 +1211,37 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
static int dvb_frontend_ioctl_properties(struct file *file,
unsigned int cmd, void *parg);
static void dtv_set_default_delivery_caps(const struct dvb_frontend *fe, struct dtv_property *p)
{
const struct dvb_frontend_info *info = &fe->ops.info;
u32 ncaps = 0;
switch (info->type) {
case FE_QPSK:
p->u.buffer.data[ncaps++] = SYS_DVBS;
if (info->caps & FE_CAN_2G_MODULATION)
p->u.buffer.data[ncaps++] = SYS_DVBS2;
if (info->caps & FE_CAN_TURBO_FEC)
p->u.buffer.data[ncaps++] = SYS_TURBO;
break;
case FE_QAM:
p->u.buffer.data[ncaps++] = SYS_DVBC_ANNEX_AC;
break;
case FE_OFDM:
p->u.buffer.data[ncaps++] = SYS_DVBT;
if (info->caps & FE_CAN_2G_MODULATION)
p->u.buffer.data[ncaps++] = SYS_DVBT2;
break;
case FE_ATSC:
if (info->caps & (FE_CAN_8VSB | FE_CAN_16VSB))
p->u.buffer.data[ncaps++] = SYS_ATSC;
if (info->caps & (FE_CAN_QAM_16 | FE_CAN_QAM_64 | FE_CAN_QAM_128 | FE_CAN_QAM_256))
p->u.buffer.data[ncaps++] = SYS_DVBC_ANNEX_B;
break;
}
p->u.buffer.len = ncaps;
}
static int dtv_property_process_get(struct dvb_frontend *fe,
struct dtv_property *tvp,
struct file *file)
@ -1229,6 +1262,9 @@ static int dtv_property_process_get(struct dvb_frontend *fe,
}
switch(tvp->cmd) {
case DTV_ENUM_DELSYS:
dtv_set_default_delivery_caps(fe, tvp);
break;
case DTV_FREQUENCY:
tvp->u.data = c->frequency;
break;

View File

@ -316,7 +316,9 @@ struct dvb_frontend_event {
#define DTV_DVBT2_PLP_ID 43
#define DTV_MAX_COMMAND DTV_DVBT2_PLP_ID
#define DTV_ENUM_DELSYS 44
#define DTV_MAX_COMMAND DTV_ENUM_DELSYS
typedef enum fe_pilot {
PILOT_ON,

View File

@ -24,6 +24,6 @@
#define _DVBVERSION_H_
#define DVB_API_VERSION 5
#define DVB_API_VERSION_MINOR 4
#define DVB_API_VERSION_MINOR 5
#endif /*_DVBVERSION_H_*/