[PATCH] DVB Satellite Channel Routing support for DVB-S

[PATCH] DVB Satellite Channel Routing support for DVB-S

[Thomas Schlöter]

Hello,

first of all, I hope this is the correct destination and submission format for this type of patch as this is my first contribution here.

I have developed some modifications to the 2.6.37 DVB frontend code to support DVB satellite channel routing (aka "SCR", "Unicable", "EN50494"). Following this standard, all satellite tuners share the same cable and each of them has a fixed intermediate frequency it is supposed to tune to. Zapping is done by sending a special DiSEqC message while SEC voltage is temporarily pulled from 14 to 18 volts. This message includes the tuner's ID from 0 to 7, the frequency, band and polarisation to tune to as well as one out of two satellite positions.

I decided this should be supported by the kernel frontend code as it is impossible to send that special DiSEqC / voltage sequence from userspace. Additionally, it adds fully transparent support for SCR to arbitrary applications that use the DVB API, such as MythTV, VDR, xine etc.

I added an ioctl command and chose command ID 120, so it does not conflict with other patches. As far as I can see, any number above 83 should work, so you might want to change this in "dvb_frontend.c" if you decide to accept the patch. By default, all SCR-code is disabled and the frontend works as usual. You can use the new ioctl command to set up SCR parameters for each tuner. Afterwards, all commands to set up SEC or frequency parameters are intercepted and their values are stored to a new struct inside both the private frontend parameters and DTV cache. This struct is also bidirectionally synced between "private frontend parameters" and dtv_cache along with existing parameters. Before actually tuning the frontend, the tuning frequency will be set to the fixed SCR frequency and the DiSEqC message is generated instead of directly tuning to the requested frequency.

All modifications do compile without warnings and work flawlessly on my Core2 Duo (using AMD64-SMP) with Hauppauge Nova-S and Nova-SE2 (budget, s5h1420, cx88_dvb, cx24123).
My DVB source is an "Inverto IDLB-QUDL41-UNI2L-1PP" Unicable LNB.

Below I paste the kernel patch as well as an example userspace utility to use the code as the linuxtv-wiki says MIME-attachments are undesired. If anything else is required, please contact me.

Regards,
Thomas Schlöter


================= Kernel patch against 2.6.37

diff -uprN a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c	2011-01-05 01:50:19.000000000 +0100
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c	2011-01-10 03:56:58.000000000 +0100
@@ -9,6 +9,8 @@
  *
  * Copyright (C) 2004 Andrew de Quincey (tuning thread cleanup)
  *
+ * Copyright (C) 2011 Thomas Schloeter (satellite channel routing)
+ *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
@@ -50,6 +52,8 @@ static int dvb_override_tune_delay;
 static int dvb_powerdown_on_sleep = 1;
 static int dvb_mfe_wait_time = 5;
 
+int scr_send_tune_cmd(struct dvb_frontend*);
+
 module_param_named(frontend_debug, dvb_frontend_debug, int, 0644);
 MODULE_PARM_DESC(frontend_debug, "Turn on/off frontend core debugging (default:off).");
 module_param(dvb_shutdown_timeout, int, 0644);
@@ -121,6 +125,9 @@ struct dvb_frontend_private {
 	int tone;
 	int voltage;
 
+	/* satellite channel routing */
+	struct dvb_scr_params dvbscr;
+
 	/* swzigzag values */
 	unsigned int state;
 	unsigned int bending;
@@ -1023,10 +1030,19 @@ static void dtv_property_cache_sync(stru
 				    struct dvb_frontend_parameters *p)
 {
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	struct dvb_frontend_private *fepriv = fe->frontend_priv;
 
 	c->frequency = p->frequency;
 	c->inversion = p->inversion;
 
+	c->dvbscr.scr_enable = fepriv->dvbscr.scr_enable;
+	c->dvbscr.scr_id = fepriv->dvbscr.scr_id;
+	c->dvbscr.scr_frequency = fepriv->dvbscr.scr_frequency;
+	c->dvbscr.scr_position = fepriv->dvbscr.scr_position;
+	c->dvbscr.scr_frequency_orig = fepriv->dvbscr.scr_frequency_orig;
+	c->dvbscr.scr_polarisation = fepriv->dvbscr.scr_polarisation;
+	c->dvbscr.scr_band = fepriv->dvbscr.scr_band;
+
 	switch (fe->ops.info.type) {
 	case FE_QPSK:
 		c->modulation = QPSK;   /* implied for DVB-S in legacy API */
@@ -1081,6 +1097,14 @@ static void dtv_property_legacy_params_s
 	p->frequency = c->frequency;
 	p->inversion = c->inversion;
 
+	fepriv->dvbscr.scr_enable = c->dvbscr.scr_enable;
+	fepriv->dvbscr.scr_id = c->dvbscr.scr_id;
+	fepriv->dvbscr.scr_frequency = c->dvbscr.scr_frequency;
+	fepriv->dvbscr.scr_position = c->dvbscr.scr_position;
+	fepriv->dvbscr.scr_frequency_orig = c->dvbscr.scr_frequency_orig;
+	fepriv->dvbscr.scr_polarisation = c->dvbscr.scr_polarisation;
+	fepriv->dvbscr.scr_band = c->dvbscr.scr_band;
+
 	switch (fe->ops.info.type) {
 	case FE_QPSK:
 		dprintk("%s() Preparing QPSK req\n", __func__);
@@ -1136,6 +1160,14 @@ static void dtv_property_adv_params_sync
 	p->frequency = c->frequency;
 	p->inversion = c->inversion;
 
