media: rc: harmonize infrared durations to microseconds

rc-core kapi uses nanoseconds for infrared durations for receiving, and
microseconds for sending. The uapi already uses microseconds for both,
so this patch does not change the uapi.

Infrared durations do not need nanosecond resolution. IR protocols do not
have durations shorter than about 100 microseconds. Some IR hardware offers
250 microseconds resolution, which is sufficient for most protocols.
Better hardware has 50 microsecond resolution and is enough for every
protocol I am aware off.

Unify on microseconds everywhere. This simplifies the code since less
conversion between microseconds and nanoseconds needs to be done.

This affects:
 - rx_resolution member of struct rc_dev
 - timeout member of struct rc_dev
 - duration member in struct ir_raw_event

Cc: "Bruno Prémont" <bonbons@linux-vserver.org>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Patrick Lerda <patrick9876@free.fr>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: "David Härdeman" <david@hardeman.nu>
Cc: Benjamin Valentin <benpicco@googlemail.com>
Cc: Antti Palosaari <crope@iki.fi>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 15 insertions, 22 deletions

diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index bea52a2fae2b..cde817e744b7 100644
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -67,17 +67,16 @@ void ir_lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev)
 		dev->gap = true;
 		dev->gap_duration = ev.duration;
 
-		sample = LIRC_TIMEOUT(ev.duration / 1000);
+		sample = LIRC_TIMEOUT(ev.duration);
 		dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample);
 
 	/* Normal sample */
 	} else {
 		if (dev->gap) {
-			dev->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
+			dev->gap_duration += ktime_to_us(ktime_sub(ktime_get(),
 							 dev->gap_start));
 
-			/* Convert to ms and cap by LIRC_VALUE_MASK */
-			do_div(dev->gap_duration, 1000);
+			/* Cap by LIRC_VALUE_MASK */
 			dev->gap_duration = min_t(u64, dev->gap_duration,
 						  LIRC_VALUE_MASK);
 
@@ -89,10 +88,10 @@ void ir_lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev)
 			dev->gap = false;
 		}
 
-		sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
-					LIRC_SPACE(ev.duration / 1000);
+		sample = ev.pulse ? LIRC_PULSE(ev.duration) :
+					LIRC_SPACE(ev.duration);
 		dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n",
-			TO_US(ev.duration), TO_STR(ev.pulse));
+			ev.duration, TO_STR(ev.pulse));
 	}
 
 	/*
@@ -296,8 +295,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 		}
 
 		for (i = 0; i < count; i++)
-			/* Convert from NS to US */
-			txbuf[i] = DIV_ROUND_UP(raw[i].duration, 1000);
+			txbuf[i] = raw[i].duration;
 
 		if (dev->s_tx_carrier) {
 			int carrier = ir_raw_encode_carrier(scan.rc_proto);
@@ -325,7 +323,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 	}
 
 	for (i = 0; i < count; i++) {
-		if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
+		if (txbuf[i] > IR_MAX_DURATION - duration || !txbuf[i]) {
 			ret = -EINVAL;
 			goto out_kfree;
 		}
@@ -517,7 +515,7 @@ static long ir_lirc_ioctl(struct file *file, unsigned int cmd,
 		if (!dev->rx_resolution)
 			ret = -ENOTTY;
 		else
-			val = dev->rx_resolution / 1000;
+			val = dev->rx_resolution;
 		break;
 
 	case LIRC_SET_WIDEBAND_RECEIVER:
@@ -539,31 +537,26 @@ static long ir_lirc_ioctl(struct file *file, unsigned int cmd,
 		if (!dev->max_timeout)
 			ret = -ENOTTY;
 		else
-			val = DIV_ROUND_UP(dev->min_timeout, 1000);
+			val = dev->min_timeout;
 		break;
 
 	case LIRC_GET_MAX_TIMEOUT:
 		if (!dev->max_timeout)
 			ret = -ENOTTY;
 		else
-			val = dev->max_timeout / 1000;
+			val = dev->max_timeout;
 		break;
 
 	case LIRC_SET_REC_TIMEOUT:
 		if (!dev->max_timeout) {
 			ret = -ENOTTY;
-		} else if (val > U32_MAX / 1000) {
-			/* Check for multiply overflow */
-			ret = -EINVAL;
 		} else {
-			u32 tmp = val * 1000;
-
-			if (tmp < dev->min_timeout || tmp > dev->max_timeout)
+			if (val < dev->min_timeout || val > dev->max_timeout)
 				ret = -EINVAL;
 			else if (dev->s_timeout)
-				ret = dev->s_timeout(dev, tmp);
+				ret = dev->s_timeout(dev, val);
 			else
-				dev->timeout = tmp;
+				dev->timeout = val;
 		}
 		break;
 
@@ -571,7 +564,7 @@ static long ir_lirc_ioctl(struct file *file, unsigned int cmd,
 		if (!dev->timeout)
 			ret = -ENOTTY;
 		else
-			val = DIV_ROUND_UP(dev->timeout, 1000);
+			val = dev->timeout;
 		break;
 
 	case LIRC_SET_REC_TIMEOUT_REPORTS: