On Tue, Aug 29, 2023 at 02:51:32PM +0530, Akash Kumar wrote: > Adding uevent from usb audio gadget driver for uac2 playback/capture > events, which userspace reads and later reads sysfs entry to know if > playback or capture has stopped or started by host application. > > /config/usb_gadget/g1/functions/uac2.0 # cat c_status > 1 --> capture started > 0 --> capture stopped > /config/usb_gadget/g1/functions/uac2.0 # cat p_status > 1 --> playback started > 0 --> playback stopped > > Signed-off-by: Akash Kumar <quic_akakum@xxxxxxxxxxx> > --- > Documentation/usb/gadget-testing.rst | 6 ++++ > drivers/usb/gadget/function/f_uac2.c | 47 ++++++++++++++++++++++++++++ > drivers/usb/gadget/function/u_uac2.h | 5 +++ > 3 files changed, 58 insertions(+) > > diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst > index 2eeb3e9299e4..b2fded232ced 100644 > --- a/Documentation/usb/gadget-testing.rst > +++ b/Documentation/usb/gadget-testing.rst > @@ -733,6 +733,12 @@ The uac2 function provides these attributes in its function directory: > p_ssize playback sample size (bytes) > req_number the number of pre-allocated request for both capture > and playback > + c_status audio capture state > + (0: capture stopped, 1: capture started) > + p_status audio playback state > + (0: playback stopped, 1: playback started) > + c_status audio capture state > + p_status audio playback state spaces not tabs? And shouldn't this also be documented in Documentation/ABI/ as well with the other attributes? > =============== ==================================================== > > The attributes have sane default values. > diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c > index db2d4980cb35..f1f7631e9380 100644 > --- a/drivers/usb/gadget/function/f_uac2.c > +++ b/drivers/usb/gadget/function/f_uac2.c > @@ -739,6 +739,8 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt) > struct usb_gadget *gadget = cdev->gadget; > struct device *dev = &gadget->dev; > int ret = 0; > + struct f_uac2_opts *audio_opts = > + container_of(fn->fi, struct f_uac2_opts, func_inst); Why assign it here and not below? > > /* No i/f has more than 2 alt settings */ > if (alt > 1) { > @@ -762,6 +764,8 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt) > ret = u_audio_start_capture(&uac2->g_audio); > else > u_audio_stop_capture(&uac2->g_audio); > + audio_opts->c_status = alt; > + schedule_work(&audio_opts->work); You are changing functionality here, not just adding statistics, why is work needed here? > } else if (intf == uac2->as_in_intf) { > uac2->as_in_alt = alt; > > @@ -769,6 +773,8 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt) > ret = u_audio_start_playback(&uac2->g_audio); > else > u_audio_stop_playback(&uac2->g_audio); > + audio_opts->p_status = alt; > + schedule_work(&audio_opts->work); Same here? > } else { > dev_err(dev, "%s:%d Error!\n", __func__, __LINE__); > return -EINVAL; > @@ -801,11 +807,16 @@ static void > afunc_disable(struct usb_function *fn) > { > struct f_uac2 *uac2 = func_to_uac2(fn); > + struct f_uac2_opts *audio_opts = > + container_of(fn->fi, struct f_uac2_opts, func_inst); Normally the bigger line goes at top. > > uac2->as_in_alt = 0; > uac2->as_out_alt = 0; > + audio_opts->p_status = 0;//alt; > + audio_opts->c_status = 0; //alt; You didn't actually mean to do this, right? Please get review from someone else in your group before sending this out for us to find obvious problems. > u_audio_stop_capture(&uac2->g_audio); > u_audio_stop_playback(&uac2->g_audio); > + schedule_work(&audio_opts->work); > } > > static int > @@ -1036,6 +1047,25 @@ UAC2_ATTRIBUTE(c_srate); > UAC2_ATTRIBUTE(c_ssize); > UAC2_ATTRIBUTE(req_number); > > +#define UAC2_ATTRIBUTE_RO(name) \ > + static ssize_t f_uac2_opts_##name##_show( \ > + struct config_item *item, \ > + char *page) \ > +{ \ > + struct f_uac2_opts *opts = to_f_uac2_opts(item); \ > + int result; \ > + \ > + mutex_lock(&opts->lock); \ > + result = scnprintf(page, PAGE_SIZE, "%u\n", opts->name); \ > + mutex_unlock(&opts->lock); \ > + \ > + return result; \ > +} \ > +CONFIGFS_ATTR_RO(f_uac2_opts_, name) > + > +UAC2_ATTRIBUTE_RO(c_status); > +UAC2_ATTRIBUTE_RO(p_status); > + > static struct configfs_attribute *f_uac2_attrs[] = { > &f_uac2_opts_attr_p_chmask, > &f_uac2_opts_attr_p_srate, > @@ -1044,6 +1074,8 @@ static struct configfs_attribute *f_uac2_attrs[] = { > &f_uac2_opts_attr_c_srate, > &f_uac2_opts_attr_c_ssize, > &f_uac2_opts_attr_req_number, > + &f_uac2_opts_attr_c_status, > + &f_uac2_opts_attr_p_status, > NULL, > }; > > @@ -1053,11 +1085,23 @@ static const struct config_item_type f_uac2_func_type = { > .ct_owner = THIS_MODULE, > }; > > +static void f_uac2_audio_status_change_work(struct work_struct *data) > +{ > + struct f_uac2_opts *audio_opts = > + container_of(data, struct f_uac2_opts, work); > + char *envp[2] = { "UAC2_STATE=Changed", NULL }; > + > + kobject_uevent_env(&audio_opts->device->kobj, > + KOBJ_CHANGE, envp); > +} > + > static void afunc_free_inst(struct usb_function_instance *f) > { > struct f_uac2_opts *opts; > > opts = container_of(f, struct f_uac2_opts, func_inst); > + device_destroy(opts->device->class, opts->device->devt); Wait, why? > + cancel_work_sync(&opts->work); > kfree(opts); > } > > @@ -1082,6 +1126,9 @@ static struct usb_function_instance *afunc_alloc_inst(void) > opts->c_srate = UAC2_DEF_CSRATE; > opts->c_ssize = UAC2_DEF_CSSIZE; > opts->req_number = UAC2_DEF_REQ_NUM; > + INIT_WORK(&opts->work, f_uac2_audio_status_change_work); > + opts->device = create_function_device("f_uac2"); A whole new device? Why? There should already be a device for this, if not, you now need to document your new device as this is a whole new thing for sysfs to show, right? > + > return &opts->func_inst; > } > > diff --git a/drivers/usb/gadget/function/u_uac2.h b/drivers/usb/gadget/function/u_uac2.h > index b5035711172d..3ccf2eb002f1 100644 > --- a/drivers/usb/gadget/function/u_uac2.h > +++ b/drivers/usb/gadget/function/u_uac2.h > @@ -36,6 +36,11 @@ struct f_uac2_opts { > > struct mutex lock; > int refcnt; > + int c_status; > + int p_status; > + struct device *device; > + struct work_struct work; Some documentation please for what these new fields are for. thanks, greg k-h