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 <tiwai@suse.de>
This commit is contained in:
Takashi Iwai
parent
a8d372f171
commit
2d3391ec0e
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@ -472,6 +472,36 @@ enum {
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SNDRV_PCM_TSTAMP_TYPE_LAST = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC,
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};
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/* channel positions */
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enum {
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SNDRV_CHMAP_UNKNOWN = 0,
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SNDRV_CHMAP_FL, /* front left */
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SNDRV_CHMAP_FC, /* front center */
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SNDRV_CHMAP_FR, /* front right */
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SNDRV_CHMAP_FLC, /* front left center */
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SNDRV_CHMAP_FRC, /* front right center */
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SNDRV_CHMAP_RL, /* rear left */
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SNDRV_CHMAP_RC, /* rear center */
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SNDRV_CHMAP_RR, /* rear right */
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SNDRV_CHMAP_RLC, /* rear left center */
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SNDRV_CHMAP_RRC, /* rear right center */
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SNDRV_CHMAP_SL, /* side left */
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SNDRV_CHMAP_SR, /* side right */
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SNDRV_CHMAP_LFE, /* LFE */
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SNDRV_CHMAP_FLW, /* front left wide */
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SNDRV_CHMAP_FRW, /* front right wide */
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SNDRV_CHMAP_FLH, /* front left high */
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SNDRV_CHMAP_FCH, /* front center high */
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SNDRV_CHMAP_FRH, /* front right high */
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SNDRV_CHMAP_TC, /* top center */
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SNDRV_CHMAP_NA, /* N/A, silent */
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SNDRV_CHMAP_LAST = SNDRV_CHMAP_NA,
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};
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#define SNDRV_CHMAP_POSITION_MASK 0xffff
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#define SNDRV_CHMAP_PHASE_INVERSE (0x01 << 16)
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#define SNDRV_CHMAP_DRIVER_SPEC (0x02 << 16)
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#define SNDRV_PCM_IOCTL_PVERSION _IOR('A', 0x00, int)
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#define SNDRV_PCM_IOCTL_INFO _IOR('A', 0x01, struct snd_pcm_info)
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#define SNDRV_PCM_IOCTL_TSTAMP _IOW('A', 0x02, int)
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@ -437,6 +437,7 @@ struct snd_pcm_str {
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struct snd_info_entry *proc_xrun_debug_entry;
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#endif
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#endif
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struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */
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};
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struct snd_pcm {
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@ -1086,4 +1087,51 @@ static inline const char *snd_pcm_stream_str(struct snd_pcm_substream *substream
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return "Capture";
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}
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/*
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* PCM channel-mapping control API
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*/
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/* array element of channel maps */
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struct snd_pcm_chmap_elem {
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unsigned char channels;
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unsigned char map[15];
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};
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/* channel map information; retrieved via snd_kcontrol_chip() */
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struct snd_pcm_chmap {
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struct snd_pcm *pcm; /* assigned PCM instance */
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int stream; /* PLAYBACK or CAPTURE */
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struct snd_kcontrol *kctl;
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const struct snd_pcm_chmap_elem *chmap;
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unsigned int max_channels;
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unsigned int channel_mask; /* optional: active channels bitmask */
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void *private_data; /* optional: private data pointer */
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};
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/* get the PCM substream assigned to the given chmap info */
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static inline struct snd_pcm_substream *
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snd_pcm_chmap_substream(struct snd_pcm_chmap *info, unsigned int idx)
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{
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struct snd_pcm_substream *s;
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for (s = info->pcm->streams[info->stream].substream; s; s = s->next)
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if (s->number == idx)
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return s;
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return NULL;
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}
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/* ALSA-standard channel maps (RL/RR prior to C/LFE) */
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extern const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[];
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/* Other world's standard channel maps (C/LFE prior to RL/RR) */
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extern const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[];
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/* bit masks to be passed to snd_pcm_chmap.channel_mask field */
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#define SND_PCM_CHMAP_MASK_24 ((1U << 2) | (1U << 4))
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#define SND_PCM_CHMAP_MASK_246 (SND_PCM_CHMAP_MASK_24 | (1U << 6))
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#define SND_PCM_CHMAP_MASK_2468 (SND_PCM_CHMAP_MASK_246 | (1U << 8))
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int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
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const struct snd_pcm_chmap_elem *chmap,
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int max_channels,
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unsigned long private_value,
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struct snd_pcm_chmap **info_ret);
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#endif /* __SOUND_PCM_H */
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@ -86,4 +86,12 @@
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#define TLV_DB_GAIN_MUTE -9999999
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/*
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* channel-mapping TLV items
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* TLV length must match with num_channels
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*/
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#define SNDRV_CTL_TLVT_CHMAP_FIXED 0x101 /* fixed channel position */
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#define SNDRV_CTL_TLVT_CHMAP_VAR 0x102 /* channels freely swappable */
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#define SNDRV_CTL_TLVT_CHMAP_PAIRED 0x103 /* pair-wise swappable */
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#endif /* __SOUND_TLV_H */
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@ -1105,6 +1105,10 @@ static int snd_pcm_dev_disconnect(struct snd_device *device)
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break;
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}
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snd_unregister_device(devtype, pcm->card, pcm->device);
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if (pcm->streams[cidx].chmap_kctl) {
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snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl);
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pcm->streams[cidx].chmap_kctl = NULL;
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}
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}
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unlock:
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mutex_unlock(®ister_mutex);
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@ -26,6 +26,7 @@
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#include <linux/export.h>
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#include <sound/core.h>
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#include <sound/control.h>
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#include <sound/tlv.h>
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#include <sound/info.h>
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#include <sound/pcm.h>
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#include <sound/pcm_params.h>
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@ -2302,3 +2303,217 @@ snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
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}
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EXPORT_SYMBOL(snd_pcm_lib_readv);
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/*
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* standard channel mapping helpers
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*/
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/* default channel maps for multi-channel playbacks, up to 8 channels */
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const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
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{ .channels = 1,
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.map = { SNDRV_CHMAP_FC } },
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{ .channels = 2,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
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{ .channels = 4,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
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SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
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{ .channels = 6,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
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SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
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SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
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{ .channels = 8,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
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SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
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SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
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SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
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{ }
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};
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EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
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/* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
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const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
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{ .channels = 1,
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.map = { SNDRV_CHMAP_FC } },
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{ .channels = 2,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
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{ .channels = 4,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
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SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
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{ .channels = 6,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
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SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
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SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
