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Release 4.7 samples/v4l/v4l2-pci-skeleton.c

Directory: samples/v4l
/*
 * This is a V4L2 PCI Skeleton Driver. It gives an initial skeleton source
 * for use with other PCI drivers.
 *
 * This skeleton PCI driver assumes that the card has an S-Video connector as
 * input 0 and an HDMI connector as input 1.
 *
 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/videodev2.h>
#include <linux/v4l2-dv-timings.h>
#include <media/v4l2-device.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-dv-timings.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-dma-contig.h>

MODULE_DESCRIPTION("V4L2 PCI Skeleton Driver");
MODULE_AUTHOR("Hans Verkuil");
MODULE_LICENSE("GPL v2");

/**
 * struct skeleton - All internal data for one instance of device
 * @pdev: PCI device
 * @v4l2_dev: top-level v4l2 device struct
 * @vdev: video node structure
 * @ctrl_handler: control handler structure
 * @lock: ioctl serialization mutex
 * @std: current SDTV standard
 * @timings: current HDTV timings
 * @format: current pix format
 * @input: current video input (0 = SDTV, 1 = HDTV)
 * @queue: vb2 video capture queue
 * @alloc_ctx: vb2 contiguous DMA context
 * @qlock: spinlock controlling access to buf_list and sequence
 * @buf_list: list of buffers queued for DMA
 * @sequence: frame sequence counter
 */

struct skeleton {
	
struct pci_dev *pdev;
	
struct v4l2_device v4l2_dev;
	
struct video_device vdev;
	
struct v4l2_ctrl_handler ctrl_handler;
	
struct mutex lock;
	
v4l2_std_id std;
	
struct v4l2_dv_timings timings;
	
struct v4l2_pix_format format;
	
unsigned input;

	
struct vb2_queue queue;
	
struct vb2_alloc_ctx *alloc_ctx;

	
spinlock_t qlock;
	
struct list_head buf_list;
	
unsigned field;
	
unsigned sequence;
};


struct skel_buffer {
	
struct vb2_buffer vb;
	
struct list_head list;
};


static inline struct skel_buffer *to_skel_buffer(struct vb2_buffer *vb2) { return container_of(vb2, struct skel_buffer, vb); }

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static const struct pci_device_id skeleton_pci_tbl[] = { /* { PCI_DEVICE(PCI_VENDOR_ID_, PCI_DEVICE_ID_) }, */ { 0, } }; MODULE_DEVICE_TABLE(pci, skeleton_pci_tbl); /* * HDTV: this structure has the capabilities of the HDTV receiver. * It is used to constrain the huge list of possible formats based * upon the hardware capabilities. */ static const struct v4l2_dv_timings_cap skel_timings_cap = { .type = V4L2_DV_BT_656_1120, /* keep this initialization for compatibility with GCC < 4.4.6 */ .reserved = { 0 }, V4L2_INIT_BT_TIMINGS( 720, 1920, /* min/max width */ 480, 1080, /* min/max height */ 27000000, 74250000, /* min/max pixelclock*/ V4L2_DV_BT_STD_CEA861, /* Supported standards */ /* capabilities */ V4L2_DV_BT_CAP_INTERLACED | V4L2_DV_BT_CAP_PROGRESSIVE ) }; /* * Supported SDTV standards. This does the same job as skel_timings_cap, but * for standard TV formats. */ #define SKEL_TVNORMS V4L2_STD_ALL /* * Interrupt handler: typically interrupts happen after a new frame has been * captured. It is the job of the handler to remove the new frame from the * internal list and give it back to the vb2 framework, updating the sequence * counter, field and timestamp at the same time. */
static irqreturn_t skeleton_irq(int irq, void *dev_id) { #ifdef TODO struct skeleton *skel = dev_id; /* handle interrupt */ /* Once a new frame has been captured, mark it as done like this: */ if (captured_new_frame) { ... spin_lock(&skel->qlock); list_del(&new_buf->list); spin_unlock(&skel->qlock); v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp); new_buf->vb.v4l2_buf.sequence = skel->sequence++; new_buf->vb.v4l2_buf.field = skel->field; if (skel->format.field == V4L2_FIELD_ALTERNATE) { if (skel->field == V4L2_FIELD_BOTTOM) skel->field = V4L2_FIELD_TOP; else if (skel->field == V4L2_FIELD_TOP) skel->field = V4L2_FIELD_BOTTOM; } vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_DONE); } #endif return IRQ_HANDLED; }

