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SubjectRe: [RFC PATCH v2 04/15] usb:cdns3: Driver initialization code.
On Sun, Nov 18, 2018 at 6:16 PM Pawel Laszczak <pawell@cadence.com> wrote:
>
> Patch adds core.c and core.h file that implements initialization
> of platform driver and adds function responsible for selecting,
> switching and running appropriate Device/Host mode.
>
> Signed-off-by: Pawel Laszczak <pawell@cadence.com>
> ---
> drivers/usb/cdns3/Makefile | 2 +
> drivers/usb/cdns3/core.c | 413 +++++++++++++++++++++++++++++++++++++
> drivers/usb/cdns3/core.h | 100 +++++++++
> 3 files changed, 515 insertions(+)
> create mode 100644 drivers/usb/cdns3/core.c
> create mode 100644 drivers/usb/cdns3/core.h
>
> diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
> index dcdd62003c6a..02d25b23c5d3 100644
> --- a/drivers/usb/cdns3/Makefile
> +++ b/drivers/usb/cdns3/Makefile
> @@ -1,3 +1,5 @@
> +obj-$(CONFIG_USB_CDNS3) += cdns3.o
> obj-$(CONFIG_USB_CDNS3_PCI_WRAP) += cdns3-pci.o
>
> +cdns3-y := core.o
> cdns3-pci-y := cdns3-pci-wrap.o
> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
> new file mode 100644
> index 000000000000..f9055d4da67f
> --- /dev/null
> +++ b/drivers/usb/cdns3/core.c
> @@ -0,0 +1,413 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Cadence USBSS DRD Driver.
> + *
> + * Copyright (C) 2018 Cadence.
> + *

Please add NXP copyright too.

> + * Author: Peter Chen <peter.chen@nxp.com>
> + * Pawel Laszczak <pawell@cadence.com>
> + */
> +
> +#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"
> +
> +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];
> +}
> +

Can we delete "current", and use cdns3_get_role_driver directly?

> +static inline int cdns3_role_start(struct cdns3 *cdns, enum cdns3_roles role)
> +{
> + int ret;
> +
> + if (role >= CDNS3_ROLE_END)
> + return 0;
> +
> + if (!cdns->roles[role])
> + return -ENXIO;
> +
> + mutex_lock(&cdns->mutex);
> + cdns->role = role;
> + ret = cdns->roles[role]->start(cdns);
> + mutex_unlock(&cdns->mutex);
> + return ret;
> +}
> +
> +static inline void cdns3_role_stop(struct cdns3 *cdns)
> +{
> + enum cdns3_roles role = cdns->role;
> +
> + if (role == CDNS3_ROLE_END)
> + return;
> +
> + mutex_lock(&cdns->mutex);
> + cdns->roles[role]->stop(cdns);
> + cdns->role = CDNS3_ROLE_END;
> + mutex_unlock(&cdns->mutex);
> +}
> +
> +static enum cdns3_roles cdns3_get_role(struct cdns3 *cdns)
> +{
> + if (cdns->roles[CDNS3_ROLE_HOST] && cdns->roles[CDNS3_ROLE_GADGET]) {
> + //TODO: implements selecting device/host mode
> + return CDNS3_ROLE_HOST;
> + }
> + return cdns->roles[CDNS3_ROLE_HOST]
> + ? CDNS3_ROLE_HOST
> + : CDNS3_ROLE_GADGET;
> +}
> +
> +/**
> + * 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 dr_mode;
> +
> + 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
> + * 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;
> + }
> +
> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
> + //TODO: implements host initialization
> + }
> +
> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
> + //TODO: implements device initialization
> + }
> +
> + if (!cdns->roles[CDNS3_ROLE_HOST] && !cdns->roles[CDNS3_ROLE_GADGET]) {
> + dev_err(dev, "no supported roles\n");
> + return -ENODEV;
> + }
> +
> + cdns->dr_mode = dr_mode;
> + return 0;
> +}
> +
> +/**
> + * cdns3_irq - interrupt handler for cdns3 core device
> + *
> + * @irq: irq number for cdns3 core device
> + * @data: structure of cdns3
> + *
> + * Returns IRQ_HANDLED or IRQ_NONE
> + */
> +static irqreturn_t cdns3_irq(int irq, void *data)
> +{
> + struct cdns3 *cdns = data;
> + irqreturn_t ret = IRQ_NONE;
> +
> + /* Handle device/host interrupt */
> + if (cdns->role != CDNS3_ROLE_END)
> + ret = cdns3_get_current_role_driver(cdns)->irq(cdns);
> +
> + return ret;
> +}
> +
> +static void cdns3_remove_roles(struct cdns3 *cdns)
> +{
> + //TODO: implements this function
> +}
> +
> +static int cdns3_do_role_switch(struct cdns3 *cdns, enum cdns3_roles role)
> +{
> + enum cdns3_roles current_role;
> + int ret = 0;
> +
> + current_role = cdns->role;
> +
> + if (role == CDNS3_ROLE_END)
> + return 0;
> +
> + dev_dbg(cdns->dev, "Switching role");
> +
> + ret = cdns3_role_start(cdns, role);
> + if (ret) {
> + /* Back to current role */
> + dev_err(cdns->dev, "set %d has failed, back to %d\n",
> + role, current_role);
> + ret = cdns3_role_start(cdns, current_role);
> + }
> +
> + return ret;
> +}
> +
> +/**
> + * cdns3_role_switch - work queue handler for role switch
> + *
> + * @work: work queue item structure
> + *
> + * Handles below events:
> + * - Role switch for dual-role devices
> + * - CDNS3_ROLE_GADGET <--> CDNS3_ROLE_END for peripheral-only devices
> + */
> +static void cdns3_role_switch(struct work_struct *work)
> +{
> + enum cdns3_roles role = CDNS3_ROLE_END;
> + struct cdns3 *cdns;
> + bool device, host;
> +
> + cdns = container_of(work, struct cdns3, role_switch_wq);
> +
> + //TODO: implements this functions.
> + //host = cdns3_is_host(cdns);
> + //device = cdns3_is_device(cdns);

