From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3070D426D26; Tue, 31 Mar 2026 18:12:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774980731; cv=none; b=mQfPNt/Ehiz0g+BkwIRzdfAKl200FMWQeeOo+mZZToC1GuhTx4j3XsEkMq30c2EtVtvRMw/v6nmZxEVAVJxijEMQFVGwxkCLyN9KGB1RQuPWa83BwWS/sHniz1Xo6UburI1el8oQEGukeO0J3PtL7RV1iyueZ2sO5n7db2XDCas= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774980731; c=relaxed/simple; bh=9vxAH8C8y+89FtnKAi3/D3aKahz/KoptlfpsLaf/1Xk=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=nykz2bz4ARVKM/qEHCfQhfxJJX4eg5xeuwcvEY3x9J9JO1hY3X8WUFO1o4L2icp+maARNHiP9w/FebFUSRQsqQ6D2zLQvENLwgsg/C4FfJazywfjbDjOwzCjGmeQDdp9Le2g0vBl7C7STT2B4sh70WqZ1xAx2CB0cMgAkoLCR7o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iHK+jU2X; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iHK+jU2X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83915C19423; Tue, 31 Mar 2026 18:12:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774980730; bh=9vxAH8C8y+89FtnKAi3/D3aKahz/KoptlfpsLaf/1Xk=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=iHK+jU2XGC2OiIYYalJktrZ3M0/4WA8HRk5Voo8WBOLHXxfU68BzcwHyeB9oiuIuU SeBkKYO/LfsTDqBGfyMG6ZvZcDlBbp+eFTlxNsLqOTBHO5qnmmqq7Xd4hGJHSS51fi +kbT2NdA1gKPx2Cf2nsFfLwWT3FTbDT/A7t0oYB9Ka0s7Ac/WrDjEIaZ2nNhFia3aE R5ZwTV4U4t9DYAhd1My95vXU+A4K3fCoqs0Uh67396NPjc2NDQI2uti5Vy814hVXE/ 8f4B0UysIxSUpRQ4GxU5i2cbavhEOxxBbVMvMbJbx4vUC30HX9u3zrvdoxQ8Zmosm6 Dovqtsgqlqdgw== Date: Tue, 31 Mar 2026 13:12:09 -0500 From: Bjorn Helgaas To: Pawel Laszczak Cc: Peter Chen , Roger Quadros , Greg Kroah-Hartman , Bjorn Helgaas , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] usb: cdnsp: Add support for device-only configuration Message-ID: <20260331181209.GA148250@bhelgaas> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260331-device_only-v1-1-00378b80365c@cadence.com> On Tue, Mar 31, 2026 at 10:19:11AM +0200, Pawel Laszczak wrote: > This patch introduces support for operating the Cadence USBSSP (cdnsp) > controller in a peripheral-only mode, bypassing the Dual-Role Device (DRD) > logic. > > The change in BAR indexing (from BAR 2 to BAR 1) is a direct > consequence of switching from 64-bit to 32-bit addressing in the > Peripheral-only configuration. > > Tested on PCI platform with Device-only configuration. Platform-side > changes are included to support the PCI glue layer's property injection. > > Signed-off-by: Pawel Laszczak > --- > NOTE: This patch depends on Peter Chen's series "usb: cdns3: Add > USBSSP platform driver support", which was recently accepted by > Greg into the usb-testing branch (commit 6076388ca1ed). > --- > drivers/usb/cdns3/cdns3-plat.c | 24 ++++++++++++--------- > drivers/usb/cdns3/cdnsp-pci.c | 47 ++++++++++++++++++++++++++++++++++-------- > drivers/usb/cdns3/core.c | 3 ++- > drivers/usb/cdns3/core.h | 5 ++++- > drivers/usb/cdns3/drd.c | 16 ++++++++++++-- > include/linux/pci_ids.h | 1 + Acked-by: Bjorn Helgaas # pci_ids.h > 6 files changed, 73 insertions(+), 23 deletions(-) > > diff --git a/drivers/usb/cdns3/cdns3-plat.c b/drivers/usb/cdns3/cdns3-plat.c > index 71c612e27b73..33746e672cda 100644 > --- a/drivers/usb/cdns3/cdns3-plat.c > +++ b/drivers/usb/cdns3/cdns3-plat.c > @@ -75,6 +75,7 @@ static int cdns3_plat_probe(struct platform_device *pdev) > if (cdns->pdata && cdns->pdata->override_apb_timeout) > cdns->override_apb_timeout = cdns->pdata->override_apb_timeout; > > + cdns->no_drd = device_property_read_bool(dev, "no_drd"); > platform_set_drvdata(pdev, cdns); > > ret = platform_get_irq_byname(pdev, "host"); > @@ -107,21 +108,23 @@ static int cdns3_plat_probe(struct platform_device *pdev) > > cdns->dev_regs = regs; > > - cdns->otg_irq = platform_get_irq_byname(pdev, "otg"); > - if (cdns->otg_irq < 0) > - return dev_err_probe(dev, cdns->otg_irq, > - "Failed to get otg IRQ\n"); > + if (!cdns->no_drd) { > + cdns->otg_irq = platform_get_irq_byname(pdev, "otg"); > + if (cdns->otg_irq < 0) > + return dev_err_probe(dev, cdns->otg_irq, > + "Failed to get otg IRQ\n"); > > - res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg"); > - if (!res) { > - dev_err(dev, "couldn't get otg resource\n"); > - return -ENXIO; > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg"); > + if (!res) { > + dev_err(dev, "couldn't get otg resource\n"); > + return -ENXIO; > + } > + > + cdns->otg_res = *res; > } > > cdns->phyrst_a_enable = device_property_read_bool(dev, "cdns,phyrst-a-enable"); > > - cdns->otg_res = *res; > - > cdns->wakeup_irq = platform_get_irq_byname_optional(pdev, "wakeup"); > if (cdns->wakeup_irq == -EPROBE_DEFER) > return cdns->wakeup_irq; > @@ -158,6 +161,7 @@ static int cdns3_plat_probe(struct platform_device *pdev) > goto err_cdns_init; > > cdns->gadget_init = cdns3_plat_gadget_init; > + > ret = cdns_core_init_role(cdns); > if (ret) > goto err_cdns_init; > diff --git a/drivers/usb/cdns3/cdnsp-pci.c b/drivers/usb/cdns3/cdnsp-pci.c > index 432007cfe695..e20c59ceb8a4 100644 > --- a/drivers/usb/cdns3/cdnsp-pci.c > +++ b/drivers/usb/cdns3/cdnsp-pci.c > @@ -19,6 +19,7 @@ > > struct cdnsp_wrap { > struct platform_device *plat_dev; > + struct property_entry prop[3]; > struct resource dev_res[6]; > int devfn; > }; > @@ -29,10 +30,15 @@ struct cdnsp_wrap { > #define RES_HOST_ID 3 > #define RES_DEV_ID 4 > #define RES_DRD_ID 5 > - > +/* DRD PCI configuration - 64-bit addressing */ > +/* First PCI function */ > #define PCI_BAR_HOST 0 > -#define PCI_BAR_OTG 0 > #define PCI_BAR_DEV 2 > +/* Second PCI function */ > +#define PCI_BAR_OTG 0 > +/* Device only PCI configuration - 32-bit addressing */ > +/* First PCI function */ > +#define PCI_BAR_ONLY_DEV 1 > > #define PCI_DEV_FN_HOST_DEVICE 0 > #define PCI_DEV_FN_OTG 1 > @@ -65,6 +71,7 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, > struct cdnsp_wrap *wrap; > struct resource *res; > struct pci_dev *func; > + bool no_drd = false; > int ret = 0; > > /* > @@ -75,11 +82,14 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, > pdev->devfn != PCI_DEV_FN_OTG)) > return -EINVAL; > > + if (pdev->device == PCI_DEVICE_ID_CDNS_UDC_USBSSP) > + no_drd = true; > + > func = cdnsp_get_second_fun(pdev); > - if (!func) > + if (!func && !no_drd) > return -EINVAL; > > - if (func->class == PCI_CLASS_SERIAL_USB_XHCI || > + if ((func && func->class == PCI_CLASS_SERIAL_USB_XHCI) || > pdev->class == PCI_CLASS_SERIAL_USB_XHCI) { > ret = -EINVAL; > goto put_pci; > @@ -93,7 +103,7 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, > > pci_set_master(pdev); > > - if (pci_is_enabled(func)) { > + if (func && pci_is_enabled(func)) { > wrap = pci_get_drvdata(func); > } else { > wrap = kzalloc_obj(*wrap); > @@ -106,10 +116,13 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, > res = wrap->dev_res; > > if (pdev->devfn == PCI_DEV_FN_HOST_DEVICE) { > + int bar_dev = no_drd ? PCI_BAR_ONLY_DEV : PCI_BAR_DEV; > + > /* Function 0: host(BAR_0) + device(BAR_2). */ > dev_dbg(&pdev->dev, "Initialize Device resources\n"); > - res[RES_DEV_ID].start = pci_resource_start(pdev, PCI_BAR_DEV); > - res[RES_DEV_ID].end = pci_resource_end(pdev, PCI_BAR_DEV); > + > + res[RES_DEV_ID].start = pci_resource_start(pdev, bar_dev); > + res[RES_DEV_ID].end = pci_resource_end(pdev, bar_dev); > res[RES_DEV_ID].name = "dev"; > res[RES_DEV_ID].flags = IORESOURCE_MEM; > dev_dbg(&pdev->dev, "USBSSP-DEV physical base addr: %pa\n", > @@ -145,9 +158,20 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, > wrap->dev_res[RES_IRQ_OTG_ID].flags = IORESOURCE_IRQ; > } > > - if (pci_is_enabled(func)) { > + if (no_drd || pci_is_enabled(func)) { > + u8 idx = 0; > + > /* set up platform device info */ > pdata.override_apb_timeout = CHICKEN_APB_TIMEOUT_VALUE; > + if (no_drd) { > + wrap->prop[idx++] = PROPERTY_ENTRY_STRING("dr_mode", "peripheral"); > + wrap->prop[idx++] = PROPERTY_ENTRY_BOOL("no_drd"); > + } else { > + wrap->prop[idx++] = PROPERTY_ENTRY_STRING("dr_mode", "otg"); > + wrap->prop[idx++] = PROPERTY_ENTRY_BOOL("usb-role-switch"); > + } > + > + wrap->prop[idx] = (struct property_entry){ }; > memset(&plat_info, 0, sizeof(plat_info)); > plat_info.parent = &pdev->dev; > plat_info.fwnode = pdev->dev.fwnode; > @@ -158,6 +182,7 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, > plat_info.dma_mask = pdev->dma_mask; > plat_info.data = &pdata; > plat_info.size_data = sizeof(pdata); > + plat_info.properties = wrap->prop; > wrap->devfn = pdev->devfn; > /* register platform device */ > wrap->plat_dev = platform_device_register_full(&plat_info); > @@ -185,13 +210,17 @@ static void cdnsp_pci_remove(struct pci_dev *pdev) > if (wrap->devfn == pdev->devfn) > platform_device_unregister(wrap->plat_dev); > > - if (!pci_is_enabled(func)) > + if (!func || !pci_is_enabled(func)) > kfree(wrap); > > pci_dev_put(func); > } > > static const struct pci_device_id cdnsp_pci_ids[] = { > + { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_UDC_USBSSP), > + .class = PCI_CLASS_SERIAL_USB_DEVICE }, > + { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_UDC_USBSSP), > + .class = PCI_CLASS_SERIAL_USB_CDNS }, > { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_USBSSP), > .class = PCI_CLASS_SERIAL_USB_DEVICE }, > { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_USBSSP), > diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c > index 10f00b6c3c83..72f7acba6258 100644 > --- a/drivers/usb/cdns3/core.c > +++ b/drivers/usb/cdns3/core.c > @@ -71,7 +71,8 @@ static void cdns_role_stop(struct cdns *cdns) > static void