Re: [PATCH v4] usb: chipidea: add role switch class support

[Peter Chen <peter.chen@nxp.com>]

On 19-08-26 18:25:12, jun.li@nxp.com wrote:
> From: Li Jun <jun.li@nxp.com>
> 
> USB role is fully controlled by usb role switch consumer(e.g. typec),
> usb port can be at host mode(USB_ROLE_HOST), device mode connected to
> host(USB_ROLE_DEVICE), or not connecting any partner(USB_ROLE_NONE).
> 
> Signed-off-by: Li Jun <jun.li@nxp.com>
> ---
> changes for v4:
> - Add spinlock for role set().
> - Select USB_ROLE_SWITCH to fix build break.
> - Add runtime PM for role set. 
> - Do flash_workqueue only in case both stop and start required
>   for role set, means role change directly from device to host
>   or vice versa.
> 
> Changes for v3:
> - Remove the patch usb: chipidea: replace ci_role with usb_role
>   as the existing ci->role usage can't map to usb_role.
> - Use the suggested ci_hdrc_cable for reuse current role change
>   handling.
> - Fix build robot warning by add usb_role head file.
> 
> Change for v2:
> - Support USB_ROLE_NONE, which for usb port not connecting any
>   device or host, and will be in low power mode.
> 
>  drivers/usb/chipidea/Kconfig |  1 +
>  drivers/usb/chipidea/ci.h    | 12 +++++++
>  drivers/usb/chipidea/core.c  | 83 ++++++++++++++++++++++++++++++++++++++++++++
>  drivers/usb/chipidea/otg.c   |  8 ++---
>  4 files changed, 100 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
> index eb37ebf..ae850b3 100644
> --- a/drivers/usb/chipidea/Kconfig
> +++ b/drivers/usb/chipidea/Kconfig
> @@ -6,6 +6,7 @@ config USB_CHIPIDEA
>  	select EXTCON
>  	select RESET_CONTROLLER
>  	select USB_ULPI_BUS
> +	select USB_ROLE_SWITCH
>  	help
>  	  Say Y here if your system has a dual role high speed USB
>  	  controller based on ChipIdea silicon IP. It supports:
> diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
> index 6a2cc5c..6911aef 100644
> --- a/drivers/usb/chipidea/ci.h
> +++ b/drivers/usb/chipidea/ci.h
> @@ -16,6 +16,7 @@
>  #include <linux/usb/gadget.h>
>  #include <linux/usb/otg-fsm.h>
>  #include <linux/usb/otg.h>
> +#include <linux/usb/role.h>
>  #include <linux/ulpi/interface.h>
>  
>  /******************************************************************************
> @@ -217,6 +218,7 @@ struct ci_hdrc {
>  	ktime_t				hr_timeouts[NUM_OTG_FSM_TIMERS];
>  	unsigned			enabled_otg_timer_bits;
>  	enum otg_fsm_timer		next_otg_timer;
> +	struct usb_role_switch		*role_switch;
>  	struct work_struct		work;
>  	struct workqueue_struct		*wq;
>  
> @@ -290,6 +292,16 @@ static inline void ci_role_stop(struct ci_hdrc *ci)
>  	ci->roles[role]->stop(ci);
>  }
>  
> +static inline enum usb_role ci_role_to_usb_role(struct ci_hdrc *ci)
> +{
> +	if (ci->role == CI_ROLE_HOST)
> +		return USB_ROLE_HOST;
> +	else if (ci->role == CI_ROLE_GADGET && ci->vbus_active)
> +		return USB_ROLE_DEVICE;
> +	else
> +		return USB_ROLE_NONE;
> +}
> +
>  /**
>   * hw_read_id_reg: reads from a identification register
>   * @ci: the controller
> diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
> index 26062d6..bfc6a18 100644
> --- a/drivers/usb/chipidea/core.c
> +++ b/drivers/usb/chipidea/core.c
> @@ -600,6 +600,71 @@ static int ci_cable_notifier(struct notifier_block *nb, unsigned long event,
>  	return NOTIFY_DONE;
>  }
>  
> +static enum usb_role ci_usb_role_switch_get(struct device *dev)
> +{
> +	struct ci_hdrc *ci = dev_get_drvdata(dev);
> +	enum usb_role role;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&ci->lock, flags);
> +	role = ci_role_to_usb_role(ci);
> +	spin_unlock_irqrestore(&ci->lock, flags);
> +
> +	return role;
> +}
> +
> +static int ci_usb_role_switch_set(struct device *dev, enum usb_role role)
> +{
> +	struct ci_hdrc *ci = dev_get_drvdata(dev);
> +	struct ci_hdrc_cable *cable = NULL;
> +	enum usb_role current_role = ci_role_to_usb_role(ci);
> +	unsigned long flags;
> +
> +	if (current_role == role)
> +		return 0;
> +
> +	pm_runtime_get_sync(ci->dev);
