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, 8 insertions, 9 deletions

diff --git a/drivers/media/rc/redrat3.c b/drivers/media/rc/redrat3.c
index aad9526f3754..2cf3377ec63a 100644
--- a/drivers/media/rc/redrat3.c
+++ b/drivers/media/rc/redrat3.c
@@ -340,7 +340,7 @@ static void redrat3_process_ir_data(struct redrat3_dev *rr3)
 {
 	struct ir_raw_event rawir = {};
 	struct device *dev;
-	unsigned int i, sig_size, single_len, offset, val;
+	unsigned int i, sig_size, offset, val;
 	u32 mod_freq;
 
 	dev = rr3->dev;
@@ -361,7 +361,6 @@ static void redrat3_process_ir_data(struct redrat3_dev *rr3)
 	for (i = 0; i < sig_size; i++) {
 		offset = rr3->irdata.sigdata[i];
 		val = get_unaligned_be16(&rr3->irdata.lens[offset]);
-		single_len = redrat3_len_to_us(val);
 
 		/* we should always get pulse/space/pulse/space samples */
 		if (i % 2)
@@ -369,7 +368,7 @@ static void redrat3_process_ir_data(struct redrat3_dev *rr3)
 		else
 			rawir.pulse = true;
 
-		rawir.duration = US_TO_NS(single_len);
+		rawir.duration = redrat3_len_to_us(val);
 		/* cap the value to IR_MAX_DURATION */
 		rawir.duration = (rawir.duration > IR_MAX_DURATION) ?
 				 IR_MAX_DURATION : rawir.duration;
@@ -495,7 +494,7 @@ static u32 redrat3_get_timeout(struct redrat3_dev *rr3)
 	return timeout;
 }
 
-static int redrat3_set_timeout(struct rc_dev *rc_dev, unsigned int timeoutns)
+static int redrat3_set_timeout(struct rc_dev *rc_dev, unsigned int timeoutus)
 {
 	struct redrat3_dev *rr3 = rc_dev->priv;
 	struct usb_device *udev = rr3->udev;
@@ -507,7 +506,7 @@ static int redrat3_set_timeout(struct rc_dev *rc_dev, unsigned int timeoutns)
 	if (!timeout)
 		return -ENOMEM;
 
-	*timeout = cpu_to_be32(redrat3_us_to_len(timeoutns / 1000));
+	*timeout = cpu_to_be32(redrat3_us_to_len(timeoutus));
 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), RR3_SET_IR_PARAM,
 		     USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
 		     RR3_IR_IO_SIG_TIMEOUT, 0, timeout, sizeof(*timeout),
@@ -947,15 +946,15 @@ static struct rc_dev *redrat3_init_rc_dev(struct redrat3_dev *rr3)
 	rc->dev.parent = dev;
 	rc->priv = rr3;
 	rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
-	rc->min_timeout = MS_TO_NS(RR3_RX_MIN_TIMEOUT);
-	rc->max_timeout = MS_TO_NS(RR3_RX_MAX_TIMEOUT);
-	rc->timeout = US_TO_NS(redrat3_get_timeout(rr3));
+	rc->min_timeout = MS_TO_US(RR3_RX_MIN_TIMEOUT);
+	rc->max_timeout = MS_TO_US(RR3_RX_MAX_TIMEOUT);
+	rc->timeout = redrat3_get_timeout(rr3);
 	rc->s_timeout = redrat3_set_timeout;
 	rc->tx_ir = redrat3_transmit_ir;
 	rc->s_tx_carrier = redrat3_set_tx_carrier;
 	rc->s_carrier_report = redrat3_wideband_receiver;
 	rc->driver_name = DRIVER_NAME;
-	rc->rx_resolution = US_TO_NS(2);
+	rc->rx_resolution = 2;
 	rc->map_name = RC_MAP_HAUPPAUGE;
 
 	ret = rc_register_device(rc);