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/* * Setup the constraints of the queue: besides setting the number of planes * per buffer and the size and allocation context of each plane, it also * checks if sufficient buffers have been allocated. Usually 3 is a good * minimum number: many DMA engines need a minimum of 2 buffers in the * queue and you need to have another available for userspace processing. */
static int queue_setup(struct vb2_queue *vq, unsigned int *nbuffers, unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[]) { struct skeleton *skel = vb2_get_drv_priv(vq); skel->field = skel->format.field; if (skel->field == V4L2_FIELD_ALTERNATE) { /* * You cannot use read() with FIELD_ALTERNATE since the field * information (TOP/BOTTOM) cannot be passed back to the user. */ if (vb2_fileio_is_active(vq)) return -EINVAL; skel->field = V4L2_FIELD_TOP; } if (vq->num_buffers + *nbuffers < 3) *nbuffers = 3 - vq->num_buffers; alloc_ctxs[0] = skel->alloc_ctx; if (*nplanes) return sizes[0] < skel->format.sizeimage ? -EINVAL : 0; *nplanes = 1; sizes[0] = skel->format.sizeimage; return 0; }

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/* * Prepare the buffer for queueing to the DMA engine: check and set the * payload size. */
static int buffer_prepare(struct vb2_buffer *vb) { struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue); unsigned long size = skel->format.sizeimage; if (vb2_plane_size(vb, 0) < size) { dev_err(&skel->pdev->dev, "buffer too small (%lu < %lu)\n", vb2_plane_size(vb, 0), size); return -EINVAL; } vb2_set_plane_payload(vb, 0, size); return 0; }

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/* * Queue this buffer to the DMA engine. */
static void buffer_queue(struct vb2_buffer *vb) { struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue); struct skel_buffer *buf = to_skel_buffer(vb); unsigned long flags; spin_lock_irqsave(&skel->qlock, flags); list_add_tail(&buf->list, &skel->buf_list); /* TODO: Update any DMA pointers if necessary */ spin_unlock_irqrestore(&skel->qlock, flags); }

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static void return_all_buffers(struct skeleton *skel, enum vb2_buffer_state state) { struct skel_buffer *buf, *node; unsigned long flags; spin_lock_irqsave(&skel->qlock, flags); list_for_each_entry_safe(buf, node, &skel->buf_list, list) { vb2_buffer_done(&buf->vb, state); list_del(&buf->list); } spin_unlock_irqrestore(&skel->qlock, flags); }

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/* * Start streaming. First check if the minimum number of buffers have been * queued. If not, then return -ENOBUFS and the vb2 framework will call * this function again the next time a buffer has been queued until enough * buffers are available to actually start the DMA engine. */
static int start_streaming(struct vb2_queue *vq, unsigned int count) { struct skeleton *skel = vb2_get_drv_priv(vq); int ret = 0; skel->sequence = 0; /* TODO: start DMA */ if (ret) { /* * In case of an error, return all active buffers to the * QUEUED state */ return_all_buffers(skel, VB2_BUF_STATE_QUEUED); } return ret; }

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/* * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued * and passed on to the vb2 framework marked as STATE_ERROR. */
static void stop_streaming(struct vb2_queue *vq) { struct skeleton *skel = vb2_get_drv_priv(vq); /* TODO: stop DMA */ /* Release all active buffers */ return_all_buffers(skel, VB2_BUF_STATE_ERROR); }

