usb: cdnsp: Add support for device-only configuration

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 <pawell@cadence.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci_ids.h
Link: https://patch.msgid.link/20260331-device_only-v1-1-00378b80365c@cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/cdns3/cdns3-plat.c b/drivers/usb/cdns3/cdns3-plat.c
index 71c612e27b730be5172447723e35cc671bad0d5d..33746e672cda0840412b6dfe789840c370f0bcab 100644 (file)
--- 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 432007cfe6954e750495bf9826880fc3e85f31fb..e20c59ceb8a42aa6963b694147e7f2b7ab1d7027 100644 (file)
--- 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 10f00b6c3c83b900c0cb28a3fb8a2a73419dab1a..72f7acba6258d98ded859c3f8979fbe7f3c46e86 100644 (file)
--- 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 dc8c4137de154e63d222379694dd8ac6fbd1c04a..6abe231f4559352b9b9e8bfbe9af4e131c0d1e8d 100644 (file)
--- 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 84fb38a5723a3bac598969f6b6710bb7ae107408..38f3051c21887481eff22d07af96b650f41a3bf0 100644 (file)
--- 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 406abf629be2e4c1cd0d407f1f01047b945eeee4..a931fb201402a2afe4875c861f279009ae178951 100644 (file)
--- 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