[ALSA] Control API - TLV implementation for additional information like dB scale
This patch implements a TLV mechanism to transfer an additional information
like dB scale to the user space. The types might be extended in future.
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/include/sound/asound.h b/include/sound/asound.h
index 41885f4..76a2040 100644
--- a/include/sound/asound.h
+++ b/include/sound/asound.h
@@ -688,7 +688,7 @@
* *
****************************************************************************/
-#define SNDRV_CTL_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 3)
+#define SNDRV_CTL_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 4)
struct snd_ctl_card_info {
int card; /* card number */
@@ -818,6 +818,12 @@
unsigned char reserved[128-sizeof(struct timespec)];
};
+struct snd_ctl_tlv {
+ unsigned int numid; /* control element numeric identification */
+ unsigned int length; /* in bytes aligned to 4 */
+ unsigned int tlv[0]; /* first TLV */
+};
+
enum {
SNDRV_CTL_IOCTL_PVERSION = _IOR('U', 0x00, int),
SNDRV_CTL_IOCTL_CARD_INFO = _IOR('U', 0x01, struct snd_ctl_card_info),
@@ -831,6 +837,7 @@
SNDRV_CTL_IOCTL_ELEM_ADD = _IOWR('U', 0x17, struct snd_ctl_elem_info),
SNDRV_CTL_IOCTL_ELEM_REPLACE = _IOWR('U', 0x18, struct snd_ctl_elem_info),
SNDRV_CTL_IOCTL_ELEM_REMOVE = _IOWR('U', 0x19, struct snd_ctl_elem_id),
+ SNDRV_CTL_IOCTL_TLV_READ = _IOWR('U', 0x1a, struct snd_ctl_tlv),
SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE = _IOWR('U', 0x20, int),
SNDRV_CTL_IOCTL_HWDEP_INFO = _IOR('U', 0x21, struct snd_hwdep_info),
SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE = _IOR('U', 0x30, int),
diff --git a/include/sound/control.h b/include/sound/control.h
index 2489b1e..a93a58d 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -42,6 +42,7 @@
snd_kcontrol_info_t *info;
snd_kcontrol_get_t *get;
snd_kcontrol_put_t *put;
+ unsigned int *tlv;
unsigned long private_value;
};
@@ -58,6 +59,7 @@
snd_kcontrol_info_t *info;
snd_kcontrol_get_t *get;
snd_kcontrol_put_t *put;
+ unsigned int *tlv;
unsigned long private_value;
void *private_data;
void (*private_free)(struct snd_kcontrol *kcontrol);
diff --git a/include/sound/tlv.h b/include/sound/tlv.h
new file mode 100644
index 0000000..b826e1d
--- /dev/null
+++ b/include/sound/tlv.h
@@ -0,0 +1,43 @@
+#ifndef __SOUND_TLV_H
+#define __SOUND_TLV_H
+
+/*
+ * Advanced Linux Sound Architecture - ALSA - Driver
+ * Copyright (c) 2006 by Jaroslav Kysela <perex@suse.cz>
+ *
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/*
+ * TLV structure is right behind the struct snd_ctl_tlv:
+ * unsigned int type - see SNDRV_CTL_TLVT_*
+ * unsigned int length
+ * .... data aligned to sizeof(unsigned int), use
+ * block_length = (length + (sizeof(unsigned int) - 1)) &
+ * ~(sizeof(unsigned int) - 1)) ....