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/* * The vb2 queue ops. Note that since q->lock is set we can use the standard * vb2_ops_wait_prepare/finish helper functions. If q->lock would be NULL, * then this driver would have to provide these ops. */ static struct vb2_ops skel_qops = { .queue_setup = queue_setup, .buf_prepare = buffer_prepare, .buf_queue = buffer_queue, .start_streaming = start_streaming, .stop_streaming = stop_streaming, .wait_prepare = vb2_ops_wait_prepare, .wait_finish = vb2_ops_wait_finish, }; /* * Required ioctl querycap. Note that the version field is prefilled with * the version of the kernel. */
static int skeleton_querycap(struct file *file, void *priv, struct v4l2_capability *cap) { struct skeleton *skel = video_drvdata(file); strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver)); strlcpy(cap->card, "V4L2 PCI Skeleton", sizeof(cap->card)); snprintf(cap->bus_info, sizeof(cap->bus_info), "PCI:%s", pci_name(skel->pdev)); return 0; }

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/* * Helper function to check and correct struct v4l2_pix_format. It's used * not only in VIDIOC_TRY/S_FMT, but also elsewhere if changes to the SDTV * standard, HDTV timings or the video input would require updating the * current format. */
static void skeleton_fill_pix_format(struct skeleton *skel, struct v4l2_pix_format *pix) { pix->pixelformat = V4L2_PIX_FMT_YUYV; if (skel->input == 0) { /* S-Video input */ pix->width = 720; pix->height = (skel->std & V4L2_STD_525_60) ? 480 : 576; pix->field = V4L2_FIELD_INTERLACED; pix->colorspace = V4L2_COLORSPACE_SMPTE170M; } else { /* HDMI input */ pix->width = skel->timings.bt.width; pix->height = skel->timings.bt.height; if (skel->timings.bt.interlaced) { pix->field = V4L2_FIELD_ALTERNATE; pix->height /= 2; } else { pix->field = V4L2_FIELD_NONE; } pix->colorspace = V4L2_COLORSPACE_REC709; } /* * The YUYV format is four bytes for every two pixels, so bytesperline * is width * 2. */ pix->bytesperline = pix->width * 2; pix->sizeimage = pix->bytesperline * pix->height; pix->priv = 0; }

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static int skeleton_try_fmt_vid_cap(struct file *file, void *priv, struct v4l2_format *f) { struct skeleton *skel = video_drvdata(file); struct v4l2_pix_format *pix = &f->fmt.pix; /* * Due to historical reasons providing try_fmt with an unsupported * pixelformat will return -EINVAL for video receivers. Webcam drivers, * however, will silently correct the pixelformat. Some video capture * applications rely on this behavior... */ if (pix->pixelformat != V4L2_PIX_FMT_YUYV) return -EINVAL; skeleton_fill_pix_format(skel, pix); return 0; }

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static int skeleton_s_fmt_vid_cap(struct file *file, void *priv, struct v4l2_format *f) { struct skeleton *skel = video_drvdata(file); int ret; ret = skeleton_try_fmt_vid_cap(file, priv, f); if (ret) return ret; /* * It is not allowed to change the format while buffers for use with * streaming have already been allocated. */ if (vb2_is_busy(&skel->queue)) return -EBUSY; /* TODO: change format */ skel->format = f->fmt.pix; return 0; }

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static int skeleton_g_fmt_vid_cap(struct file *file, void *priv, struct v4l2_format *f) { struct skeleton *skel = video_drvdata(file); f->fmt.pix = skel->format; return 0; }

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static int skeleton_enum_fmt_vid_cap(struct file *file, void *priv, struct v4l2_fmtdesc *f) { if (f->index != 0) return -EINVAL; f->pixelformat = V4L2_PIX_FMT_YUYV; return 0; }