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{ .channels = 8,
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.map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
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SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
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SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
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SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
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{ }
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};
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EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
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static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
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{
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if (ch > info->max_channels)
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return false;
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return !info->channel_mask || (info->channel_mask & (1U << ch));
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}
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static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
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struct snd_ctl_elem_info *uinfo)
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{
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struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
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uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
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uinfo->count = 0;
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uinfo->count = info->max_channels;
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uinfo->value.integer.min = 0;
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uinfo->value.integer.max = SNDRV_CHMAP_LAST;
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return 0;
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}
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/* get callback for channel map ctl element
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* stores the channel position firstly matching with the current channels
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*/
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static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
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struct snd_ctl_elem_value *ucontrol)
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{
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struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
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unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
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struct snd_pcm_substream *substream;
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const struct snd_pcm_chmap_elem *map;
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if (snd_BUG_ON(!info->chmap))
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return -EINVAL;
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substream = snd_pcm_chmap_substream(info, idx);
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if (!substream)
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return -ENODEV;
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memset(ucontrol->value.integer.value, 0,
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sizeof(ucontrol->value.integer.value));
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if (!substream->runtime)
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return 0; /* no channels set */
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for (map = info->chmap; map->channels; map++) {
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int i;
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if (map->channels == substream->runtime->channels &&
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valid_chmap_channels(info, map->channels)) {
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for (i = 0; i < map->channels; i++)
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ucontrol->value.integer.value[i] = map->map[i];
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return 0;
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}
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}
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return -EINVAL;
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}
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/* tlv callback for channel map ctl element
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* expands the pre-defined channel maps in a form of TLV
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*/
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static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
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unsigned int size, unsigned int __user *tlv)
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{
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struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
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const struct snd_pcm_chmap_elem *map;
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unsigned int __user *dst;
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int c, count = 0;
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if (snd_BUG_ON(!info->chmap))
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return -EINVAL;
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if (size < 8)
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return -ENOMEM;
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if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
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return -EFAULT;
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size -= 8;
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dst = tlv + 2;
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for (map = info->chmap; map->channels; map++) {
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int chs_bytes = map->channels * 4;
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if (!valid_chmap_channels(info, map->channels))
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continue;
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if (size < 8)
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return -ENOMEM;
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if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
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put_user(chs_bytes, dst + 1))
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return -EFAULT;
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dst += 2;
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size -= 8;
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count += 8;
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if (size < chs_bytes)
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return -ENOMEM;
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size -= chs_bytes;
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count += chs_bytes;
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for (c = 0; c < map->channels; c++) {
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if (put_user(map->map[c], dst))
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return -EFAULT;
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dst++;
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}
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}
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if (put_user(count, tlv + 1))
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return -EFAULT;
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return 0;
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}
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static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
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{
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struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
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info->pcm->streams[info->stream].chmap_kctl = NULL;
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kfree(info);
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}
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/**
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* snd_pcm_add_chmap_ctls - create channel-mapping control elements
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* @pcm: the assigned PCM instance
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* @stream: stream direction
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* @chmap: channel map elements (for query)
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* @max_channels: the max number of channels for the stream
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* @private_value: the value passed to each kcontrol's private_value field
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* @info_ret: store struct snd_pcm_chmap instance if non-NULL
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*
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* Create channel-mapping control elements assigned to the given PCM stream(s).
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* Returns zero if succeed, or a negative error value.
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*/
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int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
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const struct snd_pcm_chmap_elem *chmap,
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int max_channels,
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unsigned long private_value,
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struct snd_pcm_chmap **info_ret)
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{
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struct snd_pcm_chmap *info;
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struct snd_kcontrol_new knew = {
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.iface = SNDRV_CTL_ELEM_IFACE_PCM,
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.access = SNDRV_CTL_ELEM_ACCESS_READ |
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SNDRV_CTL_ELEM_ACCESS_VOLATILE | /* no notification */
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SNDRV_CTL_ELEM_ACCESS_TLV_READ |
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SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
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.info = pcm_chmap_ctl_info,
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.get = pcm_chmap_ctl_get,
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.tlv.c = pcm_chmap_ctl_tlv,
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};
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int err;
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info = kzalloc(sizeof(*info), GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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info->pcm = pcm;
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info->stream = stream;
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info->chmap = chmap;
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info->max_channels = max_channels;
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if (stream == SNDRV_PCM_STREAM_PLAYBACK)
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knew.name = "Playback Channel Map";
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else
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knew.name = "Capture Channel Map";
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knew.device = pcm->device;
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knew.count = pcm->streams[stream].substream_count;
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knew.private_value = private_value;
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info->kctl = snd_ctl_new1(&knew, info);
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if (!info->kctl) {
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kfree(info);
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return -ENOMEM;
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}
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info->kctl->private_free = pcm_chmap_ctl_private_free;
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err = snd_ctl_add(pcm->card, info->kctl);
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if (err < 0)
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return err;
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pcm->streams[stream].chmap_kctl = info->kctl;
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if (info_ret)
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*info_ret = info;
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return 0;
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}
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EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
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