Re: [PATCH v20 09/41] ASoC: Add SOC USB APIs for adding an USB backend

From: Amadeusz Sławiński
Date: Fri Apr 26 2024 - 09:25:18 EST


On 4/25/2024 11:50 PM, Wesley Cheng wrote:
Some platforms may have support for offloading USB audio devices to a
dedicated audio DSP. Introduce a set of APIs that allow for management of
USB sound card and PCM devices enumerated by the USB SND class driver.
This allows for the ASoC components to be aware of what USB devices are
available for offloading.

Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
---

(...)

+const char *snd_soc_usb_get_components_tag(bool playback)
+{
+ if (playback)
+ return "usbplybkoffld: 1";
+ else
+ return "usbcapoffld: 1";
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_get_components_tag);

Is this used to expose some information to userspace?
Can those be some more readable strings if so, like:
usbplaybackoffload, usbcaptureoffload

(...)

+
+ node = snd_soc_find_phandle(usbdev);
+ if (IS_ERR(node))
+ return -ENODEV;
+
+ ctx = snd_soc_find_usb_ctx(node);
+ of_node_put(node);
+ if (!ctx)
+ return -ENODEV;

Perhaps introduce some helper function, you do this snd_soc_find_phandle() followed by snd_soc_find_usb_ctx() in few places...