From nobody Wed Apr 1 12:32:53 2026 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 E8E1E3D75AA; Tue, 31 Mar 2026 08:05:13 +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=1774944314; cv=none; b=VswY97TFjK4VZ0PfoupWD8+bTJlbajB8hNsMzvrbwvIoO1xTeG9WINvuqIAe35LhFCWP5SFd1iNrIKB75RzjbdsKrXZ1HU3iIF8DLeOBWDqHGLXEGO0t1jGeABL9YposlRj27+JGVIiYM0L26UhUhKqVTPHBBz4ekLZ6kqH7Oio= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774944314; c=relaxed/simple; bh=0cZvuCg3q6ttJ602GNWrFjr3BNZ7oOzIO1zMeJHR2W8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=iS6x/bebf/Xm+lub9F/4dXiNFtOco4Ti78SSylHQGBzjcy94dJCzrRfh/PMG2hfNaNIVpE0rpHHVaAPSGwb4mo1JIdK4vGjTuyz9QW2RduBIIeJIfZr+ifyrvw1aFujCYYWIOFMGz62tng7s+JXN7Ukw3Zhi9fnTo6glXkerNGE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FCzoos7K; 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="FCzoos7K" Received: by smtp.kernel.org (Postfix) with ESMTPS id 1CB97C19423; Tue, 31 Mar 2026 08:05:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774944313; bh=0cZvuCg3q6ttJ602GNWrFjr3BNZ7oOzIO1zMeJHR2W8=; h=From:Date:Subject:To:Cc:Reply-To:From; b=FCzoos7KwR2XiL6eV7xsgFdw8oOSiCpWHBmuW1sxFNsvg0qrafmh0rt9lZtDq/fa2 IsS5q/zO5sWxkh2t+2gdXTFGs82j27RKcoEIk4Snsf+XEvUNPWY+FSvLsAztVNGXEP KzSsPIQgY6EOAe5LxkBZrTxTqTU9QhA/IqzH1qfIxZh65CEfIshDXVlUV+xpNUG6Yy RQ9Vosstm9TlaYsGRD+YT63j0BuU0rC1KYPh0ND+N3Kd9alLt2kAVHXoXClRT2dimO cJ2wsDRGVGunc7HRiRCg+UTWwkJp8NGn5LTM568oLfVZVOJBE991pj4OO+HpMQfklz 2BR7qDR71sfRw== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13D05FF60DC; Tue, 31 Mar 2026 08:05:13 +0000 (UTC) From: Pawel Laszczak via B4 Relay Date: Tue, 31 Mar 2026 10:19:11 +0200 Subject: [PATCH] usb: cdnsp: Add support for device-only configuration Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260331-device_only-v1-1-00378b80365c@cadence.com> X-B4-Tracking: v=1; b=H4sIAH6Dy2kC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDY2ND3RSgouTU+Py8nEpdQ0ujFFNjSxNjgyRTJaCOgqLUtMwKsGnRsbW 1APSz3sJdAAAA To: Peter Chen , Roger Quadros , Greg Kroah-Hartman , Bjorn Helgaas Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, pawell@cadence.com X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1774945165; l=10845; i=pawell@cadence.com; h=from:subject:message-id; bh=6OIqgxMFmEPIY1lz/0pWr94nNNQg9qsP83S9iKkdml4=; b=8R1w9k86i+MQEe4egtg5LnSARTaFCOOp61gbJ9RI8d9XrRsdnLCiD5tODDOFppJOfxsFkr/OC hIy6gF7zdCQBM3Z9P1d1h1yhRoXys4k3MpQglaU8kiFRfJw6AsyS/wq X-Developer-Key: i=pawell@cadence.com; a=ed25519; pk=EUPBvLO9CDg7j6defeDl2iqi+z5Ivqu4Z46aiqe7dYc= X-Endpoint-Received: by B4 Relay for pawell@cadence.com/default with auth_id=707 X-Original-From: Pawel Laszczak Reply-To: pawell@cadence.com From: Pawel Laszczak 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 Acked-by: Bjorn Helgaas # pci_ids.h --- NOTE: This patch depends on Peter Chen's series "usb: cdns3: Add=20 USBSSP platform driver support", which was recently accepted by=20 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 + 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 =3D cdns->pdata->override_apb_timeout; =20 + cdns->no_drd =3D device_property_read_bool(dev, "no_drd"); platform_set_drvdata(pdev, cdns); =20 ret =3D platform_get_irq_byname(pdev, "host"); @@ -107,21 +108,23 @@ static int cdns3_plat_probe(struct platform_device *p= dev) =20 cdns->dev_regs =3D regs; =20 - cdns->otg_irq =3D 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 =3D 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"); =20 - res =3D platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg"); - if (!res) { - dev_err(dev, "couldn't get otg resource\n"); - return -ENXIO; + res =3D platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg"); + if (!res) { + dev_err(dev, "couldn't get otg resource\n"); + return -ENXIO; + } + + cdns->otg_res =3D *res; } =20 cdns->phyrst_a_enable =3D device_property_read_bool(dev, "cdns,phyrst-a-e= nable"); =20 - cdns->otg_res =3D *res; - cdns->wakeup_irq =3D platform_get_irq_byname_optional(pdev, "wakeup"); if (cdns->wakeup_irq =3D=3D -EPROBE_DEFER) return cdns->wakeup_irq; @@ -158,6 +161,7 @@ static int cdns3_plat_probe(struct platform_device *pde= v) goto err_cdns_init; =20 cdns->gadget_init =3D cdns3_plat_gadget_init; + ret =3D 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 @@ =20 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 =20 #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 =3D false; int ret =3D 0; =20 /* @@ -75,11 +82,14 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, pdev->devfn !