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Message-ID: <20241011000650.2585600-54-quic_wcheng@quicinc.com>
Date: Thu, 10 Oct 2024 17:06:38 -0700
From: Wesley Cheng <quic_wcheng@...cinc.com>
To: <srinivas.kandagatla@...aro.org>, <mathias.nyman@...el.com>,
<perex@...ex.cz>, <conor+dt@...nel.org>, <dmitry.torokhov@...il.com>,
<corbet@....net>, <broonie@...nel.org>, <lgirdwood@...il.com>,
<tiwai@...e.com>, <krzk+dt@...nel.org>,
<pierre-louis.bossart@...ux.intel.com>, <Thinh.Nguyen@...opsys.com>,
<bgoswami@...cinc.com>, <robh@...nel.org>,
<gregkh@...uxfoundation.org>
CC: <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
<linux-sound@...r.kernel.org>, <linux-input@...r.kernel.org>,
<linux-usb@...r.kernel.org>, <linux-arm-msm@...r.kernel.org>,
<linux-doc@...r.kernel.org>, <alsa-devel@...a-project.org>,
Wesley Cheng
<quic_wcheng@...cinc.com>
Subject: [PATCH v28 27/33] ALSA: usb-audio: Introduce USB SND platform op callbacks
Allow for different platforms to be notified on USB SND connect/disconnect
sequences. This allows for platform USB SND modules to properly initialize
and populate internal structures with references to the USB SND chip
device.
Signed-off-by: Wesley Cheng <quic_wcheng@...cinc.com>
---
sound/usb/card.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
sound/usb/card.h | 10 ++++++++++
2 files changed, 59 insertions(+)
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1f9dfcd8f336..326292f37841 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -118,6 +118,42 @@ MODULE_PARM_DESC(skip_validation, "Skip unit descriptor validation (default: no)
static DEFINE_MUTEX(register_mutex);
static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
static struct usb_driver usb_audio_driver;
+static struct snd_usb_platform_ops *platform_ops;
+
+/*
+ * Register platform specific operations that will be notified on events
+ * which occur in USB SND. The platform driver can utilize this path to
+ * enable features, such as USB audio offloading, which allows for audio data
+ * to be queued by an audio DSP.
+ *
+ * Only one set of platform operations can be registered to USB SND. The
+ * platform register operation is protected by the register_mutex.
+ */
+int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
+{
+ guard(mutex)(®ister_mutex);
+ if (platform_ops)
+ return -EEXIST;
+
+ platform_ops = ops;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_usb_register_platform_ops);
+
+/*
+ * Unregisters the current set of platform operations. This allows for
+ * a new set to be registered if required.
+ *
+ * The platform unregister operation is protected by the register_mutex.
+ */
+int snd_usb_unregister_platform_ops(void)
+{
+ guard(mutex)(®ister_mutex);
+ platform_ops = NULL;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
/*
* Checks to see if requested audio profile, i.e sample rate, # of
@@ -946,7 +982,11 @@ static int usb_audio_probe(struct usb_interface *intf,
chip->num_interfaces++;
usb_set_intfdata(intf, chip);
atomic_dec(&chip->active);
+
+ if (platform_ops && platform_ops->connect_cb)
+ platform_ops->connect_cb(chip);
mutex_unlock(®ister_mutex);
+
return 0;
__error:
@@ -983,6 +1023,9 @@ static void usb_audio_disconnect(struct usb_interface *intf)
card = chip->card;
mutex_lock(®ister_mutex);
+ if (platform_ops && platform_ops->disconnect_cb)
+ platform_ops->disconnect_cb(chip);
+
if (atomic_inc_return(&chip->shutdown) == 1) {
struct snd_usb_stream *as;
struct snd_usb_endpoint *ep;
@@ -1130,6 +1173,9 @@ static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
chip->system_suspend = chip->num_suspended_intf;
}
+ if (platform_ops && platform_ops->suspend_cb)
+ platform_ops->suspend_cb(intf, message);
+
return 0;
}
@@ -1170,6 +1216,9 @@ static int usb_audio_resume(struct usb_interface *intf)
snd_usb_midi_v2_resume_all(chip);
+ if (platform_ops && platform_ops->resume_cb)
+ platform_ops->resume_cb(intf);
+
out:
if (chip->num_suspended_intf == chip->system_suspend) {
snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
diff --git a/sound/usb/card.h b/sound/usb/card.h
index cdafc9e9cecd..d8b8522e1613 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -209,7 +209,17 @@ struct snd_usb_stream {
struct list_head list;
};
+struct snd_usb_platform_ops {
+ void (*connect_cb)(struct snd_usb_audio *chip);
+ void (*disconnect_cb)(struct snd_usb_audio *chip);
+ void (*suspend_cb)(struct usb_interface *intf, pm_message_t message);
+ void (*resume_cb)(struct usb_interface *intf);
+};
+
struct snd_usb_stream *
snd_usb_find_suppported_substream(int card_idx, struct snd_pcm_hw_params *params,
int direction);
+
+int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
+int snd_usb_unregister_platform_ops(void);
#endif /* __USBAUDIO_CARD_H */
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