[alsa-devel] [RFC PATCH 01/11] ALSA: implement MEDIA_IOC_DEVICE_INFO
Clemens Ladisch
clemens at ladisch.de
Tue Aug 28 00:29:33 CEST 2012
Add a callback to snd_card to allow card drivers to return driver-
specific information.
Signed-off-by: Clemens Ladisch <clemens at ladisch.de>
---
include/sound/core.h | 5 +++
include/sound/media.h | 50 ++++++++++++++++++++++++++++++++
sound/core/Kconfig | 7 +++++
sound/core/Makefile | 1 +
sound/core/media.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++
sound/core/sound.c | 3 ++
6 files changed, 142 insertions(+), 0 deletions(-)
create mode 100644 include/sound/media.h
create mode 100644 sound/core/media.c
diff --git a/include/sound/core.h b/include/sound/core.h
index bc05668..5eca6f5 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -42,6 +42,7 @@ struct pci_dev;
struct module;
struct device;
struct device_attribute;
+struct snd_media_card_ops;
/* device allocation stuff */
@@ -145,6 +146,10 @@ struct snd_card {
struct snd_mixer_oss *mixer_oss;
int mixer_oss_change_count;
#endif
+
+#ifdef CONFIG_SND_MEDIA
+ const struct snd_media_card_ops *media_ops;
+#endif
};
#ifdef CONFIG_PM
diff --git a/include/sound/media.h b/include/sound/media.h
new file mode 100644
index 0000000..d196219
--- /dev/null
+++ b/include/sound/media.h
@@ -0,0 +1,50 @@
+/*
+ * media controller interface for ALSA driver
+ * Copyright (c) Clemens Ladisch <clemens at ladisch.de>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef SOUND_MEDIA_H_INCLUDED
+#define SOUND_MEDIA_H_INCLUDED
+
+#include <linux/init.h>
+
+struct snd_card;
+struct media_device_info;
+
+struct snd_media_card_ops {
+ int (*get_info)(struct snd_card *card, struct media_device_info *info);
+};
+
+#ifdef CONFIG_SND_MEDIA
+
+#define snd_card_set_media_ops(card, ops) ((card)->media_ops = (ops))
+
+void __init snd_media_init(void);
+void __exit snd_media_exit(void);
+
+#else /* CONFIG_SND_MEDIA */
+
+#define snd_card_set_media_ops(card, ops)
+
+static inline void snd_media_init()
+{ }
+static inline void snd_media_exit()
+{ }
+
+#endif /* !CONFIG_SND_MEDIA */
+
+#endif
diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index b413ed0..fadbdf5 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -147,6 +147,13 @@ config SND_SEQ_RTCTIMER_DEFAULT
If in doubt, say Y.
+config SND_MEDIA
+ bool "Media Controller API (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ Say Y here to enable the media controller API, which allows to
+ retrieve the internal topology of sound devices.
+
config SND_DYNAMIC_MINORS
bool "Dynamic device file minor numbers"
help
diff --git a/sound/core/Makefile b/sound/core/Makefile
index 43d4117..b6de542 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile
@@ -9,6 +9,7 @@ snd-$(CONFIG_SND_OSSEMUL) += sound_oss.o info_oss.o
snd-$(CONFIG_SND_VMASTER) += vmaster.o
snd-$(CONFIG_SND_KCTL_JACK) += ctljack.o
snd-$(CONFIG_SND_JACK) += jack.o
+snd-$(CONFIG_SND_MEDIA) += media.o
snd-pcm-objs := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \
pcm_memory.o
diff --git a/sound/core/media.c b/sound/core/media.c
new file mode 100644
index 0000000..6ceb12a
--- /dev/null
+++ b/sound/core/media.c
@@ -0,0 +1,76 @@
+/*
+ * media controller interface for ALSA driver
+ * Copyright (c) Clemens Ladisch <clemens at ladisch.de>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/media.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/media.h>
+
+static int snd_media_device_info(struct snd_card *card,
+ struct media_device_info __user *infop)
+{
+ struct media_device_info info;
+ int err;
+
+ memset(&info, 0, sizeof(info));
+
+ if (card->dev && card->dev->driver)
+ strlcpy(info.driver, card->dev->driver->name, sizeof(info.driver));
+ strlcpy(info.model, card->shortname, sizeof(info.model));
+ info.media_version = MEDIA_API_VERSION;
+
+ if (card->media_ops) {
+ err = card->media_ops->get_info(card, &info);
+ if (err < 0)
+ return err;
+ }
+
+ return copy_to_user(infop, &info, sizeof(info));
+}
+
+static int snd_media_control_ioctl(struct snd_card *card,
+ struct snd_ctl_file *ctl_file,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+
+ switch (cmd) {
+ case MEDIA_IOC_DEVICE_INFO:
+ return snd_media_device_info(card, argp);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+void __init snd_media_init(void)
+{
+ snd_ctl_register_ioctl(snd_media_control_ioctl);
+ snd_ctl_register_ioctl_compat(snd_media_control_ioctl);
+}
+
+void __exit snd_media_exit(void)
+{
+ snd_ctl_unregister_ioctl(snd_media_control_ioctl);
+ snd_ctl_unregister_ioctl_compat(snd_media_control_ioctl);
+}
diff --git a/sound/core/sound.c b/sound/core/sound.c
index 28f3559..7a7721c 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -30,6 +30,7 @@
#include <sound/version.h>
#include <sound/control.h>
#include <sound/initval.h>
+#include <sound/media.h>
#include <linux/kmod.h>
#include <linux/mutex.h>
@@ -467,6 +468,7 @@ static int __init alsa_sound_init(void)
return -ENOMEM;
}
snd_info_minor_register();
+ snd_media_init();
#ifndef MODULE
printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
#endif
@@ -475,6 +477,7 @@ static int __init alsa_sound_init(void)
static void __exit alsa_sound_exit(void)
{
+ snd_media_exit();
snd_info_minor_unregister();
snd_info_done();
unregister_chrdev(major, "alsa");
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