drivers/gpu/drm/nouveau/nvkm/subdev/i2c/busnv50.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/busnv50.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/subdev/i2c/busnv50.c
Extension
.c
Size
3484 bytes
Lines
114
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

struct nv50_i2c_bus {
	struct nvkm_i2c_bus base;
	u32 addr;
	u32 data;
};

static void
nv50_i2c_bus_drive_scl(struct nvkm_i2c_bus *base, int state)
{
	struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
	if (state) bus->data |= 0x01;
	else	   bus->data &= 0xfe;
	nvkm_wr32(device, bus->addr, bus->data);
}

static void
nv50_i2c_bus_drive_sda(struct nvkm_i2c_bus *base, int state)
{
	struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
	if (state) bus->data |= 0x02;
	else	   bus->data &= 0xfd;
	nvkm_wr32(device, bus->addr, bus->data);
}

static int
nv50_i2c_bus_sense_scl(struct nvkm_i2c_bus *base)
{
	struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
	return !!(nvkm_rd32(device, bus->addr) & 0x00000001);
}

static int
nv50_i2c_bus_sense_sda(struct nvkm_i2c_bus *base)
{
	struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
	return !!(nvkm_rd32(device, bus->addr) & 0x00000002);
}

static void
nv50_i2c_bus_init(struct nvkm_i2c_bus *base)
{
	struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
	nvkm_wr32(device, bus->addr, (bus->data = 0x00000007));
}

static const struct nvkm_i2c_bus_func
nv50_i2c_bus_func = {
	.init = nv50_i2c_bus_init,
	.drive_scl = nv50_i2c_bus_drive_scl,
	.drive_sda = nv50_i2c_bus_drive_sda,
	.sense_scl = nv50_i2c_bus_sense_scl,
	.sense_sda = nv50_i2c_bus_sense_sda,
	.xfer = nvkm_i2c_bit_xfer,
};

int
nv50_i2c_bus_new(struct nvkm_i2c_pad *pad, int id, u8 drive,
		 struct nvkm_i2c_bus **pbus)
{
	static const u32 addr[] = {
		0x00e138, 0x00e150, 0x00e168, 0x00e180,
		0x00e254, 0x00e274, 0x00e764, 0x00e780,
		0x00e79c, 0x00e7b8
	};
	struct nv50_i2c_bus *bus;

	if (drive >= ARRAY_SIZE(addr)) {
		nvkm_warn(&pad->i2c->subdev, "bus %d unknown\n", drive);
		return -ENODEV;
	}

	if (!(bus = kzalloc_obj(*bus)))
		return -ENOMEM;
	*pbus = &bus->base;

	nvkm_i2c_bus_ctor(&nv50_i2c_bus_func, pad, id, &bus->base);
	bus->addr = addr[drive];
	bus->data = 0x00000007;
	return 0;
}

Annotation

Implementation Notes