drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
Source file repositories/reference/linux-study-clean/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c- Extension
.c- Size
- 9273 bytes
- Lines
- 382
- 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.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/device.hlinux/pm_runtime.hmedia/v4l2-ioctl.hmedia/v4l2-mc.hmedia/videobuf2-v4l2.hsun4i_csi.h
Detected Declarations
function sun4i_csi_querycapfunction sun4i_csi_enum_inputfunction sun4i_csi_g_inputfunction sun4i_csi_s_inputfunction _sun4i_csi_try_fmtfunction sun4i_csi_try_fmt_vid_capfunction sun4i_csi_s_fmt_vid_capfunction sun4i_csi_g_fmt_vid_capfunction sun4i_csi_enum_fmt_vid_capfunction sun4i_csi_openfunction sun4i_csi_releasefunction sun4i_csi_subdev_init_statefunction sun4i_csi_subdev_get_fmtfunction sun4i_csi_subdev_set_fmtfunction sun4i_csi_subdev_enum_mbus_codefunction sun4i_csi_v4l2_register
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 NextThing Co
* Copyright (C) 2016-2019 Bootlin
*
* Author: Maxime Ripard <maxime.ripard@bootlin.com>
*/
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mc.h>
#include <media/videobuf2-v4l2.h>
#include "sun4i_csi.h"
#define CSI_DEFAULT_WIDTH 640
#define CSI_DEFAULT_HEIGHT 480
static const struct sun4i_csi_format sun4i_csi_formats[] = {
/* YUV422 inputs */
{
.mbus = MEDIA_BUS_FMT_YUYV8_2X8,
.fourcc = V4L2_PIX_FMT_YUV420M,
.input = CSI_INPUT_YUV,
.output = CSI_OUTPUT_YUV_420_PLANAR,
.num_planes = 3,
.bpp = { 8, 8, 8 },
.hsub = 2,
.vsub = 2,
},
};
const struct sun4i_csi_format *sun4i_csi_find_format(const u32 *fourcc,
const u32 *mbus)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(sun4i_csi_formats); i++) {
if (fourcc && *fourcc != sun4i_csi_formats[i].fourcc)
continue;
if (mbus && *mbus != sun4i_csi_formats[i].mbus)
continue;
return &sun4i_csi_formats[i];
}
return NULL;
}
static int sun4i_csi_querycap(struct file *file, void *priv,
struct v4l2_capability *cap)
{
strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
strscpy(cap->card, "sun4i-csi", sizeof(cap->card));
return 0;
}
static int sun4i_csi_enum_input(struct file *file, void *priv,
struct v4l2_input *inp)
{
if (inp->index != 0)
return -EINVAL;
inp->type = V4L2_INPUT_TYPE_CAMERA;
strscpy(inp->name, "Camera", sizeof(inp->name));
return 0;
}
static int sun4i_csi_g_input(struct file *file, void *fh,
unsigned int *i)
{
*i = 0;
return 0;
}
static int sun4i_csi_s_input(struct file *file, void *fh,
unsigned int i)
{
if (i != 0)
return -EINVAL;
return 0;
}
Annotation
- Immediate include surface: `linux/device.h`, `linux/pm_runtime.h`, `media/v4l2-ioctl.h`, `media/v4l2-mc.h`, `media/videobuf2-v4l2.h`, `sun4i_csi.h`.
- Detected declarations: `function sun4i_csi_querycap`, `function sun4i_csi_enum_input`, `function sun4i_csi_g_input`, `function sun4i_csi_s_input`, `function _sun4i_csi_try_fmt`, `function sun4i_csi_try_fmt_vid_cap`, `function sun4i_csi_s_fmt_vid_cap`, `function sun4i_csi_g_fmt_vid_cap`, `function sun4i_csi_enum_fmt_vid_cap`, `function sun4i_csi_open`.
- 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.