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Message-ID: <CAL411-pT+BNRzGiRRQe0FmYB18SFaRYBLi1W1NNqmnH9Che_EQ@mail.gmail.com>
Date: Wed, 5 Dec 2018 16:41:49 +0800
From: Peter Chen <hzpeterchen@...il.com>
To: rogerq@...com
Cc: pawell@...ence.com, devicetree@...r.kernel.org,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
linux-usb@...r.kernel.org, lkml <linux-kernel@...r.kernel.org>,
adouglas@...ence.com, jbergsagel@...com, nsekhar@...com, nm@...com,
sureshp@...ence.com, peter.chen@....com, pjez@...ence.com,
kurahul@...ence.com
Subject: Re: [RFC PATCH v2 06/15] usb:cdns3: Adds Host support
> > --- a/drivers/usb/cdns3/Makefile
> > +++ b/drivers/usb/cdns3/Makefile
> > @@ -2,4 +2,5 @@ obj-$(CONFIG_USB_CDNS3) += cdns3.o
> > obj-$(CONFIG_USB_CDNS3_PCI_WRAP) += cdns3-pci.o
> >
> > cdns3-y := core.o drd.o
> > +cdns3-$(CONFIG_USB_CDNS3_HOST) += host.o
> > cdns3-pci-y := cdns3-pci-wrap.o
> > diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
> > index dbee4325da7f..4cb820be9ff3 100644
> > --- a/drivers/usb/cdns3/core.c
> > +++ b/drivers/usb/cdns3/core.c
> > @@ -17,6 +17,7 @@
> >
> > #include "gadget.h"
> > #include "core.h"
> > +#include "host-export.h"
> > #include "drd.h"
> >
> > static inline struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
> > @@ -98,7 +99,8 @@ static int cdns3_core_init_role(struct cdns3 *cdns)
> > }
> >
> > if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
> > - //TODO: implements host initialization
> > + if (cdns3_host_init(cdns))
> > + dev_info(dev, "doesn't support host\n");
>
> dev_err()
>
> And you need to error out with error code.
There are two cases for it:
- There is no cdsn3_host_init implementation due to kernel configuration,
- The error happens at cdsn3_host_init
We may need to handle these two different cases.
> > + struct usb_hcd *hcd;
> > +
> > + if (dev)
> > + hcd = dev_get_drvdata(dev);
> > + else
> > + return IRQ_NONE;
> > +
> > + if (hcd)
> > + return usb_hcd_irq(cdns->irq, hcd);
> > + else
> > + return IRQ_NONE;
>
> Why can't you just reuse the xhci-platform driver and let it manage the IRQ?
> Since it is a shared IRQ, different drivers can request the same IRQ and return IRQ_NONE
> if the IRQ wasn't from their device.
>
When I began to write this code, there are not so many quirks can be
used at xhci-plat.c,
it seems we can re-use this common code at cdns3 driver now, I will
try to integrate it.
Thanks for your suggestion.
Peter
> > +}
> > +
> > +static void cdns3_host_release(struct device *dev)
> > +{
> > + struct cdns3_host *host = container_of(dev, struct cdns3_host, dev);
> > +
> > + kfree(host);
> > +}
> > +
> > +static int cdns3_host_start(struct cdns3 *cdns)
> > +{
> > + struct cdns3_host *host;
> > + struct device *dev;
> > + struct device *sysdev;
> > + struct xhci_hcd *xhci;
> > + int ret;
> > +
> > + host = kzalloc(sizeof(*host), GFP_KERNEL);
> > + if (!host)
> > + return -ENOMEM;
> > +
> > + dev = &host->dev;
> > + dev->release = cdns3_host_release;
> > + dev->parent = cdns->dev;
> > + dev_set_name(dev, "xhci-cdns3");
> > + cdns->host_dev = dev;
> > + ret = device_register(dev);
> > + if (ret)
> > + goto err1;
> > +
> > + sysdev = cdns->dev;
> > + /* Try to set 64-bit DMA first */
> > + if (WARN_ON(!sysdev->dma_mask))
> > + /* Platform did not initialize dma_mask */
> > + ret = dma_coerce_mask_and_coherent(sysdev,
> > + DMA_BIT_MASK(64));
> > + else
> > + ret = dma_set_mask_and_coherent(sysdev, DMA_BIT_MASK(64));
> > +
> > + /* If setting 64-bit DMA mask fails, fall back to 32-bit DMA mask */
> > + if (ret) {
> > + ret = dma_set_mask_and_coherent(sysdev, DMA_BIT_MASK(32));
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + pm_runtime_set_active(dev);
> > + pm_runtime_no_callbacks(dev);
> > + pm_runtime_enable(dev);
> > + host->hcd = __usb_create_hcd(&xhci_cdns3_hc_driver, sysdev, dev,
> > + dev_name(dev), NULL);
> > + if (!host->hcd) {
> > + ret = -ENOMEM;
> > + goto err2;
> > + }
> > +
> > + host->hcd->regs = cdns->xhci_regs;
> > + host->hcd->rsrc_start = cdns->xhci_res->start;
> > + host->hcd->rsrc_len = resource_size(cdns->xhci_res);
> > +
> > + device_wakeup_enable(host->hcd->self.controller);
> > + xhci = hcd_to_xhci(host->hcd);
> > +
> > + xhci->main_hcd = host->hcd;
> > + xhci->shared_hcd = __usb_create_hcd(&xhci_cdns3_hc_driver, sysdev, dev,
> > + dev_name(dev), host->hcd);
> > + if (!xhci->shared_hcd) {
> > + ret = -ENOMEM;
> > + goto err3;
> > + }
> > +
> > + host->hcd->tpl_support = of_usb_host_tpl_support(sysdev->of_node);
> > + xhci->shared_hcd->tpl_support = host->hcd->tpl_support;
> > + ret = usb_add_hcd(host->hcd, 0, IRQF_SHARED);
> > + if (ret)
> > + goto err4;
> > +
> > + ret = usb_add_hcd(xhci->shared_hcd, 0, IRQF_SHARED);
> > + if (ret)
> > + goto err5;
> > +
> > + device_set_wakeup_capable(dev, true);
>
> All this is being done by the xhci-plat.c
>
> You can make use of it by just creating a xhci-hcd platform device.
