V4L/DVB (7719): pvrusb2: Implement input selection enforcement

In the pvrusb2 driver, different interfaces (e.g. V4L, DVB) have

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/pvrusb2/pvrusb2-context.c

@@ -245,6 +245,22 @@ struct pvr2_context *pvr2_context_create(
 }
 
 
+static void pvr2_context_reset_input_limits(struct pvr2_context *mp)
+{
+	unsigned int tmsk,mmsk;
+	struct pvr2_channel *cp;
+	struct pvr2_hdw *hdw = mp->hdw;
+	mmsk = pvr2_hdw_get_input_available(hdw);
+	tmsk = mmsk;
+	for (cp = mp->mc_first; cp; cp = cp->mc_next) {
+		if (!cp->input_mask) continue;
+		tmsk &= cp->input_mask;
+	}
+	pvr2_hdw_set_input_allowed(hdw,mmsk,tmsk);
+	pvr2_hdw_commit_ctl(hdw);
+}
+
+
 static void pvr2_context_enter(struct pvr2_context *mp)
 {
 	mutex_lock(&mp->mutex);
@@ -300,7 +316,9 @@ void pvr2_channel_done(struct pvr2_channel *cp)
 {
 	struct pvr2_context *mp = cp->mc_head;
 	pvr2_context_enter(mp);
+	cp->input_mask = 0;
 	pvr2_channel_disclaim_stream(cp);
+	pvr2_context_reset_input_limits(mp);
 	if (cp->mc_next) {
 		cp->mc_next->mc_prev = cp->mc_prev;
 	} else {
@@ -316,6 +334,57 @@ void pvr2_channel_done(struct pvr2_channel *cp)
 }
 
 
+int pvr2_channel_limit_inputs(struct pvr2_channel *cp,unsigned int cmsk)
+{
+	unsigned int tmsk,mmsk;
+	int ret = 0;
+	struct pvr2_channel *p2;
+	struct pvr2_hdw *hdw = cp->hdw;
+
+	mmsk = pvr2_hdw_get_input_available(hdw);
+	cmsk &= mmsk;
+	if (cmsk == cp->input_mask) {
+		/* No change; nothing to do */
+		return 0;
+	}
+
+	pvr2_context_enter(cp->mc_head);
+	do {
+		if (!cmsk) {
+			cp->input_mask = 0;
+			pvr2_context_reset_input_limits(cp->mc_head);
+			break;
+		}
+		tmsk = mmsk;
+		for (p2 = cp->mc_head->mc_first; p2; p2 = p2->mc_next) {
+			if (p2 == cp) continue;
+			if (!p2->input_mask) continue;
+			tmsk &= p2->input_mask;
+		}
+		if (!(tmsk & cmsk)) {
+			ret = -EPERM;
+			break;
+		}
+		tmsk &= cmsk;
+		if ((ret = pvr2_hdw_set_input_allowed(hdw,mmsk,tmsk)) != 0) {
+			/* Internal failure changing allowed list; probably
+			   should not happen, but react if it does. */
+			break;
+		}
+		cp->input_mask = cmsk;
+		pvr2_hdw_commit_ctl(hdw);
+	} while (0);
+	pvr2_context_exit(cp->mc_head);
+	return ret;
+}
+
+
+unsigned int pvr2_channel_get_limited_inputs(struct pvr2_channel *cp)
+{
+	return cp->input_mask;
+}
+
+
 int pvr2_channel_claim_stream(struct pvr2_channel *cp,
 			      struct pvr2_context_stream *sp)
 {

drivers/media/video/pvrusb2/pvrusb2-context.h

@@ -62,6 +62,7 @@ struct pvr2_channel {
 	struct pvr2_channel *mc_prev;
 	struct pvr2_context_stream *stream;
 	struct pvr2_hdw *hdw;
+	unsigned int input_mask;
 	void (*check_func)(struct pvr2_channel *);
 };
 