cdns_exit_roles(struct cdns *cdns) > { > cdns_role_stop(cdns); > - cdns_drd_exit(cdns); > + if (!cdns->no_drd) > + cdns_drd_exit(cdns); > } > > /** > diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h > index dc8c4137de15..6abe231f4559 100644 > --- a/drivers/usb/cdns3/core.h > +++ b/drivers/usb/cdns3/core.h > @@ -80,9 +80,11 @@ struct cdns3_platform_data { > * @pdata: platform data from glue layer > * @lock: spinlock structure > * @xhci_plat_data: xhci private data structure pointer > + * @gadget_init: pointer to gadget initialization function > * @override_apb_timeout: hold value of APB timeout. For value 0 the default > * value in CHICKEN_BITS_3 will be preserved. > - * @gadget_init: pointer to gadget initialization function > + * @no_drd: DRD register block is inaccessible - driver handles only > + * device mode. > */ > struct cdns { > struct device *dev; > @@ -122,6 +124,7 @@ struct cdns { > struct xhci_plat_priv *xhci_plat_data; > int (*gadget_init)(struct cdns *cdns); > u32 override_apb_timeout; > + bool no_drd; > }; > > int cdns_hw_role_switch(struct cdns *cdns); > diff --git a/drivers/usb/cdns3/drd.c b/drivers/usb/cdns3/drd.c > index 84fb38a5723a..38f3051c2188 100644 > --- a/drivers/usb/cdns3/drd.c > +++ b/drivers/usb/cdns3/drd.c > @@ -107,7 +107,7 @@ void cdns_clear_vbus(struct cdns *cdns) > { > u32 reg; > > - if (cdns->version != CDNSP_CONTROLLER_V2) > + if (cdns->version != CDNSP_CONTROLLER_V2 || cdns->no_drd) > return; > > reg = readl(&cdns->otg_cdnsp_regs->override); > @@ -120,7 +120,7 @@ void cdns_set_vbus(struct cdns *cdns) > { > u32 reg; > > - if (cdns->version != CDNSP_CONTROLLER_V2) > + if (cdns->version != CDNSP_CONTROLLER_V2 || cdns->no_drd) > return; > > reg = readl(&cdns->otg_cdnsp_regs->override); > @@ -234,6 +234,9 @@ int cdns_drd_gadget_on(struct cdns *cdns) > u32 ready_bit; > int ret, val; > > + if (cdns->no_drd) > + return 0; > + > /* switch OTG core */ > writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd); > > @@ -265,6 +268,9 @@ void cdns_drd_gadget_off(struct cdns *cdns) > { > u32 val; > > + if (cdns->no_drd) > + return; > + > /* > * Driver should wait at least 10us after disabling Device > * before turning-off Device (DEV_BUS_DROP). > @@ -392,6 +398,12 @@ int cdns_drd_init(struct cdns *cdns) > u32 state, reg; > int ret; > > + if (cdns->no_drd) { > + cdns->version = CDNSP_CONTROLLER_V2; > + cdns->dr_mode = USB_DR_MODE_PERIPHERAL; > + return 0; > + } > + > regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res); > if (IS_ERR(regs)) > return PTR_ERR(regs); > diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h > index 406abf629be2..a931fb201402 100644 > --- a/include/linux/pci_ids.h > +++ b/include/linux/pci_ids.h > @@ -2424,6 +2424,7 @@ > #define PCI_DEVICE_ID_CDNS_USBSS 0x0100 > #define PCI_DEVICE_ID_CDNS_USB 0x0120 > #define PCI_DEVICE_ID_CDNS_USBSSP 0x0200 > +#define PCI_DEVICE_ID_CDNS_UDC_USBSSP 0x0400 > > #define PCI_VENDOR_ID_ARECA 0x17d3 > #define PCI_DEVICE_ID_ARECA_1110 0x1110 > > --- > base-commit: 5196f2c98340297e1fdd36555285e991ceddf776 > change-id: 20260331-device_only-192d539430b5 > > Best regards, > -- > Pawel Laszczak >