[PATCH V2 0/2] Read all configuration at init time

[PATCH V2 0/2] Read all configuration at init time

[Geoffrey D. Bennett]

Version two of patches to add support for reading the mixer volumes
and mux configuration from the hardware when the driver is
initialising.

Changes since v1:
- fix missing endian conversion spotted by ktest bot

Geoffrey D. Bennett (2):
  ALSA: usb-audio: scarlett2: Read mixer volumes at init time
  ALSA: usb-audio: scarlett2: Read mux at init time

 sound/usb/mixer_scarlett_gen2.c | 227 ++++++++++++++++++++++----------
 1 file changed, 161 insertions(+), 66 deletions(-)

-- 
2.31.1

[PATCH V2 1/2] ALSA: usb-audio: scarlett2: Read mixer volumes at init time

[Geoffrey D. Bennett]

Add support for reading the mixer volumes from the hardware when the
driver is initialising. Previously these ALSA volume controls were
initialised to zero instead of being initialised to match the hardware
state.

Fixes: 9e4d5c1be21f ("ALSA: usb-audio: Scarlett Gen 2 mixer interface")
Suggested-by: Vladimir Sadovnikov <sadko4u@gmail.com>
Tested-by: Markus Schroetter <project.m.schroetter@gmail.com>
Tested-by: Alex Fellows <alex.fellows@gmail.com>
Tested-by: Daniel Sales <daniel.sales.z@gmail.com>
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
---
 sound/usb/mixer_scarlett_gen2.c | 57 +++++++++++++++++++++++++++++++--
 1 file changed, 55 insertions(+), 2 deletions(-)

diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c
index 4caf379d5b99..5969d6bda58d 100644
--- a/sound/usb/mixer_scarlett_gen2.c
+++ b/sound/usb/mixer_scarlett_gen2.c
@@ -117,11 +117,12 @@
 #define SCARLETT2_MIXER_MAX_DB 6
 #define SCARLETT2_MIXER_MAX_VALUE \
 	((SCARLETT2_MIXER_MAX_DB - SCARLETT2_MIXER_MIN_DB) * 2)
+#define SCARLETT2_MIXER_VALUE_COUNT (SCARLETT2_MIXER_MAX_VALUE + 1)
 
 /* map from (dB + 80) * 2 to mixer value
  * for dB in 0 .. 172: int(8192 * pow(10, ((dB - 160) / 2 / 20)))
  */
-static const u16 scarlett2_mixer_values[173] = {
+static const u16 scarlett2_mixer_values[SCARLETT2_MIXER_VALUE_COUNT] = {
 	0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
 	2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 8, 8,
 	9, 9, 10, 10, 11, 12, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
@@ -465,6 +466,7 @@ static int scarlett2_get_port_start_num(const struct scarlett2_ports *ports,
 
 #define SCARLETT2_USB_INIT_SEQ 0x00000000
 #define SCARLETT2_USB_GET_METER_LEVELS 0x00001001
+#define SCARLETT2_USB_GET_MIX 0x00002001
 #define SCARLETT2_USB_SET_MIX 0x00002002
 #define SCARLETT2_USB_SET_MUX 0x00003002
 #define SCARLETT2_USB_GET_DATA 0x00800000
@@ -784,6 +786,49 @@ static int scarlett2_usb_get_volume_status(
 				 buf, sizeof(*buf));
 }
 
+/* Send a USB message to get the volumes for all inputs of one mix
+ * and put the values into private->mix[]
+ */
+static int scarlett2_usb_get_mix(struct usb_mixer_interface *mixer,
+				 int mix_num)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	const struct scarlett2_device_info *info = private->info;
+
+	int num_mixer_in =
+		info->ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_OUT];
+	int err, i, j, k;
+
+	struct {
+		__le16 mix_num;
+		__le16 count;
+	} __packed req;
+
+	__le16 data[SCARLETT2_INPUT_MIX_MAX];
+
+	req.mix_num = cpu_to_le16(mix_num);
+	req.count = cpu_to_le16(num_mixer_in);
+
+	err = scarlett2_usb(mixer, SCARLETT2_USB_GET_MIX,
+			    &req, sizeof(req),
+			    data, num_mixer_in * sizeof(u16));
+	if (err < 0)
+		return err;
+
+	for (i = 0, j = mix_num * num_mixer_in; i < num_mixer_in; i++, j++) {
+		u16 mixer_value = le16_to_cpu(data[i]);
+
+		for (k = 0; k < SCARLETT2_MIXER_VALUE_COUNT; k++)
+			if (scarlett2_mixer_values[k] >= mixer_value)
+				break;
+		if (k == SCARLETT2_MIXER_VALUE_COUNT)
+			k = SCARLETT2_MIXER_MAX_VALUE;
+		private->mix[j] = k;
+	}
+
+	return 0;
+}
+
 /* Send a USB message to set the volumes for all inputs of one mix
  * (values obtained from private->mix[])
  */
@@ -1831,7 +1876,7 @@ static int scarlett2_init_private(struct usb_mixer_interface *mixer,
 	return scarlett2_usb(mixer, SCARLETT2_USB_INIT_SEQ, NULL, 0, NULL, 0);
 }
 
