diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/dvb-core/dvb_frontend.c | 219 |
1 files changed, 109 insertions, 110 deletions
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index d0d193d1404..eaa0a74e6a8 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -1509,9 +1509,17 @@ static bool is_dvbv3_delsys(u32 delsys) return status; } -static int emulate_delivery_system(struct dvb_frontend *fe, - enum dvbv3_emulation_type type, - u32 delsys, u32 desired_system) +/** + * emulate_delivery_system - emulate a DVBv5 delivery system with a DVBv3 type + * @fe: struct frontend; + * @delsys: DVBv5 type that will be used for emulation + * + * Provides emulation for delivery systems that are compatible with the old + * DVBv3 call. Among its usages, it provices support for ISDB-T, and allows + * using a DVB-S2 only frontend just like it were a DVB-S, if the frontent + * parameters are compatible with DVB-S spec. + */ +static int emulate_delivery_system(struct dvb_frontend *fe, u32 delsys) { int i; struct dtv_frontend_properties *c = &fe->dtv_property_cache; @@ -1519,51 +1527,52 @@ static int emulate_delivery_system(struct dvb_frontend *fe, c->delivery_system = delsys; /* - * The DVBv3 or DVBv5 call is requesting a different system. So, - * emulation is needed. - * - * Emulate newer delivery systems like ISDBT, DVBT and DTMB - * for older DVBv5 applications. The emulation will try to use - * the auto mode for most things, and will assume that the desired - * delivery system is the last one at the ops.delsys[] array + * If the call is for ISDB-T, put it into full-seg, auto mode, TV */ - dev_dbg(fe->dvb->device, - "%s: Using delivery system %d emulated as if it were a %d\n", - __func__, delsys, desired_system); + if (c->delivery_system == SYS_ISDBT) { + dev_dbg(fe->dvb->device, + "%s: Using defaults for SYS_ISDBT\n", + __func__); - /* - * For now, handles ISDB-T calls. More code may be needed here for the - * other emulated stuff - */ - if (type == DVBV3_OFDM) { - if (c->delivery_system == SYS_ISDBT) { - dev_dbg(fe->dvb->device, - "%s: Using defaults for SYS_ISDBT\n", - __func__); - - if (!c->bandwidth_hz) - c->bandwidth_hz = 6000000; - - c->isdbt_partial_reception = 0; - c->isdbt_sb_mode = 0; - c->isdbt_sb_subchannel = 0; - c->isdbt_sb_segment_idx = 0; - c->isdbt_sb_segment_count = 0; - c->isdbt_layer_enabled = 0; - for (i = 0; i < 3; i++) { - c->layer[i].fec = FEC_AUTO; - c->layer[i].modulation = QAM_AUTO; - c->layer[i].interleaving = 0; - c->layer[i].segment_count = 0; - } + if (!c->bandwidth_hz) + c->bandwidth_hz = 6000000; + + c->isdbt_partial_reception = 0; + c->isdbt_sb_mode = 0; + c->isdbt_sb_subchannel = 0; + c->isdbt_sb_segment_idx = 0; + c->isdbt_sb_segment_count = 0; + c->isdbt_layer_enabled = 7; + for (i = 0; i < 3; i++) { + c->layer[i].fec = FEC_AUTO; + c->layer[i].modulation = QAM_AUTO; + c->layer[i].interleaving = 0; + c->layer[i].segment_count = 0; } } dev_dbg(fe->dvb->device, "%s: change delivery system on cache to %d\n", - __func__, c->delivery_system); + __func__, c->delivery_system); return 0; } +/** + * dvbv5_set_delivery_system - Sets the delivery system for a DVBv5 API call + * @fe: frontend struct + * @desired_system: delivery system requested by the user + * + * A DVBv5 call know what's the desired system it wants. So, set it. + * + * There are, however, a few known issues with early DVBv5 applications that + * are also handled by this logic: + * + * 1) Some early apps use SYS_UNDEFINED as the desired delivery system. + * This is an API violation, but, as we don't want to break userspace, + * convert it to the first supported delivery system. + * 2) Some apps might be using a DVBv5 call in a wrong way, passing, for + * example, SYS_DVBT instead of SYS_ISDBT. This is because early usage of + * ISDB-T provided backward compat with DVB-T. + */ static int dvbv5_set_delivery_system(struct dvb_frontend *fe, u32 desired_system) { @@ -1578,15 +1587,14 @@ static int dvbv5_set_delivery_system(struct dvb_frontend *fe, * assume that the application wants to use the first supported * delivery system. */ - if (c->delivery_system == SYS_UNDEFINED) - c->delivery_system = fe->ops.delsys[0]; + if (desired_system == SYS_UNDEFINED) + desired_system = fe->ops.delsys[0]; /* - * This is a DVBv5 call. So, it likely knows the supported - * delivery systems. - */ - - /* Check if the desired delivery system is supported */ + * This is a DVBv5 call. So, it likely knows the supported + * delivery systems. So, check if the desired delivery system is + * supported + */ ncaps = 0; while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) { if (fe->ops.delsys[ncaps] == desired_system) { @@ -1600,70 +1608,86 @@ static int dvbv5_set_delivery_system(struct dvb_frontend *fe, } /* - * Need to emulate a delivery system + * The requested delivery system isn't supported. Maybe userspace + * is requesting a DVBv3 compatible delivery system. + * + * The emulation only works if the desired system is one of the + * delivery systems supported by DVBv3 API */ - - type = dvbv3_type(desired_system); - - /* - * The delivery system is not supported. See if it can be - * emulated. - * The emulation only works if the desired system is one of the - * DVBv3 delivery systems - */ if (!is_dvbv3_delsys(desired_system)) { dev_dbg(fe->dvb->device, - "%s: can't use a DVBv3 FE_SET_FRONTEND call for this frontend\n", - __func__); + "%s: Delivery system %d not supported.