+	fepriv->dvbscr.scr_enable = c->dvbscr.scr_enable;
+	fepriv->dvbscr.scr_id = c->dvbscr.scr_id;
+	fepriv->dvbscr.scr_frequency = c->dvbscr.scr_frequency;
+	fepriv->dvbscr.scr_position = c->dvbscr.scr_position;
+	fepriv->dvbscr.scr_frequency_orig = c->dvbscr.scr_frequency_orig;
+	fepriv->dvbscr.scr_polarisation = c->dvbscr.scr_polarisation;
+	fepriv->dvbscr.scr_band = c->dvbscr.scr_band;
+
 	switch(c->modulation) {
 	case PSK_8:
 	case APSK_16:
@@ -1215,7 +1247,10 @@ static int dtv_property_process_get(stru
 
 	switch(tvp->cmd) {
 	case DTV_FREQUENCY:
-		tvp->u.data = fe->dtv_property_cache.frequency;
+		if (fe->dtv_property_cache.dvbscr.scr_enable == SCR_ON)
+			tvp->u.data = fe->dtv_property_cache.dvbscr.scr_frequency_orig;
+		else
+			tvp->u.data = fe->dtv_property_cache.frequency;
 		break;
 	case DTV_MODULATION:
 		tvp->u.data = fe->dtv_property_cache.modulation;
@@ -1242,10 +1277,18 @@ static int dtv_property_process_get(stru
 		tvp->u.data = fe->dtv_property_cache.delivery_system;
 		break;
 	case DTV_VOLTAGE:
-		tvp->u.data = fe->dtv_property_cache.voltage;
+		if (fe->dtv_property_cache.dvbscr.scr_enable == SCR_ON)
+			tvp->u.data = (fe->dtv_property_cache.dvbscr.scr_polarisation == SCR_POL_H) ?
+					SEC_VOLTAGE_18 : SEC_VOLTAGE_13;
+		else
+			tvp->u.data = fe->dtv_property_cache.voltage;
 		break;
 	case DTV_TONE:
-		tvp->u.data = fe->dtv_property_cache.sectone;
+		if (fe->dtv_property_cache.dvbscr.scr_enable == SCR_ON)
+			tvp->u.data = (fe->dtv_property_cache.dvbscr.scr_band == SCR_BAND_HI) ?
+					SEC_TONE_ON : SEC_TONE_OFF;
+		else
+			tvp->u.data = fe->dtv_property_cache.sectone;
 		break;
 	case DTV_API_VERSION:
 		tvp->u.data = (DVB_API_VERSION << 8) | DVB_API_VERSION_MINOR;
@@ -1342,8 +1385,12 @@ static int dtv_property_process_set(stru
 	dtv_property_dump(tvp);
 
 	/* Allow the frontend to validate incoming properties */
-	if (fe->ops.set_property)
-		r = fe->ops.set_property(fe, tvp);
+	if ((fe->dtv_property_cache.dvbscr.scr_enable != SCR_ON) ||
+	    (tvp->cmd != DTV_FREQUENCY) ||
+	    (tvp->cmd != DTV_VOLTAGE) ||
+	    (tvp->cmd != DTV_TONE))
+		if (fe->ops.set_property)
+			r = fe->ops.set_property(fe, tvp);
 
 	if (r < 0)
 		return r;
@@ -1369,7 +1416,10 @@ static int dtv_property_process_set(stru
 			&fepriv->parameters);
 		break;
 	case DTV_FREQUENCY:
-		fe->dtv_property_cache.frequency = tvp->u.data;
+		if (fe->dtv_property_cache.dvbscr.scr_enable == SCR_ON)
+			fe->dtv_property_cache.dvbscr.scr_frequency_orig = tvp->u.data;
+		else
+			fe->dtv_property_cache.frequency = tvp->u.data;
 		break;
 	case DTV_MODULATION:
 		fe->dtv_property_cache.modulation = tvp->u.data;
@@ -1396,14 +1446,24 @@ static int dtv_property_process_set(stru
 		fe->dtv_property_cache.delivery_system = tvp->u.data;
 		break;
 	case DTV_VOLTAGE:
-		fe->dtv_property_cache.voltage = tvp->u.data;
-		r = dvb_frontend_ioctl_legacy(file, FE_SET_VOLTAGE,
-			(void *)fe->dtv_property_cache.voltage);
+		if (fe->dtv_property_cache.dvbscr.scr_enable == SCR_ON)
+			fe->dtv_property_cache.dvbscr.scr_polarisation =
+				(tvp->u.data == SEC_VOLTAGE_18) ? SCR_POL_H : SCR_POL_V;
+		else {
+			fe->dtv_property_cache.voltage = tvp->u.data;
+			r = dvb_frontend_ioctl_legacy(file, FE_SET_VOLTAGE,
+				(void *)fe->dtv_property_cache.voltage);
+		}
 		break;
 	case DTV_TONE:
-		fe->dtv_property_cache.sectone = tvp->u.data;
-		r = dvb_frontend_ioctl_legacy(file, FE_SET_TONE,
-			(void *)fe->dtv_property_cache.sectone);
+		if (fe->dtv_property_cache.dvbscr.scr_enable == SCR_ON)
+			fe->dtv_property_cache.dvbscr.scr_band =
+				(tvp->u.data == SEC_TONE_ON) ? SCR_BAND_HI : SCR_BAND_LO;
+		else {
+			fe->dtv_property_cache.sectone = tvp->u.data;
+			r = dvb_frontend_ioctl_legacy(file, FE_SET_TONE,
+				(void *)fe->dtv_property_cache.sectone);
+		}
 		break;
 	case DTV_CODE_RATE_HP:
 		fe->dtv_property_cache.code_rate_HP = tvp->u.data;
@@ -1610,6 +1670,7 @@ static int dvb_frontend_ioctl_legacy(str
 	struct dvb_frontend *fe = dvbdev->priv;
 	struct dvb_frontend_private *fepriv = fe->frontend_priv;
 	int cb_err, err = -EOPNOTSUPP;
+	u32 fe_freq_min, fe_freq_max;
 
