1 files changed, 653 insertions, 0 deletions
diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
new file mode 100644
index 000000000000..300df58a190b
--- /dev/null
+++ b/drivers/usb/cdns3/core.c
@@ -0,0 +1,653 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence USBSS DRD Driver.
+ *
+ * Copyright (C) 2018-2019 Cadence.
+ * Copyright (C) 2017-2018 NXP
+ * Copyright (C) 2019 Texas Instruments
+ *
+ * Author: Peter Chen <peter.chen@nxp.com>
+ *         Pawel Laszczak <pawell@cadence.com>
+ *         Roger Quadros <rogerq@ti.com>
+ */
+
+#include <linux/dma-mapping.h>
+#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"
+
+static int cdns3_idle_init(struct cdns3 *cdns);
+
+static inline
+struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
+{
+	WARN_ON(!cdns->roles[cdns->role]);
+	return cdns->roles[cdns->role];
+}
+
+static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
+{
+	int ret;
+
+	if (WARN_ON(role > USB_ROLE_DEVICE))
+		return 0;
+
+	mutex_lock(&cdns->mutex);
+	cdns->role = role;
+	mutex_unlock(&cdns->mutex);
+
+	if (!cdns->roles[role])
+		return -ENXIO;
+
+	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
+		return 0;
+
+	mutex_lock(&cdns->mutex);
+	ret = cdns->roles[role]->start(cdns);
+	if (!ret)
+		cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
+	mutex_unlock(&cdns->mutex);
+
+	return ret;
+}
+
+static void cdns3_role_stop(struct cdns3 *cdns)
+{
+	enum usb_role role = cdns->role;
+
+	if (WARN_ON(role > USB_ROLE_DEVICE))
+		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);
+}
+
+static void cdns3_exit_roles(struct cdns3 *cdns)
+{
+	cdns3_role_stop(cdns);
+	cdns3_drd_exit(cdns);
+}
+
+static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *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 = USB_ROLE_NONE;
+
+	/*
+	 * If driver can't read mode by means of usb_get_dr_mode 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;
+	}
+
+	/*
+	 * At this point cdns->dr_mode contains strap configuration.
+	 * Driver try update this setting considering kernel configuration
+	 */
+	best_dr_mode = cdns->dr_mode;
+
+	ret = cdns3_idle_init(cdns);
+	if (ret)
+		return ret;
+
+	if (dr_mode == USB_DR_MODE_OTG) {
+		best_dr_mode = cdns->dr_mode;
+	} 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->dr_mode = dr_mode;
+
+	ret = cdns3_drd_update_mode(cdns);
+	if (ret)
+		goto err;
+
+	if (cdns->dr_mode != USB_DR_MODE_OTG) {
+		ret = cdns3_hw_role_switch(cdns);
+		if (ret)
+			goto err;
+	}
+
+	return ret;
+err:
+	cdns3_exit_roles(cdns);
+	return ret;
+}
+
+/**
+ * cdsn3_hw_role_state_machine  - role switch state machine based on hw events.
+ * @cdns: Pointer to controller structure.
+ *
+ * Returns next role to be entered based on hw events.
+ */
+static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
+{
+	enum usb_role role;
+	int id, vbus;
+
+	if (cdns->dr_mode != USB_DR_MODE_OTG)
+		goto not_otg;
+
+	id = cdns3_get_id(cdns);
+	vbus = cdns3_get_vbus(cdns);
+
+	/*
+	 * Role change state machine
+	 * Inputs: ID, VBUS
+	 * Previous state: cdns->role
+	 * Next state: role
+	 */
+	role = cdns->role;
+
+	switch (role) {
+	case USB_ROLE_NONE:
+		/*
+		 * Driver treats USB_ROLE_NONE synonymous to IDLE state from
+		 * controller specification.
