Re: [PATCH v2 1/8] usb: chipidea: core: add controller resume support when controller is powered off

[Peter Chen <peter.chen@kernel.org>]

On 22-10-13 23:14:35, Xu Yang wrote:
> For some SoCs, the controler's power will be off during the system
> suspend, and it needs some recovery operation to let the system back
> to workable. We add this support in this patch.
> 
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Acked-by: Peter Chen <peter.chen@kernel.org>

Peter

> 
> ---
> Changes since v1:
> - add static modifer for ci_handle_power_lost().
> ---
>  drivers/usb/chipidea/core.c | 80 ++++++++++++++++++++++++++++---------
>  drivers/usb/chipidea/otg.c  |  2 +-
>  drivers/usb/chipidea/otg.h  |  1 +
>  3 files changed, 63 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
> index ae90fee75a32..80267b973c26 100644
> --- a/drivers/usb/chipidea/core.c
> +++ b/drivers/usb/chipidea/core.c
> @@ -637,6 +637,49 @@ static int ci_usb_role_switch_set(struct usb_role_switch *sw,
>  	return 0;
>  }
>  
> +static enum ci_role ci_get_role(struct ci_hdrc *ci)
> +{
> +	enum ci_role role;
> +
> +	if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
> +		if (ci->is_otg) {
> +			role = ci_otg_role(ci);
> +			hw_write_otgsc(ci, OTGSC_IDIE, OTGSC_IDIE);
> +		} else {
> +			/*
> +			 * If the controller is not OTG capable, but support
> +			 * role switch, the defalt role is gadget, and the
> +			 * user can switch it through debugfs.
> +			 */
> +			role = CI_ROLE_GADGET;
> +		}
> +	} else {
> +		role = ci->roles[CI_ROLE_HOST] ? CI_ROLE_HOST
> +					: CI_ROLE_GADGET;
> +	}
> +
> +	return role;
> +}
> +
> +static void ci_handle_power_lost(struct ci_hdrc *ci)
> +{
> +	enum ci_role role;
> +
> +	disable_irq_nosync(ci->irq);
> +	if (!ci_otg_is_fsm_mode(ci)) {
> +		role = ci_get_role(ci);
> +
> +		if (ci->role != role) {
> +			ci_handle_id_switch(ci);
> +		} else if (role == CI_ROLE_GADGET) {
> +			if (ci->is_otg && hw_read_otgsc(ci, OTGSC_BSV))
> +				usb_gadget_vbus_connect(&ci->gadget);
> +		}
> +	}
> +
> +	enable_irq(ci->irq);
> +}
> +
>  static struct usb_role_switch_desc ci_role_switch = {
>  	.set = ci_usb_role_switch_set,
>  	.get = ci_usb_role_switch_get,
> @@ -1134,25 +1177,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
> -		if (ci->is_otg) {
> -			ci->role = ci_otg_role(ci);
> -			/* Enable ID change irq */
> -			hw_write_otgsc(ci, OTGSC_IDIE, OTGSC_IDIE);
> -		} else {
> -			/*
> -			 * If the controller is not OTG capable, but support
> -			 * role switch, the defalt role is gadget, and the
> -			 * user can switch it through debugfs.
> -			 */
> -			ci->role = CI_ROLE_GADGET;
> -		}
> -	} else {
> -		ci->role = ci->roles[CI_ROLE_HOST]
> -			? CI_ROLE_HOST
> -			: CI_ROLE_GADGET;
> -	}
> -
> +	ci->role = ci_get_role(ci);
>  	if (!ci_otg_is_fsm_mode(ci)) {
>  		/* only update vbus status for peripheral */
>  		if (ci->role == CI_ROLE_GADGET) {
> @@ -1374,8 +1399,16 @@ static int ci_suspend(struct device *dev)
>  static int ci_resume(struct device *dev)
>  {
>  	struct ci_hdrc *ci = dev_get_drvdata(dev);
> +	bool power_lost;
>  	int ret;
>  
> +	/* Since ASYNCLISTADDR (host mode) and ENDPTLISTADDR (device
> +	 * mode) share the same register address. We can check if
> +	 * controller resume from power lost based on this address
> +	 * due to this register will be reset after power lost.
> +	 */
> +	power_lost = !hw_read(ci, OP_ENDPTLISTADDR, ~0);
> +
>  	if (device_may_wakeup(dev))
>  		disable_irq_wake(ci->irq);
>  
> @@ -1383,6 +1416,15 @@ static int ci_resume(struct device *dev)
>  	if (ret)
>  		return ret;
>  
> +	if (power_lost) {
> +		/* shutdown and re-init for phy */
> +		ci_usb_phy_exit(ci);
> +		ci_usb_phy_init(ci);
> +	}
> +
> +	if (power_lost)
> +		ci_handle_power_lost(ci);
> +
>  	if (ci->supports_runtime_pm) {
>  		pm_runtime_disable(dev);
>  		pm_runtime_set_active(dev);
> diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
> index 7b53274ef966..622c3b68aa1e 100644
> --- a/drivers/usb/chipidea/otg.c
> +++ b/drivers/usb/chipidea/otg.c
> @@ -165,7 +165,7 @@ static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
>  	return 0;
>  }
>  
> -static void ci_handle_id_switch(struct ci_hdrc *ci)
> +void ci_handle_id_switch(struct ci_hdrc *ci)
>  {
>  	enum ci_role role = ci_otg_role(ci);
>  
> diff --git a/drivers/usb/chipidea/otg.h b/drivers/usb/chipidea/otg.h
> index 5e7a6e571dd2..87629b81e03e 100644
> --- a/drivers/usb/chipidea/otg.h
> +++ b/drivers/usb/chipidea/otg.h
> @@ -14,6 +14,7 @@ int ci_hdrc_otg_init(struct ci_hdrc *ci);
>  void ci_hdrc_otg_destroy(struct ci_hdrc *ci);
>  enum ci_role ci_otg_role(struct ci_hdrc *ci);
>  void ci_handle_vbus_change(struct ci_hdrc *ci);
> +void ci_handle_id_switch(struct ci_hdrc *ci);
>  static inline void ci_otg_queue_work(struct ci_hdrc *ci)
>  {
>  	disable_irq_nosync(ci->irq);
> -- 
> 2.34.1
> 

-- 

Thanks,
Peter Chen