[media] si470x: add control event support and more v4l2 compliancy fixes

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Tobias Lorenz <tobias.lorenz@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/si470x/radio-si470x-common.c

@@ -262,7 +262,7 @@ static int si470x_get_freq(struct si470x_device *radio, unsigned int *freq)
  */
 int si470x_set_freq(struct si470x_device *radio, unsigned int freq)
 {
-	unsigned int spacing, band_bottom;
+	unsigned int spacing, band_bottom, band_top;
 	unsigned short chan;
 
 	/* Spacing (kHz) */
@@ -278,19 +278,26 @@ int si470x_set_freq(struct si470x_device *radio, unsigned int freq)
 		spacing = 0.050 * FREQ_MUL; break;
 	};
 
-	/* Bottom of Band (MHz) */
+	/* Bottom/Top of Band (MHz) */
 	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_BAND) >> 6) {
 	/* 0: 87.5 - 108 MHz (USA, Europe) */
 	case 0:
-		band_bottom = 87.5 * FREQ_MUL; break;
+		band_bottom = 87.5 * FREQ_MUL;
+		band_top = 108 * FREQ_MUL;
+		break;
 	/* 1: 76   - 108 MHz (Japan wide band) */
 	default:
-		band_bottom = 76   * FREQ_MUL; break;
+		band_bottom = 76 * FREQ_MUL;
+		band_top = 108 * FREQ_MUL;
+		break;
 	/* 2: 76   -  90 MHz (Japan) */
 	case 2:
-		band_bottom = 76   * FREQ_MUL; break;
+		band_bottom = 76 * FREQ_MUL;
+		band_top = 90 * FREQ_MUL;
+		break;
 	};
 
+	freq = clamp(freq, band_bottom, band_top);
 	/* Chan = [ Freq (Mhz) - Bottom of Band (MHz) ] / Spacing (kHz) */
 	chan = (freq - band_bottom) / spacing;
 
@@ -515,17 +522,19 @@ static unsigned int si470x_fops_poll(struct file *file,
 		struct poll_table_struct *pts)
 {
 	struct si470x_device *radio = video_drvdata(file);
-	int retval = 0;
-
-	/* switch on rds reception */
+	unsigned long req_events = poll_requested_events(pts);
+	int retval = v4l2_ctrl_poll(file, pts);
 
-	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
-		si470x_rds_on(radio);
+	if (req_events & (POLLIN | POLLRDNORM)) {
+		/* switch on rds reception */
+		if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
+			si470x_rds_on(radio);
 
-	poll_wait(file, &radio->read_queue, pts);
+		poll_wait(file, &radio->read_queue, pts);
 
-	if (radio->rd_index != radio->wr_index)
-		retval = POLLIN | POLLRDNORM;
+		if (radio->rd_index != radio->wr_index)
+			retval |= POLLIN | POLLRDNORM;
+	}
 
 	return retval;
 }
@@ -637,6 +646,8 @@ static int si470x_vidioc_g_tuner(struct file *file, void *priv,
 	tuner->signal = (radio->registers[STATUSRSSI] & STATUSRSSI_RSSI);
 	/* the ideal factor is 0xffff/75 = 873,8 */
 	tuner->signal = (tuner->signal * 873) + (8 * tuner->signal / 10);
+	if (tuner->signal > 0xffff)
+		tuner->signal = 0xffff;
 
 	/* automatic frequency control: -1: freq to low, 1 freq to high */
 	/* AFCRL does only indicate that freq. differs, not if too low/high */
@@ -660,23 +671,21 @@ static int si470x_vidioc_s_tuner(struct file *file, void *priv,
 	int retval = 0;
 
 	if (tuner->index != 0)
-		goto done;
+		return -EINVAL;
 
 	/* mono/stereo selector */
 	switch (tuner->audmode) {
 	case V4L2_TUNER_MODE_MONO:
 		radio->registers[POWERCFG] |= POWERCFG_MONO;  /* force mono */
 		break;
 	case V4L2_TUNER_MODE_STEREO:
+	default:
 		radio->registers[POWERCFG] &= ~POWERCFG_MONO; /* try stereo */
 		break;
-	default:
-		goto done;
 	}
 
 	retval = si470x_set_register(radio, POWERCFG);
 
-done:
 	if (retval < 0)
 		dev_warn(&radio->videodev.dev,
 			"set tuner failed with %d\n", retval);
@@ -770,6 +779,8 @@ static const struct v4l2_ioctl_ops si470x_ioctl_ops = {
 	.vidioc_g_frequency	= si470x_vidioc_g_frequency,
 	.vidioc_s_frequency	= si470x_vidioc_s_frequency,
 	.vidioc_s_hw_freq_seek	= si470x_vidioc_s_hw_freq_seek,
+	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 };