drivers/media/pci/cx18/cx18-controls.c
Source file repositories/reference/linux-study-clean/drivers/media/pci/cx18/cx18-controls.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/media/pci/cx18/cx18-controls.c- Extension
.c- Size
- 3538 bytes
- Lines
- 118
- Domain
- Driver Families
- Bucket
- drivers/media
- 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.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/kernel.hlinux/slab.hcx18-driver.hcx18-cards.hcx18-ioctl.hcx18-audio.hcx18-mailbox.hcx18-controls.h
Detected Declarations
function Copyrightfunction cx18_s_video_encodingfunction cx18_s_audio_sampling_freqfunction cx18_s_audio_mode
Annotated Snippet
if (cx->vbi.sliced_mpeg_data[i] == NULL) {
while (--i >= 0) {
kfree(cx->vbi.sliced_mpeg_data[i]);
cx->vbi.sliced_mpeg_data[i] = NULL;
}
cx->vbi.insert_mpeg =
V4L2_MPEG_STREAM_VBI_FMT_NONE;
CX18_WARN("Unable to allocate buffers for sliced VBI data insertion\n");
return -ENOMEM;
}
}
}
cx->vbi.insert_mpeg = fmt;
CX18_DEBUG_INFO("enabled insertion of sliced VBI data into the MPEG PS,when sliced VBI is enabled\n");
/*
* If our current settings have no lines set for capture, store a valid,
* default set of service lines to capture, in our current settings.
*/
if (cx18_get_service_set(cx->vbi.sliced_in) == 0) {
if (cx->is_60hz)
cx->vbi.sliced_in->service_set =
V4L2_SLICED_CAPTION_525;
else
cx->vbi.sliced_in->service_set = V4L2_SLICED_WSS_625;
cx18_expand_service_set(cx->vbi.sliced_in, cx->is_50hz);
}
return 0;
}
static int cx18_s_video_encoding(struct cx2341x_handler *cxhdl, u32 val)
{
struct cx18 *cx = container_of(cxhdl, struct cx18, cxhdl);
int is_mpeg1 = val == V4L2_MPEG_VIDEO_ENCODING_MPEG_1;
struct v4l2_subdev_format format = {
.which = V4L2_SUBDEV_FORMAT_ACTIVE,
};
struct v4l2_mbus_framefmt *fmt = &format.format;
/* fix videodecoder resolution */
fmt->width = cxhdl->width / (is_mpeg1 ? 2 : 1);
fmt->height = cxhdl->height;
fmt->code = MEDIA_BUS_FMT_FIXED;
v4l2_subdev_call(cx->sd_av, pad, set_fmt, NULL, &format);
return 0;
}
static int cx18_s_audio_sampling_freq(struct cx2341x_handler *cxhdl, u32 idx)
{
static const u32 freqs[3] = { 44100, 48000, 32000 };
struct cx18 *cx = container_of(cxhdl, struct cx18, cxhdl);
/* The audio clock of the digitizer must match the codec sample
rate otherwise you get some very strange effects. */
if (idx < ARRAY_SIZE(freqs))
cx18_call_all(cx, audio, s_clock_freq, freqs[idx]);
return 0;
}
static int cx18_s_audio_mode(struct cx2341x_handler *cxhdl, u32 val)
{
struct cx18 *cx = container_of(cxhdl, struct cx18, cxhdl);
cx->dualwatch_stereo_mode = val;
return 0;
}
const struct cx2341x_handler_ops cx18_cxhdl_ops = {
.s_audio_mode = cx18_s_audio_mode,
.s_audio_sampling_freq = cx18_s_audio_sampling_freq,
.s_video_encoding = cx18_s_video_encoding,
.s_stream_vbi_fmt = cx18_s_stream_vbi_fmt,
};
Annotation
- Immediate include surface: `linux/kernel.h`, `linux/slab.h`, `cx18-driver.h`, `cx18-cards.h`, `cx18-ioctl.h`, `cx18-audio.h`, `cx18-mailbox.h`, `cx18-controls.h`.
- Detected declarations: `function Copyright`, `function cx18_s_video_encoding`, `function cx18_s_audio_sampling_freq`, `function cx18_s_audio_mode`.
- Atlas domain: Driver Families / drivers/media.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
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.