ALSA: PCM: volume API implementation
Introduced a new helper function snd_pcm_add_volume_ctls() to
create control elements representing the volume for each PCM
(sub)stream.
This patch also squashes the logic implemented by below change-
ASoC: Fix freed memory access of pcm stream kctl
Consider sound card instantiate fails due to
audrx init failure. In such case, all dais/ctls
are de-registered and freed. But as part of it,
access to unregistered ctls for pcm_chmap and similar
controls result in crash. Ctls are freed at disconnection
but the disconnect is called only when it was registered.
CRs-Fixed: 1038054
Change-Id: Ief8817b4ec000c058d46aa021977b7c6003c0011
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>
Signed-off-by: Damir Didjusto <damird@codeaurora.org>
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index b4db06a..df5ca27 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -518,6 +518,7 @@
#endif
#endif
struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */
+ struct snd_kcontrol *vol_kctl; /* volume controls */
struct device dev;
};
@@ -1412,6 +1413,30 @@
return 1ULL << (__force int) pcm_format;
}
+/*
+ * PCM Volume control API
+ */
+/* array element of volume */
+struct snd_pcm_volume_elem {
+ int volume;
+};
+
+/* pp information; retrieved via snd_kcontrol_chip() */
+struct snd_pcm_volume {
+ struct snd_pcm *pcm; /* assigned PCM instance */
+ int stream; /* PLAYBACK or CAPTURE */
+ struct snd_kcontrol *kctl;
+ const struct snd_pcm_volume_elem *volume;
+ int max_length;
+ void *private_data; /* optional: private data pointer */
+};
+
+int snd_pcm_add_volume_ctls(struct snd_pcm *pcm, int stream,
+ const struct snd_pcm_volume_elem *volume,
+ int max_length,
+ unsigned long private_value,
+ struct snd_pcm_volume **info_ret);
+
/* printk helpers */
#define pcm_err(pcm, fmt, args...) \
dev_err((pcm)->card->dev, fmt, ##args)
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 8e980aa..1155ecb 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -855,6 +855,10 @@
snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
pstr->chmap_kctl = NULL;
}
+ if (pstr->vol_kctl) {
+ snd_ctl_remove(pstr->pcm->card, pstr->vol_kctl);
+ pstr->vol_kctl = NULL;
+ }
}
static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 294230d..b57fc6e 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -41,6 +41,8 @@
#define trace_hw_ptr_error(substream, reason)
#endif
+#define STRING_LENGTH_OF_INT 12
+
/*
* fill ring buffer with silence
* runtime->silence_start: starting pointer to silence area
@@ -2568,6 +2570,24 @@
kfree(info);
}
+static int pcm_volume_ctl_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = 0x2000;
+ return 0;
+}
+
+static void pcm_volume_ctl_private_free(struct snd_kcontrol *kcontrol)
+{
+ struct snd_pcm_volume *info = snd_kcontrol_chip(kcontrol);
+
+ info->pcm->streams[info->stream].vol_kctl = NULL;
+ kfree(info);
+}
+
/**
* snd_pcm_add_chmap_ctls - create channel-mapping control elements
* @pcm: the assigned PCM instance
@@ -2629,3 +2649,74 @@
return 0;
}
EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
+
+/**
+ * snd_pcm_add_volume_ctls - create volume control elements
+ * @pcm: the assigned PCM instance
+ * @stream: stream direction
+ * @max_length: the max length of the volume parameter of stream
+ * @private_value: the value passed to each kcontrol's private_value field
+ * @info_ret: store struct snd_pcm_volume instance if non-NULL
+ *
+ * Create volume control elements assigned to the given PCM stream(s).
+ * Returns zero if succeed, or a negative error value.
+ */
+int snd_pcm_add_volume_ctls(struct snd_pcm *pcm, int stream,
+ const struct snd_pcm_volume_elem *volume,
+ int max_length,
+ unsigned long private_value,
+ struct snd_pcm_volume **info_ret)
+{
+ struct snd_pcm_volume *info;
+ struct snd_kcontrol_new knew = {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .access = SNDRV_CTL_ELEM_ACCESS_TLV_READ |
+ SNDRV_CTL_ELEM_ACCESS_READWRITE,
+ .info = pcm_volume_ctl_info,
+ };
+ int err;
+ int size;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ info->pcm = pcm;
+ info->stream = stream;
+ info->volume = volume;
+ info->max_length = max_length;
+ size = sizeof("Playback ") + sizeof(" Volume") +
+ STRING_LENGTH_OF_INT*sizeof(char) + 1;
+ knew.name = kzalloc(size, GFP_KERNEL);
+ if (!knew.name) {
+ kfree(info);
+ return -ENOMEM;
+ }
+ if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+ snprintf((char *)knew.name, size, "%s %d %s",
+ "Playback", pcm->device, "Volume");
+ else
+ snprintf((char *)knew.name, size, "%s %d %s",
+ "Capture", pcm->device, "Volume");
+ knew.device = pcm->device;
+ knew.count = pcm->streams[stream].substream_count;
+ knew.private_value = private_value;
+ info->kctl = snd_ctl_new1(&knew, info);
+ if (!info->kctl) {
+ kfree(info);
+ kfree(knew.name);
+ return -ENOMEM;
+ }
+ info->kctl->private_free = pcm_volume_ctl_private_free;
+ err = snd_ctl_add(pcm->card, info->kctl);
+ if (err < 0) {
+ kfree(info);
+ kfree(knew.name);
+ return -ENOMEM;
+ }
+ pcm->streams[stream].vol_kctl = info->kctl;
+ if (info_ret)
+ *info_ret = info;
+ kfree(knew.name);
+ return 0;
+}
+EXPORT_SYMBOL(snd_pcm_add_volume_ctls);