* [REVIEW PATCH] v4l2-pci-skeleton: add a V4L2 PCI skeleton driver
@ 2014-03-09 16:07 Hans Verkuil
2014-03-13 14:28 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 2+ messages in thread
From: Hans Verkuil @ 2014-03-09 16:07 UTC (permalink / raw)
To: Linux Media Mailing List
This patch is almost identical to the earlier RFC version:
https://patchwork.linuxtv.org/patch/21780/
The only changes are that it has been rebased to the latest vb2 changes so it
can take advantage of the min_buffers_needed field and it adds code to requeue
buffers in case of a failure when starting the DMA.
This example driver uses all the latest frameworks and can serve as a
starting point for a new V4L2 PCI driver.
Originally written for a presentation on how to use V4L2 frameworks
during FOSDEM 2014.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
drivers/media/pci/Kconfig | 1 +
drivers/media/pci/Makefile | 2 +
drivers/media/pci/skeleton/Kconfig | 11 +
drivers/media/pci/skeleton/Makefile | 1 +
drivers/media/pci/skeleton/v4l2-pci-skeleton.c | 912 +++++++++++++++++++++++++
5 files changed, 927 insertions(+)
create mode 100644 drivers/media/pci/skeleton/Kconfig
create mode 100644 drivers/media/pci/skeleton/Makefile
create mode 100644 drivers/media/pci/skeleton/v4l2-pci-skeleton.c
diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
index 53196f1..1717a91 100644
--- a/drivers/media/pci/Kconfig
+++ b/drivers/media/pci/Kconfig
@@ -19,6 +19,7 @@ if MEDIA_ANALOG_TV_SUPPORT
source "drivers/media/pci/ivtv/Kconfig"
source "drivers/media/pci/zoran/Kconfig"
source "drivers/media/pci/saa7146/Kconfig"
+source "drivers/media/pci/skeleton/Kconfig"
endif
if MEDIA_ANALOG_TV_SUPPORT || MEDIA_DIGITAL_TV_SUPPORT
diff --git a/drivers/media/pci/Makefile b/drivers/media/pci/Makefile
index 35cc578..ec08f46 100644
--- a/drivers/media/pci/Makefile
+++ b/drivers/media/pci/Makefile
@@ -11,11 +11,13 @@ obj-y += ttpci/ \
ngene/ \
ddbridge/ \
b2c2/ \
+ skeleton/ \
saa7146/
obj-$(CONFIG_VIDEO_IVTV) += ivtv/
obj-$(CONFIG_VIDEO_ZORAN) += zoran/
obj-$(CONFIG_VIDEO_CX18) += cx18/
+obj-$(CONFIG_VIDEO_PCI_SKELETON) += skeleton/
obj-$(CONFIG_VIDEO_CX23885) += cx23885/
obj-$(CONFIG_VIDEO_CX25821) += cx25821/
obj-$(CONFIG_VIDEO_CX88) += cx88/
diff --git a/drivers/media/pci/skeleton/Kconfig b/drivers/media/pci/skeleton/Kconfig
new file mode 100644
index 0000000..e58b150
--- /dev/null
+++ b/drivers/media/pci/skeleton/Kconfig
@@ -0,0 +1,11 @@
+config VIDEO_PCI_SKELETON
+ tristate "V4L2 PCI Skeleton Driver"
+ select VIDEOBUF2_DMA_CONTIG
+ depends on PCI && VIDEO_V4L2
+ default n
+ help
+ Say Y for support for this PCI Skeleton Driver capture
+ device.
+
+ To compile this driver as a module, choose M here: the
+ module will be called v4l2-pci-skeleton.
diff --git a/drivers/media/pci/skeleton/Makefile b/drivers/media/pci/skeleton/Makefile
new file mode 100644
index 0000000..3a935ca
--- /dev/null
+++ b/drivers/media/pci/skeleton/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_VIDEO_PCI_SKELETON) += v4l2-pci-skeleton.o
diff --git a/drivers/media/pci/skeleton/v4l2-pci-skeleton.c b/drivers/media/pci/skeleton/v4l2-pci-skeleton.c
new file mode 100644
index 0000000..53d2d7a
--- /dev/null
+++ b/drivers/media/pci/skeleton/v4l2-pci-skeleton.c
@@ -0,0 +1,912 @@
+/*
+ * 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");
+MODULE_DEVICE_TABLE(pci, skeleton_pci_tbl);
+
+/**
+ * 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 int 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, }
+};
+
+/*
+ * 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 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);
+ new_buf->vb.v4l2_buf.sequence = skel->sequence++;
+ v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
+ 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);
+
+ 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 and fill in the field. Note: if the format's field is
+ * V4L2_FIELD_ALTERNATE, then vb->v4l2_buf.field should be set in the
+ * interrupt handler since that's usually where you know if the TOP or
+ * BOTTOM field has been captured.
