> -----Original Message-----
> From: Peter Chen <peter.chen@xxxxxxx>
> Sent: Monday, June 8, 2020 3:11 PM
> To: balbi@xxxxxxxxxx; mathias.nyman@xxxxxxxxx
> Cc: linux-usb@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>;
> pawell@xxxxxxxxxxx; rogerq@xxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; Jun Li
> <jun.li@xxxxxxx>; Peter Chen <peter.chen@xxxxxxx>
> Subject: [PATCH v3 2/9] usb: cdns3: add runtime PM support
>
> Introduce runtime PM and wakeup interrupt handler for cdns3, the runtime PM is default
> off since other cdns3 may not implement glue layer support for runtime PM.
>
> One typical wakeup event use case is xHCI runtime suspend will clear USBCMD.RS bit,
> after that the xHCI will not trigger any interrupts, so its parent (cdns core device)
> needs to resume xHCI device when any (wakeup) events occurs at host port.
>
> When the controller is in low power mode, the lpm flag will be set.
> The interrupt triggered later than lpm flag is set considers as wakeup interrupt
> and handled at cdns_wakeup_irq. Once the wakeup occurs, it first disables interrupt
> to avoid later interrupt occurrence since the controller is in low power mode at
> that time, and access registers may be invalid at that time. At wakeup handler,
> it will call pm_request_resume to wakeup xHCI device, and at runtime resume handler,
> it will enable interrupt again.
>
> The API platform_suspend is introduced for glue layer to implement platform specific
> PM sequence.
>
> Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
> ---
> drivers/usb/cdns3/core.c | 155 +++++++++++++++++++++++++++++++++----
> drivers/usb/cdns3/core.h | 16 ++++
> drivers/usb/cdns3/drd.c | 3 +
> drivers/usb/cdns3/gadget.c | 4 +
> drivers/usb/cdns3/host.c | 7 ++
> 5 files changed, 168 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c index
> bfd09aa98c12..97fb082ed3b4 100644
> --- a/drivers/usb/cdns3/core.c
> +++ b/drivers/usb/cdns3/core.c
> @@ -406,6 +406,30 @@ static int cdns3_set_phy_power(struct cdns3 *cdns, bool on)
> return 0;
> }
>
> +/**
> + * cdns3_wakeup_irq - interrupt handler for wakeup events
> + *
> + * @irq: irq number for cdns3 core device
> + * @data: structure of cdns3
> + *
> + * Returns IRQ_HANDLED or IRQ_NONE
> + */
> +static irqreturn_t cdns3_wakeup_irq(int irq, void *data) {
> + struct cdns3 *cdns = data;
> +
> + if (cdns->in_lpm) {
> + disable_irq_nosync(irq);
> + cdns->wakeup_int = true;
> + if ((cdns->role == USB_ROLE_HOST) && cdns->host_dev)
> + pm_request_resume(&cdns->host_dev->dev);
> +
> + return IRQ_HANDLED;
> + }
> +
> + return IRQ_NONE;
> +}
> +
> /**
> * cdns3_probe - probe for cdns3 core device
> * @pdev: Pointer to cdns3 core platform device @@ -432,6 +456,7 @@ static int
> cdns3_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> cdns->dev = dev;
> + cdns->pdata = dev_get_platdata(dev);
>
> platform_set_drvdata(pdev, cdns);
>
> @@ -481,6 +506,15 @@ static int cdns3_probe(struct platform_device *pdev)
>
> cdns->otg_res = *res;
>
> + cdns->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
platform_get_irq_byname_optional
> + if (cdns->wakeup_irq == -EPROBE_DEFER)
> + return cdns->wakeup_irq;
> +
> + if (cdns->wakeup_irq < 0) {
> + dev_dbg(dev, "couldn't get wakeup irq\n");
> + cdns->wakeup_irq = 0x0;
> + }
> +
> mutex_init(&cdns->mutex);
>
> cdns->usb2_phy = devm_phy_optional_get(dev, "cdns3,usb2-phy"); @@ -517,6
> +551,19 @@ static int cdns3_probe(struct platform_device *pdev)
> goto err3;
> }
>
> + if (cdns->wakeup_irq) {
> + ret = devm_request_threaded_irq(cdns->dev, cdns->wakeup_irq,
> + cdns3_wakeup_irq,
> + NULL,
> + IRQF_SHARED,
> + dev_name(cdns->dev), cdns);
> +
> + if (ret) {
> + dev_err(cdns->dev, "couldn't register wakeup irq handler\n");
> + goto err3;
> + }
> + }
> +
> ret = cdns3_drd_init(cdns);
> if (ret)
> goto err4;
> @@ -525,9 +572,11 @@ static int cdns3_probe(struct platform_device *pdev)
> if (ret)
> goto err4;
>
> + spin_lock_init(&cdns->lock);
> device_set_wakeup_capable(dev, true);
> pm_runtime_set_active(dev);
> pm_runtime_enable(dev);
> + pm_runtime_forbid(dev);
>
> /*
> * The controller needs less time between bus and controller suspend, @@ -574,52
> +623,124 @@ static int cdns3_remove(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_PM
>
> -static int cdns3_suspend(struct device *dev)
> +static int cdns3_set_platform_suspend(struct device *dev,
> + bool suspend, bool wakeup)
> +{
> + struct cdns3 *cdns = dev_get_drvdata(dev);
> + int ret = 0;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&cdns->lock, flags);
This really need a big spinlock for all platforms specific
suspend operations? I see you have a 100us polling in your
platform_suspend implementation, and also the spinlock
seems can be inside your implementation to protect really
needed part.
