[PATCH 0/2] ALSA: usb-audio: add the initial mix for Presonus Studio 1824c

[PATCH 0/2] ALSA: usb-audio: add the initial mix for Presonus Studio 1824c

[Roy Vegard Ovesen]

This adds a reaonable initial mix for the Presonus Studio 1824c.

The main reason for submitting a patchset is for me to practice
the different patch submit variants.

Roy Vegard Ovesen (2):
  ALSA: usb-audio: add the initial mix for Presonus Studio 1824c
  ALSA: usb-audio: don't hardcode gain for output channel of Presonus
    Studio

 sound/usb/mixer_s1810c.c | 234 +++++++++++++++++++++++----------------
 1 file changed, 139 insertions(+), 95 deletions(-)

-- 
2.51.0

[PATCH 1/2] ALSA: usb-audio: add the initial mix for Presonus Studio 1824c

[Roy Vegard Ovesen]

A reasonable initial mix for the 1824c is the one that
Presonus Universal Control calls bypass.
It mutes all the physical inputs, and connects
Daw channel 1 to Line out channel 1 (left)
Daw channel 2 to Line out channel 2 (right)
Daw channel 3 to Line out channel 3 (left)
etc.

To get the most out of the 1824c a mixer application like
Universal Control is needed. One is available for linux
Link: https://github.com/royvegard/baton

Signed-off-by: Roy Vegard Ovesen <roy.vegard.ovesen@gmail.com>
---
 sound/usb/mixer_s1810c.c | 227 ++++++++++++++++++++++++---------------
 1 file changed, 138 insertions(+), 89 deletions(-)

diff --git a/sound/usb/mixer_s1810c.c b/sound/usb/mixer_s1810c.c
index 656f0b4bfdf0..b2658f922d07 100644
--- a/sound/usb/mixer_s1810c.c
+++ b/sound/usb/mixer_s1810c.c
@@ -215,115 +215,164 @@ snd_sc1810c_get_status_field(struct usb_device *dev,
  */
 static int snd_s1810c_init_mixer_maps(struct snd_usb_audio *chip)
 {
-	u32 a, b, c, e, n, off;
+	u32 a, b, c, e, n, off, left, right;
 	struct usb_device *dev = chip->dev;
 
-	/* Set initial volume levels ? */
-	a = 0x64;
-	e = 0xbc;
-	for (n = 0; n < 2; n++) {
-		off = n * 18;
-		for (b = off; b < 18 + off; b++) {
-			/* This channel to all outputs ? */
-			for (c = 0; c <= 8; c++) {
+	switch (chip->usb_id) {
+	case USB_ID(0x194f, 0x010c): /* 1810c */
+		/* Set initial volume levels ? */
+		a = 0x64;
+		e = 0xbc;
+		for (n = 0; n < 2; n++) {
+			off = n * 18;
+			for (b = off; b < 18 + off; b++) {
+				/* This channel to all outputs ? */
+				for (c = 0; c <= 8; c++) {
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
+				}
+				/* This channel to main output (again) */
+				snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
+				snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
+			}
+			/*
+			 * I noticed on UC that DAW channels have different
+			 * initial volumes, so this makes sense.
+			 */
+			e = 0xb53bf0;
+		}
+
+		/* Connect analog outputs ? */
+		a = 0x65;
+		e = 0x01000000;
+		for (b = 1; b < 3; b++) {
+			snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
+			snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
+		}
+		snd_s1810c_send_ctl_packet(dev, a, 0, 0, 0, e);
+		snd_s1810c_send_ctl_packet(dev, a, 0, 0, 1, e);
+
+		/* Set initial volume levels for S/PDIF mappings ? */
+		a = 0x64;
+		e = 0xbc;
+		c = 3;
+		for (n = 0; n < 2; n++) {
+			off = n * 18;
+			for (b = off; b < 18 + off; b++) {
 				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
 				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
 			}
-			/* This channel to main output (again) */
+			e = 0xb53bf0;
+		}
+
+		/* Connect S/PDIF output ? */
+		a = 0x65;
+		e = 0x01000000;
+		snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
+		snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
+
+		/* Connect all outputs (again) ? */
+		a = 0x65;
+		e = 0x01000000;
+		for (b = 0; b < 4; b++) {
 			snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
 			snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
 		}
-		/*
-		 * I noticed on UC that DAW channels have different
-		 * initial volumes, so this makes sense.
-		 */
-		e = 0xb53bf0;
-	}
 
