drivers/gpu/drm/nouveau/nvkm/engine/mpeg/nv40.c

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

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/engine/mpeg/nv40.c
Extension
.c
Size
2672 bytes
Lines
84
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

#include "nv31.h"

#include <subdev/instmem.h>

#include <nvif/class.h>

bool
nv40_mpeg_mthd_dma(struct nvkm_device *device, u32 mthd, u32 data)
{
	struct nvkm_instmem *imem = device->imem;
	struct nv31_mpeg *mpeg = nv31_mpeg(device->mpeg);
	struct nvkm_subdev *subdev = &mpeg->engine.subdev;
	u32 inst = data << 4;
	u32 dma0 = nvkm_instmem_rd32(imem, inst + 0);
	u32 dma1 = nvkm_instmem_rd32(imem, inst + 4);
	u32 dma2 = nvkm_instmem_rd32(imem, inst + 8);
	u32 base = (dma2 & 0xfffff000) | (dma0 >> 20);
	u32 size = dma1 + 1;

	/* only allow linear DMA objects */
	if (!(dma0 & 0x00002000)) {
		nvkm_error(subdev, "inst %08x dma0 %08x dma1 %08x dma2 %08x\n",
			   inst, dma0, dma1, dma2);
		return false;
	}

	if (mthd == 0x0190) {
		/* DMA_CMD */
		nvkm_mask(device, 0x00b300, 0x00030000, (dma0 & 0x00030000));
		nvkm_wr32(device, 0x00b334, base);
		nvkm_wr32(device, 0x00b324, size);
	} else
	if (mthd == 0x01a0) {
		/* DMA_DATA */
		nvkm_mask(device, 0x00b300, 0x000c0000, (dma0 & 0x00030000) << 2);
		nvkm_wr32(device, 0x00b360, base);
		nvkm_wr32(device, 0x00b364, size);
	} else {
		/* DMA_IMAGE, VRAM only */
		if (dma0 & 0x00030000)
			return false;

		nvkm_wr32(device, 0x00b370, base);
		nvkm_wr32(device, 0x00b374, size);
	}

	return true;
}

static const struct nv31_mpeg_func
nv40_mpeg = {
	.mthd_dma = nv40_mpeg_mthd_dma,
};

int
nv40_mpeg_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
	      struct nvkm_engine **pmpeg)
{
	return nv31_mpeg_new_(&nv40_mpeg, device, type, inst, pmpeg);
}

Annotation

Implementation Notes