You may improve use C comment.

> + host = 1;
> + device = 0;
> +
> + if (host)
> + role = CDNS3_ROLE_HOST;
> + else if (device)
> + role = CDNS3_ROLE_GADGET;
> +
> + if (cdns->desired_dr_mode == cdns->current_dr_mode &&
> + cdns->role == role)
> + return;
> +
> + pm_runtime_get_sync(cdns->dev);
> + cdns3_role_stop(cdns);
> +
> + if (host) {
> + if (cdns->roles[CDNS3_ROLE_HOST])
> + cdns3_do_role_switch(cdns, CDNS3_ROLE_HOST);
> + pm_runtime_put_sync(cdns->dev);
> + return;
> + }
> +
> + if (device)
> + cdns3_do_role_switch(cdns, CDNS3_ROLE_GADGET);
> + else
> + cdns3_do_role_switch(cdns, CDNS3_ROLE_END);
> +
> + pm_runtime_put_sync(cdns->dev);
> +}
> +
> +/**
> + * cdns3_probe - probe for cdns3 core device
> + * @pdev: Pointer to cdns3 core platform device
> + *
> + * Returns 0 on success otherwise negative errno
> + */
> +static int cdns3_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + struct cdns3 *cdns;
> + void __iomem *regs;
> + int ret;
> +
> + cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL);
> + if (!cdns)
> + return -ENOMEM;
> +
> + cdns->dev = dev;
> +
> + platform_set_drvdata(pdev, cdns);
> +
> + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!res) {
> + dev_err(dev, "missing IRQ\n");
> + return -ENODEV;
> + }
> + cdns->irq = res->start;
> +
> + /*
> + * Request memory region
> + * region-0: xHCI
> + * region-1: Peripheral
> + * region-2: OTG registers
> + */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + regs = devm_ioremap_resource(dev, res);
> +
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> + cdns->xhci_regs = regs;
> + cdns->xhci_res = res;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> + cdns->dev_regs = regs;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> + cdns->otg_regs = regs;
> +
> + mutex_init(&cdns->mutex);
> +
> + cdns->phy = devm_phy_get(dev, "cdns3,usbphy");
> + if (IS_ERR(cdns->phy)) {
> + dev_info(dev, "no generic phy found\n");
> + cdns->phy = NULL;
> + /*
> + * fall through here!
> + * if no generic phy found, phy init
> + * should be done under boot!
> + */

If the phy driver is defer-probed, it will be here, it is not an error.
I think you could have a generic phy driver or usb generic phy driver
(drivers/usb/phy/phy-generic.c) even you don't need any operations for
PHY. It will be easy for other platforms.