-	/* Connect analog outputs ? */
-	a = 0x65;
-	e = 0x01000000;
-	for (b = 1; b < 3; b++) {
-		snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
-		snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
-	}
-	snd_s1810c_send_ctl_packet(dev, a, 0, 0, 0, e);
-	snd_s1810c_send_ctl_packet(dev, a, 0, 0, 1, e);
-
-	/* Set initial volume levels for S/PDIF mappings ? */
-	a = 0x64;
-	e = 0xbc;
-	c = 3;
-	for (n = 0; n < 2; n++) {
-		off = n * 18;
-		for (b = off; b < 18 + off; b++) {
-			snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
-			snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
+		/* Basic routing to get sound out of the device */
+		a = 0x64;
+		e = 0x01000000;
+		for (c = 0; c < 4; c++) {
+			for (b = 0; b < 36; b++) {
+				if ((c == 0 && b == 18) ||	/* DAW1/2 -> Main */
+					(c == 1 && b == 20) ||	/* DAW3/4 -> Line3/4 */
+					(c == 2 && b == 22) ||	/* DAW4/5 -> Line5/6 */
+					(c == 3 && b == 24)) {	/* DAW5/6 -> S/PDIF */
+					/* Left */
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0);
+					b++;
+					/* Right */
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
+				} else {
+					/* Leave the rest disconnected */
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0);
+				}
+			}
 		}
-		e = 0xb53bf0;
-	}
 
-	/* Connect S/PDIF output ? */
-	a = 0x65;
-	e = 0x01000000;
-	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
-	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
-
-	/* Connect all outputs (again) ? */
-	a = 0x65;
-	e = 0x01000000;
-	for (b = 0; b < 4; b++) {
-		snd_s1810c_send_ctl_packet(dev, a, b, 0, 0, e);
-		snd_s1810c_send_ctl_packet(dev, a, b, 0, 1, e);
-	}
-
-	/* Basic routing to get sound out of the device */
-	a = 0x64;
-	e = 0x01000000;
-	for (c = 0; c < 4; c++) {
-		for (b = 0; b < 36; b++) {
-			if ((c == 0 && b == 18) ||	/* DAW1/2 -> Main */
-			    (c == 1 && b == 20) ||	/* DAW3/4 -> Line3/4 */
-			    (c == 2 && b == 22) ||	/* DAW4/5 -> Line5/6 */
-			    (c == 3 && b == 24)) {	/* DAW5/6 -> S/PDIF */
-				/* Left */
+		/* Set initial volume levels for S/PDIF (again) ? */
+		a = 0x64;
+		e = 0xbc;
+		c = 3;
+		for (n = 0; n < 2; n++) {
+			off = n * 18;
+			for (b = off; b < 18 + off; b++) {
 				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
-				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0);
-				b++;
-				/* Right */
-				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0);
 				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
-			} else {
-				/* Leave the rest disconnected */
-				snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0);
-				snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0);
 			}
+			e = 0xb53bf0;
 		}
-	}
 
-	/* Set initial volume levels for S/PDIF (again) ? */
-	a = 0x64;
-	e = 0xbc;
-	c = 3;
-	for (n = 0; n < 2; n++) {
-		off = n * 18;
-		for (b = off; b < 18 + off; b++) {
+		/* Connect S/PDIF outputs (again) ? */
+		a = 0x65;
+		e = 0x01000000;
+		snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
+		snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
+
+		/* Again ? */
+		snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
+		snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
+		break;
+
+	case USB_ID(0x194f, 0x010d): /* 1824c */
+		/* Set all output faders to unity gain */
+		a = 0x65;
+		c = 0x00;
+		e = 0x01000000;
+
+		for (b = 0; b < 9; b++) {
 			snd_s1810c_send_ctl_packet(dev, a, b, c, 0, e);
 			snd_s1810c_send_ctl_packet(dev, a, b, c, 1, e);
 		}
-		e = 0xb53bf0;
-	}
-
-	/* Connect S/PDIF outputs (again) ? */
-	a = 0x65;
-	e = 0x01000000;
-	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
-	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
-
-	/* Again ? */
-	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 0, e);
-	snd_s1810c_send_ctl_packet(dev, a, 3, 0, 1, e);
 
