On Wed, Mar 18, 2015 at 03:55:55PM +0200, Roger Quadros wrote:
> To support OTG we want a mechanism to start and stop
> the HCD from the OTG state machine. Add usb_start_hcd()
> and usb_stop_hcd().
Hi Roger,
You may not need to create another pair of hcd APIs for doing
it, you can use usb_add_hcd/usb_remove_hcd directly, it is safer
and cleaner. The chipidea uses it for both ID role switch use case
and OTG FSM use case.
Peter
>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> ---
> drivers/usb/core/hcd.c | 147 ++++++++++++++++++++++++++++++++----------------
> include/linux/usb/hcd.h | 2 +
> 2 files changed, 100 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 45a915c..e28bd9d 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2613,7 +2613,76 @@ static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
> }
>
> /**
> - * usb_add_hcd - finish generic HCD structure initialization and register
> + * usb_start_hcd - start the HCD
> + * @hcd: the usb_hcd structure to initialize
> + *
> + * calls the drivers start() routine, registers the root hub
> + * and creates the USB sysfs attributes.
> + */
> +int usb_start_hcd(struct usb_hcd *hcd)
> +{
> + int retval;
> + struct usb_device *rhdev = hcd->self.root_hub;
> +
> + if (hcd->state != HC_STATE_HALT) {
> + dev_err(hcd->self.controller, "not starting a running HCD\n");
> + return -EINVAL;
> + }
> +
> + hcd->state = HC_STATE_RUNNING;
> + retval = hcd->driver->start(hcd);
> + if (retval < 0) {
> + dev_err(hcd->self.controller, "startup error %d\n", retval);
> + hcd->state = HC_STATE_HALT;
> + return retval;
> + }
> +
> + /* starting here, usbcore will pay attention to this root hub */
> + if ((retval = register_root_hub(hcd)) != 0)
> + goto err_register_root_hub;
> +
> + retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
> + if (retval < 0) {
> + pr_err("Cannot register USB bus sysfs attributes: %d\n",
> + retval);
> + goto error_create_attr_group;
> + }
> + if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
> + usb_hcd_poll_rh_status(hcd);
> +
> + return retval;
> +
> +error_create_attr_group:
> + clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
> + if (HC_IS_RUNNING(hcd->state))
> + hcd->state = HC_STATE_QUIESCING;
> + spin_lock_irq(&hcd_root_hub_lock);
> + hcd->rh_registered = 0;
> + spin_unlock_irq(&hcd_root_hub_lock);
> +
> +#ifdef CONFIG_PM
> + cancel_work_sync(&hcd->wakeup_work);
> +#endif
> + mutex_lock(&usb_bus_list_lock);
> + usb_disconnect(&rhdev); /* Sets rhdev to NULL */
> + mutex_unlock(&usb_bus_list_lock);
> +err_register_root_hub:
> + hcd->rh_pollable = 0;
> + clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
> + del_timer_sync(&hcd->rh_timer);
> + hcd->driver->stop(hcd);
> + hcd->state = HC_STATE_HALT;
> +
> + /* In case the HCD restarted the timer, stop it again. */
> + clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
> + del_timer_sync(&hcd->rh_timer);
> +
> + return retval;
> +}
> +EXPORT_SYMBOL_GPL(usb_start_hcd);
> +
> +/**
> + * usb_add_hcd - finish generic HCD structure initialization and register.
