pipewire: device: Add a send_command method

For now, useful for sending custom commands to devices. Using this from
the command line might look something like:

```sh
$ pw-cli send-command <device-id> VolumeControl '{"volumeUp": <route-id>}'
```

src/modules/module-client-device/protocol-native.c

@@ -200,6 +200,36 @@ static int device_demarshal_set_param(void *object, const struct pw_protocol_nat
 	return 0;
 }
 
+static int device_marshal_send_command(void *object,
+		const struct spa_command *command)
+{
+	struct pw_resource *resource = object;
+	struct spa_pod_builder *b;
+
+	b = pw_protocol_native_begin_resource(resource, SPA_DEVICE_METHOD_SEND_COMMAND, NULL);
+
+	spa_pod_builder_add_struct(b,
+			SPA_POD_Pod(command));
+
+	return pw_protocol_native_end_resource(resource, b);
+}
+
+static int device_demarshal_send_command(void *object, const struct pw_protocol_native_message *msg)
+{
+	struct pw_proxy *proxy = object;
+	struct spa_pod_parser prs;
+	struct spa_command *command;
+
+	spa_pod_parser_init(&prs, msg->data, msg->size);
+	if (spa_pod_parser_get_struct(&prs,
+			SPA_POD_Pod(&command)) < 0)
+		return -EINVAL;
+
+	pw_proxy_notify(proxy, struct spa_device_methods, send_command, 1,
+					command);
+	return 0;
+}
+
 static void device_marshal_info(void *data,
 		const struct spa_device_info *info)
 {
@@ -482,7 +512,8 @@ static const struct spa_device_methods pw_protocol_native_device_method_marshal
 	.add_listener = &device_marshal_add_listener,
 	.sync = &device_marshal_sync,
 	.enum_params = &device_marshal_enum_params,
-	.set_param = &device_marshal_set_param
+	.set_param = &device_marshal_set_param,
+	.send_command = &device_marshal_send_command,
 };
 
 static const struct pw_protocol_native_demarshal
@@ -492,6 +523,7 @@ pw_protocol_native_device_method_demarshal[SPA_DEVICE_METHOD_NUM] =
 	[SPA_DEVICE_METHOD_SYNC] = { &device_demarshal_sync, 0 },
 	[SPA_DEVICE_METHOD_ENUM_PARAMS] = { &device_demarshal_enum_params, 0 },
 	[SPA_DEVICE_METHOD_SET_PARAM] = { &device_demarshal_set_param, 0 },
+	[SPA_DEVICE_METHOD_SEND_COMMAND] = { &device_demarshal_send_command, 0 },
 };
 
 static const struct spa_device_events pw_protocol_native_device_event_marshal = {

src/modules/module-protocol-native/protocol-native.c

@@ -1056,6 +1056,34 @@ static int device_demarshal_set_param(void *object, const struct pw_protocol_nat
 	return pw_resource_notify(resource, struct pw_device_methods, set_param, 0, id, flags, param);
 }
 
+static int device_marshal_send_command(void *object, const struct spa_command *command)
+{
+	struct pw_proxy *proxy = object;
+	struct spa_pod_builder *b;
+
+	b = pw_protocol_native_begin_proxy(proxy, PW_NODE_METHOD_SEND_COMMAND, NULL);
+	spa_pod_builder_add_struct(b,
+			SPA_POD_Pod(command));
+	return pw_protocol_native_end_proxy(proxy, b);
+}
+
+static int device_demarshal_send_command(void *object, const struct pw_protocol_native_message *msg)
+{
+	struct pw_resource *resource = object;
+	struct spa_pod_parser prs;
+	struct spa_command *command;
+
+	spa_pod_parser_init(&prs, msg->data, msg->size);
+	if (spa_pod_parser_get_struct(&prs,
+				SPA_POD_Pod(&command)) < 0)
+		return -EINVAL;
+
+	if (command == NULL)
+		return -EINVAL;
+
+	return pw_resource_notify(resource, struct pw_device_methods, send_command, 1, command);
+}
+
 static int factory_method_marshal_add_listener(void *object,
 			struct spa_hook *listener,
 			const struct pw_factory_events *events,
@@ -2110,6 +2138,7 @@ static const struct pw_device_methods pw_protocol_native_device_method_marshal =
 	.subscribe_params = &device_marshal_subscribe_params,
 	.enum_params = &device_marshal_enum_params,
 	.set_param = &device_marshal_set_param,
+	.send_command = &device_marshal_send_command,
 };
 
 static const struct pw_protocol_native_demarshal
@@ -2118,6 +2147,7 @@ pw_protocol_native_device_method_demarshal[PW_DEVICE_METHOD_NUM] = {
 	[PW_DEVICE_METHOD_SUBSCRIBE_PARAMS] = { &device_demarshal_subscribe_params, 0, },
 	[PW_DEVICE_METHOD_ENUM_PARAMS] = { &device_demarshal_enum_params, 0, },
 	[PW_DEVICE_METHOD_SET_PARAM] = { &device_demarshal_set_param, PW_PERM_W, },
+	[PW_DEVICE_METHOD_SEND_COMMAND] = { &device_demarshal_send_command, PW_PERM_W, },
 };
 
 static const struct pw_device_events pw_protocol_native_device_event_marshal = {

src/pipewire/device.h

@@ -5,6 +5,7 @@
 #ifndef PIPEWIRE_DEVICE_H
 #define PIPEWIRE_DEVICE_H
 
+#include <spa/pod/command.h>
 #include <spa/utils/defs.h>
 #include <spa/utils/hook.h>
 
