[RFCv4 16/21] v4l2: video_device: support for creating requests

[Alexandre Courbot]

Add a new VIDIOC_NEW_REQUEST ioctl, which allows to instanciate requests
on devices that support the request API. Requests created that way can
only control the device they originate from, making them suitable for
simple devices, but not complex pipelines.

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
---
 Documentation/ioctl/ioctl-number.txt |  1 +
 drivers/media/v4l2-core/v4l2-dev.c   |  2 ++
 drivers/media/v4l2-core/v4l2-ioctl.c | 25 +++++++++++++++++++++++++
 include/media/v4l2-dev.h             |  2 ++
 include/uapi/linux/videodev2.h       |  3 +++
 5 files changed, 33 insertions(+)

diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 6501389d55b9..afdc9ed255b0 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -286,6 +286,7 @@ Code  Seq#(hex)	Include File		Comments
 					<mailto:oe@xxxxxxx>
 'z'	10-4F	drivers/s390/crypto/zcrypt_api.h	conflict!
 '|'	00-7F	linux/media.h
+'|'	80-9F	linux/media-request.h
 0x80	00-1F	linux/fb.h
 0x89	00-06	arch/x86/include/asm/sockios.h
 0x89	0B-DF	linux/sockios.h
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 0301fe426a43..062ebee5bffc 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -559,6 +559,8 @@ static void determine_valid_ioctls(struct video_device *vdev)
 		set_bit(_IOC_NR(VIDIOC_TRY_EXT_CTRLS), valid_ioctls);
 	if (vdev->ctrl_handler || ops->vidioc_querymenu)
 		set_bit(_IOC_NR(VIDIOC_QUERYMENU), valid_ioctls);
+	if (vdev->req_mgr)
+		set_bit(_IOC_NR(VIDIOC_NEW_REQUEST), valid_ioctls);
 	SET_VALID_IOCTL(ops, VIDIOC_G_FREQUENCY, vidioc_g_frequency);
 	SET_VALID_IOCTL(ops, VIDIOC_S_FREQUENCY, vidioc_s_frequency);
 	SET_VALID_IOCTL(ops, VIDIOC_LOG_STATUS, vidioc_log_status);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index ab4968ea443f..a45fe078f8ae 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -21,6 +21,7 @@
 
 #include <linux/videodev2.h>
 
+#include <media/media-request.h>
 #include <media/v4l2-common.h>
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-ctrls.h>
@@ -842,6 +843,13 @@ static void v4l_print_freq_band(const void *arg, bool write_only)
 			p->rangehigh, p->modulation);
 }
 
+static void vidioc_print_new_request(const void *arg, bool write_only)
+{
+	const struct media_request_new *new = arg;
+
+	pr_cont("fd=0x%x\n", new->fd);
+}
+
 static void v4l_print_edid(const void *arg, bool write_only)
 {
 	const struct v4l2_edid *p = arg;
@@ -2486,6 +2494,22 @@ static int v4l_enum_freq_bands(const struct v4l2_ioctl_ops *ops,
 	return -ENOTTY;
 }
 
+static int vidioc_new_request(const struct v4l2_ioctl_ops *ops,
+			      struct file *file, void *fh, void *arg)
+{
+#if IS_ENABLED(CONFIG_MEDIA_REQUEST_API)
+	struct media_request_new *new = arg;
+	struct video_device *vfd = video_devdata(file);
+
+	if (!vfd->req_mgr)
+		return -ENOTTY;
+
+	return media_request_ioctl_new(vfd->req_mgr, new);
+#else
+	return -ENOTTY;
+#endif
+}
+
 struct v4l2_ioctl_info {
 	unsigned int ioctl;
 	u32 flags;
@@ -2617,6 +2641,7 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = {
 	IOCTL_INFO_FNC(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, v4l_print_freq_band, 0),
 	IOCTL_INFO_FNC(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, match)),
 	IOCTL_INFO_FNC(VIDIOC_QUERY_EXT_CTRL, v4l_query_ext_ctrl, v4l_print_query_ext_ctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_query_ext_ctrl, id)),
+	IOCTL_INFO_FNC(VIDIOC_NEW_REQUEST, vidioc_new_request, vidioc_print_new_request, 0),
 };
 #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)
 
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 53f32022fabe..e6c4e10889bc 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -209,6 +209,7 @@ struct v4l2_file_operations {
  * @entity: &struct media_entity
  * @intf_devnode: pointer to &struct media_intf_devnode
  * @pipe: &struct media_pipeline
+ * @req_mgr: request manager to use if this device supports creating requests
  * @fops: pointer to &struct v4l2_file_operations for the video device
  * @device_caps: device capabilities as used in v4l2_capabilities
  * @dev: &struct device for the video device
@@ -251,6 +252,7 @@ struct video_device
 	struct media_intf_devnode *intf_devnode;
 	struct media_pipeline pipe;
 #endif
+	struct media_request_mgr *req_mgr;
 	const struct v4l2_file_operations *fops;
 
 	u32 device_caps;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 91cfe0cbd5c5..35706204e81d 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -63,6 +63,7 @@
 #include <linux/compiler.h>
 #include <linux/ioctl.h>
 #include <linux/types.h>
+#include <linux/media-request.h>
 #include <linux/v4l2-common.h>
 #include <linux/v4l2-controls.h>
 
@@ -2407,6 +2408,8 @@ struct v4l2_create_buffers {
 
 #define VIDIOC_QUERY_EXT_CTRL	_IOWR('V', 103, struct v4l2_query_ext_ctrl)
 
+#define VIDIOC_NEW_REQUEST	_IOWR('V', 104, struct media_request_new)
+
 /* Reminder: when adding new ioctls please add support for them to
    drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */
 
-- 
2.16.1.291.g4437f3f132-goog