| Message ID | 20240925010000.2231406-31-quic_wcheng@quicinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce QC USB SND audio offloading support | expand |
> +static int > +snd_usb_offload_route_get(struct snd_kcontrol *kcontrol, > + struct snd_ctl_elem_value *ucontrol) > +{ > + struct device *sysdev = snd_kcontrol_chip(kcontrol); > + int ret; > + > + ret = snd_soc_usb_update_offload_route(sysdev, > + CARD_IDX(kcontrol->private_value), > + PCM_IDX(kcontrol->private_value), > + SNDRV_PCM_STREAM_PLAYBACK, > + ucontrol->value.integer.value); > + if (ret < 0) { > + ucontrol->value.integer.value[0] = -1; > + ucontrol->value.integer.value[1] = -1; > + } well this invalidates again what I understood from the last patch and goes back to what I understood initially: the error code is never returned to higher levels - when offload is not supported the kcontrol values are encoded to the -1 magic value. > + return 0; and this begs the question if this helper should return a void value. > +} > + > +static int snd_usb_offload_route_info(struct snd_kcontrol *kcontrol, > + struct snd_ctl_elem_info *uinfo) > +{ > + uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; > + uinfo->count = 2; > + uinfo->value.integer.min = -1; > + /* Arbitrary max value, as there is no 'limit' on number of PCM devices */ > + uinfo->value.integer.max = 0xff; > + > + return 0; > +} > + > +static struct snd_kcontrol_new snd_usb_offload_mapped_ctl = { > + .iface = SNDRV_CTL_ELEM_IFACE_CARD, > + .access = SNDRV_CTL_ELEM_ACCESS_READ, > + .info = snd_usb_offload_route_info, > + .get = snd_usb_offload_route_get, > +}; > + > +/** > + * snd_usb_offload_create_ctl() - Add USB offload bounded mixer > + * @chip - USB SND chip device > + * > + * Creates a sound control for a USB audio device, so that applications can > + * query for if there is an available USB audio offload path, and which > + * card is managing it. > + */ > +int snd_usb_offload_create_ctl(struct snd_usb_audio *chip) > +{ > + struct usb_device *udev = chip->dev; > + struct snd_kcontrol_new *chip_kctl; > + struct snd_usb_substream *subs; > + struct snd_usb_stream *as; > + char ctl_name[37]; that's quite a magic value. > + int ret; > + > + list_for_each_entry(as, &chip->pcm_list, list) { > + subs = &as->substream[SNDRV_PCM_STREAM_PLAYBACK]; > + if (!subs->ep_num) > + continue; > + > + chip_kctl = &snd_usb_offload_mapped_ctl; > + chip_kctl->count = 1; > + /* > + * Store the associated USB SND card number and PCM index for > + * the kctl. > + */ > + chip_kctl->private_value = as->pcm_index | > + chip->card->number << 16; > + sprintf(ctl_name, "USB Offload Playback Route PCM#%d", > + as->pcm_index); > + chip_kctl->name = ctl_name; > + ret = snd_ctl_add(chip->card, snd_ctl_new1(chip_kctl, > + udev->bus->sysdev)); > + if (ret < 0) > + break; > + } > + > + return ret; > +}
Hi Pierre, On 9/25/2024 7:54 AM, Pierre-Louis Bossart wrote: > > >> +static int >> +snd_usb_offload_route_get(struct snd_kcontrol *kcontrol, >> + struct snd_ctl_elem_value *ucontrol) >> +{ >> + struct device *sysdev = snd_kcontrol_chip(kcontrol); >> + int ret; >> + >> + ret = snd_soc_usb_update_offload_route(sysdev, >> + CARD_IDX(kcontrol->private_value), >> + PCM_IDX(kcontrol->private_value), >> + SNDRV_PCM_STREAM_PLAYBACK, >> + ucontrol->value.integer.value); >> + if (ret < 0) { >> + ucontrol->value.integer.value[0] = -1; >> + ucontrol->value.integer.value[1] = -1; >> + } > well