@@ -72,6 +73,8 @@ void pvr2_context_disconnect(struct pvr2_context *);
 
 void pvr2_channel_init(struct pvr2_channel *,struct pvr2_context *);
 void pvr2_channel_done(struct pvr2_channel *);
+int pvr2_channel_limit_inputs(struct pvr2_channel *,unsigned int);
+unsigned int pvr2_channel_get_limited_inputs(struct pvr2_channel *);
 int pvr2_channel_claim_stream(struct pvr2_channel *,
 			      struct pvr2_context_stream *);
 struct pvr2_ioread *pvr2_channel_create_mpeg_stream(

drivers/media/video/pvrusb2/pvrusb2-dvb.c

@@ -244,13 +244,10 @@ static int pvr2_dvb_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
 
 static int pvr2_dvb_bus_ctrl(struct dvb_frontend *fe, int acquire)
 {
-	/* TO DO: This function will call into the core and request for
-	 * input to be set to 'dtv' if (acquire) and if it isn't set already.
-	 *
-	 * If (!acquire) then we should do nothing -- don't switch inputs
-	 * again unless the analog side of the driver requests the bus.
-	 */
-	return 0;
+	struct pvr2_dvb_adapter *adap = fe->dvb->priv;
+	return pvr2_channel_limit_inputs(
+	    &adap->channel,
+	    (acquire ? (1 << PVR2_CVAL_INPUT_DTV) : 0));
 }
 
 static int pvr2_dvb_adapter_init(struct pvr2_dvb_adapter *adap)
@@ -320,32 +317,26 @@ static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
 {
 	struct pvr2_hdw *hdw = adap->channel.hdw;
 	struct pvr2_dvb_props *dvb_props = hdw->hdw_desc->dvb_props;
-	int ret;
+	int ret = 0;
 
 	if (dvb_props == NULL) {
 		err("fe_props not defined!");
 		return -EINVAL;
 	}
 
-	/* FIXME: This code should be moved into the core,
-	 * and should only be called if we don't already have
-	 * control of the bus.
-	 *
-	 * We can't call "pvr2_dvb_bus_ctrl(adap->fe, 1)" from here,
-	 * because adap->fe isn't defined yet.
-	 */
-	ret = pvr2_ctrl_set_value(pvr2_hdw_get_ctrl_by_id(hdw,
-							  PVR2_CID_INPUT),
-				  PVR2_CVAL_INPUT_DTV);
-	if (ret != 0)
+	ret = pvr2_channel_limit_inputs(
+	    &adap->channel,
+	    (1 << PVR2_CVAL_INPUT_DTV));
+	if (ret) {
+		err("failed to grab control of dtv input (code=%d)",
+		    ret);
 		return ret;
-
-	pvr2_hdw_commit_ctl(hdw);
-
+	}
 
 	if (dvb_props->frontend_attach == NULL) {
 		err("frontend_attach not defined!");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto done;
 	}
 
 	if ((dvb_props->frontend_attach(adap) == 0) && (adap->fe)) {
@@ -354,7 +345,8 @@ static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
 			err("frontend registration failed!");
 			dvb_frontend_detach(adap->fe);
 			adap->fe = NULL;
-			return -ENODEV;
+			ret = -ENODEV;
+			goto done;
 		}
 
 		if (dvb_props->tuner_attach)
@@ -368,10 +360,13 @@ static int pvr2_dvb_frontend_init(struct pvr2_dvb_adapter *adap)
 
 	} else {
 		err("no frontend was attached!");
-		return -ENODEV;
+		ret = -ENODEV;
+		return ret;
 	}
 
-	return 0;
+ done:
+	pvr2_channel_limit_inputs(&adap->channel, 0);
+	return ret;
 }
 
 static int pvr2_dvb_frontend_exit(struct pvr2_dvb_adapter *adap)

drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h

@@ -336,8 +336,10 @@ struct pvr2_hdw {
 	int v4l_minor_number_vbi;
 	int v4l_minor_number_radio;
 