> * @hcd: the usb_hcd structure to initialize
> * @irqnum: Interrupt line to allocate
> * @irqflags: Interrupt type flags
> @@ -2757,50 +2826,12 @@ int usb_add_hcd(struct usb_hcd *hcd,
> goto err_request_irq;
> }
>
> - hcd->state = HC_STATE_RUNNING;
> - retval = hcd->driver->start(hcd);
> - if (retval < 0) {
> - dev_err(hcd->self.controller, "startup error %d\n", retval);
> + retval = usb_start_hcd(hcd);
> + if (retval)
> goto err_hcd_driver_start;
> - }
> -
> - /* starting here, usbcore will pay attention to this root hub */
> - if ((retval = register_root_hub(hcd)) != 0)
> - goto err_register_root_hub;
> -
> - retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
> - if (retval < 0) {
> - printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
> - retval);
> - goto error_create_attr_group;
> - }
> - if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
> - usb_hcd_poll_rh_status(hcd);
> -
> - return retval;
>
> -error_create_attr_group:
> - clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
> - if (HC_IS_RUNNING(hcd->state))
> - hcd->state = HC_STATE_QUIESCING;
> - spin_lock_irq(&hcd_root_hub_lock);
> - hcd->rh_registered = 0;
> - spin_unlock_irq(&hcd_root_hub_lock);
> + return 0;
>
> -#ifdef CONFIG_PM
> - cancel_work_sync(&hcd->wakeup_work);
> -#endif
> - mutex_lock(&usb_bus_list_lock);
> - usb_disconnect(&rhdev); /* Sets rhdev to NULL */
> - mutex_unlock(&usb_bus_list_lock);
> -err_register_root_hub:
> - hcd->rh_pollable = 0;
> - clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
> - del_timer_sync(&hcd->rh_timer);
> - hcd->driver->stop(hcd);
> - hcd->state = HC_STATE_HALT;
> - clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
> - del_timer_sync(&hcd->rh_timer);
> err_hcd_driver_start:
> if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
> free_irq(irqnum, hcd);
> @@ -2830,18 +2861,20 @@ err_phy:
> EXPORT_SYMBOL_GPL(usb_add_hcd);
>
> /**
> - * usb_remove_hcd - shutdown processing for generic HCDs
> - * @hcd: the usb_hcd structure to remove
> - * Context: !in_interrupt()
> + * usb_stop_hcd - stop the HCD
> + * @hcd: the usb_hcd structure to initialize
> *
> - * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
> - * invoking the HCD's stop() method.
> + * removes the USB sysfs attributes, disconnects the root hub
> + * and calls the driver's stop() routine.
> */
> -void usb_remove_hcd(struct usb_hcd *hcd)
> +void usb_stop_hcd(struct usb_hcd *hcd)
> {
> struct usb_device *rhdev = hcd->self.root_hub;
>
> - dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
> + if (hcd->state == HC_STATE_HALT) {
> + dev_err(hcd->self.controller, "not stopping a halted HCD\n");
> + return;
> + }
>
> usb_get_dev(rhdev);
> sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
> @@ -2888,6 +2921,22 @@ void usb_remove_hcd(struct usb_hcd *hcd)
> /* In case the HCD restarted the timer, stop it again. */
> clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
> del_timer_sync(&hcd->rh_timer);
> +}
> +EXPORT_SYMBOL_GPL(usb_stop_hcd);
> +
> +/**
> + * usb_remove_hcd - shutdown processing for generic HCDs
> + * @hcd: the usb_hcd structure to remove
> + * Context: !in_interrupt()
> + *
> + * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
> + * invoking the HCD's stop() method.
> + */
> +void usb_remove_hcd(struct usb_hcd *hcd)
> +{
> + dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
> +
> + usb_stop_hcd(hcd);
>
> if (usb_hcd_is_primary_hcd(hcd)) {
> if (hcd->irq > 0)
> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> index 68b1e83..12aaf4c 100644
> --- a/include/linux/usb/hcd.h
> +++ b/include/linux/usb/hcd.h
> @@ -433,6 +433,8 @@ extern void usb_put_hcd(struct usb_hcd *hcd);
> extern int usb_hcd_is_primary_hcd(struct usb_hcd *hcd);
> extern int usb_add_hcd(struct usb_hcd *hcd,
> unsigned int irqnum, unsigned long irqflags);
> +extern int usb_start_hcd(struct usb_hcd *hcd);
> +extern void usb_stop_hcd(struct usb_hcd *hcd);
> extern void usb_remove_hcd(struct usb_hcd *hcd);
> extern int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1);
>
> --
> 2.1.0
>
--
Best Regards,
Peter Chen
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