-/* Read line-in config and line-out volume settings on start */
+/* Read configuration from the interface on start */
 static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
 {
 	struct scarlett2_mixer_data *private = mixer->private_data;
@@ -1839,6 +1884,8 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
 	const struct scarlett2_ports *ports = info->ports;
 	int num_line_out =
 		ports[SCARLETT2_PORT_TYPE_ANALOGUE].num[SCARLETT2_PORT_OUT];
+	int num_mixer_out =
+		ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_IN];
 	u8 level_switches[SCARLETT2_LEVEL_SWITCH_MAX];
 	u8 pad_switches[SCARLETT2_PAD_SWITCH_MAX];
 	struct scarlett2_usb_volume_status volume_status;
@@ -1894,6 +1941,12 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
 	for (i = 0; i < info->button_count; i++)
 		private->buttons[i] = !!volume_status.buttons[i];
 
+	for (i = 0; i < num_mixer_out; i++) {
+		err = scarlett2_usb_get_mix(mixer, i);
+		if (err < 0)
+			return err;
+	}
+
 	return 0;
 }
 
-- 
2.31.1

[PATCH V2 2/2] ALSA: usb-audio: scarlett2: Read mux at init time

[Geoffrey D. Bennett]

Add support for retrieving the mux configuration from the hardware
when the driver is initialising. Previously the ALSA controls were
initialised to a default hard-coded state instead of being initialised
to match the hardware state.

Fixes: 9e4d5c1be21f ("ALSA: usb-audio: Scarlett Gen 2 mixer interface")
Suggested-by: Vladimir Sadovnikov <sadko4u@gmail.com>
Tested-by: Markus Schroetter <project.m.schroetter@gmail.com>
Tested-by: Alex Fellows <alex.fellows@gmail.com>
Tested-by: Daniel Sales <daniel.sales.z@gmail.com>
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
---
 sound/usb/mixer_scarlett_gen2.c | 170 ++++++++++++++++++++------------
 1 file changed, 106 insertions(+), 64 deletions(-)

diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c
index 5969d6bda58d..a461317dc8c6 100644
--- a/sound/usb/mixer_scarlett_gen2.c
+++ b/sound/usb/mixer_scarlett_gen2.c
@@ -32,6 +32,10 @@
  * Scarlett 6i6 support added in June 2019 (thanks to Martin Wittmann
  * for providing usbmon output and testing).
  *
+ * Support for loading mixer volume and mux configuration from the
+ * interface during driver initialisation added in May 2021 (thanks to
+ * Vladimir Sadovnikov for figuring out how).
+ *
  * This ALSA mixer gives access to:
  *  - input, output, mixer-matrix muxes
  *  - 18x10 mixer-matrix gain stages
@@ -228,6 +232,7 @@ struct scarlett2_mixer_data {
 	struct delayed_work work;
 	const struct scarlett2_device_info *info;
 	int num_mux_srcs;
+	int num_mux_dsts;
 	u16 scarlett2_seq;
 	u8 vol_updated;
 	u8 master_vol;
@@ -468,6 +473,7 @@ static int scarlett2_get_port_start_num(const struct scarlett2_ports *ports,
 #define SCARLETT2_USB_GET_METER_LEVELS 0x00001001
 #define SCARLETT2_USB_GET_MIX 0x00002001
 #define SCARLETT2_USB_SET_MIX 0x00002002
+#define SCARLETT2_USB_GET_MUX 0x00003001
 #define SCARLETT2_USB_SET_MUX 0x00003002
 #define SCARLETT2_USB_GET_DATA 0x00800000
 #define SCARLETT2_USB_SET_DATA 0x00800001
@@ -877,6 +883,94 @@ static u32 scarlett2_mux_src_num_to_id(const struct scarlett2_ports *ports,
 	return 0;
 }
 