@@ -92,11 +93,12 @@ struct pw_device_events {
 #define PW_DEVICE_METHOD_SUBSCRIBE_PARAMS	1
 #define PW_DEVICE_METHOD_ENUM_PARAMS		2
 #define PW_DEVICE_METHOD_SET_PARAM		3
-#define PW_DEVICE_METHOD_NUM			4
+#define PW_DEVICE_METHOD_SEND_COMMAND		4
+#define PW_DEVICE_METHOD_NUM			5
 
 /** Device methods */
 struct pw_device_methods {
-#define PW_VERSION_DEVICE_METHODS	0
+#define PW_VERSION_DEVICE_METHODS	1
 	uint32_t version;
 
 	int (*add_listener) (void *object,
@@ -143,6 +145,15 @@ struct pw_device_methods {
 	 */
 	int (*set_param) (void *object, uint32_t id, uint32_t flags,
 			  const struct spa_pod *param);
+
+	/**
+	 * Send a command to the device
+	 *
+	 * \param command the command to send
+	 *
+	 * This requires X and W permissions on the device.
+	 */
+	int (*send_command) (void *object, const struct spa_command *command);
 };
 
 /** \copydoc pw_device_methods.add_listener
@@ -183,6 +194,13 @@ PW_API_DEVICE_IMPL int pw_device_set_param(struct pw_device *object, uint32_t id
 			pw_device, (struct spa_interface*)object, set_param, 0,
 			id, flags, param);
 }
+/** \copydoc pw_device_methods.send_command
+ * \sa pw_device_methods.send_command */
+PW_API_DEVICE_IMPL int pw_device_send_command(struct pw_device *object, const struct spa_command *command)
+{
+	return spa_api_method_r(int, -ENOTSUP,
+			pw_device, (struct spa_interface*)object, send_command, 0, command);
+}
 
 /**
  * \}

src/pipewire/impl-device.c

@@ -529,11 +529,30 @@ static int device_set_param(void *object, uint32_t id, uint32_t flags,
 	return res;
 }
 
+static int device_send_command(void *object, const struct spa_command *command)
+{
+	struct resource_data *data = object;
+	struct pw_impl_device *device = data->device;
+	uint32_t id = SPA_DEVICE_COMMAND_ID(command);
+	int res;
+
+	pw_log_debug("%p: got command %d (%s)", device, id,
+		    spa_debug_type_find_name(spa_type_device_command_id, id));
+
+	switch (id) {
+	default:
+		res = spa_device_send_command(device->device, command);
+		break;
+	}
+	return res;
+}
+
 static const struct pw_device_methods device_methods = {
 	PW_VERSION_DEVICE_METHODS,
 	.subscribe_params = device_subscribe_params,
 	.enum_params = device_enum_params,
-	.set_param = device_set_param
+	.set_param = device_set_param,
+	.send_command = device_send_command,
 };
 
 static int

src/tests/test-interfaces.c

@@ -153,6 +153,7 @@ static void test_device_abi(void)
 			const struct spa_pod *filter);
 		int (*set_param) (void *object, uint32_t id, uint32_t flags,
 			const struct spa_pod *param);
+		int (*send_command) (void *object, const struct spa_command *command);
 	} methods = { PW_VERSION_DEVICE_METHODS, };
 	struct {
 		uint32_t version;
@@ -167,7 +168,8 @@ static void test_device_abi(void)
 	TEST_FUNC(m, methods, subscribe_params);
 	TEST_FUNC(m, methods, enum_params);
 	TEST_FUNC(m, methods, set_param);
-	spa_assert_se(PW_VERSION_DEVICE_METHODS == 0);
+	TEST_FUNC(m, methods, send_command);
+	spa_assert_se(PW_VERSION_DEVICE_METHODS == 1);
 	spa_assert_se(sizeof(m) == sizeof(methods));
 
 	TEST_FUNC(e, events, version);

src/tools/pw-cli.c

@@ -2047,6 +2047,8 @@ static bool do_send_command(struct data *data, const char *cmd, char *args, char
 
 	if (spa_streq(global->type, PW_TYPE_INTERFACE_Node)) {
 		ti = spa_debug_type_find_short(spa_type_node_command_id, a[1]);
+	} else if (spa_streq(global->type, PW_TYPE_INTERFACE_Device)) {
+		ti = spa_debug_type_find_short(spa_type_device_command_id, a[1]);
 	} else {
 		*error = spa_aprintf("send-command not implemented on object %d type:%s",
 				atoi(a[0]), global->type);
@@ -2054,7 +2056,7 @@ static bool do_send_command(struct data *data, const char *cmd, char *args, char
 	}
 
 	if (ti == NULL) {
-		*error = spa_aprintf("%s: unknown node command type: %s", cmd, a[1]);
+		*error = spa_aprintf("%s: unknown command type: %s", cmd, a[1]);
 		return false;
 	}
 	if ((res = spa_json_to_pod(&b.b, 0, ti, a[2], strlen(a[2]))) < 0) {
@@ -2067,7 +2069,12 @@ static bool do_send_command(struct data *data, const char *cmd, char *args, char
 	}
 	spa_debug_pod(0, NULL, pod);
 
-	pw_node_send_command((struct pw_node*)global->proxy, (struct spa_command*)pod);
+	if (spa_streq(global->type, PW_TYPE_INTERFACE_Node)) {
+		pw_node_send_command((struct pw_node*)global->proxy, (struct spa_command*)pod);
+	} else if (spa_streq(global->type, PW_TYPE_INTERFACE_Device)) {
+		pw_device_send_command((struct pw_device*)global->proxy, (struct spa_command*)pod);
+	}
+
 	return true;
 }