RE: [PATCH v4 5/6] usb:cdns3 Add Cadence USB3 DRD Driver
From: Pawel Laszczak
Date: Thu Mar 28 2019 - 02:06:10 EST
Hi Roger,
>>>
>>> On 14/02/2019 21:45, Pawel Laszczak wrote:
>>>> This patch introduce new Cadence USBSS DRD driver to linux kernel.
>>>>
>>>> The Cadence USBSS DRD Driver is a highly configurable IP Core whichi
>>>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
>>>> Host Only (XHCI)configurations.
>>>>
>>>> The current driver has been validated with FPGA burned. We have support
>>>> for PCIe bus, which is used on FPGA prototyping.
>>>>
>>>> The host side of USBSS-DRD controller is compliance with XHCI
>>>> specification, so it works with standard XHCI linux driver.
>>>>
>>>> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>>>> ---
>>>> drivers/usb/Kconfig | 2 +
>>>> drivers/usb/Makefile | 2 +
>>>> drivers/usb/cdns3/Kconfig | 44 +
>>>> drivers/usb/cdns3/Makefile | 14 +
>>>> drivers/usb/cdns3/cdns3-pci-wrap.c | 155 +++
>>>> drivers/usb/cdns3/core.c | 403 ++++++
>>>> drivers/usb/cdns3/core.h | 116 ++
>>>> drivers/usb/cdns3/debug.h | 168 +++
>>>> drivers/usb/cdns3/debugfs.c | 164 +++
>>>> drivers/usb/cdns3/drd.c | 365 +++++
>>>> drivers/usb/cdns3/drd.h | 162 +++
>>>> drivers/usb/cdns3/ep0.c | 907 +++++++++++++
>>>> drivers/usb/cdns3/gadget-export.h | 28 +
>>>> drivers/usb/cdns3/gadget.c | 2003 ++++++++++++++++++++++++++++
>>>> drivers/usb/cdns3/gadget.h | 1207 +++++++++++++++++
>>>> drivers/usb/cdns3/host-export.h | 28 +
>>>> drivers/usb/cdns3/host.c | 72 +
>>>> drivers/usb/cdns3/trace.c | 23 +
>>>> drivers/usb/cdns3/trace.h | 404 ++++++
>>>> 19 files changed, 6267 insertions(+)
>>>> create mode 100644 drivers/usb/cdns3/Kconfig
>>>> create mode 100644 drivers/usb/cdns3/Makefile
>>>> create mode 100644 drivers/usb/cdns3/cdns3-pci-wrap.c
>>>> create mode 100644 drivers/usb/cdns3/core.c
>>>> create mode 100644 drivers/usb/cdns3/core.h
>>>> create mode 100644 drivers/usb/cdns3/debug.h
>>>> create mode 100644 drivers/usb/cdns3/debugfs.c
>>>> create mode 100644 drivers/usb/cdns3/drd.c
>>>> create mode 100644 drivers/usb/cdns3/drd.h
>>>> create mode 100644 drivers/usb/cdns3/ep0.c
>>>> create mode 100644 drivers/usb/cdns3/gadget-export.h
>>>> create mode 100644 drivers/usb/cdns3/gadget.c
>>>> create mode 100644 drivers/usb/cdns3/gadget.h
>>>> create mode 100644 drivers/usb/cdns3/host-export.h
>>>> create mode 100644 drivers/usb/cdns3/host.c
>>>> create mode 100644 drivers/usb/cdns3/trace.c
>>>> create mode 100644 drivers/usb/cdns3/trace.h
>>>>
>>>> diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
>>>> index 987fc5ba6321..5f9334019d04 100644
>>>> --- a/drivers/usb/Kconfig
>>>> +++ b/drivers/usb/Kconfig
>>>> @@ -112,6 +112,8 @@ source "drivers/usb/usbip/Kconfig"
>>>>
>>>> endif
>>>>
>>>> +source "drivers/usb/cdns3/Kconfig"
>>>> +
>>>> source "drivers/usb/mtu3/Kconfig"
>>>>
>>>> source "drivers/usb/musb/Kconfig"
>>>> diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
>>>> index 7d1b8c82b208..ab125b966cac 100644
>>>> --- a/drivers/usb/Makefile
>>>> +++ b/drivers/usb/Makefile
>>>> @@ -12,6 +12,8 @@ obj-$(CONFIG_USB_DWC3) += dwc3/
>>>> obj-$(CONFIG_USB_DWC2) += dwc2/
>>>> obj-$(CONFIG_USB_ISP1760) += isp1760/
>>>>
>>>> +obj-$(CONFIG_USB_CDNS3) += cdns3/
>>>> +
>>>> obj-$(CONFIG_USB_MON) += mon/
>>>> obj-$(CONFIG_USB_MTU3) += mtu3/
>>>>
>>>> diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
>>>> new file mode 100644
>>>> index 000000000000..27cb3d8dbe3d
>>>> --- /dev/null
>>>> +++ b/drivers/usb/cdns3/Kconfig
>>>> @@ -0,0 +1,44 @@
>>>> +config USB_CDNS3
>>>> + tristate "Cadence USB3 Dual-Role Controller"
>>>> + depends on USB_SUPPORT && (USB || USB_GADGET) && HAS_DMA
>>>> + help
>>>> + Say Y here if your system has a cadence USB3 dual-role controller.
