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Message-ID: <fb257d0f-2e6e-400f-a654-18e3c59af1a3@quicinc.com>
Date:   Fri, 15 Sep 2023 12:02:12 +0530
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] [PATCH v3] usb: gadget: f_uac2: uevent changes for uac2
To:     Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jing Leng <jleng@ambarella.com>,
        Felipe Balbi <balbi@kernel.org>
CC:     Pratham Pratap <quic_ppratap@quicinc.com>,
        Jack Pham <quic_jackp@quicinc.com>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20230829092132.1940-1-quic_akakum@quicinc.com>
Content-Language: en-US
From:   AKASH KUMAR <quic_akakum@quicinc.com>
In-Reply-To: <20230829092132.1940-1-quic_akakum@quicinc.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
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Precedence: bulk

Gentle Reminder!!!

On 8/29/2023 2:51 PM, 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@quicinc.com>
> ---
>   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
>   	=============== ====================================================
>   
>   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);
>   
>   	/* 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);
>   	} 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);
>   	} 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);
>   
>   	uac2->as_in_alt = 0;
>   	uac2->as_out_alt = 0;
> +	audio_opts->p_status = 0;//alt;
> +	audio_opts->c_status = 0; //alt;
>   	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);
> +	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");
> +
>   	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;
>   };
>   
> +extern struct device *create_function_device(char *name);
>   #endif