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static int skeleton_s_std(struct file *file, void *priv, v4l2_std_id std) { struct skeleton *skel = video_drvdata(file); /* S_STD is not supported on the HDMI input */ if (skel->input) return -ENODATA; /* * No change, so just return. Some applications call S_STD again after * the buffers for streaming have been set up, so we have to allow for * this behavior. */ if (std == skel->std) return 0; /* * Changing the standard implies a format change, which is not allowed * while buffers for use with streaming have already been allocated. */ if (vb2_is_busy(&skel->queue)) return -EBUSY; /* TODO: handle changing std */ skel->std = std; /* Update the internal format */ skeleton_fill_pix_format(skel, &skel->format); return 0; }

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static int skeleton_g_std(struct file *file, void *priv, v4l2_std_id *std) { struct skeleton *skel = video_drvdata(file); /* G_STD is not supported on the HDMI input */ if (skel->input) return -ENODATA; *std = skel->std; return 0; }

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/* * Query the current standard as seen by the hardware. This function shall * never actually change the standard, it just detects and reports. * The framework will initially set *std to tvnorms (i.e. the set of * supported standards by this input), and this function should just AND * this value. If there is no signal, then *std should be set to 0. */
static int skeleton_querystd(struct file *file, void *priv, v4l2_std_id *std) { struct skeleton *skel = video_drvdata(file); /* QUERY_STD is not supported on the HDMI input */ if (skel->input) return -ENODATA; #ifdef TODO /* * Query currently seen standard. Initial value of *std is * V4L2_STD_ALL. This function should look something like this: */ get_signal_info(); if (no_signal) { *std = 0; return 0; } /* Use signal information to reduce the number of possible standards */ if (signal_has_525_lines) *std &= V4L2_STD_525_60; else *std &= V4L2_STD_625_50; #endif return 0; }

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static int skeleton_s_dv_timings(struct file *file, void *_fh, struct v4l2_dv_timings *timings) { struct skeleton *skel = video_drvdata(file); /* S_DV_TIMINGS is not supported on the S-Video input */ if (skel->input == 0) return -ENODATA; /* Quick sanity check */ if (!v4l2_valid_dv_timings(timings, &skel_timings_cap, NULL, NULL)) return -EINVAL; /* Check if the timings are part of the CEA-861 timings. */ if (!v4l2_find_dv_timings_cap(timings, &skel_timings_cap, 0, NULL, NULL)) return -EINVAL; /* Return 0 if the new timings are the same as the current timings. */ if (v4l2_match_dv_timings(timings, &skel->timings, 0, false)) return 0; /* * Changing the timings implies a format change, which is not allowed * while buffers for use with streaming have already been allocated. */ if (vb2_is_busy(&skel->queue)) return -EBUSY; /* TODO: Configure new timings */ /* Save timings */ skel->timings = *timings; /* Update the internal format */ skeleton_fill_pix_format(skel, &skel->format); return 0; }

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static int skeleton_g_dv_timings(struct file *file, void *_fh, struct v4l2_dv_timings *timings) { struct skeleton *skel = video_drvdata(file); /* G_DV_TIMINGS is not supported on the S-Video input */ if (skel->input == 0) return -ENODATA; *timings = skel->timings; return 0; }

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static int skeleton_enum_dv_timings(struct file *file, void *_fh, struct v4l2_enum_dv_timings *timings) { struct skeleton *skel = video_drvdata(file); /* ENUM_DV_TIMINGS is not supported on the S-Video input */ if (skel->input == 0) return -ENODATA; return v4l2_enum_dv_timings_cap(timings, &skel_timings_cap, NULL, NULL); }