> + } else {
> + phy_init(cdns->phy);
> + }
> +
> + ret = cdns3_core_init_role(cdns);
> + if (ret)
> + goto err1;
> +
> + INIT_WORK(&cdns->role_switch_wq, cdns3_role_switch);
> + if (ret)
> + goto err2;
> +
> + if (ret)
> + goto err2;
> +
> + cdns->role = cdns3_get_role(cdns);
> +
> + ret = devm_request_irq(dev, cdns->irq, cdns3_irq, IRQF_SHARED,
> + dev_name(dev), cdns);
> +
> + if (ret)
> + goto err2;
> +
> + ret = cdns3_role_start(cdns, cdns->role);
> + if (ret) {
> + dev_err(dev, "can't start %s role\n",
> + cdns3_get_current_role_driver(cdns)->name);
> + goto err2;
> + }
> +
> + device_set_wakeup_capable(dev, true);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> +
> + /*
> + * The controller needs less time between bus and controller suspend,
> + * and we also needs a small delay to avoid frequently entering low
> + * power mode.
> + */
> + pm_runtime_set_autosuspend_delay(dev, 20);
> + pm_runtime_mark_last_busy(dev);
> + pm_runtime_use_autosuspend(dev);
> + dev_dbg(dev, "Cadence USB3 core: probe succeed\n");
> +
> + return 0;
> +
> +err2:
> + cdns3_remove_roles(cdns);
> +err1:
> + return ret;
> +}
> +
> +/**
> + * cdns3_remove - unbind drd driver and clean up
> + * @pdev: Pointer to Linux platform device
> + *
> + * Returns 0 on success otherwise negative errno
> + */
> +static int cdns3_remove(struct platform_device *pdev)
> +{
> + struct cdns3 *cdns = platform_get_drvdata(pdev);
> +
> + pm_runtime_get_sync(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> + pm_runtime_put_noidle(&pdev->dev);
> + cdns3_remove_roles(cdns);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id of_cdns3_match[] = {
> + { .compatible = "cdns,usb3" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, of_cdns3_match);
> +#endif
> +
> +#ifdef CONFIG_PM
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int cdns3_suspend(struct device *dev)
> +{
> + //TODO: implements this function
> + return 0;
> +}
> +
> +static int cdns3_resume(struct device *dev)
> +{
> + //TODO: implements this function
> + return 0;
> +}
> +#endif /* CONFIG_PM_SLEEP */
> +static int cdns3_runtime_suspend(struct device *dev)
> +{ //TODO: implements this function
> + return 0;
> +}
> +
> +static int cdns3_runtime_resume(struct device *dev)
> +{
> + //TODO: implements this function
> + return 0;
> +}
> +#endif /* CONFIG_PM */
> +
> +static const struct dev_pm_ops cdns3_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
> + SET_RUNTIME_PM_OPS(cdns3_runtime_suspend, cdns3_runtime_resume, NULL)
> +};
> +
> +static struct platform_driver cdns3_driver = {
> + .probe = cdns3_probe,
> + .remove = cdns3_remove,
> + .driver = {
> + .name = "cdns-usb3",
> + .of_match_table = of_match_ptr(of_cdns3_match),
> + .pm = &cdns3_pm_ops,
> + },
> +};
> +
> +static int __init cdns3_driver_platform_register(void)
> +{
> + return platform_driver_register(&cdns3_driver);
> +}
> +module_init(cdns3_driver_platform_register);
> +
> +static void __exit cdns3_driver_platform_unregister(void)
> +{
> + platform_driver_unregister(&cdns3_driver);
> +}
> +module_exit(cdns3_driver_platform_unregister);
> +
> +MODULE_ALIAS("platform:cdns3");
> +MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");
> diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h
> new file mode 100644
> index 000000000000..7c8204fe4d3d
> --- /dev/null
> +++ b/drivers/usb/cdns3/core.h
> @@ -0,0 +1,100 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Cadence USBSS DRD Driver.
> + *

