drivers/gpu/drm/nouveau/nvkm/subdev/bios/cstep.c
Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/subdev/bios/cstep.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/gpu/drm/nouveau/nvkm/subdev/bios/cstep.c- Extension
.c- Size
- 3467 bytes
- Lines
- 123
- 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.
- 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
subdev/bios.hsubdev/bios/bit.hsubdev/bios/cstep.h
Detected Declarations
function filesfunction nvbios_cstepEefunction nvbios_cstepEpfunction nvbios_cstepEmfunction nvbios_cstepXefunction nvbios_cstepXp
Annotated Snippet
if (cstep) {
*ver = nvbios_rd08(bios, cstep + 0);
switch (*ver) {
case 0x10:
*hdr = nvbios_rd08(bios, cstep + 1);
*cnt = nvbios_rd08(bios, cstep + 3);
*len = nvbios_rd08(bios, cstep + 2);
*xnr = nvbios_rd08(bios, cstep + 5);
*xsz = nvbios_rd08(bios, cstep + 4);
return cstep;
default:
break;
}
}
}
return 0;
}
u32
nvbios_cstepEe(struct nvkm_bios *bios, int idx, u8 *ver, u8 *hdr)
{
u8 cnt, len, xnr, xsz;
u32 data = nvbios_cstepTe(bios, ver, hdr, &cnt, &len, &xnr, &xsz);
if (data && idx < cnt) {
data = data + *hdr + (idx * len);
*hdr = len;
return data;
}
return 0;
}
u32
nvbios_cstepEp(struct nvkm_bios *bios, int idx, u8 *ver, u8 *hdr,
struct nvbios_cstepE *info)
{
u32 data = nvbios_cstepEe(bios, idx, ver, hdr);
memset(info, 0x00, sizeof(*info));
if (data) {
info->pstate = (nvbios_rd16(bios, data + 0x00) & 0x01e0) >> 5;
info->index = nvbios_rd08(bios, data + 0x03);
}
return data;
}
u32
nvbios_cstepEm(struct nvkm_bios *bios, u8 pstate, u8 *ver, u8 *hdr,
struct nvbios_cstepE *info)
{
u32 data, idx = 0;
while ((data = nvbios_cstepEp(bios, idx++, ver, hdr, info))) {
if (info->pstate == pstate)
break;
}
return data;
}
u32
nvbios_cstepXe(struct nvkm_bios *bios, int idx, u8 *ver, u8 *hdr)
{
u8 cnt, len, xnr, xsz;
u32 data = nvbios_cstepTe(bios, ver, hdr, &cnt, &len, &xnr, &xsz);
if (data && idx < xnr) {
data = data + *hdr + (cnt * len) + (idx * xsz);
*hdr = xsz;
return data;
}
return 0;
}
u32
nvbios_cstepXp(struct nvkm_bios *bios, int idx, u8 *ver, u8 *hdr,
struct nvbios_cstepX *info)
{
u32 data = nvbios_cstepXe(bios, idx, ver, hdr);
memset(info, 0x00, sizeof(*info));
if (data) {
info->freq = nvbios_rd16(bios, data + 0x00) * 1000;
info->unkn[0] = nvbios_rd08(bios, data + 0x02);
info->unkn[1] = nvbios_rd08(bios, data + 0x03);
info->voltage = nvbios_rd08(bios, data + 0x04);
}
return data;
}
Annotation
- Immediate include surface: `subdev/bios.h`, `subdev/bios/bit.h`, `subdev/bios/cstep.h`.
- Detected declarations: `function files`, `function nvbios_cstepEe`, `function nvbios_cstepEp`, `function nvbios_cstepEm`, `function nvbios_cstepXe`, `function nvbios_cstepXp`.
- Atlas domain: Driver Families / drivers/gpu.
- 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.