this invalidates again what I understood from the last patch and > goes back to what I understood initially: the error code is never > returned to higher levels - when offload is not supported the kcontrol > values are encoded to the -1 magic value. Yes, higher levels won't get an error code when they try to fetch for the kcontrol value, and if say...there is no callback to update the offload route then the -1 values are passed back. I don't think we would want to return an error code. We just want to communicate the current mapping of the offload path. >> + return 0; > and this begs the question if this helper should return a void value. This is the registered callback for the .get() call for the kcontrol, so it has to follow the definition below: typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol) >> +} >> + >> +static int snd_usb_offload_route_info(struct snd_kcontrol *kcontrol, >> + struct snd_ctl_elem_info *uinfo) >> +{ >> + uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; >> + uinfo->count = 2; >> + uinfo->value.integer.min = -1; >> + /* Arbitrary max value, as there is no 'limit' on number of PCM devices */ >> + uinfo->value.integer.max = 0xff; >> + >> + return 0; >> +} >> + >> +static struct snd_kcontrol_new snd_usb_offload_mapped_ctl = { >> + .iface = SNDRV_CTL_ELEM_IFACE_CARD, >> + .access = SNDRV_CTL_ELEM_ACCESS_READ, >> + .info = snd_usb_offload_route_info, >> + .get = snd_usb_offload_route_get, >> +}; >> + >> +/** >> + * snd_usb_offload_create_ctl() - Add USB offload bounded mixer >> + * @chip - USB SND chip device >> + * >> + * Creates a sound control for a USB audio device, so that applications can >> + * query for if there is an available USB audio offload path, and which >> + * card is managing it. >> + */ >> +int snd_usb_offload_create_ctl(struct snd_usb_audio *chip) >> +{ >> + struct usb_device *udev = chip->dev; >> + struct snd_kcontrol_new *chip_kctl; >> + struct snd_usb_substream *subs; >> + struct snd_usb_stream *as; >> + char ctl_name[37]; > that's quite a magic value. Ah, will fix this. Should be 34 ("USB Offload Playback Route PCM#" [31] + max pcm index[3]). From past discussions, technically there isn't an upper limit defined for PCM devices, but the above snd_usb_offload_route_info() has it set to 0xff, so I'll be consistent here as well and assume that if we have more than 255 PCM devices for one device, then we won't create further kcontrols. (probably still overkill, but who knows what USB audio devices are out there) Thanks Wesley Cheng >> + int ret; >> + >> + list_for_each_entry(as, &chip->pcm_list, list) { >> + subs = &as->substream[SNDRV_PCM_STREAM_PLAYBACK]; >> + if (!subs->ep_num) >> + continue; >> + >> + chip_kctl = &snd_usb_offload_mapped_ctl; >> + chip_kctl->count = 1; >> + /* >> + * Store the associated USB SND card number and PCM index for >> + * the kctl. >> + */ >> + chip_kctl->private_value = as->pcm_index | >> + chip->card->number << 16; >> + sprintf(ctl_name, "USB Offload Playback Route PCM#%d", >> + as->pcm_index); >> + chip_kctl->name = ctl_name; >> + ret = snd_ctl_add(chip->card, snd_ctl_new1(chip_kctl, >> + udev->bus->sysdev)); >> + if (ret < 0) >> + break; >> + } >> + >> + return ret; >> +}
diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig index 5cc3eaf53e6b..e3fbf9541d0b 100644 --- a/sound/usb/Kconfig +++ b/sound/usb/Kconfig @@ -176,10 +176,20 @@ config SND_BCD2000 To compile this driver as a module, choose M here: the module will be called snd-bcd2000. +config SND_USB_OFFLOAD_MIXER + tristate "USB Audio Offload mixer control" + help + Say Y to enable the USB audio offloading mixer controls. This + exposes an USB offload capable kcontrol to signal to applications + about which platform sound card can support USB audio offload. + The returning values specify the mapped ASoC card and PCM device + the USB audio device is associated to. + config SND_USB_AUDIO_QMI tristate "Qualcomm Audio Offload driver" depends on QCOM_QMI_HELPERS && SND_USB_AUDIO && USB_XHCI_SIDEBAND && SND_SOC_USB select SND_PCM + select SND_USB_OFFLOAD_MIXER help Say Y here to enable the Qualcomm USB audio offloading feature. diff --git a/sound/usb/Makefile b/sound/usb/Makefile index 54a06a2f73ca..2f19f854944c 100644 --- a/sound/usb/Makefile +++ b/sound/usb/Makefile @@ -36,3 +36,5 @@ obj-$(CONFIG_SND_USB_US122L) += snd-usbmidi-lib.o obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/ bcd2000/ qcom/ obj-$(CONFIG_SND_USB_LINE6) += line6/ + +obj-$(CONFIG_SND_USB_OFFLOAD_MIXER) += mixer_usb_offload.o diff --git a/sound/usb/mixer_usb_offload.c b/sound/usb/mixer_usb_offload.c new file mode 100644 index 000000000000..16e2fd634684 --- /dev/null +++ b/sound/usb/mixer_usb_offload.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#include <linux/usb.h> + +#include <sound/core.h> +#include <sound/control.h> +#include <sound/soc-usb.h> + +#include "usbaudio.h" +#include "card.h" +#include "helper.h" +#include "mixer.h" + +#include "mixer_usb_offload.h" + +#define PCM_IDX(n) ((n) & 0xffff) +#define CARD_IDX(n) ((n) >> 16) + +static int +snd_usb_offload_route_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct device *sysdev = snd_kcontrol_chip(kcontrol); + int ret; + + ret = snd_soc_usb_update_offload_route(sysdev, + CARD_IDX(kcontrol->private_value), + PCM_IDX(kcontrol->private_value), + SNDRV_PCM_STREAM_PLAYBACK, + ucontrol->value.integer.value); + if (ret < 0) { + ucontrol->value.integer.value[0] = -1; + ucontrol->value.integer.value[1] = -1; + } + + return 0; +} + +static int snd_usb_offload_route_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER; + uinfo->count = 2; + uinfo->value.integer.min = -1; + /* Arbitrary max value, as there is no 'limit' on number of PCM devices */ + uinfo->value.integer.max = 0xff; + + return 0; +} + +static struct snd_kcontrol_new snd_usb_offload_mapped_ctl = { + .iface = SNDRV_CTL_ELEM_IFACE_CARD, + .access = SNDRV_CTL_ELEM_ACCESS_READ, + .info = snd_usb_offload_route_info, + .get = snd_usb_offload_route_get, +}; + +/** + * snd_usb_offload_create_ctl() - Add USB offload bounded mixer + * @chip - USB SND chip device + * + * Creates a sound control for a USB audio device, so that applications can + * query for if there is an available USB audio offload path, and which + * card is managing it. + */ +int snd_usb_offload_create_ctl(struct snd_usb_audio *chip) +{ + struct usb_device *udev = chip->dev; + struct snd_kcontrol_new *chip_kctl; + struct snd_usb_substream *subs; + struct snd_usb_stream *as; + char ctl_name[37]; + int ret; + + list_for_each_entry(as, &chip->pcm_list, list) { + subs = &as->substream[SNDRV_PCM_STREAM_PLAYBACK]; + if (!subs->ep_num) + continue; + + chip_kctl = &snd_usb_offload_mapped_ctl; + chip_kctl->count = 1; + /* + * Store the associated USB SND card number and PCM index for + * the kctl. + */ + chip_kctl->private_value = as->pcm_index | + chip->card->number << 16; + sprintf(ctl_name, "USB Offload Playback Route PCM#%d", + as->pcm_index); + chip_kctl->name = ctl_name; + ret = snd_ctl_add(chip->card, snd_ctl_new1(chip_kctl, + udev->bus->sysdev)); + if (ret < 0) + break; + } + + return ret; +} +EXPORT_SYMBOL_GPL(snd_usb_offload_create_ctl); diff --git a/sound/usb/mixer_usb_offload.h b/sound/usb/mixer_usb_offload.h new file mode 100644 index 000000000000..3f6e2a8b19c8 --- /dev/null +++ b/sound/usb/mixer_usb_offload.