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/* * Query the current timings as seen by the hardware. This function shall * never actually change the timings, it just detects and reports. * If no signal is detected, then return -ENOLINK. If the hardware cannot * lock to the signal, then return -ENOLCK. If the signal is out of range * of the capabilities of the system (e.g., it is possible that the receiver * can lock but that the DMA engine it is connected to cannot handle * pixelclocks above a certain frequency), then -ERANGE is returned. */
static int skeleton_query_dv_timings(struct file *file, void *_fh, struct v4l2_dv_timings *timings) { struct skeleton *skel = video_drvdata(file); /* QUERY_DV_TIMINGS is not supported on the S-Video input */ if (skel->input == 0) return -ENODATA; #ifdef TODO /* * Query currently seen timings. This function should look * something like this: */ detect_timings(); if (no_signal) return -ENOLINK; if (cannot_lock_to_signal) return -ENOLCK; if (signal_out_of_range_of_capabilities) return -ERANGE; /* Useful for debugging */ v4l2_print_dv_timings(skel->v4l2_dev.name, "query_dv_timings:", timings, true); #endif return 0; }

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static int skeleton_dv_timings_cap(struct file *file, void *fh, struct v4l2_dv_timings_cap *cap) { struct skeleton *skel = video_drvdata(file); /* DV_TIMINGS_CAP is not supported on the S-Video input */ if (skel->input == 0) return -ENODATA; *cap = skel_timings_cap; return 0; }

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static int skeleton_enum_input(struct file *file, void *priv, struct v4l2_input *i) { if (i->index > 1) return -EINVAL; i->type = V4L2_INPUT_TYPE_CAMERA; if (i->index == 0) { i->std = SKEL_TVNORMS; strlcpy(i->name, "S-Video", sizeof(i->name)); i->capabilities = V4L2_IN_CAP_STD; } else { i->std = 0; strlcpy(i->name, "HDMI", sizeof(i->name)); i->capabilities = V4L2_IN_CAP_DV_TIMINGS; } return 0; }

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static int skeleton_s_input(struct file *file, void *priv, unsigned int i) { struct skeleton *skel = video_drvdata(file); if (i > 1) return -EINVAL; /* * Changing the input implies a format change, which is not allowed * while buffers for use with streaming have already been allocated. */ if (vb2_is_busy(&skel->queue)) return -EBUSY; skel->input = i; /* * Update tvnorms. The tvnorms value is used by the core to implement * VIDIOC_ENUMSTD so it has to be correct. If tvnorms == 0, then * ENUMSTD will return -ENODATA. */ skel->vdev.tvnorms = i ? 0 : SKEL_TVNORMS; /* Update the internal format */ skeleton_fill_pix_format(skel, &skel->format); return 0; }

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static int skeleton_g_input(struct file *file, void *priv, unsigned int *i) { struct skeleton *skel = video_drvdata(file); *i = skel->input; return 0; }

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/* The control handler. */
static int skeleton_s_ctrl(struct v4l2_ctrl *ctrl) { /*struct skeleton *skel = container_of(ctrl->handler, struct skeleton, ctrl_handler);*/ switch (ctrl->id) { case V4L2_CID_BRIGHTNESS: /* TODO: set brightness to ctrl->val */ break; case V4L2_CID_CONTRAST: /* TODO: set contrast to ctrl->val */ break; case V4L2_CID_SATURATION: /* TODO: set saturation to ctrl->val */ break; case V4L2_CID_HUE: /* TODO: set hue to ctrl->val */ break; default: return -EINVAL; } return 0; }