+ */
+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);
+ vb->v4l2_buf.field = skel->format.field;
+ 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 int 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);
+ return 0;
+}
+
+/*
+ * 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_INTERLACED;
+ 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_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;
+ /* If this bit is set, then the v4l2 core will provide the support
+ * for the VIDIOC_G/S_PRIORITY ioctls. This flag will eventually
+ * go away once all drivers have been converted to use struct v4l2_fh.
+ */
+ set_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags);
+ 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);
--
1.9.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [REVIEW PATCH] v4l2-pci-skeleton: add a V4L2 PCI skeleton driver
2014-03-09 16:07 [REVIEW PATCH] v4l2-pci-skeleton: add a V4L2 PCI skeleton driver Hans Verkuil
@ 2014-03-13 14:28 ` Mauro Carvalho Chehab
0 siblings, 0 replies; 2+ messages in thread
From: Mauro Carvalho Chehab @ 2014-03-13 14:28 UTC (permalink / raw)
To: Hans Verkuil; +Cc: Linux Media Mailing List
Hi Hans,
I don't like very much the idea of adding skeleton drivers inside
drivers/media. We have there already enough drivers to pollute
it with more skeleton ones.
I think that the best is to put it on some other place.
Eventually, we could put it at Documentation:
$ ls Documentation/*/*.c
Documentation/accounting/getdelays.c Documentation/prctl/disable-tsc-ctxt-sw-stress-test.c
Documentation/auxdisplay/cfag12864b-example.c Documentation/prctl/disable-tsc-on-off-stress-test.c
Documentation/blackfin/gptimers-example.c Documentation/prctl/disable-tsc-test.c
Documentation/connector/cn_test.c Documentation/ptp/testptp.c
Documentation/connector/ucon.c Documentation/spi/spidev_fdx.c
Documentation/filesystems/dnotify_test.c Documentation/spi/spidev_test.c
Documentation/ia64/aliasing-test.c Documentation/timers/hpet_example.c
Documentation/laptops/dslm.c Documentation/vDSO/parse_vdso.c
Documentation/laptops/hpfall.c Documentation/vDSO/vdso_test.c
Some drivers there, like:
Documentation/blackfin/gptimers-example.c
Are clearly skeleton drivers.
Regards,
Mauro
Em Sun, 09 Mar 2014 17:07:42 +0100
Hans Verkuil <hverkuil@xs4all.nl> escreveu:
> This patch is almost identical to the earlier RFC version:
>
> https://patchwork.linuxtv.org/patch/21780/
>
> The only changes are that it has been rebased to the latest vb2 changes so it
> can take advantage of the min_buffers_needed field and it adds code to requeue
> buffers in case of a failure when starting the DMA.
>
> This example driver uses all the latest frameworks and can serve as a
> starting point for a new V4L2 PCI driver.