 	if (fe->dvb->fe_ioctl_override) {
 		cb_err = fe->dvb->fe_ioctl_override(fe, cmd, parg,
@@ -1681,6 +1742,11 @@ static int dvb_frontend_ioctl_legacy(str
 		break;
 
 	case FE_DISEQC_SEND_MASTER_CMD:
+		if (fepriv->dvbscr.scr_enable == SCR_ON) {
+			dprintk("DVB: %s: Operation not available when SCR enabled\n", __FUNCTION__);
+			err = -EINVAL;
+			break;
+		}
 		if (fe->ops.diseqc_send_master_cmd) {
 			err = fe->ops.diseqc_send_master_cmd(fe, (struct dvb_diseqc_master_cmd*) parg);
 			fepriv->state = FESTATE_DISEQC;
@@ -1689,6 +1755,11 @@ static int dvb_frontend_ioctl_legacy(str
 		break;
 
 	case FE_DISEQC_SEND_BURST:
+		if (fepriv->dvbscr.scr_enable == SCR_ON) {
+			dprintk("DVB: %s: Operation not available when SCR enabled\n", __FUNCTION__);
+			err = -EINVAL;
+			break;
+		}
 		if (fe->ops.diseqc_send_burst) {
 			err = fe->ops.diseqc_send_burst(fe, (fe_sec_mini_cmd_t) parg);
 			fepriv->state = FESTATE_DISEQC;
@@ -1696,10 +1767,67 @@ static int dvb_frontend_ioctl_legacy(str
 		}
 		break;
 
+	case FE_SET_SCR:
+		if (fe->ops.info.type != FE_QPSK) {
+			dprintk("DVB: %s: SCR is supported on QPSK frontends only!\n", __FUNCTION__);
+			err = -EINVAL;
+			break;
+		}
+		fepriv->dvbscr.scr_enable = ((struct dvb_scr_params *) parg)->scr_enable;
+		fepriv->dvbscr.scr_id = ((struct dvb_scr_params *) parg)->scr_id;
+		fepriv->dvbscr.scr_position = ((struct dvb_scr_params *) parg)->scr_position;
+		fepriv->dvbscr.scr_frequency = ((struct dvb_scr_params *) parg)->scr_frequency;
+		err = 0;
+		if ((fepriv->dvbscr.scr_enable != SCR_ON) && (fepriv->dvbscr.scr_enable != SCR_OFF)) {
+			fepriv->dvbscr.scr_enable = SCR_OFF;
+			err = -EINVAL;
+			dprintk("DVB: %s: Invalid value for SCR_ON in ioctl\n", __FUNCTION__);
+		}
+		dvb_frontend_get_frequency_limits(fe, &fe_freq_min, &fe_freq_max);
+		if ((fepriv->dvbscr.scr_frequency < fe_freq_min / 1000) || (fepriv->dvbscr.scr_frequency > fe_freq_max / 1000)) {
+			fepriv->dvbscr.scr_enable = SCR_OFF;
+			fepriv->dvbscr.scr_frequency = 1400;
+			err = -EINVAL;
+			dprintk("DVB: %s: Invalid value for SCR_FREQ in ioctl\n", __FUNCTION__);
+		}
+		if ((fepriv->dvbscr.scr_position != SCR_POS_A) && (fepriv->dvbscr.scr_position != SCR_POS_B)) {
+			fepriv->dvbscr.scr_enable = SCR_OFF;
+			fepriv->dvbscr.scr_position = SCR_POS_A;
+			err = -EINVAL;
+			dprintk("DVB: %s: Invalid value for SCR_POSITION in ioctl\n", __FUNCTION__);
+		}
+		if (fepriv->dvbscr.scr_id > 7) {
+			fepriv->dvbscr.scr_enable = SCR_OFF;
+			fepriv->dvbscr.scr_id = 0;
+			err = -EINVAL;
+			dprintk("DVB: %s: Invalid value for SCR_ID in ioctl\n", __FUNCTION__);
+		}
+		if (fe->ops.set_voltage)
+			fe->ops.set_voltage(fe, SEC_VOLTAGE_13);
+		else {
+			dprintk("DVB: %s: Set Voltage not supported. SCR not possible.\n", __FUNCTION__);
+			fepriv->dvbscr.scr_enable = SCR_OFF;
+		}
+		if (fe->ops.set_tone)
+			fe->ops.set_tone(fe, SEC_TONE_OFF);
+		else {
+			dprintk("DVB: %s: Set Tone not supported. SCR not possible.\n", __FUNCTION__);
+			fepriv->dvbscr.scr_enable = SCR_OFF;
+		}
+		dtv_property_cache_sync(fe, &fepriv->parameters);
+		break;
+
 	case FE_SET_TONE:
 		if (fe->ops.set_tone) {
-			err = fe->ops.set_tone(fe, (fe_sec_tone_mode_t) parg);
-			fepriv->tone = (fe_sec_tone_mode_t) parg;
+			if (fepriv->dvbscr.scr_enable == SCR_ON) {
+				err = fe->ops.set_tone(fe, SEC_TONE_OFF);
+				fepriv->dvbscr.scr_band =
+					((fe_sec_tone_mode_t) parg == SEC_TONE_ON) ? SCR_BAND_HI : SCR_BAND_LO;
+			}
+			else {
+				err = fe->ops.set_tone(fe, (fe_sec_tone_mode_t) parg);
+				fepriv->tone = (fe_sec_tone_mode_t) parg;
+			}
 			fepriv->state = FESTATE_DISEQC;
 			fepriv->status = 0;
 		}
@@ -1707,14 +1835,26 @@ static int dvb_frontend_ioctl_legacy(str
 