>>>> + It supports: dual-role switch, Host-only, and Peripheral-only.
>>>> +
>>>> + If you choose to build this driver is a dynamically linked
>>>> + as module, the module will be called cdns3.ko.
>>>> +
>>>> +if USB_CDNS3
>>>> +
>>>> +config USB_CDNS3_GADGET
>>>> + bool "Cadence USB3 device controller"
>>>> + depends on USB_GADGET
>>>> + help
>>>> + Say Y here to enable device controller functionality of the
>>>> + cadence USBSS-DEV driver.
>>>
>>> "Cadence" ?
>>>
>>>> +
>>>> + This controller supports FF, HS and SS mode. It doesn't support
>>>> + LS and SSP mode.
>>>> +
>>>> +config USB_CDNS3_HOST
>>>> + bool "Cadence USB3 host controller"
>>>> + depends on USB_XHCI_HCD
>>>> + help
>>>> + Say Y here to enable host controller functionality of the
>>>> + cadence driver.
>>>> +
>>>> + Host controller is compliant with XHCI so it will use
>>>> + standard XHCI driver.
>>>> +
>>>> +config USB_CDNS3_PCI_WRAP
>>>> + tristate "Cadence USB3 support on PCIe-based platforms"
>>>> + depends on USB_PCI && ACPI
>>>> + default USB_CDNS3
>>>> + help
>>>> + If you're using the USBSS Core IP with a PCIe, please say
>>>> + 'Y' or 'M' here.
>>>> +
>>>> + If you choose to build this driver as module it will
>>>> + be dynamically linked and module will be called cdns3-pci.ko
>>>> +
>>>> +endif
>>>> diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
>>>> new file mode 100644
>>>> index 000000000000..8f9438593375
>>>> --- /dev/null
>>>> +++ b/drivers/usb/cdns3/Makefile
>>>> @@ -0,0 +1,14 @@
>>>> +# SPDX-License-Identifier: GPL-2.0
>>>> +# define_trace.h needs to know how to find our header
>>>> +CFLAGS_trace.o := -I$(src)
>>>> +
>>>> +cdns3-y := core.o drd.o trace.o
>>>> +
>>>> +obj-$(CONFIG_USB_CDNS3) += cdns3.o
>>>> +ifneq ($(CONFIG_DEBUG_FS),)
>>>> + cdns3-y += debugfs.o
>>>> +endif
>>>> +
>>>> +cdns3-$(CONFIG_USB_CDNS3_GADGET) += gadget.o ep0.o
>>>> +cdns3-$(CONFIG_USB_CDNS3_HOST) += host.o
>>>> +obj-$(CONFIG_USB_CDNS3_PCI_WRAP) += cdns3-pci-wrap.o
>>>> diff --git a/drivers/usb/cdns3/cdns3-pci-wrap.c b/drivers/usb/cdns3/cdns3-pci-wrap.c
>>>> new file mode 100644
>>>> index 000000000000..d0b2d3d9b983
>>>> --- /dev/null
>>>> +++ b/drivers/usb/cdns3/cdns3-pci-wrap.c
>>>> @@ -0,0 +1,155 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * Cadence USBSS PCI Glue driver
>>>> + *
>>>> + * Copyright (C) 2018 Cadence.