+		 */
+		if (!id)
+			role = USB_ROLE_HOST;
+		else if (vbus)
+			role = USB_ROLE_DEVICE;
+		break;
+	case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
+		if (id)
+			role = USB_ROLE_NONE;
+		break;
+	case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
+		if (!vbus)
+			role = USB_ROLE_NONE;
+		break;
+	}
+
+	dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);
+
+	return role;
+
+not_otg:
+	if (cdns3_is_host(cdns))
+		role = USB_ROLE_HOST;
+	if (cdns3_is_device(cdns))
+		role = USB_ROLE_DEVICE;
+
+	return role;
+}
+
+static int cdns3_idle_role_start(struct cdns3 *cdns)
+{
+	return 0;
+}
+
+static void cdns3_idle_role_stop(struct cdns3 *cdns)
+{
+	/* Program Lane swap and bring PHY out of RESET */
+	phy_reset(cdns->usb3_phy);
+}
+
+static int cdns3_idle_init(struct cdns3 *cdns)
+{
+	struct cdns3_role_driver *rdrv;
+
+	rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
+	if (!rdrv)
+		return -ENOMEM;
+
+	rdrv->start = cdns3_idle_role_start;
+	rdrv->stop = cdns3_idle_role_stop;
+	rdrv->state = CDNS3_ROLE_STATE_INACTIVE;
+	rdrv->suspend = NULL;
+	rdrv->resume = NULL;
+	rdrv->name = "idle";
+
+	cdns->roles[USB_ROLE_NONE] = rdrv;
+
+	return 0;
+}
+
+/**
+ * cdns3_hw_role_switch - switch roles based on HW state
+ * @cdns3: controller
+ */
+int cdns3_hw_role_switch(struct cdns3 *cdns)
+{
+	enum usb_role real_role, current_role;
+	int ret = 0;
+
+	/* Do nothing if role based on syfs. */
+	if (cdns->role_override)
+		return 0;
+
+	pm_runtime_get_sync(cdns->dev);
+
+	current_role = cdns->role;
+	real_role = cdsn3_hw_role_state_machine(cdns);
+
+	/* Do nothing if nothing changed */
+	if (current_role == real_role)
+		goto exit;
+
+	cdns3_role_stop(cdns);
+
+	dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
+
+	ret = cdns3_role_start(cdns, real_role);
+	if (ret) {
+		/* Back to current role */
+		dev_err(cdns->dev, "set %d has failed, back to %d\n",
+			real_role, current_role);
+		ret = cdns3_role_start(cdns, current_role);
+		if (ret)
+			dev_err(cdns->dev, "back to %d failed too\n",
+				current_role);
+	}
+exit:
+	pm_runtime_put_sync(cdns->dev);
+	return ret;
+}
+
+/**
+ * cdsn3_role_get - get current role of controller.
+ *
+ * @dev: Pointer to device structure
+ *
+ * Returns role
+ */
+static enum usb_role cdns3_role_get(struct device *dev)
+{
+	struct cdns3 *cdns = dev_get_drvdata(dev);
+
+	return cdns->role;
+}
+
+/**
+ * cdns3_role_set - set current role of controller.
+ *
+ * @dev: pointer to device object
+ * @role - the previous role
+ * Handles below events:
+ * - Role switch for dual-role devices
+ * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
+ */
+static int cdns3_role_set(struct device *dev, enum usb_role role)
+{
+	struct cdns3 *cdns = dev_get_drvdata(dev);
+	int ret = 0;
+
+	pm_runtime_get_sync(cdns->dev);
+
+	/*
+	 * FIXME: switch role framework should be extended to meet
+	 * requirements. Driver assumes that role can be controlled
+	 * by SW or HW. Temporary workaround is to use USB_ROLE_NONE to
+	 * switch from SW to HW control.
+	 *
+	 * For dr_mode == USB_DR_MODE_OTG:
+	 *	if user sets USB_ROLE_HOST or USB_ROLE_DEVICE then driver
+	 *	sets role_override flag and forces that role.
+	 *	if user sets USB_ROLE_NONE, driver clears role_override and lets
+	 *	HW state machine take over.
+	 *
+	 * For dr_mode != USB_DR_MODE_OTG:
+	 *	Assumptions:
+	 *	1. Restricted user control between NONE and dr_mode.
+	 *	2. Driver doesn't need to rely on role_override flag.
+	 *	3. Driver needs to ensure that HW state machine is never called
+	 *	   if dr_mode != USB_DR_MODE_OTG.
+	 */
+	if (role == USB_ROLE_NONE)
+		cdns->role_override = 0;
+	else
+		cdns->role_override = 1;
+
+	/*
+	 * HW state might have changed so driver need to trigger
+	 * HW state machine if dr_mode == USB_DR_MODE_OTG.