+ */
+
+#define SNDRV_CTL_TLVT_CONTAINER 0 /* one level down - group of TLVs */
+#define SNDRV_CTL_TLVT_DB_SCALE 1 /* dB scale */
+
+#define DECLARE_TLV_DB_SCALE(name, min, step, mute) \
+unsigned int name[] = { \
+ SNDRV_CTL_TLVT_DB_SCALE, 2 * sizeof(unsigned int), \
+ (min), ((step) & 0xffff) | ((mute) ? 0x10000 : 0) \
+}
+
+#endif /* __SOUND_TLV_H */
diff --git a/sound/core/control.c b/sound/core/control.c
index bb397ea..e9c8854 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -241,6 +241,7 @@
kctl.info = ncontrol->info;
kctl.get = ncontrol->get;
kctl.put = ncontrol->put;
+ kctl.tlv = ncontrol->tlv;
kctl.private_value = ncontrol->private_value;
kctl.private_data = private_data;
return snd_ctl_new(&kctl, access);
@@ -1067,6 +1068,40 @@
return 0;
}
+static int snd_ctl_tlv_read(struct snd_card *card,
+ struct snd_ctl_tlv __user *_tlv)
+{
+ struct snd_ctl_tlv tlv;
+ struct snd_kcontrol *kctl;
+ unsigned int len;
+ int err = 0;
+
+ if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
+ return -EFAULT;
+ if (tlv.length < sizeof(unsigned int) * 3)
+ return -EINVAL;
+ down_read(&card->controls_rwsem);
+ kctl = snd_ctl_find_numid(card, tlv.numid);
+ if (kctl == NULL) {
+ err = -ENOENT;
+ goto __kctl_end;
+ }
+ if (kctl->tlv == NULL) {
+ err = -ENXIO;
+ goto __kctl_end;
+ }
+ len = kctl->tlv[1] + 2 * sizeof(unsigned int);
+ if (tlv.length < len) {
+ err = -ENOMEM;
+ goto __kctl_end;
+ }
+ if (copy_to_user(_tlv->tlv, kctl->tlv, len))
+ err = -EFAULT;
+ __kctl_end:
+ up_read(&card->controls_rwsem);
+ return err;
+}
+
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct snd_ctl_file *ctl;
@@ -1086,11 +1121,11 @@
case SNDRV_CTL_IOCTL_CARD_INFO:
return snd_ctl_card_info(card, ctl, cmd, argp);
case SNDRV_CTL_IOCTL_ELEM_LIST:
- return snd_ctl_elem_list(ctl->card, argp);
+ return snd_ctl_elem_list(card, argp);
case SNDRV_CTL_IOCTL_ELEM_INFO:
return snd_ctl_elem_info_user(ctl, argp);
case SNDRV_CTL_IOCTL_ELEM_READ:
- return snd_ctl_elem_read_user(ctl->card, argp);
+ return snd_ctl_elem_read_user(card, argp);
case SNDRV_CTL_IOCTL_ELEM_WRITE:
return snd_ctl_elem_write_user(ctl, argp);
case SNDRV_CTL_IOCTL_ELEM_LOCK:
@@ -1105,6 +1140,8 @@
return snd_ctl_elem_remove(ctl, argp);
case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
return snd_ctl_subscribe_events(ctl, ip);
+ case SNDRV_CTL_IOCTL_TLV_READ:
+ return snd_ctl_tlv_read(card, argp);
case SNDRV_CTL_IOCTL_POWER:
return -ENOPROTOOPT;
case SNDRV_CTL_IOCTL_POWER_STATE:
diff --git a/sound/pci/ca0106/ca0106_mixer.c b/sound/pci/ca0106/ca0106_mixer.c
index 146eed70d..35309b3 100644
--- a/sound/pci/ca0106/ca0106_mixer.c
+++ b/sound/pci/ca0106/ca0106_mixer.c
@@ -70,9 +70,12 @@
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include <sound/info.h>
+#include <sound/tlv.h>
#include "ca0106.h"
+static DECLARE_TLV_DB_SCALE(snd_ca0106_db_scale, -5150, 75, 1);
+
static int snd_ca0106_shared_spdif_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
@@ -472,6 +475,7 @@
.info = snd_ca0106_volume_info, \
.get = snd_ca0106_volume_get, \
.put = snd_ca0106_volume_put, \
+ .tlv = snd_ca0106_db_scale, \
.private_value = ((chid) << 8) | (reg) \
}