>>>
>>> 2018-2019?
>>>
>>>> + *
>>>> + * Author: Pawel Laszczak <pawell@xxxxxxxxxxx>
>>>> + */
>>>> +
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/pci.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/dma-mapping.h>
>>>> +#include <linux/slab.h>
>>>> +
>>>> +struct cdns3_wrap {
>>>> + struct platform_device *plat_dev;
>>>> + struct pci_dev *hg_dev;
>>>> + struct resource dev_res[4];
>>>> +};
>>>> +
>>>> +struct cdns3_wrap wrap;
>>>> +
>>>> +#define RES_IRQ_ID 0
>>>> +#define RES_HOST_ID 1
>>>> +#define RES_DEV_ID 2
>>>> +#define RES_DRD_ID 3
>>>> +
>>>> +#define PCI_BAR_HOST 0
>>>> +#define PCI_BAR_DEV 2
>>>> +#define PCI_BAR_OTG 4
>>>> +
>>>> +#define PCI_DEV_FN_HOST_DEVICE 0
>>>> +#define PCI_DEV_FN_OTG 1
>>>> +
>>>> +#define PCI_DRIVER_NAME "cdns3-pci-usbss"
>>>> +#define PLAT_DRIVER_NAME "cdns-usb3"
>>>> +
>>>> +#define CDNS_VENDOR_ID 0x17cd
>>>> +#define CDNS_DEVICE_ID 0x0100
>>>> +
>>>> +/**
>>>> + * cdns3_pci_probe - Probe function for Cadence USB wrapper driver
>>>> + * @pdev: platform device object
>>>> + * @id: pci device id
>>>> + *
>>>> + * Returns 0 on success otherwise negative errno
>>>> + */
>>>> +static int cdns3_pci_probe(struct pci_dev *pdev,
>>>> + const struct pci_device_id *id)
>>>> +{
>>>> + struct platform_device_info plat_info;
>>>> + struct cdns3_wrap *wrap;
>>>> + struct resource *res;
>>>> + int err;
>>>> +
>>>> + /*
>>>> + * for GADGET/HOST PCI (devfn) function number is 0,
>>>> + * for OTG PCI (devfn) function number is 1
>>>> + */
>>>> + if (!id || pdev->devfn != PCI_DEV_FN_HOST_DEVICE)
>>>> + return -EINVAL;
>>>> +
>>>> + err = pcim_enable_device(pdev);
>>>> + if (err) {
>>>> + dev_err(&pdev->dev, "Enabling PCI device has failed %d\n", err);
>>>> + return err;
>>>> + }
>>>> +
>>>> + pci_set_master(pdev);
>>>> + wrap = devm_kzalloc(&pdev->dev, sizeof(*wrap), GFP_KERNEL);
>>>> + if (!wrap) {
>>>> + dev_err(&pdev->dev, "Failed to allocate memory\n");
>>>> + return -ENOMEM;
>>>> + }
>>>> +
>>>> + /* function 0: host(BAR_0) + device(BAR_1) + otg(BAR_2)). */
>>>> + memset(wrap->dev_res, 0x00,
>>>> + sizeof(struct resource) * ARRAY_SIZE(wrap->dev_res));
>>>> + dev_dbg(&pdev->dev, "Initialize Device resources\n");
>>>> + res = wrap->dev_res;
>>>> +
>>>> + 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].name = "dev";
>>>> + res[RES_DEV_ID].flags = IORESOURCE_MEM;
>>>> + dev_dbg(&pdev->dev, "USBSS-DEV physical base addr: %pa\n",
>>>> + &res[RES_DEV_ID].start);
>>>> +
>>>> + res[RES_HOST_ID].start = pci_resource_start(pdev, PCI_BAR_HOST);
>>>> + res[RES_HOST_ID].end = pci_resource_end(pdev, PCI_BAR_HOST);