>
> Originally written for a presentation on how to use V4L2 frameworks
> during FOSDEM 2014.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
> drivers/media/pci/Kconfig | 1 +
> drivers/media/pci/Makefile | 2 +
> drivers/media/pci/skeleton/Kconfig | 11 +
> drivers/media/pci/skeleton/Makefile | 1 +
> drivers/media/pci/skeleton/v4l2-pci-skeleton.c | 912 +++++++++++++++++++++++++
> 5 files changed, 927 insertions(+)
> create mode 100644 drivers/media/pci/skeleton/Kconfig
> create mode 100644 drivers/media/pci/skeleton/Makefile
> create mode 100644 drivers/media/pci/skeleton/v4l2-pci-skeleton.c
>
> diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
> index 53196f1..1717a91 100644
> --- a/drivers/media/pci/Kconfig
> +++ b/drivers/media/pci/Kconfig
> @@ -19,6 +19,7 @@ if MEDIA_ANALOG_TV_SUPPORT
> source "drivers/media/pci/ivtv/Kconfig"
> source "drivers/media/pci/zoran/Kconfig"
> source "drivers/media/pci/saa7146/Kconfig"
> +source "drivers/media/pci/skeleton/Kconfig"
> endif
>
> if MEDIA_ANALOG_TV_SUPPORT || MEDIA_DIGITAL_TV_SUPPORT
> diff --git a/drivers/media/pci/Makefile b/drivers/media/pci/Makefile
> index 35cc578..ec08f46 100644
> --- a/drivers/media/pci/Makefile
> +++ b/drivers/media/pci/Makefile
> @@ -11,11 +11,13 @@ obj-y += ttpci/ \
> ngene/ \
> ddbridge/ \
> b2c2/ \
> + skeleton/ \
> saa7146/
>
> obj-$(CONFIG_VIDEO_IVTV) += ivtv/
> obj-$(CONFIG_VIDEO_ZORAN) += zoran/
> obj-$(CONFIG_VIDEO_CX18) += cx18/
> +obj-$(CONFIG_VIDEO_PCI_SKELETON) += skeleton/
> obj-$(CONFIG_VIDEO_CX23885) += cx23885/
> obj-$(CONFIG_VIDEO_CX25821) += cx25821/
> obj-$(CONFIG_VIDEO_CX88) += cx88/
> diff --git a/drivers/media/pci/skeleton/Kconfig b/drivers/media/pci/skeleton/Kconfig
> new file mode 100644
> index 0000000..e58b150
> --- /dev/null
> +++ b/drivers/media/pci/skeleton/Kconfig
> @@ -0,0 +1,11 @@
> +config VIDEO_PCI_SKELETON
> + tristate "V4L2 PCI Skeleton Driver"
> + select VIDEOBUF2_DMA_CONTIG
> + depends on PCI && VIDEO_V4L2
> + default n
> + help
> + Say Y for support for this PCI Skeleton Driver capture
> + device.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called v4l2-pci-skeleton.
> diff --git a/drivers/media/pci/skeleton/Makefile b/drivers/media/pci/skeleton/Makefile
> new file mode 100644
> index 0000000..3a935ca
> --- /dev/null
> +++ b/drivers/media/pci/skeleton/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_VIDEO_PCI_SKELETON) += v4l2-pci-skeleton.o
> diff --git a/drivers/media/pci/skeleton/v4l2-pci-skeleton.c b/drivers/media/pci/skeleton/v4l2-pci-skeleton.c
> new file mode 100644
> index 0000000..53d2d7a
> --- /dev/null
> +++ b/drivers/media/pci/skeleton/v4l2-pci-skeleton.c
> @@ -0,0 +1,912 @@
> +/*
> + * 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");
> +MODULE_DEVICE_TABLE(pci, skeleton_pci_tbl);
> +
> +/**
> + * 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 int 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, }
> +};
> +
> +/*
> + * 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 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);
> + new_buf->vb.v4l2_buf.sequence = skel->sequence++;
> + v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
> + 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);
> +
> + 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 and fill in the field. Note: if the format's field is
> + * V4L2_FIELD_ALTERNATE, then vb->v4l2_buf.field should be set in the
> + * interrupt handler since that's usually where you know if the TOP or
> + * BOTTOM field has been captured.
> + */
> +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);
> + vb->v4l2_buf.field = skel->format.field;
> + 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 int 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);
> + return 0;
> +}
> +
> +/*
> + * 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_INTERLACED;
> + 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_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;
> + /* If this bit is set, then the v4l2 core will provide the support
> + * for the VIDIOC_G/S_PRIORITY ioctls. This flag will eventually
> + * go away once all drivers have been converted to use struct v4l2_fh.
> + */
> + set_bit(V4L2_FL_USE_FH_PRIO, &vdev->flags);
> + 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);
--
Regards,
Mauro
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2014-03-13 14:28 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
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2014-03-09 16:07 [REVIEW PATCH] v4l2-pci-skeleton: add a V4L2 PCI skeleton driver Hans Verkuil
2014-03-13 14:28 ` Mauro Carvalho Chehab
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