[PATCH 18/37] dvb: let other frontends support FE_DISHNETWORK_SEND_LEGACY_CMD

[PATCH 18/37] dvb: let other frontends support FE_DISHNETWORK_SEND_LEGACY_CMD

[Michael Krufky]

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From: NooneImportant <nxhxzi702@sneakemail.com>

Add support to FE_DISHNETWORK_SEND_LEGACY_CMD code to support other
frontends besides stv0299.  The generic code is a fallback in the case
that it doesn't work for some specific frontends (again stv0299 being
a good example).

Signed-off-by: NooneImportant <nxhxzi702@sneakemail.com>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>

 drivers/media/dvb/dvb-core/dvb_frontend.c |   97 ++++++++++++++++++++++++++++++
 drivers/media/dvb/dvb-core/dvb_frontend.h |    3 
 drivers/media/dvb/frontends/stv0299.c     |   38 +----------
 3 files changed, 104 insertions(+), 34 deletions(-)

--- linux-2.6.14-git3.orig/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ linux-2.6.14-git3/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -577,6 +577,49 @@
 				fepriv->thread_pid);
 }
 
+s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime)
+{
+	return ((curtime.tv_usec < lasttime.tv_usec) ?
+		1000000 - lasttime.tv_usec + curtime.tv_usec :
+		curtime.tv_usec - lasttime.tv_usec);
+}
+EXPORT_SYMBOL(timeval_usec_diff);
+
+static inline void timeval_usec_add(struct timeval *curtime, u32 add_usec)
+{
+	curtime->tv_usec += add_usec;
+	if (curtime->tv_usec >= 1000000) {
+		curtime->tv_usec -= 1000000;
+		curtime->tv_sec++;
+	}
+}
+
+/*
+ * Sleep until gettimeofday() > waketime + add_usec
+ * This needs to be as precise as possible, but as the delay is
+ * usually between 2ms and 32ms, it is done using a scheduled msleep
+ * followed by usleep (normally a busy-wait loop) for the remainder
+ */
+void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec)
+{
+	struct timeval lasttime;
+	s32 delta, newdelta;
+
+	timeval_usec_add(waketime, add_usec);
+
+	do_gettimeofday(&lasttime);
+	delta = timeval_usec_diff(lasttime, *waketime);
+	if (delta > 2500) {
+		msleep((delta - 1500) / 1000);
+		do_gettimeofday(&lasttime);
+		newdelta = timeval_usec_diff(lasttime, *waketime);
+		delta = (newdelta > delta) ? 0 : newdelta;
+	}
+	if (delta > 0)
+		udelay(delta);
+}
+EXPORT_SYMBOL(dvb_frontend_sleep_until);
+
 static int dvb_frontend_start(struct dvb_frontend *fe)
 {
 	int ret;
@@ -728,6 +771,60 @@
 			err = fe->ops->dishnetwork_send_legacy_command(fe, (unsigned int) parg);
 			fepriv->state = FESTATE_DISEQC;
 			fepriv->status = 0;
+		} else if (fe->ops->set_voltage) {
+			/*
+			 * NOTE: This is a fallback condition.  Some frontends
+			 * (stv0299 for instance) take longer than 8msec to
+			 * respond to a set_voltage command.  Those switches
+			 * need custom routines to switch properly.  For all
+			 * other frontends, the following shoule work ok.
+			 * Dish network legacy switches (as used by Dish500)
+			 * are controlled by sending 9-bit command words
+			 * spaced 8msec apart.
+			 * the actual command word is switch/port dependant
+			 * so it is up to the userspace application to send
+			 * the right command.
+			 * The command must always start with a '0' after
+			 * initialization, so parg is 8 bits and does not
+			 * include the initialization or start bit
+			 */
+			unsigned int cmd = ((unsigned int) parg) << 1;
+			struct timeval nexttime;
+			struct timeval tv[10];
+			int i;
+			u8 last = 1;
+			if (dvb_frontend_debug)
+				printk("%s switch command: 0x%04x\n", __FUNCTION__, cmd);
+			do_gettimeofday(&nexttime);
+			if (dvb_frontend_debug)
+				memcpy(&tv[0], &nexttime, sizeof(struct timeval));
+			/* before sending a command, initialize by sending
+			 * a 32ms 18V to the switch
+			 */
+			fe->ops->set_voltage(fe, SEC_VOLTAGE_18);
+			dvb_frontend_sleep_until(&nexttime, 32000);
+
+			for (i = 0; i < 9; i++) {
+				if (dvb_frontend_debug)
+					do_gettimeofday(&tv[i + 1]);
+				if ((cmd & 0x01) != last) {
+					/* set voltage to (last ? 13V : 18V) */
+					fe->ops->set_voltage(fe, (last) ? SEC_VOLTAGE_13 : SEC_VOLTAGE_18);
+					last = (last) ? 0 : 1;
+				}
+				cmd = cmd >> 1;
+				if (i != 8)
+					dvb_frontend_sleep_until(&nexttime, 8000);
+			}
+			if (dvb_frontend_debug) {
+				printk("%s(%d): switch delay (should be 32k followed by all 8k\n",
+					__FUNCTION__, fe->dvb->num);
+				for (i = 1; i < 10; i++)
+					printk("%d: %d\n", i, timeval_usec_diff(tv[i-1] , tv[i]));
+			}
+			err = 0;
+			fepriv->state = FESTATE_DISEQC;
+			fepriv->status = 0;
 		}
 		break;
 
