On Fri, 2020-08-21 at 10:48 +0800, Peter Chen wrote:
> 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.
>
> Reviewed-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
> Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
> ---
> drivers/usb/cdns3/core.c | 153 ++++++++++++++++++++++++++++++++-----
> 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, 166 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
> index e56dbb6a898c..8e588eef38df 100644
> --- a/drivers/usb/cdns3/core.c
> +++ b/drivers/usb/cdns3/core.c
> @@ -392,6 +392,30 @@ static void set_phy_power_off(struct cdns3 *cdns)
> phy_power_off(cdns->usb2_phy);
> }
>
> +/**
> + * cdns3_wakeup_irq - interrupt handler for wakeup events
> + *
remove blank line?
"Do not leave a blank line between the function description and the
arguments, nor between the arguments"
see kernel-doc.rst, Function parameters
> + * @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_pending = 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
> @@ -418,6 +442,7 @@ static int cdns3_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> cdns->dev = dev;
> + cdns->pdata = dev_get_platdata(dev);
>
> platform_set_drvdata(pdev, cdns);
>
> @@ -466,6 +491,15 @@ static int cdns3_probe(struct platform_device *pdev)
>
> cdns->otg_res = *res;
>
> + cdns->wakeup_irq = platform_get_irq_byname_optional(pdev, "wakeup");
> + 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");
> @@ -502,6 +536,19 @@ 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;
> @@ -510,9 +557,11 @@ 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,
> @@ -559,52 +608,122 @@ static int cdns3_remove(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_PM
What about using __maybe_unused instead of #ifdef ?
>
> -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;
> +
> + if (cdns->pdata && cdns->pdata->platform_suspend)
> + ret = cdns->pdata->platform_suspend(dev, suspend, wakeup);
> +
> + 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);
> + set_phy_power_off(cdns);
> + spin_lock_irqsave(&cdns->lock, flags);
> + cdns->in_lpm = true;
> + spin_unlock_irqrestore(&cdns->lock, flags);
> + dev_dbg(cdns->dev, "%s ends\n", __func__);
>
> 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 = set_phy_power_on(cdns);
> + 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_pending) {
> + cdns->wakeup_pending = false;
> + enable_irq(cdns->wakeup_irq);
> + }
> + dev_dbg(cdns->dev, "%s ends\n", __func__);
> +
> + 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..1b1707796db2 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
> + * @wakeup_irq: irq number for wakeup event, it is optional
> * @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_pending: wakeup interrupt pending
> + * @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_pending;
> + 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 6234bcd6158a..5f2685cadf5e 100644
> --- a/drivers/usb/cdns3/drd.c
> +++ b/drivers/usb/cdns3/drd.c
> @@ -293,6 +293,9 @@ static irqreturn_t cdns3_drd_irq(int irq, void *data)
> if (cdns->dr_mode != USB_DR_MODE_OTG)
> return IRQ_NONE;
>
> + 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 dea649ee173b..8bbb38cd560b 100644
> --- a/drivers/usb/cdns3/gadget.c
> +++ b/drivers/usb/cdns3/gadget.c
> @@ -1769,9 +1769,13 @@ 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 36c63d9ecd37..b3e2cb69762c 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_host_on(cdns);
>
> @@ -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);