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/* ------------------------------------------------------------------ File operations for the device ------------------------------------------------------------------*/ static const struct v4l2_ctrl_ops skel_ctrl_ops = { .s_ctrl = skeleton_s_ctrl, }; /* * The set of all supported ioctls. Note that all the streaming ioctls * use the vb2 helper functions that take care of all the locking and * that also do ownership tracking (i.e. only the filehandle that requested * the buffers can call the streaming ioctls, all other filehandles will * receive -EBUSY if they attempt to call the same streaming ioctls). * * The last three ioctls also use standard helper functions: these implement * standard behavior for drivers with controls. */ static const struct v4l2_ioctl_ops skel_ioctl_ops = { .vidioc_querycap = skeleton_querycap, .vidioc_try_fmt_vid_cap = skeleton_try_fmt_vid_cap, .vidioc_s_fmt_vid_cap = skeleton_s_fmt_vid_cap, .vidioc_g_fmt_vid_cap = skeleton_g_fmt_vid_cap, .vidioc_enum_fmt_vid_cap = skeleton_enum_fmt_vid_cap, .vidioc_g_std = skeleton_g_std, .vidioc_s_std = skeleton_s_std, .vidioc_querystd = skeleton_querystd, .vidioc_s_dv_timings = skeleton_s_dv_timings, .vidioc_g_dv_timings = skeleton_g_dv_timings, .vidioc_enum_dv_timings = skeleton_enum_dv_timings, .vidioc_query_dv_timings = skeleton_query_dv_timings, .vidioc_dv_timings_cap = skeleton_dv_timings_cap, .vidioc_enum_input = skeleton_enum_input, .vidioc_g_input = skeleton_g_input, .vidioc_s_input = skeleton_s_input, .vidioc_reqbufs = vb2_ioctl_reqbufs, .vidioc_create_bufs = vb2_ioctl_create_bufs, .vidioc_querybuf = vb2_ioctl_querybuf, .vidioc_qbuf = vb2_ioctl_qbuf, .vidioc_dqbuf = vb2_ioctl_dqbuf, .vidioc_expbuf = vb2_ioctl_expbuf, .vidioc_streamon = vb2_ioctl_streamon, .vidioc_streamoff = vb2_ioctl_streamoff, .vidioc_log_status = v4l2_ctrl_log_status, .vidioc_subscribe_event = v4l2_ctrl_subscribe_event, .vidioc_unsubscribe_event = v4l2_event_unsubscribe, }; /* * The set of file operations. Note that all these ops are standard core * helper functions. */ static const struct v4l2_file_operations skel_fops = { .owner = THIS_MODULE, .open = v4l2_fh_open, .release = vb2_fop_release, .unlocked_ioctl = video_ioctl2, .read = vb2_fop_read, .mmap = vb2_fop_mmap, .poll = vb2_fop_poll, }; /* * The initial setup of this device instance. Note that the initial state of * the driver should be complete. So the initial format, standard, timings * and video input should all be initialized to some reasonable value. */
static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { /* The initial timings are chosen to be 720p60. */ static const struct v4l2_dv_timings timings_def = V4L2_DV_BT_CEA_1280X720P60; struct skeleton *skel; struct video_device *vdev; struct v4l2_ctrl_handler *hdl; struct vb2_queue *q; int ret; /* Enable PCI */ ret = pci_enable_device(pdev); if (ret) return ret; ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32)); if (ret) { dev_err(&pdev->dev, "no suitable DMA available.\n"); goto disable_pci; } /* Allocate a new instance */ skel = devm_kzalloc(&pdev->dev, sizeof(struct skeleton), GFP_KERNEL); if (!skel) return -ENOMEM; /* Allocate the interrupt */ ret = devm_request_irq(&pdev->dev, pdev->irq, skeleton_irq, 0, KBUILD_MODNAME, skel); if (ret) { dev_err(&pdev->dev, "request_irq failed\n"); goto disable_pci; } skel->pdev = pdev; /* Fill in the initial format-related settings */ skel->timings = timings_def; skel->std = V4L2_STD_625_50; skeleton_fill_pix_format(skel, &skel->format); /* Initialize the top-level structure */ ret = v4l2_device_register(&pdev->dev, &skel->v4l2_dev); if (ret) goto disable_pci; mutex_init(&skel->lock); /* Add the controls */ hdl = &skel->ctrl_handler; v4l2_ctrl_handler_init(hdl, 