> +	/* Stop current role */
> +	spin_lock_irqsave(&ci->lock, flags);
> +	if (current_role == USB_ROLE_DEVICE)
> +		cable = &ci->platdata->vbus_extcon;
> +	else if (current_role == USB_ROLE_HOST)
> +		cable = &ci->platdata->id_extcon;
> +
> +	if (cable) {
> +		cable->changed = true;
> +		cable->connected = false;
> +		ci_irq(ci->irq, ci);
> +		spin_unlock_irqrestore(&ci->lock, flags);
> +		if (ci->wq && role != USB_ROLE_NONE)
> +			flush_workqueue(ci->wq);
> +		spin_lock_irqsave(&ci->lock, flags);
> +	}
> +
> +	cable = NULL;
> +
> +	/* Start target role */
> +	if (role == USB_ROLE_DEVICE)
> +		cable = &ci->platdata->vbus_extcon;
> +	else if (role == USB_ROLE_HOST)
> +		cable = &ci->platdata->id_extcon;
> +
> +	if (cable) {
> +		cable->changed = true;
> +		cable->connected = true;
> +		ci_irq(ci->irq, ci);
> +	}
> +	spin_unlock_irqrestore(&ci->lock, flags);
> +	pm_runtime_put_sync(ci->dev);
> +
> +	return 0;
> +}
> +
> +static struct usb_role_switch_desc ci_role_switch = {
> +	.set = ci_usb_role_switch_set,
> +	.get = ci_usb_role_switch_get,
> +};
> +
>  static int ci_get_platdata(struct device *dev,
>  		struct ci_hdrc_platform_data *platdata)
>  {
> @@ -726,6 +791,9 @@ static int ci_get_platdata(struct device *dev,
>  			cable->connected = false;
>  	}
>  
> +	if (device_property_read_bool(dev, "usb-role-switch"))
> +		ci_role_switch.fwnode = dev->fwnode;
> +
>  	platdata->pctl = devm_pinctrl_get(dev);
>  	if (!IS_ERR(platdata->pctl)) {
>  		struct pinctrl_state *p;
> @@ -1051,6 +1119,15 @@ static int ci_hdrc_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	if (ci_role_switch.fwnode) {
> +		ci->role_switch = usb_role_switch_register(dev,
> +					&ci_role_switch);
> +		if (IS_ERR(ci->role_switch)) {
> +			ret = PTR_ERR(ci->role_switch);
> +			goto deinit_otg;
> +		}
> +	}
> +
>  	if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
>  		if (ci->is_otg) {
>  			ci->role = ci_otg_role(ci);
> @@ -1115,6 +1192,9 @@ static int ci_hdrc_probe(struct platform_device *pdev)
>  remove_debug:
>  	dbg_remove_files(ci);
>  stop:
> +	if (ci->role_switch)
> +		usb_role_switch_unregister(ci->role_switch);
> +deinit_otg:
>  	if (ci->is_otg && ci->roles[CI_ROLE_GADGET])
>  		ci_hdrc_otg_destroy(ci);
>  deinit_gadget:
> @@ -1133,6 +1213,9 @@ static int ci_hdrc_remove(struct platform_device *pdev)
>  {
>  	struct ci_hdrc *ci = platform_get_drvdata(pdev);
>  
> +	if (ci->role_switch)
> +		usb_role_switch_unregister(ci->role_switch);
> +
>  	if (ci->supports_runtime_pm) {
>  		pm_runtime_get_sync(&pdev->dev);
>  		pm_runtime_disable(&pdev->dev);
> diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
> index f25d482..fbfb02e 100644
> --- a/drivers/usb/chipidea/otg.c
> +++ b/drivers/usb/chipidea/otg.c
> @@ -35,7 +35,7 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
>  	 * detection overwrite OTGSC register value
>  	 */
>  	cable = &ci->platdata->vbus_extcon;
> -	if (!IS_ERR(cable->edev)) {
> +	if (!IS_ERR(cable->edev) || ci->role_switch) {
>  		if (cable->changed)
>  			val |= OTGSC_BSVIS;
>  		else
> @@ -53,7 +53,7 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
>  	}
>  
>  	cable = &ci->platdata->id_extcon;
> -	if (!IS_ERR(cable->edev)) {
> +	if (!IS_ERR(cable->edev) || ci->role_switch) {
>  		if (cable->changed)
>  			val |= OTGSC_IDIS;
>  		else
> @@ -83,7 +83,7 @@ void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
>  	struct ci_hdrc_cable *cable;
>  
>  	cable = &ci->platdata->vbus_extcon;
> -	if (!IS_ERR(cable->edev)) {
> +	if (!IS_ERR(cable->edev) || ci->role_switch) {
>  		if (data & mask & OTGSC_BSVIS)
>  			cable->changed = false;
>  
> @@ -97,7 +97,7 @@ void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
>  	}
>  
>  	cable = &ci->platdata->id_extcon;
> -	if (!IS_ERR(cable->edev)) {
> +	if (!IS_ERR(cable->edev) || ci->role_switch) {
>  		if (data & mask & OTGSC_IDIS)
>  			cable->changed = false;
>  
> -- 
> 2.7.4
> 

Applied, thanks.

Peter