V4L/DVB (5496): Pluto2: fix incorrect TSCR register setting

The ADEF bits in the TSCR register have different meanings in read and
write mode. For this reason ADEF has to be reset on every
read-modify-write operation.
This patch introduces a special write function for this register, which
takes care of it.

Thanks to Holger Magnussen for pointing my nose at this problem.

Signed-off-by: Andreas Oberritter <obi@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/pluto2/pluto2.c b/drivers/media/dvb/pluto2/pluto2.c
index ffda71d..058df5c 100644
--- a/drivers/media/dvb/pluto2/pluto2.c
+++ b/drivers/media/dvb/pluto2/pluto2.c
@@ -149,6 +149,15 @@
 	writel(val, &pluto->io_mem[reg]);
 }
 
+static void pluto_write_tscr(struct pluto *pluto, u32 val)
+{
+	/* set the number of packets */
+	val &= ~TSCR_ADEF;
+	val |= TS_DMA_PACKETS / 2;
+
+	pluto_writereg(pluto, REG_TSCR, val);
+}
+
 static void pluto_setsda(void *data, int state)
 {
 	struct pluto *pluto = data;
@@ -213,11 +222,11 @@
 
 	if (val & TSCR_RSTN) {
 		val &= ~TSCR_RSTN;
-		pluto_writereg(pluto, REG_TSCR, val);
+		pluto_write_tscr(pluto, val);
 	}
 	if (reenable) {
 		val |= TSCR_RSTN;
-		pluto_writereg(pluto, REG_TSCR, val);
+		pluto_write_tscr(pluto, val);
 	}
 }
 
@@ -339,7 +348,7 @@
 	}
 
 	/* ACK the interrupt */
-	pluto_writereg(pluto, REG_TSCR, tscr | TSCR_IACK);
+	pluto_write_tscr(pluto, tscr | TSCR_IACK);
 
 	return IRQ_HANDLED;
 }
@@ -348,9 +357,6 @@
 {
 	u32 val = pluto_readreg(pluto, REG_TSCR);
 
-	/* set the number of packets */
-	val &= ~TSCR_ADEF;
-	val |= TS_DMA_PACKETS / 2;
 	/* disable AFUL and LOCK interrupts */
 	val |= (TSCR_MSKA | TSCR_MSKL);
 	/* enable DMA and OVERFLOW interrupts */
@@ -358,7 +364,7 @@
 	/* clear pending interrupts */
 	val |= TSCR_IACK;
 
-	pluto_writereg(pluto, REG_TSCR, val);
+	pluto_write_tscr(pluto, val);
 }
 
 static void pluto_disable_irqs(struct pluto *pluto)
@@ -370,7 +376,7 @@
 	/* clear pending interrupts */
 	val |= TSCR_IACK;
 
-	pluto_writereg(pluto, REG_TSCR, val);
+	pluto_write_tscr(pluto, val);
 }
 
 static int __devinit pluto_hw_init(struct pluto *pluto)