From abe342c13b3d2a6523eccc35ff4a9d124e48cc59 Mon Sep 17 00:00:00 2001 From: Sudheer Papothi Date: Fri, 29 Jan 2016 02:40:28 +0530 Subject: [PATCH] ALSA: PCM: User contol API implementation Introduced a new helper function snd_pcm_add_usr_ctls() to create control elements representing the user control for each PCM (sub)stream Signed-off-by: Jayasena Sangaraboina Signed-off-by: Banajit Goswami Signed-off-by: Sudheer Papothi --- include/sound/pcm.h | 25 ++++++++++++ sound/core/pcm.c | 4 ++ sound/core/pcm_lib.c | 93 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 122 insertions(+) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 048b456ca32d..d27aed5c6f4e 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -519,6 +519,7 @@ struct snd_pcm_str { #endif struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */ struct snd_kcontrol *vol_kctl; /* volume controls */ + struct snd_kcontrol *usr_kctl; /* user controls */ struct device dev; }; @@ -1435,6 +1436,30 @@ int snd_pcm_add_volume_ctls(struct snd_pcm *pcm, int stream, unsigned long private_value, struct snd_pcm_volume **info_ret); +/* + * PCM User control API + */ +/* array element of usr elem */ +struct snd_pcm_usr_elem { + int val[128]; +}; + +/* pp information; retrieved via snd_kcontrol_chip() */ +struct snd_pcm_usr { + struct snd_pcm *pcm; /* assigned PCM instance */ + int stream; /* PLAYBACK or CAPTURE */ + struct snd_kcontrol *kctl; + const struct snd_pcm_usr_elem *usr; + int max_length; + void *private_data; /* optional: private data pointer */ +}; + +int snd_pcm_add_usr_ctls(struct snd_pcm *pcm, int stream, + const struct snd_pcm_usr_elem *usr, + int max_length, int max_control_str_len, + unsigned long private_value, + struct snd_pcm_usr **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 e43571e70ef6..019751a83e25 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -1143,6 +1143,10 @@ static int snd_pcm_dev_disconnect(struct snd_device *device) snd_ctl_remove(pcm->card, pcm->streams[cidx].vol_kctl); pcm->streams[cidx].vol_kctl = NULL; } + if (pcm->streams[cidx].usr_kctl) { + snd_ctl_remove(pcm->card, pcm->streams[cidx].usr_kctl); + pcm->streams[cidx].usr_kctl = NULL; + } } mutex_unlock(&pcm->open_mutex); mutex_unlock(®ister_mutex); diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 0632ebf0d971..9b17cc9bd459 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -42,6 +42,7 @@ #endif #define STRING_LENGTH_OF_INT 12 +#define MAX_USR_CTRL_CNT 128 /* * fill ring buffer with silence @@ -2728,3 +2729,95 @@ int snd_pcm_add_volume_ctls(struct snd_pcm *pcm, int stream, return 0; } EXPORT_SYMBOL_GPL(snd_pcm_add_volume_ctls); + +static int pcm_usr_ctl_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; + uinfo->count = MAX_USR_CTRL_CNT; + uinfo->value.integer.min = 0; + uinfo->value.integer.max = INT_MAX; + return 0; +} + +static void pcm_usr_ctl_private_free(struct snd_kcontrol *kcontrol) +{ + struct snd_pcm_usr *info = snd_kcontrol_chip(kcontrol); + info->pcm->streams[info->stream].usr_kctl = NULL; + kfree(info); +} + +/** + * snd_pcm_add_usr_ctls - create user control elements + * @pcm: the assigned PCM instance + * @stream: stream direction + * @max_length: the max length of the user parameter of stream + * @private_value: the value passed to each kcontrol's private_value field + * @info_ret: store struct snd_pcm_usr instance if non-NULL + * + * Create usr control elements assigned to the given PCM stream(s). + * Returns zero if succeed, or a negative error value. + */ +int snd_pcm_add_usr_ctls(struct snd_pcm *pcm, int stream, + const struct snd_pcm_usr_elem *usr, + int max_length, int max_kctrl_str_len, + unsigned long private_value, + struct snd_pcm_usr **info_ret) +{ + struct snd_pcm_usr *info; + struct snd_kcontrol_new knew = { + .iface = SNDRV_CTL_ELEM_IFACE_MIXER, + .access = SNDRV_CTL_ELEM_ACCESS_READWRITE, + .info = pcm_usr_ctl_info, + }; + int err; + char *buf; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + pr_err("%s: snd_pcm_usr alloc failed\n", __func__); + return -ENOMEM; + } + info->pcm = pcm; + info->stream = stream; + info->usr = usr; + info->max_length = max_length; + buf = kzalloc(max_kctrl_str_len, GFP_KERNEL); + if (!buf) { + pr_err("%s: buffer allocation failed\n", __func__); + kfree(info); + return -ENOMEM; + } + knew.name = buf; + if (stream == SNDRV_PCM_STREAM_PLAYBACK) + snprintf(buf, max_kctrl_str_len, "%s %d %s", + "Playback", pcm->device, "User kcontrol"); + else + snprintf(buf, max_kctrl_str_len, "%s %d %s", + "Capture", pcm->device, "User kcontrol"); + 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); + pr_err("%s: snd_ctl_new failed\n", __func__); + return -ENOMEM; + } + info->kctl->private_free = pcm_usr_ctl_private_free; + err = snd_ctl_add(pcm->card, info->kctl); + if (err < 0) { + kfree(info); + kfree(knew.name); + pr_err("%s: snd_ctl_add failed:%d\n", __func__, + err); + return -ENOMEM; + } + pcm->streams[stream].usr_kctl = info->kctl; + if (info_ret) + *info_ret = info; + kfree(knew.name); + return 0; +} +EXPORT_SYMBOL(snd_pcm_add_usr_ctls);