4); v4l2_ctrl_new_std(hdl, &skel_ctrl_ops, V4L2_CID_BRIGHTNESS, 0, 255, 1, 127); v4l2_ctrl_new_std(hdl, &skel_ctrl_ops, V4L2_CID_CONTRAST, 0, 255, 1, 16); v4l2_ctrl_new_std(hdl, &skel_ctrl_ops, V4L2_CID_SATURATION, 0, 255, 1, 127); v4l2_ctrl_new_std(hdl, &skel_ctrl_ops, V4L2_CID_HUE, -128, 127, 1, 0); if (hdl->error) { ret = hdl->error; goto free_hdl; } skel->v4l2_dev.ctrl_handler = hdl; /* Initialize the vb2 queue */ q = &skel->queue; q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ; q->drv_priv = skel; q->buf_struct_size = sizeof(struct skel_buffer); q->ops = &skel_qops; q->mem_ops = &vb2_dma_contig_memops; q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; /* * Assume that this DMA engine needs to have at least two buffers * available before it can be started. The start_streaming() op * won't be called until at least this many buffers are queued up. */ q->min_buffers_needed = 2; /* * The serialization lock for the streaming ioctls. This is the same * as the main serialization lock, but if some of the non-streaming * ioctls could take a long time to execute, then you might want to * have a different lock here to prevent VIDIOC_DQBUF from being * blocked while waiting for another action to finish. This is * generally not needed for PCI devices, but USB devices usually do * want a separate lock here. */ q->lock = &skel->lock; /* * Since this driver can only do 32-bit DMA we must make sure that * the vb2 core will allocate the buffers in 32-bit DMA memory. */ q->gfp_flags = GFP_DMA32; ret = vb2_queue_init(q); if (ret) goto free_hdl; skel->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev); if (IS_ERR(skel->alloc_ctx)) { dev_err(&pdev->dev, "Can't allocate buffer context"); ret = PTR_ERR(skel->alloc_ctx); goto free_hdl; } INIT_LIST_HEAD(&skel->buf_list); spin_lock_init(&skel->qlock); /* Initialize the video_device structure */ vdev = &skel->vdev; strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name)); /* * There is nothing to clean up, so release is set to an empty release * function. The release callback must be non-NULL. */ vdev->release = video_device_release_empty; vdev->fops = &skel_fops, vdev->ioctl_ops = &skel_ioctl_ops, vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE | V4L2_CAP_STREAMING; /* * The main serialization lock. All ioctls are serialized by this * lock. Exception: if q->lock is set, then the streaming ioctls * are serialized by that separate lock. */ vdev->lock = &skel->lock; vdev->queue = q; vdev->v4l2_dev = &skel->v4l2_dev; /* Supported SDTV standards, if any */ vdev->tvnorms = SKEL_TVNORMS; video_set_drvdata(vdev, skel); ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1); if (ret) goto free_ctx; dev_info(&pdev->dev, "V4L2 PCI Skeleton Driver loaded\n"); return 0; free_ctx: vb2_dma_contig_cleanup_ctx(skel->alloc_ctx); free_hdl: v4l2_ctrl_handler_free(&skel->ctrl_handler); v4l2_device_unregister(&skel->v4l2_dev); disable_pci: pci_disable_device(pdev); return ret; }

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static void skeleton_remove(struct pci_dev *pdev) { struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev); struct skeleton *skel = container_of(v4l2_dev, struct skeleton, v4l2_dev); video_unregister_device(&skel->vdev); v4l2_ctrl_handler_free(&skel->ctrl_handler); vb2_dma_contig_cleanup_ctx(skel->alloc_ctx); v4l2_device_unregister(&skel->v4l2_dev); pci_disable_device(skel->pdev); }

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static struct pci_driver skeleton_driver = { .name = KBUILD_MODNAME, .probe = skeleton_probe, .remove = skeleton_remove, .id_table = skeleton_pci_tbl, }; module_pci_driver(skeleton_driver);

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Directory: samples/v4l
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