</orderedlist>
</section>
+ <section>
+ <title>V4L2 in Linux 3.16</title>
+ <orderedlist>
+ <listitem>
+ <para>Added event V4L2_EVENT_SOURCE_CHANGE.
+ </para>
+ </listitem>
+ </orderedlist>
+ </section>
+
+ <section>
+ <title>V4L2 in Linux 3.17</title>
+ <orderedlist>
+ <listitem>
+ <para>Extended &v4l2-pix-format;. Added format flags.
+ </para>
+ </listitem>
+ <listitem>
+ <para>Added compound control types and &VIDIOC-QUERY-EXT-CTRL;.
+ </para>
+ </listitem>
+ </orderedlist>
+ </section>
+
<section id="other">
<title>Relation of V4L2 to other Linux multimedia APIs</title>
to accept data for output.</para>
<para>When streaming I/O has been negotiated this function waits
-until a buffer has been filled or displayed and can be dequeued with
-the &VIDIOC-DQBUF; ioctl. When buffers are already in the outgoing
-queue of the driver the function returns immediately.</para>
+until a buffer has been filled by the capture device and can be dequeued
+with the &VIDIOC-DQBUF; ioctl. For output devices this function waits
+until the device is ready to accept a new buffer to be queued up with
+the &VIDIOC-QBUF; ioctl for display. When buffers are already in the outgoing
+queue of the driver (capture) or the incoming queue isn't full (display)
+the function returns immediately.</para>
<para>On success <function>poll()</function> returns the number of
file descriptors that have been selected (that is, file descriptors
flags. When the function timed out it returns a value of zero, on
failure it returns <returnvalue>-1</returnvalue> and the
<varname>errno</varname> variable is set appropriately. When the
-application did not call &VIDIOC-QBUF; or &VIDIOC-STREAMON; yet the
+application did not call &VIDIOC-STREAMON; the
<function>poll()</function> function succeeds, but sets the
<constant>POLLERR</constant> flag in the
-<structfield>revents</structfield> field.</para>
+<structfield>revents</structfield> field. When the
+application has called &VIDIOC-STREAMON; for a capture device but hasn't
+yet called &VIDIOC-QBUF;, the <function>poll()</function> function
+succeeds and sets the <constant>POLLERR</constant> flag in the
+<structfield>revents</structfield> field. For output devices this
+same situation will cause <function>poll()</function> to succeed
+as well, but it sets the <constant>POLLOUT</constant> and
+<constant>POLLWRNORM</constant> flags in the <structfield>revents</structfield>
+field.</para>
+
+ <para>If an event occurred (see &VIDIOC-DQEVENT;) then
+<constant>POLLPRI</constant> will be set in the <structfield>revents</structfield>
+field and <function>poll()</function> will return.</para>
<para>When use of the <function>read()</function> function has
been negotiated and the driver does not capture yet, the
may return immediately.</para>
<para>When use of the <function>write()</function> function has
-been negotiated the <function>poll</function> function just waits
+been negotiated and the driver does not stream yet, the
+<function>poll</function> function starts streaming. When that fails
+it returns a <constant>POLLERR</constant> as above. Otherwise it waits
until the driver is ready for a non-blocking
<function>write()</function> call.</para>
+ <para>If the caller is only interested in events (just
+<constant>POLLPRI</constant> is set in the <structfield>events</structfield>
+field), then <function>poll()</function> will <emphasis>not</emphasis>
+start streaming if the driver does not stream yet. This makes it
+possible to just poll for events and not for buffers.</para>
+
<para>All drivers implementing the <function>read()</function> or
<function>write()</function> function or streaming I/O must also
support the <function>poll()</function> function.</para>
applications. -->
<revision>
- <revnumber>3.16</revnumber>
- <date>2014-05-27</date>
- <authorinitials>lp</authorinitials>
- <revremark>Extended &v4l2-pix-format;. Added format flags.
+ <revnumber>3.17</revnumber>
+ <date>2014-08-04</date>
+ <authorinitials>lp, hv</authorinitials>
+ <revremark>Extended &v4l2-pix-format;. Added format flags. Added compound control types
+and VIDIOC_QUERY_EXT_CTRL.
