2023-02-13 19:31:37

by Elson Serrao

[permalink] [raw]
Subject: [PATCH v4 3/5] usb: gadget: Add function wakeup support

A function which is in function suspend state has to send a
function wake notification to the host in case it needs to
exit from this state and resume data transfer. Add support to
handle such requests by exposing a new gadget op.

Signed-off-by: Elson Roy Serrao <[email protected]>
---
drivers/usb/gadget/composite.c | 24 ++++++++++++++++++++++++
drivers/usb/gadget/udc/core.c | 21 +++++++++++++++++++++
include/linux/usb/composite.h | 6 ++++++
include/linux/usb/gadget.h | 4 ++++
4 files changed, 55 insertions(+)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index a37a8f4..51d6ee9 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -492,6 +492,30 @@ int usb_interface_id(struct usb_configuration *config,
}
EXPORT_SYMBOL_GPL(usb_interface_id);

+int usb_func_wakeup(struct usb_function *func)
+{
+ int ret, id;
+
+ if (!func->func_wakeup_armed) {
+ ERROR(func->config->cdev, "not armed for func remote wakeup\n");
+ return -EINVAL;
+ }
+
+ for (id = 0; id < MAX_CONFIG_INTERFACES; id++)
+ if (func->config->interface[id] == func)
+ break;
+
+ if (id == MAX_CONFIG_INTERFACES) {
+ ERROR(func->config->cdev, "Invalid function id:%d\n", id);
+ return -EINVAL;
+ }
+
+ ret = usb_gadget_func_wakeup(func->config->cdev->gadget, id);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_func_wakeup);
+
static u8 encode_bMaxPower(enum usb_device_speed speed,
struct usb_configuration *c)
{
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 3dcbba7..59e7a7e 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -846,6 +846,27 @@ int usb_gadget_activate(struct usb_gadget *gadget)
}
EXPORT_SYMBOL_GPL(usb_gadget_activate);

+/**
+ * usb_gadget_func_wakeup - sends function wake notification to the host.
+ * @gadget: controller used to wake up the host
+ * @interface_id: interface on which function wake notification is sent.
+ *
+ * On completion, function wake notification is sent. If the device is in
+ * low power state it tries to bring the device to active state before sending
+ * the wake notification. Since it is a synchronous call, caller must take care
+ * of not calling it in interrupt context.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_gadget_func_wakeup(struct usb_gadget *gadget, int intf_id)
+{
+ if (!gadget->ops->func_wakeup)
+ return -EOPNOTSUPP;
+
+ return gadget->ops->func_wakeup(gadget, intf_id);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_func_wakeup);
+
/* ------------------------------------------------------------------------- */

#ifdef CONFIG_HAS_DMA
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index d949e91..a2448e9 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -150,6 +150,9 @@ struct usb_os_desc_table {
* GetStatus() request when the recipient is Interface.
* @func_suspend: callback to be called when
* SetFeature(FUNCTION_SUSPEND) is reseived
+ * @func_suspended: Indicates whether the function is in function suspend state.
+ * @func_wakeup_armed: Indicates whether the function is armed by the host for
+ * wakeup signaling.
*
* A single USB function uses one or more interfaces, and should in most
* cases support operation at both full and high speeds. Each function is
@@ -220,6 +223,8 @@ struct usb_function {
int (*get_status)(struct usb_function *);
int (*func_suspend)(struct usb_function *,
u8 suspend_opt);
+ bool func_suspended;
+ bool func_wakeup_armed;
/* private: */
/* internals */
struct list_head list;
@@ -241,6 +246,7 @@ int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,

int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
struct usb_ep *_ep);
+int usb_func_wakeup(struct usb_function *func);

#define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */

diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 1d79612..2a512c5 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -310,6 +310,7 @@ struct usb_udc;
struct usb_gadget_ops {
int (*get_frame)(struct usb_gadget *);
int (*wakeup)(struct usb_gadget *);
+ int (*func_wakeup)(struct usb_gadget *gadget, int intf_id);
int (*set_remote_wakeup)(struct usb_gadget *, int set);
int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
int (*vbus_session) (struct usb_gadget *, int is_active);
@@ -617,6 +618,7 @@ int usb_gadget_disconnect(struct usb_gadget *gadget);
int usb_gadget_deactivate(struct usb_gadget *gadget);
int usb_gadget_activate(struct usb_gadget *gadget);
int usb_gadget_check_config(struct usb_gadget *gadget);
+int usb_gadget_func_wakeup(struct usb_gadget *gadget, int intf_id);
#else
static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
{ return 0; }
@@ -644,6 +646,8 @@ static inline int usb_gadget_activate(struct usb_gadget *gadget)
{ return 0; }
static inline int usb_gadget_check_config(struct usb_gadget *gadget)
{ return 0; }
+static inline int usb_gadget_func_wakeup(struct usb_gadget *gadget, int intf_id)
+{ return 0; }
#endif /* CONFIG_USB_GADGET */