--- linux-2.6.14-git3.orig/drivers/media/dvb/dvb-core/dvb_frontend.h
+++ linux-2.6.14-git3/drivers/media/dvb/dvb-core/dvb_frontend.h
@@ -101,4 +101,7 @@
 
 extern int dvb_unregister_frontend(struct dvb_frontend* fe);
 
+extern void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec);
+extern s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime);
+
 #endif
--- linux-2.6.14-git3.orig/drivers/media/dvb/frontends/stv0299.c
+++ linux-2.6.14-git3/drivers/media/dvb/frontends/stv0299.c
@@ -387,36 +387,6 @@
 	};
 }
 
-static inline s32 stv0299_calc_usec_delay (struct timeval lasttime, struct timeval curtime)
-{
-	return ((curtime.tv_usec < lasttime.tv_usec) ?
-		1000000 - lasttime.tv_usec + curtime.tv_usec :
-		curtime.tv_usec - lasttime.tv_usec);
-}
-
-static void stv0299_sleep_until (struct timeval *waketime, u32 add_usec)
-{
-	struct timeval lasttime;
-	s32 delta, newdelta;
-
-	waketime->tv_usec += add_usec;
-	if (waketime->tv_usec >= 1000000) {
-		waketime->tv_usec -= 1000000;
-		waketime->tv_sec++;
-	}
-
-	do_gettimeofday (&lasttime);
-	delta = stv0299_calc_usec_delay (lasttime, *waketime);
-	if (delta > 2500) {
-		msleep ((delta - 1500) / 1000);
-		do_gettimeofday (&lasttime);
-		newdelta = stv0299_calc_usec_delay (lasttime, *waketime);
-		delta = (newdelta > delta) ? 0 : newdelta;
-	}
-	if (delta > 0)
-		udelay (delta);
-}
-
 static int stv0299_send_legacy_dish_cmd (struct dvb_frontend* fe, u32 cmd)
 {
 	struct stv0299_state* state = fe->demodulator_priv;
@@ -444,7 +414,7 @@
 		memcpy (&tv[0], &nexttime, sizeof (struct timeval));
 	stv0299_writeregI (state, 0x0c, reg0x0c | 0x50); /* set LNB to 18V */
 
-	stv0299_sleep_until (&nexttime, 32000);
+	dvb_frontend_sleep_until(&nexttime, 32000);
 
 	for (i=0; i<9; i++) {
 		if (debug_legacy_dish_switch)
@@ -458,13 +428,13 @@
 		cmd = cmd >> 1;
 
 		if (i != 8)
-			stv0299_sleep_until (&nexttime, 8000);
+			dvb_frontend_sleep_until(&nexttime, 8000);
 	}
 	if (debug_legacy_dish_switch) {
 		printk ("%s(%d): switch delay (should be 32k followed by all 8k\n",
 			__FUNCTION__, fe->dvb->num);
-		for (i=1; i < 10; i++)
-			printk ("%d: %d\n", i, stv0299_calc_usec_delay (tv[i-1] , tv[i]));
+		for (i = 1; i < 10; i++)
+			printk ("%d: %d\n", i, timeval_usec_diff(tv[i-1] , tv[i]));
 	}
 
 	return 0;

