On Thu, May 18, 2017 at 08:49:00AM +0800, Peter Chen wrote:
> Some hard-wired USB devices need to do power sequence to let the
> device work normally, the typical power sequence like: enable USB
> PHY clock, toggle reset pin, etc. But current Linux USB driver
> lacks of such code to do it, it may cause some hard-wired USB devices
> works abnormal or can't be recognized by controller at all.
>
> In this patch, it calls power sequence library APIs to finish
> the power sequence events. It will do power on sequence at hub's
> probe for all devices under this hub (includes root hub).
> At hub_disconnect, it will do power off sequence which is at powered
> on list.
>
Greg, Alan, would you please help on reviewing it? It seems Rafael
is waiting for USB MAINTAINERS's comments or ack. It resolves some
USB HUB issues for several persons.
Peter
> Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
> Tested-by Joshua Clayton <stillcompiling@xxxxxxxxx>
> Tested-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Vaibhav Hiremath <hvaibhav.linux@xxxxxxxxx>
> ---
> drivers/usb/Kconfig | 1 +
> drivers/usb/core/hub.c | 49 +++++++++++++++++++++++++++++++++++++++++++++----
> drivers/usb/core/hub.h | 1 +
> 3 files changed, 47 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
> index 939a63b..b6f626e 100644
> --- a/drivers/usb/Kconfig
> +++ b/drivers/usb/Kconfig
> @@ -39,6 +39,7 @@ config USB
> tristate "Support for Host-side USB"
> depends on USB_ARCH_HAS_HCD
> select USB_COMMON
> + select POWER_SEQUENCE
> select NLS # for UTF-8 strings
> ---help---
> Universal Serial Bus (USB) is a specification for a serial bus
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 9dca59e..7a67296 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -28,6 +28,7 @@
> #include <linux/mutex.h>
> #include <linux/random.h>
> #include <linux/pm_qos.h>
> +#include <linux/power/pwrseq.h>
>
> #include <linux/uaccess.h>
> #include <asm/byteorder.h>
> @@ -1619,6 +1620,7 @@ static void hub_disconnect(struct usb_interface *intf)
> hub->error = 0;
> hub_quiesce(hub, HUB_DISCONNECT);
>
> + of_pwrseq_off_list(&hub->pwrseq_on_list);
> mutex_lock(&usb_port_peer_mutex);
>
> /* Avoid races with recursively_mark_NOTATTACHED() */
> @@ -1646,12 +1648,42 @@ static void hub_disconnect(struct usb_interface *intf)
> kref_put(&hub->kref, hub_release);
> }
>
> +#ifdef CONFIG_OF
> +static int hub_of_pwrseq_on(struct usb_hub *hub)
> +{
> + struct device *parent;
> + struct usb_device *hdev = hub->hdev;
> + struct device_node *np;
> + int ret;
> +
> + if (hdev->parent)
> + parent = &hdev->dev;
> + else
> + parent = bus_to_hcd(hdev->bus)->self.sysdev;
> +
> + for_each_child_of_node(parent->of_node, np) {
> + ret = of_pwrseq_on_list(np, &hub->pwrseq_on_list);
> + /* Maybe no power sequence library is chosen */
> + if (ret && ret != -ENOENT)
> + return ret;
> + }
> +
> + return 0;
> +}
> +#else
> +static int hub_of_pwrseq_on(struct usb_hub *hub)
> +{
> + return 0;
> +}
> +#endif
> +
> static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> {
> struct usb_host_interface *desc;
> struct usb_endpoint_descriptor *endpoint;
> struct usb_device *hdev;
> struct usb_hub *hub;
> + int ret = -ENODEV;
>
> desc = intf->cur_altsetting;
> hdev = interface_to_usbdev(intf);
> @@ -1756,6 +1788,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> INIT_DELAYED_WORK(&hub->leds, led_work);
> INIT_DELAYED_WORK(&hub->init_work, NULL);
> INIT_WORK(&hub->events, hub_event);
> + INIT_LIST_HEAD(&hub->pwrseq_on_list);
> usb_get_intf(intf);
> usb_get_dev(hdev);
>
> @@ -1769,11 +1802,14 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
> hub->quirk_check_port_auto_suspend = 1;
>
> - if (hub_configure(hub, endpoint) >= 0)
> - return 0;
> + if (hub_configure(hub, endpoint) >= 0) {
> + ret = hub_of_pwrseq_on(hub);
> + if (!ret)
> + return 0;
> + }
>
> hub_disconnect(intf);
> - return -ENODEV;
> + return ret;
> }
>
> static int
> @@ -3593,14 +3629,19 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
>
> /* stop hub_wq and related activity */
> hub_quiesce(hub, HUB_SUSPEND);
> - return 0;
> + return pwrseq_suspend_list(&hub->pwrseq_on_list);
> }
>
> static int hub_resume(struct usb_interface *intf)
> {
> struct usb_hub *hub = usb_get_intfdata(intf);
> + int ret;
>
> dev_dbg(&intf->dev, "%s\n", __func__);
> + ret = pwrseq_resume_list(&hub->pwrseq_on_list);
> + if (ret)
> + return ret;
> +
> hub_activate(hub, HUB_RESUME);
> return 0;
> }
> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> index 34c1a7e..cd86f91 100644
> --- a/drivers/usb/core/hub.h
> +++ b/drivers/usb/core/hub.h
> @@ -78,6 +78,7 @@ struct usb_hub {
> struct delayed_work init_work;
> struct work_struct events;
> struct usb_port **ports;
> + struct list_head pwrseq_on_list; /* powered pwrseq node list */
> };
>
> /**
> --
> 2.7.4
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Best Regards,
Peter Chen
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