-	/* Bit mask of PVR2_CVAL_INPUT choices which are valid */
+	/* Bit mask of PVR2_CVAL_INPUT choices which are valid for the hardware */
 	unsigned int input_avail_mask;
+	/* Bit mask of PVR2_CVAL_INPUT choices which are currenly allowed */
+	unsigned int input_allowed_mask;
 
 	/* Location of eeprom or a negative number if none */
 	int eeprom_addr;

drivers/media/video/pvrusb2/pvrusb2-hdw.c

@@ -249,6 +249,7 @@ static const struct pvr2_fx2cmd_descdef pvr2_fx2cmd_desc[] = {
 };
 
 
+static int pvr2_hdw_set_input(struct pvr2_hdw *hdw,int v);
 static void pvr2_hdw_state_sched(struct pvr2_hdw *);
 static int pvr2_hdw_state_eval(struct pvr2_hdw *);
 static void pvr2_hdw_set_cur_freq(struct pvr2_hdw *,unsigned long);
@@ -404,30 +405,12 @@ static int ctrl_get_input(struct pvr2_ctrl *cptr,int *vp)
 
 static int ctrl_check_input(struct pvr2_ctrl *cptr,int v)
 {
-	return ((1 << v) & cptr->hdw->input_avail_mask) != 0;
+	return ((1 << v) & cptr->hdw->input_allowed_mask) != 0;
 }
 
 static int ctrl_set_input(struct pvr2_ctrl *cptr,int m,int v)
 {
-	struct pvr2_hdw *hdw = cptr->hdw;
-
-	if (hdw->input_val != v) {
-		hdw->input_val = v;
-		hdw->input_dirty = !0;
-	}
-
-	/* Handle side effects - if we switch to a mode that needs the RF
-	   tuner, then select the right frequency choice as well and mark
-	   it dirty. */
-	if (hdw->input_val == PVR2_CVAL_INPUT_RADIO) {
-		hdw->freqSelector = 0;
-		hdw->freqDirty = !0;
-	} else if ((hdw->input_val == PVR2_CVAL_INPUT_TV) ||
-		   (hdw->input_val == PVR2_CVAL_INPUT_DTV)) {
-		hdw->freqSelector = 1;
-		hdw->freqDirty = !0;
-	}
-	return 0;
+	return pvr2_hdw_set_input(cptr->hdw,v);
 }
 
 static int ctrl_isdirty_input(struct pvr2_ctrl *cptr)
@@ -1916,6 +1899,7 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	if (hdw_desc->flag_has_composite) m |= 1 << PVR2_CVAL_INPUT_COMPOSITE;
 	if (hdw_desc->flag_has_fmradio) m |= 1 << PVR2_CVAL_INPUT_RADIO;
 	hdw->input_avail_mask = m;
+	hdw->input_allowed_mask = hdw->input_avail_mask;
 
 	/* If not a hybrid device, pathway_state never changes.  So
 	   initialize it here to what it should forever be. */
@@ -3948,6 +3932,24 @@ static int pvr2_hdw_state_update(struct pvr2_hdw *hdw)
 }
 