> + if (cdns->pdata && cdns->pdata->platform_suspend)
> + ret = cdns->pdata->platform_suspend(dev, suspend, wakeup);
> +
> + spin_unlock_irqrestore(&cdns->lock, flags);
> +
> + return ret;
> +}
> +
> +static int cdns3_controller_suspend(struct device *dev, pm_message_t
> +msg)
> {
> struct cdns3 *cdns = dev_get_drvdata(dev);
> + bool wakeup;
> unsigned long flags;
>
> - if (cdns->role == USB_ROLE_HOST)
> + if (cdns->in_lpm)
> return 0;
>
> - if (pm_runtime_status_suspended(dev))
> - pm_runtime_resume(dev);
> + if (PMSG_IS_AUTO(msg))
> + wakeup = true;
> + else
> + wakeup = device_may_wakeup(dev);
>
> - if (cdns->roles[cdns->role]->suspend) {
> - spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
> - cdns->roles[cdns->role]->suspend(cdns, false);
> - spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
> - }
> + cdns3_set_platform_suspend(cdns->dev, true, wakeup);
> + cdns3_set_phy_power(cdns, false);
> + spin_lock_irqsave(&cdns->lock, flags);
> + cdns->in_lpm = true;
> + spin_unlock_irqrestore(&cdns->lock, flags);
>
> return 0;
> }
>
> -static int cdns3_resume(struct device *dev)
> +static int cdns3_controller_resume(struct device *dev, pm_message_t
> +msg)
> {
> struct cdns3 *cdns = dev_get_drvdata(dev);
> + int ret;
> unsigned long flags;
>
> - if (cdns->role == USB_ROLE_HOST)
> + if (!cdns->in_lpm)
> return 0;
>
> - if (cdns->roles[cdns->role]->resume) {
> - spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
> + ret = cdns3_set_phy_power(cdns, true);
> + if (ret)
> + return ret;
> +
> + cdns3_set_platform_suspend(cdns->dev, false, false);
> +
> + spin_lock_irqsave(&cdns->lock, flags);
> + if (cdns->roles[cdns->role]->resume && !PMSG_IS_AUTO(msg))
> cdns->roles[cdns->role]->resume(cdns, false);
> - spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
> +
> + cdns->in_lpm = false;
> + spin_unlock_irqrestore(&cdns->lock, flags);
> + if (cdns->wakeup_int) {
> + cdns->wakeup_int = false;
> + enable_irq(cdns->otg_irq);
enable_irq(cdns->wakeup_irq)
> }
>
> + return ret;
> +}
> +
> +static int cdns3_runtime_suspend(struct device *dev) {
> + return cdns3_controller_suspend(dev, PMSG_AUTO_SUSPEND); }
> +
> +static int cdns3_runtime_resume(struct device *dev) {
> + return cdns3_controller_resume(dev, PMSG_AUTO_RESUME); } #ifdef
> +CONFIG_PM_SLEEP
> +
> +static int cdns3_suspend(struct device *dev) {
> + struct cdns3 *cdns = dev_get_drvdata(dev);
> + unsigned long flags;
> +
> + if (pm_runtime_status_suspended(dev))
> + pm_runtime_resume(dev);
> +
> + if (cdns->roles[cdns->role]->suspend) {
> + spin_lock_irqsave(&cdns->lock, flags);
> + cdns->roles[cdns->role]->suspend(cdns, false);
> + spin_unlock_irqrestore(&cdns->lock, flags);
> + }
> +
> + return cdns3_controller_suspend(dev, PMSG_SUSPEND); }
> +
> +static int cdns3_resume(struct device *dev) {
> + int ret;
> +
> + ret = cdns3_controller_resume(dev, PMSG_RESUME);
> + if (ret)
> + return ret;
> +
> pm_runtime_disable(dev);
> pm_runtime_set_active(dev);
> pm_runtime_enable(dev);
>
> - return 0;
> + return ret;
> }
> -#endif
> +#endif /* CONFIG_PM_SLEEP */
> +#endif /* CONFIG_PM */
>
> static const struct dev_pm_ops cdns3_pm_ops = {
> SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
> + SET_RUNTIME_PM_OPS(cdns3_runtime_suspend, cdns3_runtime_resume, NULL)
> };
>
> #ifdef CONFIG_OF
> diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h index
> 1ad1f1fe61e9..fdbcf557a61f 100644
> --- a/drivers/usb/cdns3/core.h
> +++ b/drivers/usb/cdns3/core.h
> @@ -38,6 +38,12 @@ struct cdns3_role_driver { };
>
> #define CDNS3_XHCI_RESOURCES_NUM 2
> +
> +struct cdns3_platform_data {
> + int (*platform_suspend)(struct device *dev,
> + bool suspend, bool wakeup);
> +};
> +
> /**
> * struct cdns3 - Representation of Cadence USB3 DRD controller.
