drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv40.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv40.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv40.c
Extension
.c
Size
2650 bytes
Lines
90
Domain
Driver Families
Bucket
drivers/gpu
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

if (!n || !d) {
			n = 1;
			d = 1;
		}
		nvkm_warn(subdev, "unknown input clock freq\n");
	}

	/* reduce ratio to acceptable values */
	while (((n % 5) == 0) && ((d % 5) == 0)) {
		n /= 5;
		d /= 5;
	}

	while (((n % 2) == 0) && ((d % 2) == 0)) {
		n /= 2;
		d /= 2;
	}

	while (n > 0xffff || d > 0xffff) {
		n >>= 1;
		d >>= 1;
	}

	nvkm_debug(subdev, "input frequency : %dHz\n", f);
	nvkm_debug(subdev, "numerator       : %08x\n", n);
	nvkm_debug(subdev, "denominator     : %08x\n", d);
	nvkm_debug(subdev, "timer frequency : %dHz\n", f * d / n);

	nvkm_wr32(device, NV04_PTIMER_NUMERATOR, n);
	nvkm_wr32(device, NV04_PTIMER_DENOMINATOR, d);
}

static const struct nvkm_timer_func
nv40_timer = {
	.init = nv40_timer_init,
	.intr = nv04_timer_intr,
	.read = nv04_timer_read,
	.time = nv04_timer_time,
	.alarm_init = nv04_timer_alarm_init,
	.alarm_fini = nv04_timer_alarm_fini,
};

int
nv40_timer_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
	       struct nvkm_timer **ptmr)
{
	return nvkm_timer_new_(&nv40_timer, device, type, inst, ptmr);
}

Annotation

Implementation Notes