>>>> + res[RES_HOST_ID].name = "xhci";
>>>> + res[RES_HOST_ID].flags = IORESOURCE_MEM;
>>>> + dev_dbg(&pdev->dev, "USBSS-XHCI physical base addr: %pa\n",
>>>> + &res[RES_HOST_ID].start);
>>>> +
>>>> + res[RES_DRD_ID].start = pci_resource_start(pdev, PCI_BAR_OTG);
>>>> + res[RES_DRD_ID].end = pci_resource_end(pdev, PCI_BAR_OTG);
>>>> + res[RES_DRD_ID].name = "otg";
>>>> + res[RES_DRD_ID].flags = IORESOURCE_MEM;
>>>> + dev_dbg(&pdev->dev, "USBSS-DRD physical base addr: %pa\n",
>>>> + &res[RES_DRD_ID].start);
>>>> +
>>>> + /* Interrupt common for both device and XHCI */
>>>> + wrap->dev_res[RES_IRQ_ID].start = pdev->irq;
>>>> + wrap->dev_res[RES_IRQ_ID].name = "cdns3-irq";
>>>> + wrap->dev_res[RES_IRQ_ID].flags = IORESOURCE_IRQ;
>>>> +
>>>> + /* set up platform device info */
>>>> + memset(&plat_info, 0, sizeof(plat_info));
>>>> + plat_info.parent = &pdev->dev;
>>>> + plat_info.fwnode = pdev->dev.fwnode;
>>>> + plat_info.name = PLAT_DRIVER_NAME;
>>>> + plat_info.id = pdev->devfn;
>>>> + plat_info.res = wrap->dev_res;
>>>> + plat_info.num_res = ARRAY_SIZE(wrap->dev_res);
>>>> + plat_info.dma_mask = pdev->dma_mask;
>>>> +
>>>> + /* register platform device */
>>>> + wrap->plat_dev = platform_device_register_full(&plat_info);
>>>> + if (IS_ERR(wrap->plat_dev))
>>>> + return PTR_ERR(wrap->plat_dev);
>>>> +
>>>> + pci_set_drvdata(pdev, wrap);
>>>> +
>>>> + return err;
>>>> +}
>>>> +
>>>> +void cdns3_pci_remove(struct pci_dev *pdev)
>>>> +{
>>>> + struct cdns3_wrap *wrap = (struct cdns3_wrap *)pci_get_drvdata(pdev);
>>>> +
>>>> + platform_device_unregister(wrap->plat_dev);
>>>> +}
>>>> +
>>>> +static const struct pci_device_id cdns3_pci_ids[] = {
>>>> + { PCI_DEVICE(CDNS_VENDOR_ID, CDNS_DEVICE_ID), },
>>>> + { 0, }
>>>> +};
>>>> +
>>>> +static struct pci_driver cdns3_pci_driver = {
>>>> + .name = PCI_DRIVER_NAME,
>>>> + .id_table = cdns3_pci_ids,
>>>> + .probe = cdns3_pci_probe,
>>>> + .remove = cdns3_pci_remove,
>>>> +};
>>>> +
>>>> +module_pci_driver(cdns3_pci_driver);
>>>> +MODULE_DEVICE_TABLE(pci, cdns3_pci_ids);
>>>> +
>>>> +MODULE_AUTHOR("Pawel Laszczak <pawell@xxxxxxxxxxx>");
>>>> +MODULE_LICENSE("GPL v2");
>>>> +MODULE_DESCRIPTION("Cadence USBSS PCI wrapperr");
>>>> +
>>>> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
>>>> new file mode 100644
>>>> index 000000000000..aa2f63241dab
>>>> --- /dev/null
>>>> +++ b/drivers/usb/cdns3/core.c
>>>> @@ -0,0 +1,403 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * Cadence USBSS DRD Driver.
>>>> + *
>>>> + * Copyright (C) 2018 Cadence.
