sound/soc/codecs/adau-utils.c

Source file repositories/reference/linux-study-clean/sound/soc/codecs/adau-utils.c

File Facts

System
Linux kernel
Corpus path
sound/soc/codecs/adau-utils.c
Extension
.c
Size
1253 bytes
Lines
61
Domain
Driver Families
Bucket
sound/soc
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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

if (freq_out % freq_in != 0) {
			div = DIV_ROUND_UP(freq_in, 13500000);
			freq_in /= div;
			r = freq_out / freq_in;
			i = freq_out % freq_in;
			j = gcd(i, freq_in);
			n = i / j;
			m = freq_in / j;
			div--;
		} else {
			r = freq_out / freq_in;
			n = 0;
			m = 0;
			div = 0;
		}
		if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2)
			return -EINVAL;
	}

	regs[0] = m >> 8;
	regs[1] = m & 0xff;
	regs[2] = n >> 8;
	regs[3] = n & 0xff;
	regs[4] = (r << 3) | (div << 1);
	if (m != 0)
		regs[4] |= 1; /* Fractional mode */

	return 0;
}
EXPORT_SYMBOL_GPL(adau_calc_pll_cfg);

MODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL v2");

Annotation

Implementation Notes