> * @dev: pointer to Cadence device struct @@ -50,6 +56,7 @@ struct cdns3_role_driver
> {
> * @otg_regs: pointer to base of otg registers
> * @otg_irq: irq number for otg controller
> * @dev_irq: irq number for device controller
> + * @dev_irq: irq number for wakeup event
@wakeup_irq
> * @roles: array of supported roles for this controller
> * @role: current role
> * @host_dev: the child host device pointer for cdns3 core @@ -62,6 +69,10 @@ struct
> cdns3_role_driver {
> * This field based on firmware setting, kernel configuration
> * and hardware configuration.
> * @role_sw: pointer to role switch object.
> + * @in_lpm: indicate the controller is in low power mode
> + * @wakeup_int: wakeup interrupt occurs
> + * @pdata: platform data from glue layer
> + * @lock: spinlock structure
> */
> struct cdns3 {
> struct device *dev;
> @@ -79,6 +90,7 @@ struct cdns3 {
>
> int otg_irq;
> int dev_irq;
> + int wakeup_irq;
> struct cdns3_role_driver *roles[USB_ROLE_DEVICE + 1];
> enum usb_role role;
> struct platform_device *host_dev;
> @@ -89,6 +101,10 @@ struct cdns3 {
> struct mutex mutex;
> enum usb_dr_mode dr_mode;
> struct usb_role_switch *role_sw;
> + bool in_lpm;
> + bool wakeup_int;
Too close to wakeup_irq, maybe wakeup_pending?
Li Jun
> + struct cdns3_platform_data *pdata;
> + spinlock_t lock;
> };
>
> int cdns3_hw_role_switch(struct cdns3 *cdns); diff --git
> a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c index
> 58089841ed52..ac90a484e63c 100644
> --- a/drivers/usb/cdns3/drd.c
> +++ b/drivers/usb/cdns3/drd.c
> @@ -281,6 +281,9 @@ static irqreturn_t cdns3_drd_irq(int irq, void *data)
> if (cdns->dr_mode != USB_DR_MODE_OTG)
> return ret;
>
> + if (cdns->in_lpm)
> + return ret;
> +
> reg = readl(&cdns->otg_regs->ivect);
>
> if (!reg)
> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c index
> 7babba9dd916..eac01b1a4958 100644
> --- a/drivers/usb/cdns3/gadget.c
> +++ b/drivers/usb/cdns3/gadget.c
> @@ -1765,9 +1765,13 @@ static void cdns3_check_usb_interrupt_proceed(struct
> cdns3_device *priv_dev, static irqreturn_t cdns3_device_irq_handler(int irq, void
> *data) {
> struct cdns3_device *priv_dev = data;
> + struct cdns3 *cdns = dev_get_drvdata(priv_dev->dev);
> irqreturn_t ret = IRQ_NONE;
> u32 reg;
>
> + if (cdns->in_lpm)
> + return ret;
> +
> /* check USB device interrupt */
> reg = readl(&priv_dev->regs->usb_ists);
> if (reg) {
> diff --git a/drivers/usb/cdns3/host.c b/drivers/usb/cdns3/host.c index
> ad788bf3fe4f..b579ef15f4e0 100644
> --- a/drivers/usb/cdns3/host.c
> +++ b/drivers/usb/cdns3/host.c
> @@ -13,11 +13,13 @@
> #include "core.h"
> #include "drd.h"
> #include "host-export.h"
> +#include <linux/usb/hcd.h>
>
> static int __cdns3_host_init(struct cdns3 *cdns) {
> struct platform_device *xhci;
> int ret;
> + struct usb_hcd *hcd;
>
> cdns3_drd_switch_host(cdns, 1);
>
> @@ -43,6 +45,11 @@ static int __cdns3_host_init(struct cdns3 *cdns)
> goto err1;
> }
>
> + /* Glue needs to access xHCI region register for Power management */
> + hcd = platform_get_drvdata(xhci);
> + if (hcd)
> + cdns->xhci_regs = hcd->regs;
> +
> return 0;
> err1:
> platform_device_put(xhci);
> --
> 2.17.1