+/* Convert a hardware ID to a port number index */
+static u32 scarlett2_mux_id_to_num(const struct scarlett2_ports *ports,
+				   int direction,
+				   u32 id)
+{
+	int port_type;
+	int port_num = 0;
+
+	for (port_type = 0;
+	     port_type < SCARLETT2_PORT_TYPE_COUNT;
+	     port_type++) {
+		struct scarlett2_ports port = ports[port_type];
+		int count = port.num[direction];
+
+		if (id >= port.id && id < port.id + count)
+			return port_num + id - port.id;
+		port_num += count;
+	}
+
+	/* Oops */
+	return -1;
+}
+
+/* Convert one mux entry from the interface and load into private->mux[] */
+static void scarlett2_usb_populate_mux(struct scarlett2_mixer_data *private,
+				       u32 mux_entry)
+{
+	const struct scarlett2_device_info *info = private->info;
+	const struct scarlett2_ports *ports = info->ports;
+
+	int dst_idx, src_idx;
+
+	dst_idx = scarlett2_mux_id_to_num(ports, SCARLETT2_PORT_OUT,
+					  mux_entry & 0xFFF);
+	if (dst_idx < 0)
+		return;
+
+	if (dst_idx >= private->num_mux_dsts) {
+		usb_audio_err(private->mixer->chip,
+			"BUG: scarlett2_mux_id_to_num(%06x, OUT): %d >= %d",
+			mux_entry, dst_idx, private->num_mux_dsts);
+		return;
+	}
+
+	src_idx = scarlett2_mux_id_to_num(ports, SCARLETT2_PORT_IN,
+					  mux_entry >> 12);
+	if (src_idx < 0)
+		return;
+
+	if (src_idx >= private->num_mux_srcs) {
+		usb_audio_err(private->mixer->chip,
+			"BUG: scarlett2_mux_id_to_num(%06x, IN): %d >= %d",
+			mux_entry, src_idx, private->num_mux_srcs);
+		return;
+	}
+
+	private->mux[dst_idx] = src_idx;
+}
+
+/* Send USB message to get mux inputs and then populate private->mux[] */
+static int scarlett2_usb_get_mux(struct usb_mixer_interface *mixer)
+{
+	struct scarlett2_mixer_data *private = mixer->private_data;
+	int count = private->num_mux_dsts;
+	int err, i;
+
+	struct {
+		__le16 num;
+		__le16 count;
+	} __packed req;
+
+	__le32 data[SCARLETT2_MUX_MAX];
+
+	req.num = 0;
+	req.count = cpu_to_le16(count);
+
+	err = scarlett2_usb(mixer, SCARLETT2_USB_GET_MUX,
+			    &req, sizeof(req),
+			    data, count * sizeof(u32));
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < count; i++)
+		scarlett2_usb_populate_mux(private, le32_to_cpu(data[i]));
+
+	return 0;
+}
+
 /* Send USB messages to set mux inputs */
 static int scarlett2_usb_set_mux(struct usb_mixer_interface *mixer)
 {
@@ -1783,72 +1877,23 @@ static void scarlett2_private_suspend(struct usb_mixer_interface *mixer)
 
 /*** Initialisation ***/
 
-static int scarlett2_count_mux_srcs(const struct scarlett2_ports *ports)
+static void scarlett2_count_mux_io(struct scarlett2_mixer_data *private)
 {
-	int port_type, count = 0;
+	const struct scarlett2_ports *ports = private->info->ports;
+	int port_type, srcs = 0, dsts = 0;
 
