From 2d3391ec0ecca37efb6bc995906292f47522b471 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 27 Jul 2012 18:27:00 +0200 Subject: [PATCH] ALSA: PCM: channel mapping API implementation This patch implements the basic data types for the standard channel mapping API handling. - The definitions of the channel positions and the new TLV types are added in sound/asound.h and sound/tlv.h, so that they can be referred from user-space. - Introduced a new helper function snd_pcm_add_chmap_ctls() to create control elements representing the channel maps for each PCM (sub)stream. - Some standard pre-defined channel maps are provided for convenience. Signed-off-by: Takashi Iwai --- include/sound/asound.h | 30 ++++++ include/sound/pcm.h | 48 +++++++++ include/sound/tlv.h | 8 ++ sound/core/pcm.c | 4 + sound/core/pcm_lib.c | 215 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 305 insertions(+) diff --git a/include/sound/asound.h b/include/sound/asound.h index 0876a1e76aef..376e75632e07 100644 --- a/include/sound/asound.h +++ b/include/sound/asound.h @@ -472,6 +472,36 @@ enum { SNDRV_PCM_TSTAMP_TYPE_LAST = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC, }; +/* channel positions */ +enum { + SNDRV_CHMAP_UNKNOWN = 0, + SNDRV_CHMAP_FL, /* front left */ + SNDRV_CHMAP_FC, /* front center */ + SNDRV_CHMAP_FR, /* front right */ + SNDRV_CHMAP_FLC, /* front left center */ + SNDRV_CHMAP_FRC, /* front right center */ + SNDRV_CHMAP_RL, /* rear left */ + SNDRV_CHMAP_RC, /* rear center */ + SNDRV_CHMAP_RR, /* rear right */ + SNDRV_CHMAP_RLC, /* rear left center */ + SNDRV_CHMAP_RRC, /* rear right center */ + SNDRV_CHMAP_SL, /* side left */ + SNDRV_CHMAP_SR, /* side right */ + SNDRV_CHMAP_LFE, /* LFE */ + SNDRV_CHMAP_FLW, /* front left wide */ + SNDRV_CHMAP_FRW, /* front right wide */ + SNDRV_CHMAP_FLH, /* front left high */ + SNDRV_CHMAP_FCH, /* front center high */ + SNDRV_CHMAP_FRH, /* front right high */ + SNDRV_CHMAP_TC, /* top center */ + SNDRV_CHMAP_NA, /* N/A, silent */ + SNDRV_CHMAP_LAST = SNDRV_CHMAP_NA, +}; + +#define SNDRV_CHMAP_POSITION_MASK 0xffff +#define SNDRV_CHMAP_PHASE_INVERSE (0x01 << 16) +#define SNDRV_CHMAP_DRIVER_SPEC (0x02 << 16) + #define SNDRV_PCM_IOCTL_PVERSION _IOR('A', 0x00, int) #define SNDRV_PCM_IOCTL_INFO _IOR('A', 0x01, struct snd_pcm_info) #define SNDRV_PCM_IOCTL_TSTAMP _IOW('A', 0x02, int) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index cdca2ab1e711..669c85a7fb03 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -437,6 +437,7 @@ struct snd_pcm_str { struct snd_info_entry *proc_xrun_debug_entry; #endif #endif + struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */ }; struct snd_pcm { @@ -1086,4 +1087,51 @@ static inline const char *snd_pcm_stream_str(struct snd_pcm_substream *substream return "Capture"; } +/* + * PCM channel-mapping control API + */ +/* array element of channel maps */ +struct snd_pcm_chmap_elem { + unsigned char channels; + unsigned char map[15]; +}; + +/* channel map information; retrieved via snd_kcontrol_chip() */ +struct snd_pcm_chmap { + struct snd_pcm *pcm; /* assigned PCM instance */ + int stream; /* PLAYBACK or CAPTURE */ + struct snd_kcontrol *kctl; + const struct snd_pcm_chmap_elem *chmap; + unsigned int max_channels; + unsigned int channel_mask; /* optional: active channels bitmask */ + void *private_data; /* optional: private data pointer */ +}; + +/* get the PCM substream assigned to the given chmap info */ +static inline struct snd_pcm_substream * +snd_pcm_chmap_substream(struct snd_pcm_chmap *info, unsigned int idx) +{ + struct snd_pcm_substream *s; + for (s = info->pcm->streams[info->stream].substream; s; s = s->next) + if (s->number == idx) + return s; + return NULL; +} + +/* ALSA-standard channel maps (RL/RR prior to C/LFE) */ +extern const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[]; +/* Other world's standard channel maps (C/LFE prior to RL/RR) */ +extern const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[]; + +/* bit masks to be