=3D PCI_DEV_FN_OTG)) return -EINVAL; =20 + if (pdev->device =3D=3D PCI_DEVICE_ID_CDNS_UDC_USBSSP) + no_drd =3D true; + func =3D cdnsp_get_second_fun(pdev); - if (!func) + if (!func && !no_drd) return -EINVAL; =20 - if (func->class =3D=3D PCI_CLASS_SERIAL_USB_XHCI || + if ((func && func->class =3D=3D PCI_CLASS_SERIAL_USB_XHCI) || pdev->class =3D=3D PCI_CLASS_SERIAL_USB_XHCI) { ret =3D -EINVAL; goto put_pci; @@ -93,7 +103,7 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, =20 pci_set_master(pdev); =20 - if (pci_is_enabled(func)) { + if (func && pci_is_enabled(func)) { wrap =3D pci_get_drvdata(func); } else { wrap =3D kzalloc_obj(*wrap); @@ -106,10 +116,13 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, res =3D wrap->dev_res; =20 if (pdev->devfn =3D=3D PCI_DEV_FN_HOST_DEVICE) { + int bar_dev =3D 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 =3D pci_resource_start(pdev, PCI_BAR_DEV); - res[RES_DEV_ID].end =3D pci_resource_end(pdev, PCI_BAR_DEV); + + res[RES_DEV_ID].start =3D pci_resource_start(pdev, bar_dev); + res[RES_DEV_ID].end =3D pci_resource_end(pdev, bar_dev); res[RES_DEV_ID].name =3D "dev"; res[RES_DEV_ID].flags =3D 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 =3D IORESOURCE_IRQ; } =20 - if (pci_is_enabled(func)) { + if (no_drd || pci_is_enabled(func)) { + u8 idx =3D 0; + /* set up platform device info */ pdata.override_apb_timeout =3D CHICKEN_APB_TIMEOUT_VALUE; + if (no_drd) { + wrap->prop[idx++] =3D PROPERTY_ENTRY_STRING("dr_mode", "peripheral"); + wrap->prop[idx++] =3D PROPERTY_ENTRY_BOOL("no_drd"); + } else { + wrap->prop[idx++] =3D PROPERTY_ENTRY_STRING("dr_mode", "otg"); + wrap->prop[idx++] =3D PROPERTY_ENTRY_BOOL("usb-role-switch"); + } + + wrap->prop[idx] =3D (struct property_entry){ }; memset(&plat_info, 0, sizeof(plat_info)); plat_info.parent =3D &pdev->dev; plat_info.fwnode =3D pdev->dev.fwnode; @@ -158,6 +182,7 @@ static int cdnsp_pci_probe(struct pci_dev *pdev, plat_info.dma_mask =3D pdev->dma_mask; plat_info.data =3D &pdata; plat_info.size_data =3D sizeof(pdata); + plat_info.properties =3D wrap->prop; wrap->devfn =3D pdev->devfn; /* register platform device */ wrap->plat_dev =3D platform_device_register_full(&plat_info); @@ -185,13 +210,17 @@ static void cdnsp_pci_remove(struct pci_dev *pdev) if (wrap->devfn =3D=3D pdev->devfn) platform_device_unregister(wrap->plat_dev); =20 - if (!pci_is_enabled(func)) + if (!func || !pci_is_enabled(func)) kfree(wrap); =20 pci_dev_put(func); } =20 static const struct pci_device_id cdnsp_pci_ids[] =3D { + { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_UDC_USBSSP), + .class =3D PCI_CLASS_SERIAL_USB_DEVICE }, + { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_UDC_USBSSP), + .class =3D PCI_CLASS_SERIAL_USB_CDNS }, { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_USBSSP), .class =3D 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); } =20 /** 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 defau= lt * 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; }; =20 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; =20 - if (cdns->version !=3D CDNSP_CONTROLLER_V2) + if (cdns->version !=3D CDNSP_CONTROLLER_V2 || cdns->no_drd) return; =20 reg =3D readl(&cdns->otg_cdnsp_regs->override); @@ -120,7 +120,7 @@ void cdns_set_vbus(struct cdns *cdns) { u32 reg; =20 - if (cdns->version !=3D CDNSP_CONTROLLER_V2) + if (cdns->version !=3D CDNSP_CONTROLLER_V2 || cdns->no_drd) return; =20 reg =3D readl(&cdns->otg_cdnsp_regs->override); @@ -234,6 +234,9 @@ int cdns_drd_gadget_on(struct cdns *cdns) u32 ready_bit; int ret, val; =20 + if (cdns->no_drd) + return 0; + /* switch OTG core */ writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd); =20 @@ -265,6 +268,9 @@ void cdns_drd_gadget_off(struct cdns *cdns) { u32 val; =20 + 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; =20 + if (cdns->no_drd) { + cdns->version =3D CDNSP_CONTROLLER_V2; + cdns->dr_mode =3D USB_DR_MODE_PERIPHERAL; + return 0; + } + regs =3D 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 =20 #define PCI_VENDOR_ID_ARECA 0x17d3 #define PCI_DEVICE_ID_ARECA_1110 0x1110 --- base-commit: 5196f2c98340297e1fdd36555285e991ceddf776 change-id: 20260331-device_only-192d539430b5 Best regards, --=20 Pawel Laszczak