</revremark>
</revision>
</partinfo>
<title>Video for Linux Two API Specification</title>
- <subtitle>Revision 3.14</subtitle>
+ <subtitle>Revision 3.17</subtitle>
<chapter id="common">
&sub-common;
</row>
<row>
<entry>&v4l2-rect;</entry>
- <entry><structfield>rect</structfield></entry>
+ <entry><structfield>r</structfield></entry>
<entry>Selection rectangle, in pixels.</entry>
</row>
<row>
{
struct v4l2_ctrl_config cfg;
+ memset(&cfg, 0, sizeof(cfg));
cx2341x_ctrl_fill(id, &cfg.name, &cfg.type, &min, &max, &step, &def, &cfg.flags);
cfg.ops = &cx2341x_ops;
cfg.id = id;
sizeof(state->tuner_i2c_adapter.name));
state->tuner_i2c_adapter.algo = &cx24123_tuner_i2c_algo;
state->tuner_i2c_adapter.algo_data = NULL;
+ state->tuner_i2c_adapter.dev.parent = i2c->dev.parent;
i2c_set_adapdata(&state->tuner_i2c_adapter, state);
if (i2c_add_adapter(&state->tuner_i2c_adapter) < 0) {
err("tuner i2c bus could not be initialized\n");
v4l2_info(sd, "HDCP keys read: %s%s\n",
(hdmi_read(sd, 0x04) & 0x20) ? "yes" : "no",
(hdmi_read(sd, 0x04) & 0x10) ? "ERROR" : "");
- if (!is_hdmi(sd)) {
+ if (is_hdmi(sd)) {
bool audio_pll_locked = hdmi_read(sd, 0x04) & 0x01;
bool audio_sample_packet_detect = hdmi_read(sd, 0x18) & 0x01;
bool audio_mute = io_read(sd, 0x65) & 0x40;
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/io.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <linux/kthread.h>
struct em28xx *dev = video_drvdata(file);
struct em28xx_v4l2 *v4l2 = dev->v4l2;
- if (v4l2->streaming_users > 0)
+ if (vb2_is_busy(&v4l2->vb_vidq))
return -EBUSY;
vidioc_try_fmt_vid_cap(file, priv, f);
return -EINVAL;
}
- em28xx_videodbg("open dev=%s type=%s\n",
- video_device_node_name(vdev), v4l2_type_names[fh_type]);
+ em28xx_videodbg("open dev=%s type=%s users=%d\n",
+ video_device_node_name(vdev), v4l2_type_names[fh_type],
+ v4l2->users);
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
return ret;
}
- if (v4l2_fh_is_singular_file(filp)) {
- em28xx_videodbg("first opened filehandle, initializing device\n");
-
+ if (v4l2->users == 0) {
em28xx_set_mode(dev, EM28XX_ANALOG_MODE);
if (vdev->vfl_type != VFL_TYPE_RADIO)
* of some i2c devices
*/
em28xx_wake_i2c(dev);
- } else {
- em28xx_videodbg("further filehandles are already opened\n");
}
if (vdev->vfl_type == VFL_TYPE_RADIO) {
kref_get(&dev->ref);
kref_get(&v4l2->ref);
+ v4l2->users++;
mutex_unlock(&dev->lock);
struct em28xx_v4l2 *v4l2 = dev->v4l2;
int errCode;
- mutex_lock(&dev->lock);
+ em28xx_videodbg("users=%d\n", v4l2->users);
- if (v4l2_fh_is_singular_file(filp)) {
- em28xx_videodbg("last opened filehandle, shutting down device\n");
+ vb2_fop_release(filp);
+ mutex_lock(&dev->lock);
+ if (v4l2->users == 1) {
/* No sense to try to write to the device */
if (dev->disconnected)
goto exit;
em28xx_errdev("cannot change alternate number to "
"0 (error=%i)\n", errCode);
}
- } else {
- em28xx_videodbg("further opened filehandles left\n");
}
exit:
- vb2_fop_release(filp);
+ v4l2->users--;
kref_put(&v4l2->ref, em28xx_free_v4l2);
mutex_unlock(&dev->lock);
kref_put(&dev->ref, em28xx_free_device);
int sensor_yres;
int sensor_xtal;
+ int users; /* user count for exclusive use */
int streaming_users; /* number of actively streaming users */
u32 frequency; /* selected tuner frequency */
* to the userspace.