\n", + __func__, desired_system); return -EINVAL; } + type = dvbv3_type(desired_system); + /* * Get the last non-DVBv3 delivery system that has the same type * of the desired system */ ncaps = 0; while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) { - if ((dvbv3_type(fe->ops.delsys[ncaps]) == type) && - !is_dvbv3_delsys(fe->ops.delsys[ncaps])) + if (dvbv3_type(fe->ops.delsys[ncaps]) == type) delsys = fe->ops.delsys[ncaps]; ncaps++; } + /* There's nothing compatible with the desired delivery system */ if (delsys == SYS_UNDEFINED) { dev_dbg(fe->dvb->device, - "%s: Incompatible DVBv3 FE_SET_FRONTEND call for this frontend\n", - __func__); + "%s: Delivery system %d not supported on emulation mode.\n", + __func__, desired_system); return -EINVAL; } - return emulate_delivery_system(fe, type, delsys, desired_system); + dev_dbg(fe->dvb->device, + "%s: Using delivery system %d emulated as if it were %d\n", + __func__, delsys, desired_system); + + return emulate_delivery_system(fe, desired_system); } +/** + * dvbv3_set_delivery_system - Sets the delivery system for a DVBv3 API call + * @fe: frontend struct + * + * A DVBv3 call doesn't know what's the desired system it wants. It also + * doesn't allow to switch between different types. Due to that, userspace + * should use DVBv5 instead. + * However, in order to avoid breaking userspace API, limited backward + * compatibility support is provided. + * + * There are some delivery systems that are incompatible with DVBv3 calls. + * + * This routine should work fine for frontends that support just one delivery + * system. + * + * For frontends that support multiple frontends: + * 1) It defaults to use the first supported delivery system. There's an + * userspace application that allows changing it at runtime; + * + * 2) If the current delivery system is not compatible with DVBv3, it gets + * the first one that it is compatible. + * + * NOTE: in order for this to work with applications like Kaffeine that + * uses a DVBv5 call for DVB-S2 and a DVBv3 call to go back to + * DVB-S, drivers that support both DVB-S and DVB-S2 should have the + * SYS_DVBS entry before the SYS_DVBS2, otherwise it won't switch back + * to DVB-S. + */ static int dvbv3_set_delivery_system(struct dvb_frontend *fe) { int ncaps; - u32 desired_system; u32 delsys = SYS_UNDEFINED; struct dtv_frontend_properties *c = &fe->dtv_property_cache; - enum dvbv3_emulation_type type; /* If not set yet, defaults to the first supported delivery system */ if (c->delivery_system == SYS_UNDEFINED) c->delivery_system = fe->ops.delsys[0]; /* - * A DVBv3 call doesn't know what's the desired system. - * Also, DVBv3 applications don't know that ops.info->type - * could be changed, and they simply don't tune when it doesn't - * match. - * So, don't change the current delivery system, as it - * may be trying to do the wrong thing, like setting an - * ISDB-T frontend as DVB-T. Instead, find the closest - * DVBv3 system that matches the delivery system. - */ - - /* * Trivial case: just use the current one, if it already a DVBv3 * delivery system */ @@ -1674,50 +1698,25 @@ static int dvbv3_set_delivery_system(struct dvb_frontend *fe) return 0; } - /* Convert from DVBv3 into DVBv5 namespace */ - type = dvbv3_type(c->delivery_system); - switch (type) { - case DVBV3_QPSK: - desired_system = SYS_DVBS; - break; - case DVBV3_QAM: - desired_system = SYS_DVBC_ANNEX_A; - break; - case DVBV3_ATSC: - desired_system = SYS_ATSC; - break; - case DVBV3_OFDM: - desired_system = SYS_DVBT; - break; - default: - dev_dbg(fe->dvb->device, "%s: This frontend doesn't support DVBv3 calls\n", - __func__); - return -EINVAL; - } - /* - * Get a delivery system that is compatible with DVBv3 - * NOTE: in order for this to work with softwares like Kaffeine that - * uses a DVBv5 call for DVB-S2 and a DVBv3 call to go back to - * DVB-S, drivers that support both should put the SYS_DVBS entry - * before the SYS_DVBS2, otherwise it won't switch back to DVB-S. - * The real fix is that userspace applications should not use DVBv3 - * and not trust on calling FE_SET_FRONTEND to switch the delivery - * system. + * Seek for the first delivery system that it is compatible with a + * DVBv3 standard */ ncaps = 0; while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) { - if (fe->ops.delsys[ncaps] == desired_system) { - delsys = desired_system; + if (dvbv3_type(fe->ops.delsys[ncaps]) != DVBV3_UNKNOWN) { + delsys = fe->ops.delsys[ncaps]; break; } ncaps++; } if (delsys == SYS_UNDEFINED) { - dev_dbg(fe->dvb->device, "%s: Couldn't find a delivery system that matches %d\n", - __func__, desired_system); + dev_dbg(fe->dvb->device, + "%s: Couldn't find a delivery system that works with FE_SET_FRONTEND\n", + __func__); + return -EINVAL; } - return emulate_delivery_system(fe, type, delsys, desired_system); + return emulate_delivery_system(fe, delsys); } static int dtv_property_process_set(struct dvb_frontend *fe, |