Add a kcontrol to the platform sound card to fetch the current offload status. This can allow for userspace to ensure/check which USB SND resources are actually busy versus having to attempt opening the USB SND devices, which will result in an error if offloading is active.
Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com --- include/sound/soc-usb.h | 27 ++++++++ sound/soc/soc-usb.c | 150 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 175 insertions(+), 2 deletions(-)
diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h index 195300510acc..b0dbb89316fe 100644 --- a/include/sound/soc-usb.h +++ b/include/sound/soc-usb.h @@ -6,6 +6,24 @@ #ifndef __LINUX_SND_SOC_USB_H #define __LINUX_SND_SOC_USB_H
+enum snd_soc_usb_dai_state { + SND_SOC_USB_IDLE, + SND_SOC_USB_PREPARED, + SND_SOC_USB_RUNNING, +}; + +/** + * struct snd_soc_usb_session + * @active_card_idx - active offloaded sound card + * @active_pcm_idx - active offloaded PCM device + * @state - USB BE DAI link PCM state + */ +struct snd_soc_usb_session { + int active_card_idx; + int active_pcm_idx; + enum snd_soc_usb_dai_state state; +}; + /** * struct snd_soc_usb_device * @card_idx - sound card index associated with USB device @@ -25,6 +43,8 @@ struct snd_soc_usb_device { * @list - list head for SND SOC struct list * @dev - USB backend device reference * @component - reference to ASoC component + * @active_list - active sessions + * @num_supported_streams - number of supported concurrent sessions * @connection_status_cb - callback to notify connection events * @put_offload_dev - callback to select USB sound card/PCM device * @get_offload_dev - callback to fetch selected USB sound card/PCM device @@ -33,6 +53,8 @@ struct snd_soc_usb_device { struct snd_soc_usb { struct list_head list; struct snd_soc_component *component; + struct snd_soc_usb_session *active_list; + unsigned int num_supported_streams; int (*connection_status_cb)(struct snd_soc_usb *usb, struct snd_soc_usb_device *sdev, bool connected); int (*put_offload_dev)(struct snd_kcontrol *kcontrol, @@ -50,6 +72,11 @@ int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev); int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev); void *snd_soc_usb_find_priv_data(struct device *dev);
+int snd_soc_usb_prepare_session(struct snd_soc_usb *usb, int card_idx, int pcm_idx); +int snd_soc_usb_shutdown_session(struct snd_soc_usb *usb, int session_id); +int snd_soc_usb_set_session_state(struct snd_soc_usb *usb, int session_id, + enum snd_soc_usb_dai_state state); + struct snd_soc_usb *snd_soc_usb_allocate_port(struct snd_soc_component *component, int num_supported_streams, void *data); void snd_soc_usb_free_port(struct snd_soc_usb *usb); diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c index 622916a82b77..50cd53db365f 100644 --- a/sound/soc/soc-usb.c +++ b/sound/soc/soc-usb.c @@ -42,11 +42,62 @@ static struct snd_soc_usb *snd_soc_find_usb_ctx(struct device_node *node) }
/* SOC USB sound kcontrols */ +static int snd_soc_usb_get_offload_status(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct snd_soc_component *component = snd_kcontrol_chip(kcontrol); + struct snd_soc_usb *ctx = snd_soc_find_usb_ctx(component->dev->of_node); + int control_idx = 0; + int pcm_idx; + int card_idx; + int i; + + for (i = 0; i < ctx->num_supported_streams; i++) { + card_idx = -1; + pcm_idx = -1; + + if (ctx->active_list[i].state == SND_SOC_USB_RUNNING) { + card_idx = ctx->active_list[i].active_card_idx; + pcm_idx = ctx->active_list[i].active_pcm_idx; + } + + ucontrol->value.integer.value[control_idx] = card_idx; + control_idx++; + ucontrol->value.integer.value[control_idx] = pcm_idx; + control_idx++; + } + + return 0; +} + +static int snd_soc_usb_offload_status_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + struct snd_soc_component *component = snd_kcontrol_chip(kcontrol); + struct snd_soc_usb *ctx = snd_soc_find_usb_ctx(component->dev->of_node); + + uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; + uinfo->count = 2*ctx->num_supported_streams; + uinfo->value.integer.min = -1; + uinfo->value.integer.max = SNDRV_CARDS; + + return 0; +} + +static const struct snd_kcontrol_new soc_usb_status_ctrl = { + .iface = SNDRV_CTL_ELEM_IFACE_CARD, + .access = SNDRV_CTL_ELEM_ACCESS_READ, + .name = "SNDUSB OFFLD playback status", + .info = snd_soc_usb_offload_status_info, + .get = snd_soc_usb_get_offload_status, + .put = NULL, +}; + static int soc_usb_put_offload_dev(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_soc_component *component = snd_kcontrol_chip(kcontrol); - struct snd_soc_usb *ctx = snd_soc_usb_find_priv_data(component->dev); + struct snd_soc_usb *ctx = snd_soc_find_usb_ctx(component->dev->of_node); int ret = 0;
