diff options
Diffstat (limited to 'kernel/Documentation/video4linux/v4l2-pci-skeleton.c')
| -rw-r--r-- | kernel/Documentation/video4linux/v4l2-pci-skeleton.c | 924 |
1 files changed, 924 insertions, 0 deletions
diff --git a/kernel/Documentation/video4linux/v4l2-pci-skeleton.c b/kernel/Documentation/video4linux/v4l2-pci-skeleton.c new file mode 100644 index 000000000..7bd1b975b --- /dev/null +++ b/kernel/Documentation/video4linux/v4l2-pci-skeleton.c @@ -0,0 +1,924 @@ +/* + * 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-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); +} + +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; +} + +/* + * 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, const struct v4l2_format *fmt, + 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; + + if (fmt && fmt->fmt.pix.sizeimage < skel->format.sizeimage) + return -EINVAL; + *nplanes = 1; + sizes[0] = fmt ? fmt->fmt.pix.sizeimage : skel->format.sizeimage; + alloc_ctxs[0] = skel->alloc_ctx; + return 0; +} + +/* + * 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; +} + +/* + * 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); +} + +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); +} + +/* + * 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; +} + +/* + * 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); +} + +/* + * 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)); + cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE | + V4L2_CAP_STREAMING; + cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS; + return 0; +} + +/* + * 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; +} + +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; +} + +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; +} + +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; +} + +static int skeleton_enum_fmt_vid_cap(struct file *file, void *priv, + struct v4l2_fmtdesc *f) +{ + if (f->index != 0) + return -EINVAL; + + strlcpy(f->description, "4:2:2, packed, YUYV", sizeof(f->description)); + f->pixelformat = V4L2_PIX_FMT_YUYV; + f->flags = 0; + return 0; +} + +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; +} + +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; +} + +/* + * 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; +} + +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)) + 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; +} + +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; +} + +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); +} + +/* + * 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; +} + +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; +} + +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; +} + +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; +} + +static int skeleton_g_input(struct file *file, void *priv, unsigned int *i) +{ + struct skeleton *skel = video_drvdata(file); + + *i = skel->input; + return 0; +} + +/* 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; +} + +/* ------------------------------------------------------------------ + 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, + /* + * 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; +} + +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); +} + +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); |