 
+static unsigned int print_input_mask(unsigned int msk,
+				     char *buf,unsigned int acnt)
+{
+	unsigned int idx,ccnt;
+	unsigned int tcnt = 0;
+	for (idx = 0; idx < ARRAY_SIZE(control_values_input); idx++) {
+		if (!((1 << idx) & msk)) continue;
+		ccnt = scnprintf(buf+tcnt,
+				 acnt-tcnt,
+				 "%s%s",
+				 (tcnt ? ", " : ""),
+				 control_values_input[idx]);
+		tcnt += ccnt;
+	}
+	return tcnt;
+}
+
+
 static const char *pvr2_pathway_state_name(int id)
 {
 	switch (id) {
@@ -4016,6 +4018,28 @@ static unsigned int pvr2_hdw_report_unlocked(struct pvr2_hdw *hdw,int which,
 			"state: %s",
 			pvr2_get_state_name(hdw->master_state));
 	case 4: {
+		unsigned int tcnt = 0;
+		unsigned int ccnt;
+
+		ccnt = scnprintf(buf,
+				 acnt,
+				 "Hardware supported inputs: ");
+		tcnt += ccnt;
+		tcnt += print_input_mask(hdw->input_avail_mask,
+					 buf+tcnt,
+					 acnt-tcnt);
+		if (hdw->input_avail_mask != hdw->input_allowed_mask) {
+			ccnt = scnprintf(buf+tcnt,
+					 acnt-tcnt,
+					 "; allowed inputs: ");
+			tcnt += ccnt;
+			tcnt += print_input_mask(hdw->input_allowed_mask,
+						 buf+tcnt,
+						 acnt-tcnt);
+		}
+		return tcnt;
+	}
+	case 5: {
 		struct pvr2_stream_stats stats;
 		if (!hdw->vid_stream) break;
 		pvr2_stream_get_stats(hdw->vid_stream,
@@ -4210,6 +4234,74 @@ unsigned int pvr2_hdw_get_input_available(struct pvr2_hdw *hdw)
 }
 
 
+unsigned int pvr2_hdw_get_input_allowed(struct pvr2_hdw *hdw)
+{
+	return hdw->input_allowed_mask;
+}
+
+
+static int pvr2_hdw_set_input(struct pvr2_hdw *hdw,int v)
+{
+	if (hdw->input_val != v) {
+		hdw->input_val = v;
+		hdw->input_dirty = !0;
+	}
+
+	/* Handle side effects - if we switch to a mode that needs the RF
+	   tuner, then select the right frequency choice as well and mark
+	   it dirty. */
+	if (hdw->input_val == PVR2_CVAL_INPUT_RADIO) {
+		hdw->freqSelector = 0;
+		hdw->freqDirty = !0;
+	} else if ((hdw->input_val == PVR2_CVAL_INPUT_TV) ||
+		   (hdw->input_val == PVR2_CVAL_INPUT_DTV)) {
+		hdw->freqSelector = 1;
+		hdw->freqDirty = !0;
+	}
+	return 0;
+}
+
+
+int pvr2_hdw_set_input_allowed(struct pvr2_hdw *hdw,
+			       unsigned int change_mask,
+			       unsigned int change_val)
+{
+	int ret = 0;
+	unsigned int nv,m,idx;
+	LOCK_TAKE(hdw->big_lock);
+	do {
+		nv = hdw->input_allowed_mask & ~change_mask;
+		nv |= (change_val & change_mask);
+		nv &= hdw->input_avail_mask;
+		if (!nv) {
+			/* No legal modes left; return error instead. */
+			ret = -EPERM;
+			break;
+		}
+		hdw->input_allowed_mask = nv;
+		if ((1 << hdw->input_val) & hdw->input_allowed_mask) {
+			/* Current mode is still in the allowed mask, so
+			   we're done. */
+			break;
+		}
+		/* Select and switch to a mode that is still in the allowed
+		   mask */
+		if (!hdw->input_allowed_mask) {
+			/* Nothing legal; give up */
+			break;
+		}
+		m = hdw->input_allowed_mask;
+		for (idx = 0; idx < (sizeof(m) << 3); idx++) {
+			if (!((1 << idx) & m)) continue;
+			pvr2_hdw_set_input(hdw,idx);
+			break;
+		}
+	} while (0);
+	LOCK_GIVE(hdw->big_lock);
+	return ret;
+}
+
+
 /* Find I2C address of eeprom */
 static int pvr2_hdw_get_eeprom_addr(struct pvr2_hdw *hdw)
 {