device: add device object

Make a device object, let the v4l2 monitor create device objects
The device object is responsible for dynamically creating nodes.

spa/plugins/v4l2/v4l2-device.c

@@ -0,0 +1,218 @@
+/* Spa V4l2 Source
+ *
+ * Copyright © 2018 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * 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 <stddef.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <linux/videodev2.h>
+
+#include <spa/support/log.h>
+#include <spa/support/loop.h>
+#include <spa/monitor/device.h>
+#include <spa/debug/pod.h>
+
+#include "v4l2.h"
+
+#define NAME "v4l2-device"
+
+static const char default_device[] = "/dev/video0";
+
+extern const struct spa_handle_factory spa_v4l2_source_factory;
+
+struct props {
+	char device[64];
+	char device_name[128];
+	int device_fd;
+};
+
+static void reset_props(struct props *props)
+{
+	strncpy(props->device, default_device, 64);
+}
+
+struct impl {
+	struct spa_handle handle;
+	struct spa_device device;
+
+	struct spa_log *log;
+	struct spa_loop *main_loop;
+
+	struct props props;
+
+	const struct spa_device_callbacks *callbacks;
+	void *callbacks_data;
+
+	struct spa_v4l2_device dev;
+};
+
+static int impl_device_set_callbacks(struct spa_device *device,
+				   const struct spa_device_callbacks *callbacks,
+				   void *data)
+{
+	struct impl *this;
+	struct spa_dict_item items[1];
+
+	spa_return_val_if_fail(device != NULL, -EINVAL);
+
+	this = SPA_CONTAINER_OF(device, struct impl, device);
+
+	this->callbacks = callbacks;
+	this->callbacks_data = data;
+
+	if (callbacks) {
+		if (spa_v4l2_is_capture(&this->dev)) {
+			items[0] = SPA_DICT_ITEM_INIT("device.path", this->props.device);
+
+			if (callbacks->add)
+				callbacks->add(data, 0,
+					&spa_v4l2_source_factory,
+					SPA_TYPE_INTERFACE_Node,
+					&SPA_DICT_INIT(items, 1));
+		}
+
+
+	}
+
+	return 0;
+}
+
+static const struct spa_dict_item info_items[] = {
+	{ "media.class", "Video/Device" },
+};
+
+static const struct spa_dict info = {
+	info_items,
+	SPA_N_ELEMENTS(info_items)
+};
+
+static const struct spa_device impl_device = {
+	SPA_VERSION_DEVICE,
+	&info,
+	impl_device_set_callbacks,
+};
+
+static int impl_get_interface(struct spa_handle *handle, uint32_t type, void **interface)
+{
+	struct impl *this;
+
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+	spa_return_val_if_fail(interface != NULL, -EINVAL);
+
+	this = (struct impl *) handle;
+
+	if (type == SPA_TYPE_INTERFACE_Device)
+		*interface = &this->device;
+	else
+		return -ENOENT;
+
+	return 0;
+}
+
+static int impl_clear(struct spa_handle *handle)
+{
+	return 0;
+}
+
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
+static int
+impl_init(const struct spa_handle_factory *factory,
+	  struct spa_handle *handle,
+	  const struct spa_dict *info,
+	  const struct spa_support *support,
+	  uint32_t n_support)
+{
+	struct impl *this;
+	uint32_t i;
+	const char *str;
+	int res;
+
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+
+	handle->get_interface = impl_get_interface;
+	handle->clear = impl_clear, this = (struct impl *) handle;
+
+	for (i = 0; i < n_support; i++) {
+		if (support[i].type == SPA_TYPE_INTERFACE_Log)
+			this->log = support[i].data;
+		else if (support[i].type == SPA_TYPE_INTERFACE_MainLoop)
+			this->main_loop = support[i].data;
+	}
+	if (this->main_loop == NULL) {
+		spa_log_error(this->log, "a main_loop is needed");
+		return -EINVAL;
+	}
+
+	this->device = impl_device;
+	this->dev.log = this->log;
+	this->dev.fd = -1;
+
+	reset_props(&this->props);
+
+	if (info && (str = spa_dict_lookup(info, "device.path"))) {
+		strncpy(this->props.device, str, 63);
+		if ((res = spa_v4l2_open(&this->dev, this->props.device)) < 0)
+			return res;
+		spa_v4l2_close(&this->dev);
+	}
+
+	return 0;
+}
+
+static const struct spa_interface_info impl_interfaces[] = {
+	{SPA_TYPE_INTERFACE_Device,},
+};
+
+static int impl_enum_interface_info(const struct spa_handle_factory *factory,
+				    const struct spa_interface_info **info,
+				    uint32_t *index)
+{
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(info != NULL, -EINVAL);
+	spa_return_val_if_fail(index != NULL, -EINVAL);
+
+	if (*index >= SPA_N_ELEMENTS(impl_interfaces))
+		return 0;
+
+	*info = &impl_interfaces[(*index)++];
+
+	return 1;
+}
+
+const struct spa_handle_factory spa_v4l2_device_factory = {
+	SPA_VERSION_HANDLE_FACTORY,
+	NAME,
+	NULL,
+	impl_get_size,
+	impl_init,
+	impl_enum_interface_info,
+};