>
> e.g.
> platform_device_alloc("xhci-hcd", PLATFORM_DEVID_AUTO);
> platform_device_add_resources() to add IRQ and memory resource.
> platform_device_add_properties() to add any quirks.
> platform_device_add()
>
>
> > +
> > + return 0;
> > +
> > +err5:
> > + usb_remove_hcd(host->hcd);
> > +err4:
> > + usb_put_hcd(xhci->shared_hcd);
> > +err3:
> > + usb_put_hcd(host->hcd);
> > +err2:
> > + device_del(dev);
> > +err1:
> > + put_device(dev);
> > + cdns->host_dev = NULL;
> > + return ret;
> > +}
> > +
> > +static void cdns3_host_stop(struct cdns3 *cdns)
> > +{
> > + struct device *dev = cdns->host_dev;
> > + struct xhci_hcd *xhci;
> > + struct usb_hcd *hcd;
> > +
> > + if (dev) {
> > + hcd = dev_get_drvdata(dev);
> > + xhci = hcd_to_xhci(hcd);
> > + usb_remove_hcd(xhci->shared_hcd);
> > + usb_remove_hcd(hcd);
> > + synchronize_irq(cdns->irq);
> > + usb_put_hcd(xhci->shared_hcd);
> > + usb_put_hcd(hcd);
> > + cdns->host_dev = NULL;
> > + pm_runtime_set_suspended(dev);
> > + pm_runtime_disable(dev);
> > + device_del(dev);
> > + put_device(dev);
> > + }
>
> You can replace this with just
> platform_device_unregister(xhci_dev);
>
> > +}
> > +
> > +#if CONFIG_PM
> > +static int cdns3_host_suspend(struct cdns3 *cdns, bool do_wakeup)
> > +{
> > + struct device *dev = cdns->host_dev;
> > + struct xhci_hcd *xhci;
> > +
> > + if (!dev)
> > + return 0;
> > +
> > + xhci = hcd_to_xhci(dev_get_drvdata(dev));
> > + return xhci_suspend(xhci, do_wakeup);
> > +}
> > +
> > +static int cdns3_host_resume(struct cdns3 *cdns, bool hibernated)
> > +{
> > + struct device *dev = cdns->host_dev;
> > + struct xhci_hcd *xhci;
> > +
> > + if (!dev)
> > + return 0;
> > +
> > + xhci = hcd_to_xhci(dev_get_drvdata(dev));
> > + return xhci_resume(xhci, hibernated);
> > +}
>
> These won't be required any more as xhci-plat is doing this.
>
> > +#endif /* CONFIG_PM */
> > +
> > +int cdns3_host_init(struct cdns3 *cdns)
> > +{
> > + struct cdns3_role_driver *rdrv;
> > +
> > + rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
> > + if (!rdrv)
> > + return -ENOMEM;
> > +
> > + rdrv->start = cdns3_host_start;
> > + rdrv->stop = cdns3_host_stop;
> > + rdrv->irq = cdns3_host_irq;
> > +#if CONFIG_PM
> > + rdrv->suspend = cdns3_host_suspend;
> > + rdrv->resume = cdns3_host_resume;
> > +#endif /* CONFIG_PM */
> > + rdrv->name = "host";
> > + cdns->roles[CDNS3_ROLE_HOST] = rdrv;
> > +
> > + return 0;
> > +}
> > +
> > +void cdns3_host_remove(struct cdns3 *cdns)
> > +{
> > + cdns3_host_stop(cdns);
>
> calling cdns3_host_stop() here can lead to problems as Controller might be in
> peripheral mode at this point. The core driver needs to ensure that relevant role
> is stopped before calling cdns3_host_remove().
>
> Here you need to unregister the role driver though.
>
> cdns->roles[CDNS3_ROLE_HOST] = NULL;
>
> > +}
> > +
> > +void __init cdns3_host_driver_init(void)
> > +{
> > + xhci_init_driver(&xhci_cdns3_hc_driver, &xhci_cdns3_overrides);
> > +}
> >
>
> cheers,
> -roger
>
> --
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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