sound/usb/card.h

Source file repositories/reference/linux-study-clean/sound/usb/card.h

File Facts

System
Linux kernel
Corpus path
sound/usb/card.h
Extension
.h
Size
9040 bytes
Lines
228
Domain
Driver Families
Bucket
sound/usb
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct audioformat {
	struct list_head list;
	u64 formats;			/* ALSA format bits */
	unsigned int channels;		/* # channels */
	unsigned int fmt_type;		/* USB audio format type (1-3) */
	unsigned int fmt_bits;		/* number of significant bits */
	unsigned int fmt_sz;		/* overall audio sub frame/slot size */
	unsigned int frame_size;	/* samples per frame for non-audio */
	unsigned char iface;		/* interface number */
	unsigned char altsetting;	/* corresponding alternate setting */
	unsigned char ep_idx;		/* endpoint array index */
	unsigned char altset_idx;	/* array index of alternate setting */
	unsigned char attributes;	/* corresponding attributes of cs endpoint */
	unsigned char endpoint;		/* endpoint */
	unsigned char ep_attr;		/* endpoint attributes */
	bool implicit_fb;		/* implicit feedback endpoint */
	unsigned char sync_ep;		/* sync endpoint number */
	unsigned char sync_iface;	/* sync EP interface */
	unsigned char sync_altsetting;	/* sync EP alternate setting */
	unsigned char sync_ep_idx;	/* sync EP array index */
	unsigned char datainterval;	/* log_2 of data packet interval */
	unsigned char protocol;		/* UAC_VERSION_1/2/3 */
	unsigned int maxpacksize;	/* max. packet size */
	unsigned int rates;		/* rate bitmasks */
	unsigned int rate_min, rate_max;	/* min/max rates */
	unsigned int nr_rates;		/* number of rate table entries */
	unsigned int *rate_table;	/* rate table */
	unsigned char clock;		/* associated clock */
	struct snd_pcm_chmap_elem *chmap; /* (optional) channel map */
	bool dsd_dop;			/* add DOP headers in case of DSD samples */
	bool dsd_bitrev;		/* reverse the bits of each DSD sample */
	bool dsd_raw;			/* altsetting is raw DSD */
};

struct snd_usb_substream;
struct snd_usb_iface_ref;
struct snd_usb_clock_ref;
struct snd_usb_endpoint;
struct snd_usb_power_domain;

struct snd_urb_ctx {
	struct urb *urb;
	unsigned int buffer_size;	/* size of data buffer, if data URB */
	struct snd_usb_substream *subs;
	struct snd_usb_endpoint *ep;
	int index;	/* index for urb array */
	int packets;	/* number of packets per urb */
	int queued;	/* queued data bytes by this urb */
	int packet_size[MAX_PACKS_HS]; /* size of packets for next submission */
	struct list_head ready_list;
};

struct snd_usb_endpoint {
	struct snd_usb_audio *chip;
	struct snd_usb_iface_ref *iface_ref;
	struct snd_usb_clock_ref *clock_ref;

	int opened;		/* open refcount; protect with chip->mutex */
	atomic_t running;	/* running status */
	int ep_num;		/* the referenced endpoint number */
	int type;		/* SND_USB_ENDPOINT_TYPE_* */

	unsigned char iface;		/* interface number */
	unsigned char altsetting;	/* corresponding alternate setting */
	unsigned char ep_idx;		/* endpoint array index */

	atomic_t state;		/* running state */

	int (*prepare_data_urb) (struct snd_usb_substream *subs,
				 struct urb *urb,
				 bool in_stream_lock);
	void (*retire_data_urb) (struct snd_usb_substream *subs,
				 struct urb *urb);

	struct snd_usb_substream *data_subs;
	struct snd_usb_endpoint *sync_source;
	struct snd_usb_endpoint *sync_sink;

	struct snd_urb_ctx urb[MAX_URBS];

	struct snd_usb_packet_info {
		int packet_size[MAX_PACKS_HS];
		int packets;
	} next_packet[MAX_URBS];
	unsigned int next_packet_head;	/* ring buffer offset to read */
	unsigned int next_packet_queued; /* queued items in the ring buffer */
	struct list_head ready_playback_urbs; /* playback URB FIFO for implicit fb */

	unsigned int nurbs;		/* # urbs */
	unsigned long active_mask;	/* bitmask of active urbs */

Annotation

Implementation Notes