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

Markus project.m.schroetter at gmail.com
Sun Jun 6 16:33:14 CEST 2021


On 06.06.21 16:17, Geoffrey D. Bennett wrote:

> 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 at gmail.com>
> Signed-off-by: Geoffrey D. Bennett <g at b4.vu>

Tested-by: Markus Schroetter <project.m.schroetter at gmail.com>

> ---
>  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 b0043906c77f..48cf3e1954e0 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;


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