/*-------------------------------------------------------------------------*/
--
2.7.4



2023-02-15 00:55:48

by Thinh Nguyen

[permalink] [raw]
Subject: Re: [PATCH v4 3/5] usb: gadget: Add function wakeup support

On Mon, Feb 13, 2023, Elson Roy Serrao wrote:
> A function which is in function suspend state has to send a
> function wake notification to the host in case it needs to
> exit from this state and resume data transfer. Add support to
> handle such requests by exposing a new gadget op.
>
> Signed-off-by: Elson Roy Serrao <[email protected]>
> ---
> drivers/usb/gadget/composite.c | 24 ++++++++++++++++++++++++
> drivers/usb/gadget/udc/core.c | 21 +++++++++++++++++++++
> include/linux/usb/composite.h | 6 ++++++
> include/linux/usb/gadget.h | 4 ++++
> 4 files changed, 55 insertions(+)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index a37a8f4..51d6ee9 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -492,6 +492,30 @@ int usb_interface_id(struct usb_configuration *config,
> }
> EXPORT_SYMBOL_GPL(usb_interface_id);
>
> +int usb_func_wakeup(struct usb_function *func)
> +{
> + int ret, id;
> +
> + if (!func->func_wakeup_armed) {
> + ERROR(func->config->cdev, "not armed for func remote wakeup\n");
> + return -EINVAL;
> + }
> +
> + for (id = 0; id < MAX_CONFIG_INTERFACES; id++)
> + if (func->config->interface[id] == func)
> + break;
> +
> + if (id == MAX_CONFIG_INTERFACES) {
> + ERROR(func->config->cdev, "Invalid function id:%d\n", id);

The print of id here is always MAX_CONFIG_INTERFACES right?

Thanks,
Thinh

> + return -EINVAL;
> + }
> +
> + ret = usb_gadget_func_wakeup(func->config->cdev->gadget, id);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_func_wakeup);
> +

2023-02-15 02:11:04

by Elson Serrao

[permalink] [raw]
Subject: Re: [PATCH v4 3/5] usb: gadget: Add function wakeup support



On 2/14/2023 4:55 PM, Thinh Nguyen wrote:
> On Mon, Feb 13, 2023, Elson Roy Serrao wrote:
>> A function which is in function suspend state has to send a
>> function wake notification to the host in case it needs to
>> exit from this state and resume data transfer. Add support to
>> handle such requests by exposing a new gadget op.
>>
>> Signed-off-by: Elson Roy Serrao <[email protected]>
>> ---
>> drivers/usb/gadget/composite.c | 24 ++++++++++++++++++++++++
>> drivers/usb/gadget/udc/core.c | 21 +++++++++++++++++++++
>> include/linux/usb/composite.h | 6 ++++++
>> include/linux/usb/gadget.h | 4 ++++
>> 4 files changed, 55 insertions(+)
>>
>> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
>> index a37a8f4..51d6ee9 100644
>> --- a/drivers/usb/gadget/composite.c
>> +++ b/drivers/usb/gadget/composite.c
>> @@ -492,6 +492,30 @@ int usb_interface_id(struct usb_configuration *config,
>> }
>> EXPORT_SYMBOL_GPL(usb_interface_id);
>>
>> +int usb_func_wakeup(struct usb_function *func)
>> +{
>> + int ret, id;
>> +
>> + if (!func->func_wakeup_armed) {
>> + ERROR(func->config->cdev, "not armed for func remote wakeup\n");
>> + return -EINVAL;
>> + }
>> +
>> + for (id = 0; id < MAX_CONFIG_INTERFACES; id++)
>> + if (func->config->interface[id] == func)
>> + break;
>> +
>> + if (id == MAX_CONFIG_INTERFACES) {
>> + ERROR(func->config->cdev, "Invalid function id:%d\n", id);
>
> The print of id here is always MAX_CONFIG_INTERFACES right?
>
> Thanks,
> Thinh
>
Thanks for catching this. Will rectify this in v5

>> + return -EINVAL;
>> + }
>> +
>> + ret = usb_gadget_func_wakeup(func->config->cdev->gadget, id);
>> +
>> + return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(usb_func_wakeup);
>> +