[media] rc-core: move timeout and checks to lirc

The lirc TX functionality expects the process which writes (TX) data to
the lirc dev to sleep until the actual data has been transmitted by the
hardware.

Since the same timeout calculation is duplicated in more than one driver
(and would have to be duplicated in even more drivers as they gain TX
support), it makes sense to move this timeout calculation to the lirc
layer instead.

At the same time, centralize some of the sanity checks.
Signed-off-by: David Härdeman <david@hardeman.nu>
Cc: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/ir-lirc-codec.c

@@ -107,6 +107,12 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 	unsigned int *txbuf; /* buffer with values to transmit */
 	ssize_t ret = -EINVAL;
 	size_t count;
+	ktime_t start;
+	s64 towait;
+	unsigned int duration = 0; /* signal duration in us */
+	int i;
+
+	start = ktime_get();
 
 	lirc = lirc_get_pdata(file);
 	if (!lirc)
@@ -129,11 +135,30 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 		goto out;
 	}
 
-	if (dev->tx_ir)
-		ret = dev->tx_ir(dev, txbuf, count);
+	if (!dev->tx_ir) {
+		ret = -ENOSYS;
+		goto out;
+	}
+
+	ret = dev->tx_ir(dev, txbuf, (u32)n);
+	if (ret < 0)
+		goto out;
+
+	for (i = 0; i < ret; i++)
+		duration += txbuf[i];
 
-	if (ret > 0)
-		ret *= sizeof(unsigned);
+	ret *= sizeof(unsigned int);
+
+	/*
+	 * The lircd gap calculation expects the write function to
+	 * wait for the actual IR signal to be transmitted before
+	 * returning.
+	 */
+	towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
+	if (towait > 0) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(usecs_to_jiffies(towait));
+	}
 
 out:
 	kfree(txbuf);

drivers/media/rc/mceusb.c

@@ -791,10 +791,6 @@ static int mceusb_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 	int i, ret = 0;
 	int cmdcount = 0;
 	unsigned char *cmdbuf; /* MCE command buffer */
-	long signal_duration = 0; /* Singnal length in us */
-	struct timeval start_time, end_time;
-
-	do_gettimeofday(&start_time);
 
 	cmdbuf = kzalloc(sizeof(unsigned) * MCE_CMDBUF_SIZE, GFP_KERNEL);
 	if (!cmdbuf)
@@ -807,7 +803,6 @@ static int mceusb_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 
 	/* Generate mce packet data */
 	for (i = 0; (i < count) && (cmdcount < MCE_CMDBUF_SIZE); i++) {
-		signal_duration += txbuf[i];
 		txbuf[i] = txbuf[i] / MCE_TIME_UNIT;
 
 		do { /* loop to support long pulses/spaces > 127*50us=6.35ms */
@@ -850,19 +845,6 @@ static int mceusb_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 	/* Transmit the command to the mce device */
 	mce_async_out(ir, cmdbuf, cmdcount);
 
-	/*
-	 * The lircd gap calculation expects the write function to
-	 * wait the time it takes for the ircommand to be sent before
-	 * it returns.
-	 */
-	do_gettimeofday(&end_time);
-	signal_duration -= (end_time.tv_usec - start_time.tv_usec) +
-			   (end_time.tv_sec - start_time.tv_sec) * 1000000;
-
-	/* delay with the closest number of ticks */
-	set_current_state(TASK_INTERRUPTIBLE);
-	schedule_timeout(usecs_to_jiffies(signal_duration));
-
 out:
 	kfree(cmdbuf);
 	return ret ? ret : count;

drivers/media/rc/rc-loopback.c

@@ -105,18 +105,9 @@ static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 {
 	struct loopback_dev *lodev = dev->priv;
 	u32 rxmask;
-	unsigned total_duration = 0;
 	unsigned i;
 	DEFINE_IR_RAW_EVENT(rawir);
 
-	for (i = 0; i < count; i++)
-		total_duration += abs(txbuf[i]);
-
-	if (total_duration == 0) {
-		dprintk("invalid tx data, total duration zero\n");
-		return -EINVAL;
-	}
-
 	if (lodev->txcarrier < lodev->rxcarriermin ||
 	    lodev->txcarrier > lodev->rxcarriermax) {
 		dprintk("ignoring tx, carrier out of range\n");
@@ -148,9 +139,6 @@ static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 	ir_raw_event_handle(dev);
 
 out:
-	/* Lirc expects this function to take as long as the total duration */
-	set_current_state(TASK_INTERRUPTIBLE);
-	schedule_timeout(usecs_to_jiffies(total_duration));
 	return count;
 }