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (c) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#ifndef __USB_OFFLOAD_MIXER_H +#define __USB_OFFLOAD_MIXER_H + +#if IS_ENABLED(CONFIG_SND_USB_OFFLOAD_MIXER) +int snd_usb_offload_create_ctl(struct snd_usb_audio *chip); +#else +static inline int snd_usb_offload_create_ctl(struct snd_usb_audio *chip) +{ + return 0; +} +#endif +#endif /* __USB_OFFLOAD_MIXER_H */ diff --git a/sound/usb/qcom/Makefile b/sound/usb/qcom/Makefile index a81c9b28d484..4005e8391ab9 100644 --- a/sound/usb/qcom/Makefile +++ b/sound/usb/qcom/Makefile @@ -1,2 +1,2 @@ snd-usb-audio-qmi-objs := usb_audio_qmi_v01.o qc_audio_offload.o -obj-$(CONFIG_SND_USB_AUDIO_QMI) += snd-usb-audio-qmi.o \ No newline at end of file +obj-$(CONFIG_SND_USB_AUDIO_QMI) += snd-usb-audio-qmi.o diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c index a7ad15404fd1..5b9262a116be 100644 --- a/sound/usb/qcom/qc_audio_offload.c +++ b/sound/usb/qcom/qc_audio_offload.c @@ -36,6 +36,7 @@ #include "../helper.h" #include "../pcm.h" #include "../power.h" +#include "../mixer_usb_offload.h" #include "usb_audio_qmi_v01.h" @@ -1703,6 +1704,7 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip) sdev->card_idx = chip->card->number; sdev->chip_idx = chip->index; + snd_usb_offload_create_ctl(chip); snd_soc_usb_connect(usb_get_usb_backend(udev), sdev); }
In order to allow userspace/applications know about USB offloading status, expose a sound kcontrol that fetches information about which sound card and PCM index the USB device is mapped to for supporting offloading. In the USB audio offloading framework, the ASoC BE DAI link is the entity responsible for registering to the SOC USB layer. It is expected for the USB SND offloading driver to add the kcontrol to the sound card associated with the USB audio device. An example output would look like: tinymix -D 1 get 'USB Offload Playback Route PCM#0' -1, -1 (range -1->255) This example signifies that there is no mapped ASoC path available for the USB SND device. tinymix -D 1 get 'USB Offload Playback Route PCM#0' 0, 0 (range -1->255) This example signifies that the offload path is available over ASoC sound card index#0 and PCM device#0. The USB offload kcontrol will be added in addition to the existing kcontrols identified by the USB SND mixer. The kcontrols used to modify the USB audio device specific parameters are still valid and expected to be used. These parameters are not mirrored to the ASoC subsystem. Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com> --- sound/usb/Kconfig | 10 +++ sound/usb/Makefile | 2 + sound/usb/mixer_usb_offload.c | 102 ++++++++++++++++++++++++++++++ sound/usb/mixer_usb_offload.h | 17 +++++ sound/usb/qcom/Makefile | 2 +- sound/usb/qcom/qc_audio_offload.c | 2 + 6 files changed, 134 insertions(+), 1 deletion(-) create mode 100644 sound/usb/mixer_usb_offload.c create mode 100644 sound/usb/mixer_usb_offload.h