Commit 9930c260 authored by Geoffrey D. Bennett's avatar Geoffrey D. Bennett Committed by Takashi Iwai
Browse files

ALSA: scarlett2: Add support for device map retrieval 



Add support for retrieving the device map from Focusrite Scarlett 4th
Gen and Vocaster devices. The device map is a base64-encoded,
zlib-compressed JSON description of the device's capabilities and
configuration.

This patch adds:
- a has_devmap field to the scarlett2_device_info struct
- a /proc/asound/cardX/device-map.json.zz.b64 file when supported

Signed-off-by: default avatarGeoffrey D. Bennett <g@b4.vu>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/e86380c6792460d8d05a8ecc37c9ebd072be25a5.1727971672.git.g@b4.vu
parent 8eba063b

sound/usb/mixer_scarlett2.c

+138 −1
Original line number Diff line number Diff line
@@ -1079,6 +1079,9 @@ struct scarlett2_device_info { 
	/* minimum firmware version required */

	u16 min_firmware_version;



	/* has a downloadable device map */

	u8 has_devmap;



	/* support for main/alt speaker switching */

	u8 has_speaker_switching;
@@ -1773,6 +1776,7 @@ static const struct scarlett2_device_info s18i20_gen3_info = { 
static const struct scarlett2_device_info vocaster_one_info = {

	.config_set = &scarlett2_config_set_vocaster,

	.min_firmware_version = 1769,

	.has_devmap = 1,



	.phantom_count = 1,

	.inputs_per_phantom = 1,
@@ -1815,6 +1819,7 @@ static const struct scarlett2_device_info vocaster_one_info = { 
static const struct scarlett2_device_info vocaster_two_info = {

	.config_set = &scarlett2_config_set_vocaster,

	.min_firmware_version = 1769,

	.has_devmap = 1,



	.phantom_count = 2,

	.inputs_per_phantom = 1,
@@ -1858,6 +1863,7 @@ static const struct scarlett2_device_info vocaster_two_info = { 
static const struct scarlett2_device_info solo_gen4_info = {

	.config_set = &scarlett2_config_set_gen4_solo,

	.min_firmware_version = 2115,

	.has_devmap = 1,



	.level_input_count = 1,

	.air_input_count = 1,
@@ -1912,6 +1918,7 @@ static const struct scarlett2_device_info solo_gen4_info = { 
static const struct scarlett2_device_info s2i2_gen4_info = {

	.config_set = &scarlett2_config_set_gen4_2i2,

	.min_firmware_version = 2115,

	.has_devmap = 1,



	.level_input_count = 2,

	.air_input_count = 2,
@@ -1966,6 +1973,7 @@ static const struct scarlett2_device_info s2i2_gen4_info = { 
static const struct scarlett2_device_info s4i4_gen4_info = {

	.config_set = &scarlett2_config_set_gen4_4i4,

	.min_firmware_version = 2089,

	.has_devmap = 1,



	.level_input_count = 2,

	.air_input_count = 2,
@@ -2264,6 +2272,8 @@ static int scarlett2_get_port_start_num( 
#define SCARLETT2_USB_GET_DATA      0x00800000

#define SCARLETT2_USB_SET_DATA      0x00800001

#define SCARLETT2_USB_DATA_CMD      0x00800002

#define SCARLETT2_USB_INFO_DEVMAP   0x0080000c

#define SCARLETT2_USB_GET_DEVMAP    0x0080000d



#define SCARLETT2_USB_CONFIG_SAVE 6
@@ -2277,6 +2287,14 @@ static int scarlett2_get_port_start_num( 
#define SCARLETT2_SEGMENT_SETTINGS_NAME "App_Settings"

#define SCARLETT2_SEGMENT_FIRMWARE_NAME "App_Upgrade"



/* Gen 4 device firmware provides access to a base64-encoded

 * zlib-compressed JSON description of the device's capabilities and

 * configuration. This device map is made available in

 * /proc/asound/cardX/device-map.json.zz.b64

 */

#define SCARLETT2_DEVMAP_BLOCK_SIZE 1024

#define SCARLETT2_DEVMAP_FILENAME "device-map.json.zz.b64"