 	case FE_SET_VOLTAGE:
 		if (fe->ops.set_voltage) {
-			err = fe->ops.set_voltage(fe, (fe_sec_voltage_t) parg);
-			fepriv->voltage = (fe_sec_voltage_t) parg;
+			if (fepriv->dvbscr.scr_enable == SCR_ON) {
+				err = fe->ops.set_voltage(fe, SEC_VOLTAGE_13);
+				fepriv->dvbscr.scr_polarisation =
+					((fe_sec_voltage_t) parg == SEC_VOLTAGE_18) ? SCR_POL_H : SCR_POL_V;
+			}
+			else {
+				err = fe->ops.set_voltage(fe, (fe_sec_voltage_t) parg);
+				fepriv->voltage = (fe_sec_voltage_t) parg;
+			}
 			fepriv->state = FESTATE_DISEQC;
 			fepriv->status = 0;
 		}
 		break;
 
 	case FE_DISHNETWORK_SEND_LEGACY_CMD:
+		if (fepriv->dvbscr.scr_enable == SCR_ON) {
+			dprintk("DVB: %s: Operation not available when SCR enabled\n", __FUNCTION__);
+			err = -EINVAL;
+			break;
+		}
 		if (fe->ops.dishnetwork_send_legacy_command) {
 			err = fe->ops.dishnetwork_send_legacy_command(fe, (unsigned long) parg);
 			fepriv->state = FESTATE_DISEQC;
@@ -1805,6 +1945,13 @@ static int dvb_frontend_ioctl_legacy(str
 			dtv_property_cache_sync(fe, &fepriv->parameters);
 		}
 
+		/* intercept tuning info and replace with SCR parameters */
+		if (fepriv->dvbscr.scr_enable == SCR_ON) {
+			fepriv->dvbscr.scr_frequency_orig = fepriv->parameters.frequency;
+			fepriv->parameters.frequency = (uint32_t) fepriv->dvbscr.scr_frequency * 1000;
+			scr_send_tune_cmd(fe);
+		}
+
 		memset(&fetunesettings, 0, sizeof(struct dvb_frontend_tune_settings));
 		memcpy(&fetunesettings.parameters, parg,
 		       sizeof (struct dvb_frontend_parameters));
@@ -1877,6 +2024,10 @@ static int dvb_frontend_ioctl_legacy(str
 		if (fe->ops.get_frontend) {
 			memcpy (parg, &fepriv->parameters, sizeof (struct dvb_frontend_parameters));
 			err = fe->ops.get_frontend(fe, (struct dvb_frontend_parameters*) parg);
+			if (fepriv->dvbscr.scr_enable == SCR_ON) {
+				((struct dvb_frontend_parameters*) parg)->frequency =
+					fepriv->dvbscr.scr_frequency_orig;
+			}
 		}
 		break;
 
@@ -2068,6 +2219,16 @@ int dvb_register_frontend(struct dvb_ada
 	fe->dvb = dvb;
 	fepriv->inversion = INVERSION_OFF;
 