Re: [PATCH 18/37] dvb: let other frontends support FE_DISHNETWORK_SEND_LEGACY_CMD

[Andrew Morton]

Michael Krufky <mkrufky@m1k.net> wrote:
>
> +s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime)
>  +{
>  +	return ((curtime.tv_usec < lasttime.tv_usec) ?
>  +		1000000 - lasttime.tv_usec + curtime.tv_usec :
>  +		curtime.tv_usec - lasttime.tv_usec);
>  +}
>  +EXPORT_SYMBOL(timeval_usec_diff);
>  +
>  +static inline void timeval_usec_add(struct timeval *curtime, u32 add_usec)
>  +{
>  +	curtime->tv_usec += add_usec;
>  +	if (curtime->tv_usec >= 1000000) {
>  +		curtime->tv_usec -= 1000000;
>  +		curtime->tv_sec++;
>  +	}
>  +}

timeval arithmetic like this really shouldn't be hidden in a dvb driver -
it's generic code.

>  +/*
>  + * Sleep until gettimeofday() > waketime + add_usec
>  + * This needs to be as precise as possible, but as the delay is
>  + * usually between 2ms and 32ms, it is done using a scheduled msleep
>  + * followed by usleep (normally a busy-wait loop) for the remainder
>  + */
>  +void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec)
>  +{
>  +	struct timeval lasttime;
>  +	s32 delta, newdelta;
>  +
>  +	timeval_usec_add(waketime, add_usec);
>  +
>  +	do_gettimeofday(&lasttime);
>  +	delta = timeval_usec_diff(lasttime, *waketime);
>  +	if (delta > 2500) {
>  +		msleep((delta - 1500) / 1000);
>  +		do_gettimeofday(&lasttime);
>  +		newdelta = timeval_usec_diff(lasttime, *waketime);
>  +		delta = (newdelta > delta) ? 0 : newdelta;
>  +	}
>  +	if (delta > 0)
>  +		udelay(delta);
>  +}
>  +EXPORT_SYMBOL(dvb_frontend_sleep_until);

However I don't believe that the driver should be using timevals and
do_gettimeofday() at all.  Why not use jiffies-based timing like so
many other parts of the kernel?

Re: [PATCH 18/37] dvb: let other frontends support FE_DISHNETWORK_SEND_LEGACY_CMD

[NooneImportant]

On 11/2/05, Andrew Morton wrote:
> Michael Krufky <mkrufky@m1k.net> wrote:
> >
> > +s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime)
> >  +{
> >  +    return ((curtime.tv_usec < lasttime.tv_usec) ?
> >  +            1000000 - lasttime.tv_usec + curtime.tv_usec :
> >  +            curtime.tv_usec - lasttime.tv_usec);
> >  +}
> >  +EXPORT_SYMBOL(timeval_usec_diff);
> >  +
> >  +static inline void timeval_usec_add(struct timeval *curtime, u32 add_usec)
> >  +{
> >  +    curtime->tv_usec += add_usec;
> >  +    if (curtime->tv_usec >= 1000000) {
> >  +            curtime->tv_usec -= 1000000;
> >  +            curtime->tv_sec++;
> >  +    }
> >  +}
>
> timeval arithmetic like this really shouldn't be hidden in a dvb driver -
> it's generic code.
> However I don't believe that the driver should be using timevals and
> do_gettimeofday() at all.  Why not use jiffies-based timing like so
> many other parts of the kernel?
>
To be honest, I don't like this solution very much either.  It only
works when HZ is ~1000, and even then isn't reliable for everyone who
uses this code.  All this is attempting to be is a high precision 8ms
timer.  Accuracy needs to be +/- 500us for the code to work.  I am not
a (very good) kernel programmer, and didn't find anything that would
really fit the bill when trying to figure out how to ensure a routine
gets called every 8ms (9 times).  The ktimers stuff I saw recently on
lwn would seem to work well here, but if there is a way to do it with
what is in the kernel today, I'm just not aware of how to do it.  So
if someone will show me the right way (or point me in the irght
direction even), I'll be happy to rework the patch.

Thanks,
Noone