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path: root/drivers/media/dvb-core/dvb_frontend.c
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Diffstat (limited to 'drivers/media/dvb-core/dvb_frontend.c')
-rw-r--r--drivers/media/dvb-core/dvb_frontend.c333
1 files changed, 184 insertions, 149 deletions
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index 6e50a758156..57601c0704c 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -920,7 +920,7 @@ static int dvb_frontend_clear_cache(struct dvb_frontend *fe)
u32 delsys;
delsys = c->delivery_system;
- memset(c, 0, sizeof(struct dtv_frontend_properties));
+ memset(c, 0, offsetof(struct dtv_frontend_properties, strength));
c->delivery_system = delsys;
c->state = DTV_CLEAR;
@@ -1509,9 +1509,74 @@ static bool is_dvbv3_delsys(u32 delsys)
return status;
}
-static int set_delivery_system(struct dvb_frontend *fe, 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 ncaps, i;
+ int i;
+ struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+ c->delivery_system = delsys;
+
+ /*
+ * If the call is for ISDB-T, put it into full-seg, auto mode, TV
+ */
+ 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 = 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);
+
+ 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)
+{
+ int ncaps;
u32 delsys = SYS_UNDEFINED;
struct dtv_frontend_properties *c = &fe->dtv_property_cache;
enum dvbv3_emulation_type type;
@@ -1522,166 +1587,136 @@ static int set_delivery_system(struct dvb_frontend *fe, u32 desired_system)
* 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];
- if (desired_system == SYS_UNDEFINED) {
- /*
- * 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 dies 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.
- */
- if (is_dvbv3_delsys(c->delivery_system)) {
+ /*
+ * 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) {
+ c->delivery_system = desired_system;
dev_dbg(fe->dvb->device,
- "%s: Using delivery system to %d\n",
- __func__, c->delivery_system);
- return 0;
- }
- 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.
- */
- ncaps = 0;
- while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) {
- if (fe->ops.delsys[ncaps] == desired_system) {
- delsys = desired_system;
- break;
- }
- ncaps++;
- }
- if (delsys == SYS_UNDEFINED) {
- dev_dbg(fe->dvb->device, "%s: Couldn't find a delivery system that matches %d\n",
+ "%s: Changing delivery system to %d\n",
__func__, desired_system);
+ return 0;
}
- } else {
- /*
- * This is a DVBv5 call. So, it likely knows the supported
- * delivery systems.
- */
+ ncaps++;
+ }
- /* 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) {
- c->delivery_system = desired_system;
- dev_dbg(fe->dvb->device,
- "%s: Changing delivery system to %d\n",
- __func__, desired_system);
- return 0;
- }
- ncaps++;
- }
- type = dvbv3_type(desired_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
+ */
+ if (!is_dvbv3_delsys(desired_system)) {
+ dev_dbg(fe->dvb->device,
+ "%s: Delivery system %d not supported.\n",
+ __func__, desired_system);
+ return -EINVAL;
+ }
- /*
- * 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 on this frontend\n",
- __func__);
- 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]))
- 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__);
- return -EINVAL;
- }
+ /*
+ * 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)
+ delsys = fe->ops.delsys[ncaps];
+ ncaps++;
}
- c->delivery_system = delsys;
+ /* There's nothing compatible with the desired delivery system */
+ if (delsys == SYS_UNDEFINED) {
+ dev_dbg(fe->dvb->device,
+ "%s: Delivery system %d not supported on emulation mode.\n",
+ __func__, desired_system);
+ return -EINVAL;
+ }
+
+ 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 delsys = SYS_UNDEFINED;
+ struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+ /* If not set yet, defaults to the first supported delivery system */
+ if (c->delivery_system == SYS_UNDEFINED)
+ c->delivery_system = fe->ops.delsys[0];
/*
- * 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
+ * Trivial case: just use the current one, if it already a DVBv3
+ * delivery system
*/
- dev_dbg(fe->dvb->device,
- "%s: Using delivery system %d emulated as if it were a %d\n",
- __func__, delsys, desired_system);
+ if (is_dvbv3_delsys(c->delivery_system)) {
+ dev_dbg(fe->dvb->device,
+ "%s: Using delivery system to %d\n",
+ __func__, c->delivery_system);
+ return 0;
+ }
/*
- * For now, handles ISDB-T calls. More code may be needed here for the
- * other emulated stuff
+ * Seek for the first delivery system that it is compatible with a
+ * DVBv3 standard
*/
- 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;
- }
+ ncaps = 0;
+ while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) {
+ if (dvbv3_type(fe->ops.delsys[ncaps]) != DVBV3_UNKNOWN) {
+ delsys = fe->ops.delsys[ncaps];
+ break;
}
+ ncaps++;
}
- dev_dbg(fe->dvb->device, "%s: change delivery system on cache to %d\n",
- __func__, c->delivery_system);
-
- return 0;
+ if (delsys == SYS_UNDEFINED) {
+ 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, delsys);
}
static int dtv_property_process_set(struct dvb_frontend *fe,
@@ -1742,7 +1777,7 @@ static int dtv_property_process_set(struct dvb_frontend *fe,
c->rolloff = tvp->u.data;
break;
case DTV_DELIVERY_SYSTEM:
- r = set_delivery_system(fe, tvp->u.data);
+ r = dvbv5_set_delivery_system(fe, tvp->u.data);
break;
case DTV_VOLTAGE:
c->voltage = tvp->u.data;
@@ -2335,7 +2370,7 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
break;
case FE_SET_FRONTEND:
- err = set_delivery_system(fe, SYS_UNDEFINED);
+ err = dvbv3_set_delivery_system(fe);
if (err)
break;
@@ -2594,7 +2629,7 @@ int dvb_register_frontend(struct dvb_adapter* dvb,
* first supported delivery system (ops->delsys[0])
*/
- fe->dtv_property_cache.delivery_system = fe->ops.delsys[0];
+ fe->dtv_property_cache.delivery_system = fe->ops.delsys[0];
dvb_frontend_clear_cache(fe);
mutex_unlock(&frontend_mutex);