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Subject[RFC PATCH v2 04/15] usb:cdns3: Driver initialization code.
Date
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.
+ *
+ * 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];
+}
+
+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);
+ 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!
+ */
+ } 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.
+ *
+ * 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.
+ * @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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