+	/* initialize SCR parameters */
+	fepriv->dvbscr.scr_enable = SCR_OFF;
+	fepriv->dvbscr.scr_id = 0;
+	fepriv->dvbscr.scr_frequency = 1400;
+	fepriv->dvbscr.scr_position = SCR_POS_A;
+	fe->dtv_property_cache.dvbscr.scr_enable = SCR_OFF;
+	fe->dtv_property_cache.dvbscr.scr_id = 0;
+	fe->dtv_property_cache.dvbscr.scr_frequency = 1400;
+	fe->dtv_property_cache.dvbscr.scr_position = SCR_POS_A;
+
 	printk ("DVB: registering adapter %i frontend %i (%s)...\n",
 		fe->dvb->num,
 		fe->id,
@@ -2141,3 +2302,64 @@ void dvb_frontend_detach(struct dvb_fron
 }
 #endif
 EXPORT_SYMBOL(dvb_frontend_detach);
+
+int scr_send_tune_cmd(struct dvb_frontend * fe) {
+	struct dvb_frontend_private *fepriv = fe->frontend_priv;
+	int err = 0;
+	struct timeval waketime;
+	struct dvb_diseqc_master_cmd tunecmd;
+	uint8_t channel_byte_1, channel_byte_2;
+	uint16_t frequency_calc;
+    
+	dprintk ("DVB: Tuning to %u, %s, %s using SCR. ID=%u, POS=%s, FREQ=%u\n",
+		fepriv->dvbscr.scr_frequency_orig,
+		((fepriv->dvbscr.scr_polarisation == SCR_POL_H) ? "H" : 
+		((fepriv->dvbscr.scr_polarisation == SCR_POL_V) ? "V" : "?")),
+		((fepriv->dvbscr.scr_band == SCR_BAND_HI) ? "HiBand" : "LoBand"),
+		fepriv->dvbscr.scr_id,
+		((fepriv->dvbscr.scr_position == SCR_POS_A) ? "A" : "B"),
+		fepriv->dvbscr.scr_frequency);             
+    
+	if (fepriv->dvbscr.scr_id > 7) {
+		dprintk ("DVB: %s - wrong SCR ID\n", __FUNCTION__);
+		fepriv->dvbscr.scr_id = 0;
+	}
+    
+	channel_byte_1 = (uint8_t) (fepriv->dvbscr.scr_id << 5);
+
+	if (fepriv->dvbscr.scr_position != SCR_POS_A)
+		channel_byte_1 |= (1 << 4);
+   
+	if (fepriv->dvbscr.scr_polarisation == SCR_POL_H)
+		channel_byte_1 |= (1 << 3);
+    
+	if (fepriv->dvbscr.scr_band == SCR_BAND_HI)
+		channel_byte_1 |= (1 << 2);
+            
+	if (fepriv->dvbscr.scr_frequency_orig == 0) {
+		dprintk ("DVB: %s - invalid SCR tuning\n", __FUNCTION__);
+	}
+    
+	frequency_calc = (uint16_t) ((((fepriv->dvbscr.scr_frequency_orig / 1000) + fepriv->dvbscr.scr_frequency) / 4) - 350);
+	channel_byte_1 |= (((uint8_t) (frequency_calc >> 8)) & 0x03);
+	channel_byte_2 = (uint8_t) (frequency_calc & 0x00FF);
+
+	// Send DiSEqC code E0 10 5A channel_byte_1 channel_byte_2
+	tunecmd.msg_len = 5;
+	tunecmd.msg[0] = 0xE0;
+	tunecmd.msg[1] = 0x10;
+	tunecmd.msg[2] = 0x5A;
+	tunecmd.msg[3] = channel_byte_1;
+	tunecmd.msg[4] = channel_byte_2;
+  
+	do_gettimeofday(&waketime);
+	if ((err = fe->ops.set_voltage(fe, SEC_VOLTAGE_18)) != 0) return err;
+	dvb_frontend_sleep_until(&waketime, 6000);
+	if ((err = fe->ops.diseqc_send_master_cmd(fe, &tunecmd)) != 0) return err;
+	do_gettimeofday(&waketime);
+	dvb_frontend_sleep_until(&waketime, 4000);
+	if ((err = fe->ops.set_voltage(fe, SEC_VOLTAGE_13)) != 0) return err;
+
+	return 0;
+}
+
diff -uprN a/drivers/media/dvb/dvb-core/dvb_frontend.h b/drivers/media/dvb/dvb-core/dvb_frontend.h
--- a/drivers/media/dvb/dvb-core/dvb_frontend.h	2011-01-05 01:50:19.000000000 +0100
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.h	2011-01-10 03:12:12.000000000 +0100
@@ -343,6 +343,9 @@ struct dtv_frontend_properties {
 
 	fe_delivery_system_t	delivery_system;
 
+	/* satellite channel routing */
+	struct dvb_scr_params	dvbscr;
+
 	/* ISDB-T specifics */
 	u8			isdbt_partial_reception;
 	u8			isdbt_sb_mode;
diff -uprN a/include/linux/dvb/frontend.h b/include/linux/dvb/frontend.h
--- a/include/linux/dvb/frontend.h	2011-01-05 01:50:19.000000000 +0100
+++ b/include/linux/dvb/frontend.h	2011-01-10 03:35:47.000000000 +0100
@@ -203,6 +203,36 @@ typedef enum fe_hierarchy {
 	HIERARCHY_AUTO
 } fe_hierarchy_t;
 