>>>> + * Copyright (C) 2017-2018 NXP
>>>> + *
>>>> + * Author: Peter Chen <peter.chen@xxxxxxx>
>>>> + * Pawel Laszczak <pawell@xxxxxxxxxxx>
>>>> + */
>>>> +
>>>> +#include <linux/module.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/interrupt.h>
>>>> +#include <linux/io.h>
>>>> +#include <linux/pm_runtime.h>
>>>> +
>>>> +#include "gadget.h"
>>>> +#include "core.h"
>>>> +#include "host-export.h"
>>>> +#include "gadget-export.h"
>>>> +#include "drd.h"
>>>> +#include "debug.h"
>>>> +
>>>> +static inline
>>>> +struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
>>>> +{
>>>> + WARN_ON(cdns->role >= CDNS3_ROLE_END || !cdns->roles[cdns->role]);
>>>> + return cdns->roles[cdns->role];
>>>> +}
>>>> +
>>>> +static int cdns3_role_start(struct cdns3 *cdns, enum cdns3_roles role)
>>>> +{
>>>> + int ret;
>>>> +
>>>> + if (WARN_ON(role >= CDNS3_ROLE_END))
>>>> + return 0;
>>>> +
>>>> + if (!cdns->roles[role])
>>>> + return -ENXIO;
>>>> +
>>>> + if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
>>>> + return 0;
>>>> +
>>>> + mutex_lock(&cdns->mutex);
>>>> + cdns->role = role;
>>>> + ret = cdns->roles[role]->start(cdns);
>>>> + if (!ret)
>>>> + cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
>>>> + mutex_unlock(&cdns->mutex);
>>>> + return ret;
>>>> +}
>>>> +
>>>> +void cdns3_role_stop(struct cdns3 *cdns)
>>>> +{
>>>> + enum cdns3_roles role = cdns->role;
>>>> +
>>>> + if (role >= CDNS3_ROLE_END) {
>>>> + WARN_ON(role > CDNS3_ROLE_END);
>>>> + return;
>>>> + }
>>>> +
>>>> + if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
>>>> + return;
>>>> +
>>>> + mutex_lock(&cdns->mutex);
>>>> + cdns->roles[role]->stop(cdns);
>>>> + cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
>>>> + mutex_unlock(&cdns->mutex);
>>>> +}
>>>> +
>>>> +/*
>>>> + * cdns->role gets from cdns3_get_initial_role, and this API tells role at the
>>>> + * runtime.
>>>> + * If both roles are supported, the role is selected based on vbus/id.
>>>> + * It could be read from OTG register or external connector.
>>>> + * If only single role is supported, only one role structure
>>>> + * is allocated, cdns->roles[CDNS3_ROLE_HOST] or cdns->roles[CDNS3_ROLE_GADGET].
>>>> + */
>>>> +static enum cdns3_roles cdns3_get_initial_role(struct cdns3 *cdns)
>>>> +{
>>>> + if (cdns->roles[CDNS3_ROLE_HOST] && cdns->roles[CDNS3_ROLE_GADGET]) {
>>>> + if (cdns3_is_host(cdns))
>>>> + return CDNS3_ROLE_HOST;
>>>> + if (cdns3_is_device(cdns))
>>>> + return CDNS3_ROLE_GADGET;
>>>> + }
>>>> + return cdns->roles[CDNS3_ROLE_HOST]
>>>> + ? CDNS3_ROLE_HOST
>>>> + : CDNS3_ROLE_GADGET;
>>>> +}
>>>> +
>>>> +static void cdns3_exit_roles(struct cdns3 *cdns)
>>>> +{
>>>> + cdns3_role_stop(cdns);
>>>> + cdns3_drd_exit(cdns);
>>>> +}
>>>> +
>>>> +/**
>>>> + * cdns3_core_init_role - initialize role of operation
>>>> + * @cdns: Pointer to cdns3 structure
>>>> + *
>>>> + * Returns 0 on success otherwise negative errno
>>>> + */
>>>> +static int cdns3_core_init_role(struct cdns3 *cdns)
>>>> +{
>>>> + struct device *dev = cdns->dev;
>>>> + enum usb_dr_mode best_dr_mode;
>>>> + enum usb_dr_mode dr_mode;
>>>> + int ret = 0;
>>>> +
>>>> + dr_mode = usb_get_dr_mode(dev);
>>>> + cdns->role = CDNS3_ROLE_END;
>>>> +
>>>> + /*
>>>> + * If driver can't read mode by means of usb_get_dr_mdoe function then
>>>
>>> s/mdoe/mode
>>>
>>>> + * chooses mode according with Kernel configuration. This setting
>>>> + * can be restricted later depending on strap pin configuration.
