sound/firewire/motu/motu-protocol-v1.c

Source file repositories/reference/linux-study-clean/sound/firewire/motu/motu-protocol-v1.c

File Facts

System: Linux kernel
Corpus path: sound/firewire/motu/motu-protocol-v1.c
Extension: .c
Size: 13468 bytes
Lines: 468
Domain: Driver Families
Bucket: sound/firewire
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.

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.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

motu.h
linux/delay.h

Detected Declarations

function parse_clock_rate_828
function get_clock_rate_828
function parse_clock_rate_896
function get_clock_rate_896
function snd_motu_protocol_v1_get_clock_rate
function set_clock_rate_828
function set_clock_rate_896
function snd_motu_protocol_v1_set_clock_rate
function get_clock_source_828
function get_clock_source_896
function snd_motu_protocol_v1_get_clock_source
function switch_fetching_mode_828
function switch_fetching_mode_896
function snd_motu_protocol_v1_switch_fetching_mode
function detect_packet_formats_828
function detect_packet_formats_896
function snd_motu_protocol_v1_cache_packet_formats

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
// motu-protocol-v1.c - a part of driver for MOTU FireWire series
//
// Copyright (c) 2021 Takashi Sakamoto <o-takashi@sakamocchi.jp>

#include "motu.h"

#include <linux/delay.h>

// Status register for MOTU 828 (0x'ffff'f000'0b00).
//
// 0xffff0000: ISOC_COMM_CONTROL_MASK in motu-stream.c.
// 0x00008000: mode of optical input interface.
//   0x00008000: for S/PDIF signal.
//   0x00000000: disabled or for ADAT signal.
// 0x00004000: mode of optical output interface.
//   0x00004000: for S/PDIF signal.
//   0x00000000: disabled or for ADAT signal.
// 0x00003f00: monitor input mode.
//   0x00000800: analog-1/2
//   0x00001a00: analog-3/4
//   0x00002c00: analog-5/6
//   0x00003e00: analog-7/8
//   0x00000000: analog-1
//   0x00000900: analog-2
//   0x00001200: analog-3
//   0x00001b00: analog-4
//   0x00002400: analog-5
//   0x00002d00: analog-6
//   0x00003600: analog-7
//   0x00003f00: analog-8
// 0x00000080: enable stream input.
// 0x00000040: disable monitor input.
// 0x00000008: enable main out.
// 0x00000004: rate of sampling clock.
//   0x00000004: 48.0 kHz
//   0x00000000: 44.1 kHz
// 0x00000023: source of sampling clock.
//   0x00000003: source packet header (SPH)
//   0x00000002: S/PDIF on optical/coaxial interface.
//   0x00000021: ADAT on optical interface
//   0x00000001: ADAT on Dsub 9pin
//   0x00000000: internal

#define CLK_828_STATUS_OFFSET				0x0b00
#define  CLK_828_STATUS_MASK				0x0000ffff
#define  CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF	0x00008000
#define  CLK_828_STATUS_FLAG_OPT_OUT_IFACE_IS_SPDIF	0x00004000
#define  CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES		0x00000080
#define  CLK_828_STATUS_FLAG_ENABLE_OUTPUT		0x00000008
#define  CLK_828_STATUS_FLAG_RATE_48000			0x00000004
#define  CLK_828_STATUS_MASK_SRC			0x00000023
#define   CLK_828_STATUS_FLAG_SRC_ADAT_ON_OPT		0x00000021
#define   CLK_828_STATUS_FLAG_SRC_SPH			0x00000003
#define   CLK_828_STATUS_FLAG_SRC_SPDIF			0x00000002
#define   CLK_828_STATUS_FLAG_SRC_ADAT_ON_DSUB		0x00000001
#define   CLK_828_STATUS_FLAG_SRC_INTERNAL		0x00000000

// Status register for MOTU 896 (0x'ffff'f000'0b14).
//
// 0xf0000000: enable physical and stream input to DAC.
//   0x80000000: disable
//   0x40000000: disable
//   0x20000000: enable (prior to the other bits)
//   0x10000000: disable
//   0x00000000: disable
// 0x08000000: speed of word clock signal output on BNC interface.
//   0x00000000: force to low rate (44.1/48.0 kHz).
//   0x08000000: follow to system clock.
// 0x04000000: something relevant to clock.
// 0x03000000: enable output.
//  0x02000000: enabled irreversibly once standing unless the device voluntarily disables it.
//  0x01000000: enabled irreversibly once standing unless the device voluntarily disables it.
// 0x00ffff00: monitor input mode.
//   0x00000000: disabled
//   0x00004800: analog-1/2
//   0x00005a00: analog-3/4
//   0x00006c00: analog-5/6
//   0x00007e00: analog-7/8
//   0x00104800: AES/EBU-1/2
//   0x00004000: analog-1
//   0x00004900: analog-2
//   0x00005200: analog-3
//   0x00005b00: analog-4
//   0x00006400: analog-5
//   0x00006d00: analog-6
//   0x00007600: analog-7
//   0x00007f00: analog-8
//   0x00104000: AES/EBU-1
//   0x00104900: AES/EBU-2

Annotation

Immediate include surface: `motu.h`, `linux/delay.h`.
Detected declarations: `function parse_clock_rate_828`, `function get_clock_rate_828`, `function parse_clock_rate_896`, `function get_clock_rate_896`, `function snd_motu_protocol_v1_get_clock_rate`, `function set_clock_rate_828`, `function set_clock_rate_896`, `function snd_motu_protocol_v1_set_clock_rate`, `function get_clock_source_828`, `function get_clock_source_896`.
Atlas domain: Driver Families / sound/firewire.
Implementation status: source implementation candidate.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.