>
> usb: phy: hold wakeupsource when USB is enumerated in peripheral mode
>
> Some systems require a mechanism to prevent system to enter into suspend
> state when USB is connected and enumerated in peripheral mode.
>
> This patch provides an interface to hold a wakeupsource to prevent suspend.
> PHY drivers can use this interface when USB is connected and enumerated in
> peripheral mode.
>
> A timed wakeupsource is temporarily held on USB disconnect events, to allow
> the rest of the system to react to the USB disconnection (dropping host
> sessions, updating charger status, etc.) prior to re-allowing suspend.
>
Hi Kiran & Felipe,
Just two questions for this series
- Will it be the default behavior for all peripheral drivers?
- If the peripheral driver's PHY driver does not vbus event, how to support it?
For example, chipidea udc driver has its vbus interface at its controller
register.
Peter
> Cc: Felipe Balbi <ba...@ti.com>
> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-...@vger.kernel.org
> Cc: Android Kernel Team <kernel-t...@android.com>
> Cc: John Stultz <john.stu...@linaro.org>
> Cc: Sumit Semwal <sumit.sem...@linaro.org>
> Cc: Arve Hjønnevåg <a...@android.com>
> Cc: Benoit Goby <ben...@android.com>
> [Original patch in Android from Todd]
> Cc: Todd Poynor <toddpoy...@google.com>
> Signed-off-by: Kiran Raparthy <kiran.ku...@linaro.org>
> ---
> drivers/usb/phy/phy.c | 29 +++++++++++++++++++++++++++--
> include/linux/usb/phy.h | 5 +++++
> 2 files changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c index
> b4066a0..8c87bc3 100644
> --- a/drivers/usb/phy/phy.c
> +++ b/drivers/usb/phy/phy.c
> @@ -331,6 +331,7 @@ int usb_add_phy(struct usb_phy *x, enum
> usb_phy_type type)
> int ret = 0;
> unsigned long flags;
> struct usb_phy *phy;
> + char wsource_name[40];
>
> if (x->type != USB_PHY_TYPE_UNDEFINED) {
> dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
> @@ -353,6 +354,10 @@ int usb_add_phy(struct usb_phy *x, enum
> usb_phy_type type)
> x->type = type;
> list_add_tail(&x->head, &phy_list);
>
> + snprintf(wsource_name, sizeof(wsource_name), "vbus-%s",
> + dev_name(x->dev));
> + wakeup_source_init(&x->wsource, wsource_name);
> +
> out:
> spin_unlock_irqrestore(&phy_lock, flags);
> return ret;
> @@ -404,6 +409,7 @@ void usb_remove_phy(struct usb_phy *x)
>
> spin_lock_irqsave(&phy_lock, flags);
> if (x) {
> + wakeup_source_trash(&x->wsource);
> list_for_each_entry(phy_bind, &phy_bind_list, list)
> if (phy_bind->phy == x)
> phy_bind->phy = NULL;
> @@ -448,13 +454,32 @@ int usb_bind_phy(const char *dev_name, u8 index,
> EXPORT_SYMBOL_GPL(usb_bind_phy);
>
> /**
> - * usb_phy_set_event - set event to phy event
> + * usb_phy_set_event - set event to phy event and
> + * hold/temporarily hold wakeupsource
> * @x: the phy returned by usb_get_phy();
> *
> - * This sets event to phy event
> + * This holds per-PHY wakeupsource/timed wakeupsource
> */
> void usb_phy_set_event(struct usb_phy *x, unsigned long event) {
> +
> x->last_event = event;
> +
> + switch (event) {
> + case USB_EVENT_ENUMERATED:
> + __pm_stay_awake(&x->wsource);
> + break;
> +
> + case USB_EVENT_NONE:
> + case USB_EVENT_ID:
> + case USB_EVENT_VBUS:
> + case USB_EVENT_CHARGER:
> + __pm_wakeup_event(&x->wsource,
> + USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT);
> + break;
> +
> + default:
> + break;
> + }
> }
> EXPORT_SYMBOL_GPL(usb_phy_set_event);
> diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h index
> f499c23..63a56bf 100644
> --- a/include/linux/usb/phy.h
> +++ b/include/linux/usb/phy.h
> @@ -12,6 +12,8 @@
> #include <linux/notifier.h>
> #include <linux/usb.h>
>
> +#define USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT
> msecs_to_jiffies(2000)
> +
> enum usb_phy_interface {
> USBPHY_INTERFACE_MODE_UNKNOWN,
> USBPHY_INTERFACE_MODE_UTMI,
> @@ -88,6 +90,9 @@ struct usb_phy {
> /* for notification of usb_phy_events */
> struct atomic_notifier_head notifier;
>
> + /* wakeup source */
> + struct wakeup_source wsource;
> +
> /* to pass extra port status to the root hub */
> u16 port_status;
> u16 port_change;
> --
> 1.9.1
>
> --
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