/* proprietary request/response format */

struct scarlett2_usb_packet {

	__le32 cmd;
@@ -9562,6 +9580,116 @@ static int scarlett2_hwdep_init(struct usb_mixer_interface *mixer) 
	return 0;

}



/*** device-map file ***/



static ssize_t scarlett2_devmap_read(

	struct snd_info_entry *entry,

	void                  *file_private_data,

	struct file           *file,

	char __user           *buf,

	size_t                 count,

	loff_t                 pos)

{

	struct usb_mixer_interface *mixer = entry->private_data;

	u8           *resp_buf;

	const size_t  block_size = SCARLETT2_DEVMAP_BLOCK_SIZE;

	size_t        copied = 0;



	if (pos >= entry->size)

		return 0;



	if (pos + count > entry->size)

		count = entry->size - pos;



	resp_buf = kmalloc(block_size, GFP_KERNEL);

	if (!resp_buf)

		return -ENOMEM;



	while (count > 0) {

		/* SCARLETT2_USB_GET_DEVMAP reads only on block boundaries,

		 * so we need to read a whole block and copy the requested

		 * chunk to userspace.

		 */



		__le32 req;

		int    err;



		/* offset within the block that we're reading */

		size_t offset = pos % block_size;



		/* read_size is block_size except for the last block */

		size_t block_start = pos - offset;

		size_t read_size = min_t(size_t,

					 block_size,

					 entry->size - block_start);



		/* size of the chunk to copy to userspace */

		size_t copy_size = min_t(size_t, count, read_size - offset);



		/* request the block */

		req = cpu_to_le32(pos / block_size);

		err = scarlett2_usb(mixer, SCARLETT2_USB_GET_DEVMAP,

				    &req, sizeof(req), resp_buf, read_size);

		if (err < 0) {

			kfree(resp_buf);

			return copied ? copied : err;

		}



		if (copy_to_user(buf, resp_buf + offset, copy_size)) {

			kfree(resp_buf);

			return -EFAULT;

		}



		buf += copy_size;

		pos += copy_size;

		copied += copy_size;

		count -= copy_size;

	}



	kfree(resp_buf);

	return copied;

}



static const struct snd_info_entry_ops scarlett2_devmap_ops = {

	.read = scarlett2_devmap_read,

};



static int scarlett2_devmap_init(struct usb_mixer_interface *mixer)

{

	struct snd_card *card = mixer->chip->card;

	struct scarlett2_data *private = mixer->private_data;

	const struct scarlett2_device_info *info = private->info;

	__le16 config_len_buf[2];

	int config_len;

	struct snd_info_entry *entry;

	int err;



	/* If the device doesn't support the DEVMAP commands, don't

	 * create the /proc/asound/cardX/scarlett.json.zlib entry

	 */

	if (!info->has_devmap)

		return 0;



	err = scarlett2_usb(mixer, SCARLETT2_USB_INFO_DEVMAP,

			    NULL, 0, &config_len_buf, sizeof(config_len_buf));

	if (err < 0)

		return err;



	config_len = le16_to_cpu(config_len_buf[1]);



	err = snd_card_proc_new(card, SCARLETT2_DEVMAP_FILENAME, &entry);

	if (err < 0)

		return err;



	entry->content = SNDRV_INFO_CONTENT_DATA;

	entry->private_data = mixer;

	entry->c.ops = &scarlett2_devmap_ops;

	entry->size = config_len;

	entry->mode = S_IFREG | 0444;



	return 0;

}



int snd_scarlett2_init(struct usb_mixer_interface *mixer)

{

	struct snd_usb_audio *chip = mixer->chip;
@@ -9612,11 +9740,20 @@ int snd_scarlett2_init(struct usb_mixer_interface *mixer) 
	}



	err = scarlett2_hwdep_init(mixer);

	if (err < 0)

	if (err < 0) {

		usb_audio_err(mixer->chip,

			      "Error creating %s hwdep device: %d",

			      entry->series_name,

			      err);

		return err;

	}



	err = scarlett2_devmap_init(mixer);

	if (err < 0)

		usb_audio_err(mixer->chip,

			      "Error creating %s devmap entry: %d",

			      entry->series_name,

			      err);



	return err;

}