passed to snd_pcm_chmap.channel_mask field */ +#define SND_PCM_CHMAP_MASK_24 ((1U << 2) | (1U << 4)) +#define SND_PCM_CHMAP_MASK_246 (SND_PCM_CHMAP_MASK_24 | (1U << 6)) +#define SND_PCM_CHMAP_MASK_2468 (SND_PCM_CHMAP_MASK_246 | (1U << 8)) + +int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream, + const struct snd_pcm_chmap_elem *chmap, + int max_channels, + unsigned long private_value, + struct snd_pcm_chmap **info_ret); + #endif /* __SOUND_PCM_H */ diff --git a/include/sound/tlv.h b/include/sound/tlv.h index a64d8fe3f855..28c65e1ada21 100644 --- a/include/sound/tlv.h +++ b/include/sound/tlv.h @@ -86,4 +86,12 @@ #define TLV_DB_GAIN_MUTE -9999999 +/* + * channel-mapping TLV items + * TLV length must match with num_channels + */ +#define SNDRV_CTL_TLVT_CHMAP_FIXED 0x101 /* fixed channel position */ +#define SNDRV_CTL_TLVT_CHMAP_VAR 0x102 /* channels freely swappable */ +#define SNDRV_CTL_TLVT_CHMAP_PAIRED 0x103 /* pair-wise swappable */ + #endif /* __SOUND_TLV_H */ diff --git a/sound/core/pcm.c b/sound/core/pcm.c index 1a3070b4e5b5..f2991940b271 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -1105,6 +1105,10 @@ static int snd_pcm_dev_disconnect(struct snd_device *device) break; } snd_unregister_device(devtype, pcm->card, pcm->device); + if (pcm->streams[cidx].chmap_kctl) { + snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl); + pcm->streams[cidx].chmap_kctl = NULL; + } } unlock: mutex_unlock(®ister_mutex); diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 7ae671923393..565102705eda 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -2302,3 +2303,217 @@ snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream, } EXPORT_SYMBOL(snd_pcm_lib_readv); + +/* + * standard channel mapping helpers + */ + +/* default channel maps for multi-channel playbacks, up to 8 channels */ +const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = { + { .channels = 1, + .map = { SNDRV_CHMAP_FC } }, + { .channels = 2, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } }, + { .channels = 4, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, + SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } }, + { .channels = 6, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, + SNDRV_CHMAP_RL, SNDRV_CHMAP_RR, + SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } }, + { .channels = 8, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, + SNDRV_CHMAP_RL, SNDRV_CHMAP_RR, + SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE, + SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } }, + { } +}; +EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps); + +/* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */ +const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = { + { .channels = 1, + .map = { SNDRV_CHMAP_FC } }, + { .channels = 2, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } }, + { .channels = 4, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, + SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } }, + { .channels = 6, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, + SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE, + SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } }, + { .channels = 8, + .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR, + SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE, + SNDRV_CHMAP_RL, SNDRV_CHMAP_RR, + SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } }, + { } +}; +EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps); + +static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch) +{ + if (ch > info->max_channels) + return false; + return !info->channel_mask || (info->channel_mask & (1U << ch)); +} + +static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); + + uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; + uinfo->count = 0; + uinfo->count = info->max_channels; + uinfo->value.integer.min = 0; + uinfo->value.integer.max = SNDRV_CHMAP_LAST; + return 0; +} + +/* get callback for channel map ctl element + * stores the channel position firstly matching with the current channels + */ +static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); + unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id); + struct snd_pcm_substream *substream; + const struct snd_pcm_chmap_elem *map; + + if (snd_BUG_ON(!info->chmap)) + return -EINVAL; + substream = snd_pcm_chmap_substream(info, idx); + if (!substream) + return -ENODEV; + memset(ucontrol->value.integer.value, 0, + sizeof(ucontrol->value.integer.value)); + if (!substream->runtime) + return 0; /* no channels set */ + for (map = info->chmap; map->channels; map++) { + int i; + if (map->channels == substream->runtime->channels && + valid_chmap_channels(info, map->channels)) { + for (i = 0; i < map->channels; i++) + ucontrol->value.integer.value[i] = map->map[i]; + return 0; + } + } + return -EINVAL; +} + +/* tlv callback for channel map ctl element + * expands the pre-defined channel maps in a form of TLV + */ +static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag, + unsigned int size, unsigned int __user *tlv) +{ + struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); + const struct snd_pcm_chmap_elem *map; + unsigned int __user *dst; + int c, count = 0; + + if (snd_BUG_ON(!info->chmap)) + return -EINVAL; + if (size < 8) + return -ENOMEM; + if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv)) + return -EFAULT; + size -= 8; + dst = tlv + 2; + for (map = info->chmap; map->channels; map++) { + int chs_bytes = map->channels * 4; + if (!valid_chmap_channels(info, map->channels)) + continue; + if (size < 8) + return -ENOMEM; + if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) || + put_user(chs_bytes, dst + 1)) + return -EFAULT; + dst += 2; + size -= 8; + count += 8; + if (size < chs_bytes) + return -ENOMEM; + size -= chs_bytes; + count += chs_bytes; + for (c = 0; c < map->channels; c++) { + if (put_user(map->map[c], dst)) + return -EFAULT; + dst++; + } + } + if (put_user(count, tlv + 1)) + return -EFAULT; + return 0; +} + +static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol) +{ + struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol); + info->pcm->streams[info->stream].chmap_kctl = NULL; + kfree(info); +} + +/** + * snd_pcm_add_chmap_ctls - create channel-mapping control elements + * @pcm: the assigned PCM instance + * @stream: stream direction + * @chmap: channel map elements (for query) + * @max_channels: the max number of channels for the stream + * @private_value: the value passed to each kcontrol's private_value field + * @info_ret: store struct snd_pcm_chmap instance if non-NULL + * + * Create channel-mapping control elements assigned to the given PCM stream(s). + * Returns zero if succeed, or a negative error value. + */ +int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream, + const struct snd_pcm_chmap_elem *chmap, + int max_channels, + unsigned long private_value, + struct snd_pcm_chmap **info_ret) +{ + struct snd_pcm_chmap *info; + struct snd_kcontrol_new knew = { + .iface = SNDRV_CTL_ELEM_IFACE_PCM, + .access = SNDRV_CTL_ELEM_ACCESS_READ | + SNDRV_CTL_ELEM_ACCESS_VOLATILE | /* no notification */ + SNDRV_CTL_ELEM_ACCESS_TLV_READ | + SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK, + .info = pcm_chmap_ctl_info, + .get = pcm_chmap_ctl_get, + .tlv.c = pcm_chmap_ctl_tlv, + }; + int err; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + info->pcm = pcm; + info->stream = stream; + info->chmap = chmap; + info->max_channels = max_channels; + if (stream == SNDRV_PCM_STREAM_PLAYBACK) + knew.name = "Playback Channel Map"; + else + knew.name = "Capture Channel Map"; + 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); + return -ENOMEM; + } + info->kctl->private_free = pcm_chmap_ctl_private_free; + err = snd_ctl_add(pcm->card, info->kctl); + if (err < 0) + return err; + pcm->streams[stream].chmap_kctl = info->kctl; + if (info_ret) + *info_ret = info; + return 0; +} +EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);