>>>> + */
>>>> + if (dr_mode == USB_DR_MODE_UNKNOWN) {
>>>> + if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
>>>> + IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
>>>> + dr_mode = USB_DR_MODE_OTG;
>>>> + else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
>>>> + dr_mode = USB_DR_MODE_HOST;
>>>> + else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
>>>> + dr_mode = USB_DR_MODE_PERIPHERAL;
>>>> + }
>>>> +
>>>> + best_dr_mode = USB_DR_MODE_OTG;
>>>
>>> Might be worth mentioning that cdns->dr_mode is strap configuration
>>> at this point.
>> I added such information. It could help in understanding code.
>>>
>>> What exactly are we trying to do here?
>>> My guess is that choosen dr_mode can be equal to or subset of strap configuration?
>>>
>> We have three possibility regarding dr_mode:
>> 1. It can be read from strap bits
>> 2. we have kernel configuration
>> 3. we can read it from dts.
>>
>> I assume that driver should select dr_mode considering these three settings.
>>
>>> Does this work?
>>
>>>
>>> if (cdns->dr_mode != USB_DR_MODE_OTG) {
>>> if (cdns->dr_mode != dr_mode) {
>>> dev_err(dev, "Incorrect dr_mode configuration: strap %d: requested %d\n",
>>> cdns->dr_mode, dr_mode);
>>> }
>>> }
>>>
>>> At this point, dr_mode contains the mode we need to use.
>>
>> I don't understand. Do you want to replace below block with above condition ?
>
>Yes.
>
>> If yes, what with case cdns->dr_mode = USB_DR_MODE_OTG (strap configuration)
>> and dr_mode = USB_DR_MODE_HOST (Kernel configuration).
>> I think that in this case driver should limit cdns->dr_mode to USB_DR_MODE_HOST
>> because gadget driver is disabled.
>
>You are right. It won't work there.
>
>> Of course we can also consider such case as incorrect kernel configuration.
>
>No. It is correct.
>I was thinking if we can get rid of best_dr_mode variable entirely, but nevermind.
>
>>
>>>
>>>> +
>>>> + if (dr_mode == USB_DR_MODE_OTG) {
>>>> + best_dr_mode = cdns->dr_mode;
>
>I think this is wrong. Why do you want to limit to strap configuration when
>user wants it to be in OTG?
The code should look like:
best_dr_mode = cdns->dr_mode; //this line was incorrect
if (dr_mode == USB_DR_MODE_OTG) {
best_dr_mode = cdns->dr_mode;
...
In cdns3_drd_init driver set cdns->dr_mode according to STRAP configuration.
In cdns3_core_init_role driver set dr_mode according to Kernel configuration.
Then if this two setting is not compatible with each other then driver tray to choose
the best solution.
Let's assume:
cdns->dr_mode == USB_DR_MODE_HOST - based on STRAP.
dr_mode == USB_DR_MODE_OTG - based on kernel configuration.
In this case we should consider only USB_DR_MODE_HOST because
CONFIG_USB_CDNS3_GADGET is not set so we don't have compiled
part of driver responsible for device side.
>
>>>> + } else if (cdns->dr_mode == USB_DR_MODE_OTG) {
>>>> + best_dr_mode = dr_mode;
>>>> + } else if (cdns->dr_mode != dr_mode) {
>>>> + dev_err(dev, "Incorrect DRD configuration\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + dr_mode = best_dr_mode;
>>>> +
>>>> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
>>>> + ret = cdns3_host_init(cdns);
>>>> + if (ret) {
>>>> + dev_err(dev, "Host initialization failed with %d\n",
>>>> + ret);
>>>> + goto err;
>>>> + }
>>>> + }
>>>> +
>>>> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
>>>> + ret = cdns3_gadget_init(cdns);
>>>> + if (ret) {
>>>> + dev_err(dev, "Device initialization failed with %d\n",
>>>> + ret);
>>>> + goto err;
>>>> + }
>>>> + }> +
>>>> + cdns->desired_dr_mode = dr_mode;
>>>> + cdns->dr_mode = dr_mode;
>>>> + /*
>>>> + * dr_mode could be change so DRD must update controller
>>>
>>> "desired_dr_mode might have changed so we need to update the controller configuration"?
>>
>> Sounds better.
>>
>
><snip>
>
Cheers,
Pawel