+/* satellite channel routing */
+typedef enum scr_status {
+	SCR_OFF,
+	SCR_ON
+} scr_status_t;
+
+typedef enum scr_positions {
+	SCR_POS_A,
+	SCR_POS_B
+} scr_position_t;
+
+typedef enum scr_polarisations {
+	SCR_POL_V,
+	SCR_POL_H
+} scr_polarisation_t;
+
+typedef enum scr_bands {
+	SCR_BAND_LO,
+	SCR_BAND_HI
+} scr_band_t;
+
+struct dvb_scr_params {
+	scr_status_t		scr_enable;		/* enable or disable SCR */
+	__u8			scr_id;			/* internal SCR id */
+	scr_position_t		scr_position;		/* SCR satellite position (A or B) */
+	__u32			scr_frequency;		/* SCR frequency we tune to */
+	__u32			scr_frequency_orig;	/* DVB frequency sent to router */
+	scr_polarisation_t	scr_polarisation;	/* DVB polarisation (replaces SEC voltage) */
+	scr_band_t		scr_band;		/* DVB band (replaces SEC tone) */
+};
 
 struct dvb_qpsk_parameters {
 	__u32		symbol_rate;  /* symbol rate in Symbols per second */
@@ -411,4 +441,7 @@ struct dtv_properties {
 
 #define FE_DISHNETWORK_SEND_LEGACY_CMD _IO('o', 80) /* unsigned int */
 
+/* satellite channel routing */
+#define FE_SET_SCR                 _IOW('o', 120, struct dvb_scr_params)
+
 #endif /*_DVBFRONTEND_H_*/


================= End of file

================= Userspace utility (requires "frontend.h" from include/linux/dvb directory to compile):


/* dvb-scr-setup.c */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

/* It will take some time until new ioctls are available
 * from default include directories, so use our own copy
 * #include <linux/dvb/frontend.h> */
#include "frontend.h"

void showerr (int, const char *, const char *);

int main (int argc, char ** argv) {
    char frontend_devname [80];
    const int fe_open_mode;
    struct dvb_scr_params scrparms;    
    fe_status_t stat;
    int fd_frontend;
    int adapter = 0;
    int frontend = 0;
    int enable = -1;
    int frequency = 1400;
    int position = 0;
    int scrid = 0;
    int quiet = 0;
    int opt;

    while ((opt = getopt(argc, argv, "a:f:p:i:o:e:q")) != -1) {
        switch (opt) {
            case 'a':
                adapter = strtoul(optarg, NULL, 0);
                break;
            case 'f':
                frontend = strtoul(optarg, NULL, 0);
                break;
            case 'p':
                position = strtoul(optarg, NULL, 0);
                break;
            case 'i':
                scrid = strtoul(optarg, NULL, 0);
                break;
            case 'o':
                frequency = strtoul(optarg, NULL, 0);
                break;
            case 'e':
                enable = strtoul(optarg, NULL, 0);
                break;
            case 'q':
	    	quiet = 1;
		break;
            default:
                showerr (1, "Bad command line", argv[0]);
        };
    }
   
    if ((enable != 0) && (enable != 1)) showerr (1, "Bad value for -e", argv[0]);
    if ((frontend < 0) || (frontend > 8)) showerr (1, "Bad frontend ID", argv[0]);
    if ((adapter < 0) || (adapter > 8)) showerr (1, "Bad adapter ID", argv[0]);
    if ((position < 0) || (position > 1)) showerr (1, "Bad position", argv[0]);
    if ((scrid < 0) || (scrid > 7)) showerr (1, "Bad SCR ID", argv[0]);                                               
    if ((frequency < 950) || (frequency > 2150)) showerr (1, "Bad frequency", argv[0]);
    
    if (! quiet) {
        printf("DVB SCR Setup Tool by Thomas Schloeter\n\n");
	printf("Set DVB adapter %u, frontend %u to following values:\n", adapter, frontend);
	printf("\tSatellite Position:\t%s\n\tSCR-ID:\t\t\t%u\n\tSCR-Frequency:\t\t%u MHz\n\n", position ? "B" : "A", scrid, frequency);
    }

    snprintf (frontend_devname, sizeof(frontend_devname),
              "/dev/dvb/adapter%i/frontend%i", adapter, frontend);
    
    if ((fd_frontend = open (frontend_devname, O_RDWR)) < 0) {
        fprintf (stderr, "ERROR: failed to open '%s': %s\n", frontend_devname, strerror(errno));
    	showerr (0, "No frontend device", argv[0]);
    }

    scrparms.scr_enable = (enable != 0) ? SCR_ON : SCR_OFF;
    scrparms.scr_id = scrid;
    scrparms.scr_position = (position == 0) ? SCR_POS_A : SCR_POS_B;
    scrparms.scr_frequency = frequency;
    
    if (ioctl(fd_frontend, FE_SET_SCR, &scrparms) < 0)
        fprintf (stderr, "ERROR: FE_SET_SCR failed: %s\n", strerror(errno));

    close (fd_frontend);
    
