Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 176 insertions, 0 deletions

diff --git a/sound/core/seq/seq_system.c b/sound/core/seq/seq_system.c
new file mode 100644
index 000000000..32c2d9b57
--- /dev/null
+++ b/sound/core/seq/seq_system.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   ALSA sequencer System services Client
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include "seq_system.h"
+#include "seq_timer.h"
+#include "seq_queue.h"
+
+/* internal client that provide system services, access to timer etc. */
+
+/*
+ * Port "Timer"
+ *      - send tempo /start/stop etc. events to this port to manipulate the 
+ *        queue's timer. The queue address is specified in
+ *	  data.queue.queue.
+ *      - this port supports subscription. The received timer events are 
+ *        broadcasted to all subscribed clients. The modified tempo
+ *	  value is stored on data.queue.value.
+ *	  The modifier client/port is not send.
+ *
+ * Port "Announce"
+ *      - does not receive message
+ *      - supports supscription. For each client or port attaching to or 
+ *        detaching from the system an announcement is send to the subscribed
+ *        clients.
+ *
+ * Idea: the subscription mechanism might also work handy for distributing 
+ * synchronisation and timing information. In this case we would ideally have
+ * a list of subscribers for each type of sync (time, tick), for each timing
+ * queue.
+ *
+ * NOTE: the queue to be started, stopped, etc. must be specified
+ *	 in data.queue.addr.queue field.  queue is used only for
+ *	 scheduling, and no longer referred as affected queue.
+ *	 They are used only for timer broadcast (see above).
+ *							-- iwai
+ */
+
+
+/* client id of our system client */
+static int sysclient = -1;
+
+/* port id numbers for this client */
+static int announce_port = -1;
+
+
+
+/* fill standard header data, source port & channel are filled in */
+static int setheader(struct snd_seq_event * ev, int client, int port)
+{
+	if (announce_port < 0)
+		return -ENODEV;
+
+	memset(ev, 0, sizeof(struct snd_seq_event));
+
+	ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+	ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
+
+	ev->source.client = sysclient;
+	ev->source.port = announce_port;
+	ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+
+	/* fill data */
+	/*ev->data.addr.queue = SNDRV_SEQ_ADDRESS_UNKNOWN;*/
+	ev->data.addr.client = client;
+	ev->data.addr.port = port;
+
+	return 0;
+}
+
+
+/* entry points for broadcasting system events */
+void snd_seq_system_broadcast(int client, int port, int type)
+{
+	struct snd_seq_event ev;
+	
+	if (setheader(&ev, client, port) < 0)
+		return;
+	ev.type = type;
+	snd_seq_kernel_client_dispatch(sysclient, &ev, 0, 0);
+}
+
+/* entry points for broadcasting system events */
+int snd_seq_system_notify(int client, int port, struct snd_seq_event *ev)
+{
+	ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+	ev->source.client = sysclient;
+	ev->source.port = announce_port;
+	ev->dest.client = client;
+	ev->dest.port = port;
+	return snd_seq_kernel_client_dispatch(sysclient, ev, 0, 0);
+}
+
+/* call-back handler for timer events */
+static int event_input_timer(struct snd_seq_event * ev, int direct, void *private_data, int atomic, int hop)
+{
+	return snd_seq_control_queue(ev, atomic, hop);
+}
+
+/* register our internal client */
+int __init snd_seq_system_client_init(void)
+{
+	struct snd_seq_port_callback pcallbacks;
+	struct snd_seq_port_info *port;
+	int err;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	memset(&pcallbacks, 0, sizeof(pcallbacks));
+	pcallbacks.owner = THIS_MODULE;
+	pcallbacks.event_input = event_input_timer;
+
+	/* register client */
+	sysclient = snd_seq_create_kernel_client(NULL, 0, "System");
+	if (sysclient < 0) {
+		kfree(port);
+		return sysclient;
+	}
+
+	/* register timer */
+	strcpy(port->name, "Timer");
+	port->capability = SNDRV_SEQ_PORT_CAP_WRITE; /* accept queue control */
+	port->capability |= SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast */
+	port->kernel = &pcallbacks;
+	port->type = 0;
+	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+	port->addr.client = sysclient;
+	port->addr.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
+	err = snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT,
+					port);
+	if (err < 0)
+		goto error_port;
+
+	/* register announcement port */
+	strcpy(port->name, "Announce");
+	port->capability = SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast only */
+	port->kernel = NULL;
+	port->type = 0;
+	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+	port->addr.client = sysclient;
+	port->addr.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
+	err = snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT,
+					port);
+	if (err < 0)
+		goto error_port;
+	announce_port = port->addr.port;
+
+	kfree(port);
+	return 0;
+
+ error_port:
+	snd_seq_system_client_done();
+	kfree(port);
+	return err;
+}
+
+
+/* unregister our internal client */
+void snd_seq_system_client_done(void)
+{
+	int oldsysclient = sysclient;
+
+	if (oldsysclient >= 0) {
+		sysclient = -1;
+		announce_port = -1;
+		snd_seq_delete_kernel_client(oldsysclient);
+	}
+}