 	for (port_type = 0;
 	     port_type < SCARLETT2_PORT_TYPE_COUNT;
-	     port_type++)
-		count += ports[port_type].num[SCARLETT2_PORT_IN];
-
-	return count;
-}
-
-/* Default routing connects PCM outputs and inputs to Analogue,
- * S/PDIF, then ADAT
- */
-static void scarlett2_init_routing(u8 *mux,
-				   const struct scarlett2_ports *ports)
-{
-	int i, input_num, input_count, port_type;
-	int output_num, output_count, port_type_connect_num;
-
-	static const int connect_order[] = {
-		SCARLETT2_PORT_TYPE_ANALOGUE,
-		SCARLETT2_PORT_TYPE_SPDIF,
-		SCARLETT2_PORT_TYPE_ADAT,
-		-1
-	};
-
-	/* Assign PCM inputs (routing outputs) */
-	output_num = scarlett2_get_port_start_num(ports,
-						  SCARLETT2_PORT_OUT,
-						  SCARLETT2_PORT_TYPE_PCM);
-	output_count = ports[SCARLETT2_PORT_TYPE_PCM].num[SCARLETT2_PORT_OUT];
-
-	for (port_type = connect_order[port_type_connect_num = 0];
-	     port_type >= 0;
-	     port_type = connect_order[++port_type_connect_num]) {
-		input_num = scarlett2_get_port_start_num(
-			ports, SCARLETT2_PORT_IN, port_type);
-		input_count = ports[port_type].num[SCARLETT2_PORT_IN];
-		for (i = 0;
-		     i < input_count && output_count;
-		     i++, output_count--)
-			mux[output_num++] = input_num++;
+	     port_type++) {
+		srcs += ports[port_type].num[SCARLETT2_PORT_IN];
+		dsts += ports[port_type].num[SCARLETT2_PORT_OUT_44];
 	}
 
-	/* Assign PCM outputs (routing inputs) */
-	input_num = scarlett2_get_port_start_num(ports,
-						 SCARLETT2_PORT_IN,
-						 SCARLETT2_PORT_TYPE_PCM);
-	input_count = ports[SCARLETT2_PORT_TYPE_PCM].num[SCARLETT2_PORT_IN];
-
-	for (port_type = connect_order[port_type_connect_num = 0];
-	     port_type >= 0;
-	     port_type = connect_order[++port_type_connect_num]) {
-		output_num = scarlett2_get_port_start_num(
-			ports, SCARLETT2_PORT_OUT, port_type);
-		output_count = ports[port_type].num[SCARLETT2_PORT_OUT];
-		for (i = 0;
-		     i < output_count && input_count;
-		     i++, input_count--)
-			mux[output_num++] = input_num++;
-	}
+	private->num_mux_srcs = srcs;
+	private->num_mux_dsts = dsts;
 }
 
-/* Initialise private data, routing, sequence number */
+/* Initialise private data and sequence number */
 static int scarlett2_init_private(struct usb_mixer_interface *mixer,
 				  const struct scarlett2_device_info *info)
 {
@@ -1862,16 +1907,13 @@ static int scarlett2_init_private(struct usb_mixer_interface *mixer,
 	mutex_init(&private->data_mutex);
 	INIT_DELAYED_WORK(&private->work, scarlett2_config_save_work);
 	private->info = info;
-	private->num_mux_srcs = scarlett2_count_mux_srcs(info->ports);
+	scarlett2_count_mux_io(private);
 	private->scarlett2_seq = 0;
 	private->mixer = mixer;
 	mixer->private_data = private;
 	mixer->private_free = scarlett2_private_free;
 	mixer->private_suspend = scarlett2_private_suspend;
 
-	/* Setup default routing */
-	scarlett2_init_routing(private->mux, info->ports);
-
 	/* Initialise the sequence number used for the proprietary commands */
 	return scarlett2_usb(mixer, SCARLETT2_USB_INIT_SEQ, NULL, 0, NULL, 0);
 }
@@ -1947,7 +1989,7 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
 			return err;
 	}
 
-	return 0;
+	return scarlett2_usb_get_mux(mixer);
 }
 
 /* Notify on volume change */
@@ -2055,7 +2097,7 @@ static int snd_scarlett_gen2_controls_create(struct usb_mixer_interface *mixer,
 {
 	int err;
 
-	/* Initialise private data, routing, sequence number */
+	/* Initialise private data and sequence number */
 	err = scarlett2_init_private(mixer, info);
 	if (err < 0)
 		return err;
-- 
2.31.1

Re: [PATCH V2 0/2] Read all configuration at init time

[Takashi Iwai]

On Mon, 07 Jun 2021 21:13:11 +0200,
Geoffrey D. Bennett wrote:
> 
> Version two of patches to add support for reading the mixer volumes
> and mux configuration from the hardware when the driver is
> initialising.
> 
> Changes since v1:
> - fix missing endian conversion spotted by ktest bot
> 
> Geoffrey D. Bennett (2):
>   ALSA: usb-audio: scarlett2: Read mixer volumes at init time
>   ALSA: usb-audio: scarlett2: Read mux at init time

Applied both patches now.


thanks,

Takashi