    return 0;
}

void showerr (int showusage, const char * msg, const char * progname) {
    fprintf (stderr, "ERROR: %s.\n\n", msg);
    if (showusage) {
        fprintf (stderr, "Usage: %s [-a <adapter>] [-f <frontend>] [-p <pos>] [-i <ID>] [-o <freq>] -e <0/1> [-q]\n\n", progname);
        fprintf (stderr, "\t-a <adapter>:\tDVB adapter number (optional, default: 0)\n");
        fprintf (stderr, "\t-f <frontend>:\tDVB frontend number (optional, default: 0)\n");
        fprintf (stderr, "\t-p <pos>:\tSCR satellite position [0: A, 1: B] (optional, default: 0)\n");
        fprintf (stderr, "\t-i <ID>:\tSCR participant ID [0-7] (optional, default = 0)\n");
        fprintf (stderr, "\t-o <freq>:\tSCR participant frequency [950-2150] (optional, default: 1400)\n");
        fprintf (stderr, "\t-q:\t\tQuiet operation\n");
        fprintf (stderr, "\t-e:\t\tEnable transparent SCR [0 | 1] (mandatory)\n");
    }
    exit (-1);
}

================= End of file

Signed-off-by: Thomas Schloeter <thomas.schloeter@gmx.net>

Re: [PATCH] DVB Satellite Channel Routing support for DVB-S

[Andreas Oberritter]

Hallo Thomas,

thank you for your contribution. However, I'm against applying it.

On 01/10/2011 05:19 AM, Thomas Schlöter wrote:
> I have developed some modifications to the 2.6.37 DVB frontend code to support DVB satellite channel routing (aka "SCR", "Unicable", "EN50494"). Following this standard, all satellite tuners share the same cable and each of them has a fixed intermediate frequency it is supposed to tune to. Zapping is done by sending a special DiSEqC message while SEC voltage is temporarily pulled from 14 to 18 volts. This message includes the tuner's ID from 0 to 7, the frequency, band and polarisation to tune to as well as one out of two satellite positions.
> 
> I decided this should be supported by the kernel frontend code as it is impossible to send that special DiSEqC / voltage sequence from userspace.

Why do you think that's impossible? There's a userspace implementation
in Enigma2.

> Additionally, it adds fully transparent support for SCR to arbitrary applications that use the DVB API, such as MythTV, VDR, xine etc.

That statement is not true, because you have to configure Unicable LNBs,
which you do using dvb-scr-setup.c.

Regards,
Andreas

Re: [PATCH] DVB Satellite Channel Routing support for DVB-S

[Thomas Schlöter]

Hallo Andreas,

Am 10.01.2011 um 14:09 schrieb Andreas Oberritter:

> Hallo Thomas,
> 
> thank you for your contribution. However, I'm against applying it.
> 
> On 01/10/2011 05:19 AM, Thomas Schlöter wrote:
>> I have developed some modifications to the 2.6.37 DVB frontend code to support DVB satellite channel routing (aka "SCR", "Unicable", "EN50494"). Following this standard, all satellite tuners share the same cable and each of them has a fixed intermediate frequency it is supposed to tune to. Zapping is done by sending a special DiSEqC message while SEC voltage is temporarily pulled from 14 to 18 volts. This message includes the tuner's ID from 0 to 7, the frequency, band and polarisation to tune to as well as one out of two satellite positions.
>> 
>> I decided this should be supported by the kernel frontend code as it is impossible to send that special DiSEqC / voltage sequence from userspace.
> 
> Why do you think that's impossible? There's a userspace implementation
> in Enigma2.

I think the kernel implementation would be superior for two reasons:
- There are some timing requirements regarding the 14/18V transitions and the DiSEqC message which could perform better directly from the frontend code,

- In many TV recording applications there is no support for SCR and it would be harder to implement in these. For VDR, there is a patch which is difficult to configure and has some technical limitations. In MythTV and XMBC I could not find any support for SCR. Their Wiki pages or forums say, that there are no plans for Unicable support as it would take huge changes.

> 
>> Additionally, it adds fully transparent support for SCR to arbitrary applications that use the DVB API, such as MythTV, VDR, xine etc.
> 
> That statement is not true, because you have to configure Unicable LNBs,
> which you do using dvb-scr-setup.c.

Sure, you have to configure Unicable LNBs as you have to configure for example Universal LNBs. So the viewer software has to be aware of your DVB setup's parameters. If you want to have a configuration menu in the viewer software, this software only needs to send a simple ioctl message to the frontend to configure Unicable. If you want to use Unicable with viewers that do not support it, you only have to set your parameters at boot time using dvb-scr-setup.c.

That way, they are also a bit more protected against unintentional changes. In a Unicable system, all participants have interferences if there is one participant using bad settings. So if you start a DVB viewer which is badly or not yet configured, all other participants are disturbed. If you configure your Unicable system using e.g. an init-script, it is impossible to disturb anyone by starting some "Non-Unicable" software.

This can be compared to the setup of serial ports, I think. As far as I know, there is a setup utility to have the parameters set (probably at boot time), afterwards you start the actual application.

Regards,
Thomas

Re: [PATCH] DVB Satellite Channel Routing support for DVB-S

[Andreas Oberritter]

On 01/10/2011 04:07 PM, Thomas Schlöter wrote:
>>> I decided this should be supported by the kernel frontend code as it is impossible to send that special DiSEqC / voltage sequence from userspace.
>>
>> Why do you think that's impossible? There's a userspace implementation
>> in Enigma2.
> 
> I think the kernel implementation would be superior for two reasons:
> - There are some timing requirements regarding the 14/18V transitions and the DiSEqC message which could perform better directly from the frontend code,

Unless there's proof, I won't believe that. We're not talking about
nanoseconds, but milliseconds, and it's about setting registers of slow
I2C devices. The same timing requirements are valid for each and every
backwards compatible DiSEqC sequence, which is the most common setting.