+		/* Set
+		 * Daw 1 -> Line out 1 (left), Daw 2 -> Line out 2 (right)
+		 * Daw 3 -> Line out 3, (left) Daw 4 -> Line out 4 (right)
+		 * Daw 5 -> Line out 5, (left) Daw 6 -> Line out 6 (right)
+		 * Daw 7 -> Line out 7, (left) Daw 8 -> Line out 8 (right)
+		 * Daw 9 -> SPDIF out 1, (left) Daw 10 -> SPDIF out 2 (right)
+		 * Daw 11 -> ADAT out 1, (left) Daw 12 -> ADAT out 2 (right)
+		 * Daw 13 -> ADAT out 3, (left) Daw 14 -> ADAT out 4 (right)
+		 * Daw 15 -> ADAT out 5, (left) Daw 16 -> ADAT out 6 (right)
+		 * Daw 17 -> ADAT out 7, (left) Daw 18 -> ADAT out 8 (right)
+		 * Everything else muted
+		 */
+		a = 0x64;
+		/* The first Daw channel is channel 18 */
+		left = 18;
+
+		for (c = 0; c < 9; c++) {
+			right = left + 1;
+
+			for (b = 0; b < 36; b++) {
+				if (b == left) {
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0x01000000);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0x00);
+				} else if (b == right) {
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0x00);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0x01000000);
+				} else {
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 0, 0x00);
+					snd_s1810c_send_ctl_packet(dev, a, b, c, 1, 0x00);
+				}
+			}
+			left += 2;
+		}
+		break;
+	}
 	return 0;
 }
 
-- 
2.51.0

[PATCH 2/2] ALSA: usb-audio: don't hardcode gain for output channel of Presonus Studio

[Roy Vegard Ovesen]

On the 1824c output channel 4 left/right is the S/PDIF output,
so this needs to be able to be set.

I'm guessing that for the 1810c since it has no output channel 4,
it does not matter what the gain value of this channel is set to.

Signed-off-by: Roy Vegard Ovesen <roy.vegard.ovesen@gmail.com>
---
 sound/usb/mixer_s1810c.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/sound/usb/mixer_s1810c.c b/sound/usb/mixer_s1810c.c
index b2658f922d07..15960d25e748 100644
--- a/sound/usb/mixer_s1810c.c
+++ b/sound/usb/mixer_s1810c.c
@@ -147,12 +147,7 @@ snd_s1810c_send_ctl_packet(struct usb_device *dev, u32 a,
 	pkt.b = b;
 	pkt.c = c;
 	pkt.d = d;
-	/*
-	 * Value for settings 0/1 for this
-	 * output channel is always 0 (probably because
-	 * there is no ADAT output on 1810c)
-	 */
-	pkt.e = (c == 4) ? 0 : e;
+	pkt.e = e;
 
 	ret = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
 			      SC1810C_CMD_REQ,
-- 
2.51.0

Re: [PATCH 0/2] ALSA: usb-audio: add the initial mix for Presonus Studio 1824c

[Takashi Iwai]

On Sun, 28 Sep 2025 13:37:44 +0200,
Roy Vegard Ovesen wrote:
> 
> This adds a reaonable initial mix for the Presonus Studio 1824c.
> 
> The main reason for submitting a patchset is for me to practice
> the different patch submit variants.
> 
> Roy Vegard Ovesen (2):
>   ALSA: usb-audio: add the initial mix for Presonus Studio 1824c
>   ALSA: usb-audio: don't hardcode gain for output channel of Presonus
>     Studio

Applied both patches now.  Thanks.


Takashi