drivers/media/pci/cx18/cx18-av-audio.c

Source file repositories/reference/linux-study-clean/drivers/media/pci/cx18/cx18-av-audio.c

File Facts

System: Linux kernel
Corpus path: drivers/media/pci/cx18/cx18-av-audio.c
Extension: .c
Size: 12789 bytes
Lines: 458
Domain: Driver Families
Bucket: drivers/media
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

cx18-driver.h

Detected Declarations

function Copyright
function value
function cx18_av_audio_set_path
function set_volume
function set_bass
function set_treble
function set_balance
function set_mute
function cx18_av_s_clock_freq
function cx18_av_audio_s_ctrl

Annotated Snippet

switch (freq) {
		case 32000:
			/*
			 * VID_PLL Integer = 0x0f, VID_PLL Post Divider = 0x04
			 * AUX_PLL Integer = 0x0d, AUX PLL Post Divider = 0x20
			 */
			cx18_av_write4(cx, 0x108, 0x200d040f);

			/* VID_PLL Fraction = 0x2be2fe */
			/* xtal * 0xf.15f17f0/4 = 108 MHz: 432 MHz pre-postdiv*/
			cx18_av_write4(cx, 0x10c, 0x002be2fe);

			/* AUX_PLL Fraction = 0x176740c */
			/* xtal * 0xd.bb3a060/0x20 = 32000 * 384: 393 MHz p-pd*/
			cx18_av_write4(cx, 0x110, 0x0176740c);

			/* src3/4/6_ctl */
			/* 0x1.f77f = (4 * xtal/8*2/455) / 32000 */
			cx18_av_write4(cx, 0x900, 0x0801f77f);
			cx18_av_write4(cx, 0x904, 0x0801f77f);
			cx18_av_write4(cx, 0x90c, 0x0801f77f);

			/* SA_MCLK_SEL=1, SA_MCLK_DIV=0x20 */
			cx18_av_write(cx, 0x127, 0x60);

			/* AUD_COUNT = 0x2fff = 8 samples * 4 * 384 - 1 */
			cx18_av_write4(cx, 0x12c, 0x11202fff);

			/*
			 * EN_AV_LOCK = 0
			 * VID_COUNT = 0x0d2ef8 = 107999.000 * 8 =
			 *  ((8 samples/32,000) * (13,500,000 * 8) * 4 - 1) * 8
			 */
			cx18_av_write4(cx, 0x128, 0xa00d2ef8);
			break;

		case 44100:
			/*
			 * VID_PLL Integer = 0x0f, VID_PLL Post Divider = 0x04
			 * AUX_PLL Integer = 0x0e, AUX PLL Post Divider = 0x18
			 */
			cx18_av_write4(cx, 0x108, 0x180e040f);

			/* VID_PLL Fraction = 0x2be2fe */
			/* xtal * 0xf.15f17f0/4 = 108 MHz: 432 MHz pre-postdiv*/
			cx18_av_write4(cx, 0x10c, 0x002be2fe);

			/* AUX_PLL Fraction = 0x062a1f2 */
			/* xtal * 0xe.3150f90/0x18 = 44100 * 384: 406 MHz p-pd*/
			cx18_av_write4(cx, 0x110, 0x0062a1f2);

			/* src3/4/6_ctl */
			/* 0x1.6d59 = (4 * xtal/8*2/455) / 44100 */
			cx18_av_write4(cx, 0x900, 0x08016d59);
			cx18_av_write4(cx, 0x904, 0x08016d59);
			cx18_av_write4(cx, 0x90c, 0x08016d59);

			/* SA_MCLK_SEL=1, SA_MCLK_DIV=0x18 */
			cx18_av_write(cx, 0x127, 0x58);

			/* AUD_COUNT = 0x92ff = 49 samples * 2 * 384 - 1 */
			cx18_av_write4(cx, 0x12c, 0x112092ff);

			/*
			 * EN_AV_LOCK = 0
			 * VID_COUNT = 0x1d4bf8 = 239999.000 * 8 =
			 *  ((49 samples/44,100) * (13,500,000 * 8) * 2 - 1) * 8
			 */
			cx18_av_write4(cx, 0x128, 0xa01d4bf8);
			break;

		case 48000:
			/*
			 * VID_PLL Integer = 0x0f, VID_PLL Post Divider = 0x04
			 * AUX_PLL Integer = 0x0e, AUX PLL Post Divider = 0x16
			 */
			cx18_av_write4(cx, 0x108, 0x160e040f);

			/* VID_PLL Fraction = 0x2be2fe */
			/* xtal * 0xf.15f17f0/4 = 108 MHz: 432 MHz pre-postdiv*/
			cx18_av_write4(cx, 0x10c, 0x002be2fe);

			/* AUX_PLL Fraction = 0x05227ad */
			/* xtal * 0xe.2913d68/0x16 = 48000 * 384: 406 MHz p-pd*/
			cx18_av_write4(cx, 0x110, 0x005227ad);

			/* src3/4/6_ctl */
			/* 0x1.4faa = (4 * xtal/8*2/455) / 48000 */
			cx18_av_write4(cx, 0x900, 0x08014faa);
			cx18_av_write4(cx, 0x904, 0x08014faa);

Annotation

Immediate include surface: `cx18-driver.h`.
Detected declarations: `function Copyright`, `function value`, `function cx18_av_audio_set_path`, `function set_volume`, `function set_bass`, `function set_treble`, `function set_balance`, `function set_mute`, `function cx18_av_s_clock_freq`, `function cx18_av_audio_s_ctrl`.
Atlas domain: Driver Families / drivers/media.
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.