+	 */
+	if (!cdns->role_override && cdns->dr_mode == USB_DR_MODE_OTG) {
+		cdns3_hw_role_switch(cdns);
+		goto pm_put;
+	}
+
+	if (cdns->role == role)
+		goto pm_put;
+
+	if (cdns->dr_mode == USB_DR_MODE_HOST) {
+		switch (role) {
+		case USB_ROLE_NONE:
+		case USB_ROLE_HOST:
+			break;
+		default:
+			ret = -EPERM;
+			goto pm_put;
+		}
+	}
+
+	if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
+		switch (role) {
+		case USB_ROLE_NONE:
+		case USB_ROLE_DEVICE:
+			break;
+		default:
+			ret = -EPERM;
+			goto pm_put;
+		}
+	}
+
+	cdns3_role_stop(cdns);
+	ret = cdns3_role_start(cdns, role);
+	if (ret) {
+		dev_err(cdns->dev, "set role %d has failed\n", role);
+		ret = -EPERM;
+	}
+
+pm_put:
+	pm_runtime_put_sync(cdns->dev);
+	return ret;
+}
+
+static const struct usb_role_switch_desc cdns3_switch_desc = {
+	.set = cdns3_role_set,
+	.get = cdns3_role_get,
+	.allow_userspace_control = true,
+};
+
+/**
+ * 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;
+
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "error setting dma mask: %d\n", ret);
+		return -ENODEV;
+	}
+
+	cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL);
+	if (!cdns)
+		return -ENOMEM;
+
+	cdns->dev = dev;
+
+	platform_set_drvdata(pdev, cdns);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "host");
+	if (!res) {
+		dev_err(dev, "missing host IRQ\n");
+		return -ENODEV;
+	}
+
+	cdns->xhci_res[0] = *res;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xhci");
+	if (!res) {
+		dev_err(dev, "couldn't get xhci resource\n");
+		return -ENXIO;
+	}
+
+	cdns->xhci_res[1] = *res;
+
+	cdns->dev_irq = platform_get_irq_byname(pdev, "peripheral");
+	if (cdns->dev_irq == -EPROBE_DEFER)
+		return cdns->dev_irq;
+
+	if (cdns->dev_irq < 0)
+		dev_err(dev, "couldn't get peripheral irq\n");
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dev");
+	regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(regs)) {
+		dev_err(dev, "couldn't iomap dev resource\n");
+		return PTR_ERR(regs);
+	}
+	cdns->dev_regs	= regs;
+
+	cdns->otg_irq = platform_get_irq_byname(pdev, "otg");
+	if (cdns->otg_irq == -EPROBE_DEFER)
+		return cdns->otg_irq;
+
+	if (cdns->otg_irq < 0) {
+		dev_err(dev, "couldn't get otg irq\n");
+		return cdns->otg_irq;
+	}
+
+	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;
+
+	mutex_init(&cdns->mutex);
+
+	cdns->usb2_phy = devm_phy_optional_get(dev, "cdns3,usb2-phy");
+	if (IS_ERR(cdns->usb2_phy))
+		return PTR_ERR(cdns->usb2_phy);
+
+	ret = phy_init(cdns->usb2_phy);
+	if (ret)
+		return ret;
+
+	cdns->usb3_phy = devm_phy_optional_get(dev, "cdns3,usb3-phy");
+	if (IS_ERR(cdns->usb3_phy))
+		return PTR_ERR(cdns->usb3_phy);
+
+	ret = phy_init(cdns->usb3_phy);
+	if (ret)
+		goto err1;
+
+	ret = phy_power_on(cdns->usb2_phy);
+	if (ret)
+		goto err2;
+
+	ret = phy_power_on(cdns->usb3_phy);
+	if (ret)
+		goto err3;
+
+	cdns->role_sw = usb_role_switch_register(dev, &cdns3_switch_desc);
+	if (IS_ERR(cdns->role_sw)) {
+		ret = PTR_ERR(cdns->role_sw);
+		dev_warn(dev, "Unable to register Role Switch\n");
+		goto err4;
+	}
+
+	ret = cdns3_drd_init(cdns);
+	if (ret)
+		goto err5;
+
+	ret = cdns3_core_init_role(cdns);
+	if (ret)
+		goto err5;
+
+	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;
+err5:
+	cdns3_drd_exit(cdns);
+	usb_role_switch_unregister(cdns->role_sw);
+err4:
+	phy_power_off(cdns->usb3_phy);
+
+err3:
+	phy_power_off(cdns->usb2_phy);
+err2:
+	phy_exit(cdns->usb3_phy);
+err1:
+	phy_exit(cdns->usb2_phy);
+
+	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_exit_roles(cdns);
+	usb_role_switch_unregister(cdns->role_sw);
+	phy_power_off(cdns->usb2_phy);
+	phy_power_off(cdns->usb3_phy);
+	phy_exit(cdns->usb2_phy);
+	phy_exit(cdns->usb3_phy);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int cdns3_suspend(struct device *dev)
+{
+	struct cdns3 *cdns = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	if (cdns->role == USB_ROLE_HOST)
+		return 0;
+
+	if (pm_runtime_status_suspended(dev))
+		pm_runtime_resume(dev);
+
+	if (cdns->roles[cdns->role]->suspend) {
+		spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
+		cdns->roles[cdns->role]->suspend(cdns, false);
+		spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
+	}
+
+	return 0;
+}
+
+static int cdns3_resume(struct device *dev)
+{
+	struct cdns3 *cdns = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	if (cdns->role == USB_ROLE_HOST)
+		return 0;
+
+	if (cdns->roles[cdns->role]->resume) {
+		spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
+		cdns->roles[cdns->role]->resume(cdns, false);
+		spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
+	}
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops cdns3_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_cdns3_match[] = {
+	{ .compatible = "cdns,usb3" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, of_cdns3_match);
+#endif
+
+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,
+	},
+};
+
+module_platform_driver(cdns3_driver);
+
+MODULE_ALIAS("platform:cdns3");
+MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");