mutex_lock(&ctx_mutex); @@ -61,7 +112,7 @@ static int soc_usb_get_offload_dev(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_soc_component *component = snd_kcontrol_chip(kcontrol); - struct snd_soc_usb *ctx = snd_soc_usb_find_priv_data(component->dev); + struct snd_soc_usb *ctx = snd_soc_find_usb_ctx(component->dev->of_node); int ret = 0;
mutex_lock(&ctx_mutex); @@ -95,10 +146,96 @@ static const struct snd_kcontrol_new soc_usb_dev_ctrl = {
static int snd_soc_usb_control_init(struct snd_soc_component *component) { + int ret; + + ret = snd_ctl_add(component->card->snd_card, + snd_ctl_new1(&soc_usb_status_ctrl, component)); + if (ret < 0) + return ret; + return snd_ctl_add(component->card->snd_card, snd_ctl_new1(&soc_usb_dev_ctrl, component)); }
+/** + * snd_soc_usb_set_session_state() - Set the session state for a session + * @usb: SOC USB device + * @session_id: index to active_list + * @state: USB PCM device index + * + * Set the session state for an entry in active_list. This should be only + * called after snd_soc_usb_prepare_session. + * + * Returns 0 on success, negative on error. + * + */ +int snd_soc_usb_set_session_state(struct snd_soc_usb *usb, int session_id, + enum snd_soc_usb_dai_state state) +{ + if (session_id < 0 || session_id >= usb->num_supported_streams) + return -EINVAL; + + mutex_lock(&ctx_mutex); + if (usb->active_list[session_id].state == state) { + mutex_unlock(&ctx_mutex); + return 0; + } + + usb->active_list[session_id].state = state; + mutex_unlock(&ctx_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(snd_soc_usb_set_session_state); + +/** + * snd_soc_usb_prepare_session() - Find and prepare a session + * @usb: SOC USB device + * @card_idx: USB card index + * @pcm_idx: USB PCM device index + * + * Find an open active session slot on the SOC USB device. If all slots + * are busy, return an error. If not, claim the slot and place it into + * the SND_SOC_USB_PREPARED state. This should be called first before + * calling snd_soc_usb_set_session_state or snd_soc_usb_shutdown_session. + * + * Returns the session id (index) to active_list, negative on error. + * + */ +int snd_soc_usb_prepare_session(struct snd_soc_usb *usb, int card_idx, int pcm_idx) +{ + int i; + + mutex_lock(&ctx_mutex); + for (i = 0; i < usb->num_supported_streams; i++) { + if (usb->active_list[i].state == SND_SOC_USB_IDLE) { + usb->active_list[i].active_card_idx = card_idx; + usb->active_list[i].active_pcm_idx = pcm_idx; + usb->active_list[i].state = SND_SOC_USB_PREPARED; + mutex_unlock(&ctx_mutex); + return i; + } + } + mutex_unlock(&ctx_mutex); + + return -EBUSY; +} +EXPORT_SYMBOL_GPL(snd_soc_usb_prepare_session); + +/** + * snd_soc_usb_shutdown_session() - Set USB SOC to idle state + * @usb: SOC USB device + * @session_id: index to active_list + * + * Place the session specified by session_id into the idle/shutdown state. + * + */ +int snd_soc_usb_shutdown_session(struct snd_soc_usb *usb, int session_id) +{ + return snd_soc_usb_set_session_state(usb, session_id, SND_SOC_USB_IDLE); +} +EXPORT_SYMBOL_GPL(snd_soc_usb_shutdown_session); + /** * snd_soc_usb_get_components_tag() - Retrieve SOC USB component tag * @playback: direction of audio stream @@ -185,8 +322,16 @@ struct snd_soc_usb *snd_soc_usb_allocate_port(struct snd_soc_component *componen if (!usb) return ERR_PTR(-ENOMEM);
+ usb->active_list = kcalloc(num_streams, sizeof(struct snd_soc_usb_session), + GFP_KERNEL); + if (!usb->active_list) { + kfree(usb); + return ERR_PTR(-ENOMEM); + } + usb->component = component; usb->priv_data = data; + usb->num_supported_streams = num_streams;
return usb; } @@ -202,6 +347,7 @@ EXPORT_SYMBOL_GPL(snd_soc_usb_allocate_port); void snd_soc_usb_free_port(struct snd_soc_usb *usb) { snd_soc_usb_remove_port(usb); + kfree(usb->active_list); kfree(usb); } EXPORT_SYMBOL_GPL(snd_soc_usb_free_port);