> - In many TV recording applications there is no support for SCR and it would be harder to implement in these. For VDR, there is a patch which is difficult to configure and has some technical limitations. In MythTV and XMBC I could not find any support for SCR. Their Wiki pages or forums say, that there are no plans for Unicable support as it would take huge changes.

Many of these applications didn't or don't support DiSEqC 1.1
(uncommittted switches) or DiSEqC 1.2 (rotor commands) or USALS. Still,
we don't put this logic into the kernel to make their life easier. Don't
add unneeded complexity to the kernel.

Of course, one could decide to start a reusable library to take care of
that stuff. Honestly, I don't know whether such a library exists today.

If you find the patch was simple enough to be applied to the kernel, it
must be as simple to patch your favourite application, even in a
platform independent way (not taking into account the required changes
to the UI, which have to be done anyway).

Regards,
Andreas

Re: [PATCH] DVB Satellite Channel Routing support for DVB-S

[Oliver Endriss]

On Monday 10 January 2011 16:54:14 Andreas Oberritter wrote:
> On 01/10/2011 04:07 PM, Thomas Schlöter wrote:
> >>> I decided this should be supported by the kernel frontend code as it is impossible to send that special DiSEqC / voltage sequence from userspace.
> >>
> >> Why do you think that's impossible? There's a userspace implementation
> >> in Enigma2.
> > 
> > I think the kernel implementation would be superior for two reasons:
> > - There are some timing requirements regarding the 14/18V transitions and the DiSEqC message which could perform better directly from the frontend code,
> 
> Unless there's proof, I won't believe that. We're not talking about
> nanoseconds, but milliseconds, and it's about setting registers of slow
> I2C devices. The same timing requirements are valid for each and every
> backwards compatible DiSEqC sequence, which is the most common setting.
> 
> > - In many TV recording applications there is no support for SCR and it would be harder to implement in these. For VDR, there is a patch which is difficult to configure and has some technical limitations. In MythTV and XMBC I could not find any support for SCR. Their Wiki pages or forums say, that there are no plans for Unicable support as it would take huge changes.
> 
> Many of these applications didn't or don't support DiSEqC 1.1
> (uncommittted switches) or DiSEqC 1.2 (rotor commands) or USALS. Still,
> we don't put this logic into the kernel to make their life easier. Don't
> add unneeded complexity to the kernel.
> 
> Of course, one could decide to start a reusable library to take care of
> that stuff. Honestly, I don't know whether such a library exists today.
> 
> If you find the patch was simple enough to be applied to the kernel, it
> must be as simple to patch your favourite application, even in a
> platform independent way (not taking into account the required changes
> to the UI, which have to be done anyway).

Ack, this stuff should be implemented as a userspace library.
(Btw, there is an experimental unicable patch for VDR.)

CU
Oliver

-- 
----------------------------------------------------------------
VDR Remote Plugin 0.4.0: http://www.escape-edv.de/endriss/vdr/
4 MByte Mod: http://www.escape-edv.de/endriss/dvb-mem-mod/
Full-TS Mod: http://www.escape-edv.de/endriss/dvb-full-ts-mod/
----------------------------------------------------------------

Re: [PATCH] DVB Satellite Channel Routing support for DVB-S

[Thomas Schlöter]

Am 10.01.2011 um 16:54 schrieb Andreas Oberritter:
> 
>> - In many TV recording applications there is no support for SCR and it would be harder to implement in these. For VDR, there is a patch which is difficult to configure and has some technical limitations. In MythTV and XMBC I could not find any support for SCR. Their Wiki pages or forums say, that there are no plans for Unicable support as it would take huge changes.
> 
> Many of these applications didn't or don't support DiSEqC 1.1
> (uncommittted switches) or DiSEqC 1.2 (rotor commands) or USALS. Still,
> we don't put this logic into the kernel to make their life easier.

> Don't add unneeded complexity to the kernel.

I think this is the point we are talking about and I understand the feature might not be critical enough to justify a kernel implementation.

Regards,
Thomas

Re: [InfraSchlot SPAM Check] Re: [PATCH] DVB Satellite Channel Routing support for DVB-S

[Thomas Schlöter]

Hello Oliver,

Am 10.01.2011 um 18:28 schrieb Oliver Endriss:

> Ack, this stuff should be implemented as a userspace library.
> (Btw, there is an experimental unicable patch for VDR.)

Yes, there is. I have not testet it as I am going to use MythTV, but for what I have read in some forums, many people have problems using that patch. This is why I decided to make a kernel implementation for my system. But I agree it could also be implemented as a wrapper application between frontend device and viewer application (the quick and dirty way) or native support in a userspace library (which will take some time until it is used in all DVB applications).

What I thought makes my solution attractive is, that you can even use dvbscan, szap etc. without modification, which works perfectly in my setup. But anyway the purpose might be too special to have it inside the kernel.

Regards,
Thomas