*/
req->count = allocated_buffers;
+ q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
return 0;
}
memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
q->memory = create->memory;
+ q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
}
num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
*/
void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
{
- if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
+ if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
return NULL;
return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
return;
- if (!q->start_streaming_called) {
- if (WARN_ON(state != VB2_BUF_STATE_QUEUED))
- state = VB2_BUF_STATE_QUEUED;
- } else if (WARN_ON(state != VB2_BUF_STATE_DONE &&
- state != VB2_BUF_STATE_ERROR)) {
- state = VB2_BUF_STATE_ERROR;
- }
+ if (WARN_ON(state != VB2_BUF_STATE_DONE &&
+ state != VB2_BUF_STATE_ERROR &&
+ state != VB2_BUF_STATE_QUEUED))
+ state = VB2_BUF_STATE_ERROR;
#ifdef CONFIG_VIDEO_ADV_DEBUG
/*
q->start_streaming_called = 0;
dprintk(1, "driver refused to start streaming\n");
+ /*
+ * If you see this warning, then the driver isn't cleaning up properly
+ * after a failed start_streaming(). See the start_streaming()
+ * documentation in videobuf2-core.h for more information how buffers
+ * should be returned to vb2 in start_streaming().
+ */
if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
unsigned i;
/* Must be zero now */
WARN_ON(atomic_read(&q->owned_by_drv_count));
}
+ /*
+ * If done_list is not empty, then start_streaming() didn't call
+ * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
+ * STATE_DONE.
+ */
+ WARN_ON(!list_empty(&q->done_list));
return ret;
}
*/
list_add_tail(&vb->queued_entry, &q->queued_list);
q->queued_count++;
+ q->waiting_for_buffers = false;
vb->state = VB2_BUF_STATE_QUEUED;
if (V4L2_TYPE_IS_OUTPUT(q->type)) {
/*
if (q->start_streaming_called)
call_void_qop(q, stop_streaming, q);
+ /*
+ * If you see this warning, then the driver isn't cleaning up properly
+ * in stop_streaming(). See the stop_streaming() documentation in
+ * videobuf2-core.h for more information how buffers should be returned
+ * to vb2 in stop_streaming().
+ */
if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
for (i = 0; i < q->num_buffers; ++i)
if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
* their normal dequeued state.
*/
__vb2_queue_cancel(q);
+ q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
dprintk(3, "successful\n");
return 0;
}
/*
- * There is nothing to wait for if no buffer has been queued and the
- * queue isn't streaming, or if the error flag is set.
+ * There is nothing to wait for if the queue isn't streaming, or if the
+ * error flag is set.
+ */
+ if (!vb2_is_streaming(q) || q->error)
+ return res | POLLERR;
+ /*
+ * For compatibility with vb1: if QBUF hasn't been called yet, then
+ * return POLLERR as well. This only affects capture queues, output
+ * queues will always initialize waiting_for_buffers to false.
*/
- if ((list_empty(&q->queued_list) && !vb2_is_streaming(q)) || q->error)
+ if (q->waiting_for_buffers)
return res | POLLERR;
/*
goto fail_pages_alloc;
ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
- buf->num_pages, 0, size, gfp_flags);
+ buf->num_pages, 0, size, GFP_KERNEL);
if (ret)
goto fail_table_alloc;
* can return an error if hardware fails, in that case all
* buffers that have been already given by the @buf_queue
* callback are to be returned by the driver by calling
- * @vb2_buffer_done(VB2_BUF_STATE_DEQUEUED).
+ * @vb2_buffer_done(VB2_BUF_STATE_QUEUED).
* If you need a minimum number of buffers before you can
* start streaming, then set @min_buffers_needed in the
* vb2_queue structure. If that is non-zero then
* @start_streaming_called: start_streaming() was called successfully and we
* started streaming.
* @error: a fatal error occurred on the queue
+ * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
+ * buffers. Only set for capture queues if qbuf has not yet been
+ * called since poll() needs to return POLLERR in that situation.
* @fileio: file io emulator internal data, used only if emulator is active
* @threadio: thread io internal data, used only if thread is active
*/
unsigned int streaming:1;
unsigned int start_streaming_called:1;
unsigned int error:1;
+ unsigned int waiting_for_buffers:1;
struct vb2_fileio_data *fileio;
struct vb2_threadio_data *threadio;
projects / linux-2.6-block.git / commitdiff