Header file

> + * Copyright (C) 2017 NXP
> + * Copyright (C) 2018 Cadence.
> + *
> + * Authors: Peter Chen <peter.chen@nxp.com>
> + * Pawel Laszczak <pawell@cadence.com>
> + */
> +#include <linux/usb/otg.h>
> +
> +#ifndef __LINUX_CDNS3_CORE_H
> +#define __LINUX_CDNS3_CORE_H
> +
> +struct cdns3;
> +enum cdns3_roles {
> + CDNS3_ROLE_HOST = 0,
> + CDNS3_ROLE_GADGET,
> + CDNS3_ROLE_END,
> +};
> +
> +/**
> + * struct cdns3_role_driver - host/gadget role driver
> + * @start: start this role
> + * @stop: stop this role
> + * @suspend: suspend callback for this role
> + * @resume: resume callback for this role
> + * @irq: irq handler for this role
> + * @name: role name string (host/gadget)
> + */
> +struct cdns3_role_driver {
> + int (*start)(struct cdns3 *cdns);
> + void (*stop)(struct cdns3 *cdns);
> + int (*suspend)(struct cdns3 *cdns, bool do_wakeup);
> + int (*resume)(struct cdns3 *cdns, bool hibernated);
> + irqreturn_t (*irq)(struct cdns3 *cdns);
> + const char *name;
> +};
> +
> +#define CDNS3_NUM_OF_CLKS 5
> +/**
> + * struct cdns3 - Representation of Cadence USB3 DRD controller.
> + * @dev: pointer to Cadence device struct
> + * @xhci_regs: pointer to base of xhci registers
> + * @xhci_res: the resource for xhci
> + * @dev_regs: pointer to base of dev registers
> + * @otg_regs: pointer to base of otg registers
> + * @irq: irq number for controller
> + * @roles: array of supported roles for this controller
> + * @role: current role
> + * @host_dev: the child host device pointer for cdns3 core
> + * @gadget_dev: the child gadget device pointer for cdns3 core
> + * @usb: phy for this controller
> + * @role_switch_wq: work queue item for role switch
> + * @in_lpm: the controller in low power mode
> + * @wakeup_int: the wakeup interrupt
> + * @mutex: the mutex for concurrent code at driver
> + * @dr_mode: supported mode of operation it can be only Host, only Device
> + * or OTG mode that allow to switch between Device and Host mode.
> + * This field based on hardware configuration and cant't be changed.

Based on firmware setting, kernel configuration and hardware configuration.

> + * @current_dr_role: current mode of operation when in dual-role mode
> + * @desired_dr_role: desired mode of operation when in dual-role mode.
> + * This value can be changed during runtime.
> + * Available options depends on dr_mode:
> + * dr_mode | desired_dr_role and current_dr_role
> + * ----------------------------------------------------------------
> + * USB_DR_MODE_HOST | only USB_DR_MODE_HOST
> + * USB_DR_MODE_PERIPHERAL | only USB_DR_MODE_PERIPHERAL
> + * USB_DR_MODE_OTG | only USB_DR_MODE_HOST
> + * USB_DR_MODE_OTG | only USB_DR_MODE_PERIPHERAL
> + * USB_DR_MODE_OTG | USB_DR_MODE_OTG
> + *
> + * Desired_dr_role can be changed by means of debugfs.
> + * @root: debugfs root folder pointer
> + */
> +struct cdns3 {
> + struct device *dev;
> + void __iomem *xhci_regs;
> + struct resource *xhci_res;
> + struct cdns3_usb_regs __iomem *dev_regs;
> + struct cdns3_otg_regs *otg_regs;
> + int irq;
> + struct cdns3_role_driver *roles[CDNS3_ROLE_END];
> + enum cdns3_roles role;
> + struct device *host_dev;
> + struct device *gadget_dev;
> + struct phy *phy;
> + struct work_struct role_switch_wq;
> + int in_lpm:1;
> + int wakeup_int:1;
> + /* mutext used in workqueue*/
> + struct mutex mutex;
> + enum usb_dr_mode dr_mode;
> + enum usb_dr_mode current_dr_mode;
> + enum usb_dr_mode desired_dr_mode;
> + struct dentry *root;
> +};
> +
> +#endif /* __LINUX_CDNS3_CORE_H */
> --
> 2.17.1
>

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