usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver

This patch introduces the main part of Cadence USBSSP DRD driver
to Linux kernel.
To reduce the patch size a little bit, the header file gadget.h was
intentionally added as separate patch.

The Cadence USBSSP DRD Controller is a highly configurable IP Core which
can be instantiated as Dual-Role Device (DRD), Peripheral Only and
Host Only (XHCI)configurations.

The current driver has been validated with FPGA platform. We have
support for PCIe bus, which is used on FPGA prototyping.

The host side of USBSS DRD controller is compliant with XHCI.
The architecture for device side is almost the same as for host side,
and most of the XHCI specification can be used to understand how
this controller operates.

Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

1 files changed, 477 insertions, 0 deletions

diff --git a/drivers/usb/cdns3/cdnsp-ep0.c b/drivers/usb/cdns3/cdnsp-ep0.c
new file mode 100644
index 000000000000..aa220d06d887
--- /dev/null
+++ b/drivers/usb/cdns3/cdnsp-ep0.c
@@ -0,0 +1,477 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence CDNSP DRD Driver.
+ *
+ * Copyright (C) 2020 Cadence.
+ *
+ * Author: Pawel Laszczak <pawell@cadence.com>
+ *
+ */
+
+#include <linux/usb/composite.h>
+#include <linux/usb/gadget.h>
+#include <linux/list.h>
+
+#include "cdnsp-gadget.h"
+
+static void cdnsp_ep0_stall(struct cdnsp_device *pdev)
+{
+	struct cdnsp_request *preq;
+	struct cdnsp_ep *pep;
+
+	pep = &pdev->eps[0];
+	preq = next_request(&pep->pending_list);
+
+	if (pdev->three_stage_setup) {
+		cdnsp_halt_endpoint(pdev, pep, true);
+
+		if (preq)
+			cdnsp_gadget_giveback(pep, preq, -ECONNRESET);
+	} else {
+		pep->ep_state |= EP0_HALTED_STATUS;
+
+		if (preq)
+			list_del(&preq->list);
+
+		cdnsp_status_stage(pdev);
+	}
+}
+
+static int cdnsp_ep0_delegate_req(struct cdnsp_device *pdev,
+				  struct usb_ctrlrequest *ctrl)
+{
+	int ret;
+
+	spin_unlock(&pdev->lock);
+	ret = pdev->gadget_driver->setup(&pdev->gadget, ctrl);
+	spin_lock(&pdev->lock);
+
+	return ret;
+}
+
+static int cdnsp_ep0_set_config(struct cdnsp_device *pdev,
+				struct usb_ctrlrequest *ctrl)
+{
+	enum usb_device_state state = pdev->gadget.state;
+	u32 cfg;
+	int ret;
+
+	cfg = le16_to_cpu(ctrl->wValue);
+
+	switch (state) {
+	case USB_STATE_ADDRESS:
+		break;
+	case USB_STATE_CONFIGURED:
+		break;
+	default:
+		dev_err(pdev->dev, "Set Configuration - bad device state\n");
+		return -EINVAL;
+	}
+
+	ret = cdnsp_ep0_delegate_req(pdev, ctrl);
+	if (ret)
+		return ret;
+
+	if (!cfg)
+		usb_gadget_set_state(&pdev->gadget, USB_STATE_ADDRESS);
+
+	return 0;
+}
+
+static int cdnsp_ep0_set_address(struct cdnsp_device *pdev,
+				 struct usb_ctrlrequest *ctrl)
+{
+	enum usb_device_state state = pdev->gadget.state;
+	struct cdnsp_slot_ctx *slot_ctx;
+	unsigned int slot_state;
+	int ret;
+	u32 addr;
+
+	addr = le16_to_cpu(ctrl->wValue);
+
+	if (addr > 127) {
+		dev_err(pdev->dev, "Invalid device address %d\n", addr);
+		return -EINVAL;
+	}
+
+	slot_ctx = cdnsp_get_slot_ctx(&pdev->out_ctx);
+
+	if (state == USB_STATE_CONFIGURED) {
+		dev_err(pdev->dev, "Can't Set Address from Configured State\n");
+		return -EINVAL;
+	}
+
+	pdev->device_address = le16_to_cpu(ctrl->wValue);
+
+	slot_ctx = cdnsp_get_slot_ctx(&pdev->out_ctx);
+	slot_state = GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state));
+	if (slot_state == SLOT_STATE_ADDRESSED)
+		cdnsp_reset_device(pdev);
+
+	/*set device address*/
+	ret = cdnsp_setup_device(pdev, SETUP_CONTEXT_ADDRESS);
+	if (ret)
+		return ret;
+
+	if (addr)
+		usb_gadget_set_state(&pdev->gadget, USB_STATE_ADDRESS);
+	else
+		usb_gadget_set_state(&pdev->gadget, USB_STATE_DEFAULT);
+
+	return 0;
+}
+
+int cdnsp_status_stage(struct cdnsp_device *pdev)
+{
+	pdev->ep0_stage = CDNSP_STATUS_STAGE;
+	pdev->ep0_preq.request.length = 0;
+
+	return cdnsp_ep_enqueue(pdev->ep0_preq.pep, &pdev->ep0_preq);
+}
+
+static int cdnsp_w_index_to_ep_index(__le32  wIndex)
+{
+	wIndex = le32_to_cpu(wIndex);
+
+	if (!(wIndex & USB_ENDPOINT_NUMBER_MASK))
+		return 0;
+
+	return ((wIndex & USB_ENDPOINT_NUMBER_MASK) * 2) +
+		(wIndex & USB_ENDPOINT_DIR_MASK ? 1 : 0) - 1;
+}
+
+static int cdnsp_ep0_handle_status(struct cdnsp_device *pdev,
+				   struct usb_ctrlrequest *ctrl)
+{
+	struct cdnsp_ep *pep;
+	__le16 *response;
+	int ep_sts = 0;
+	u16 status = 0;
+	u32 recipient;
+
+	recipient = ctrl->bRequestType & USB_RECIP_MASK;
+
+	switch (recipient) {
+	case USB_RECIP_DEVICE:
+		status = pdev->gadget.is_selfpowered;
+		status |= pdev->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
+
+		if (pdev->gadget.speed >= USB_SPEED_SUPER) {
+			status |= pdev->u1_allowed << USB_DEV_STAT_U1_ENABLED;
+			status |= pdev->u2_allowed << USB_DEV_STAT_U2_ENABLED;
+		}
+		break;
+	case USB_RECIP_INTERFACE:
+		/*
+		 * Function Remote Wake Capable	D0
+		 * Function Remote Wakeup	D1
+		 */
+		return cdnsp_ep0_delegate_req(pdev, ctrl);
+	case USB_RECIP_ENDPOINT:
+		pep = &pdev->eps[cdnsp_w_index_to_ep_index(ctrl->wIndex)];
+		ep_sts = GET_EP_CTX_STATE(pep->out_ctx);
+
+		/* check if endpoint is stalled */
+		if (ep_sts == EP_STATE_HALTED)
+			status =  BIT(USB_ENDPOINT_HALT);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	response = (__le16 *)pdev->setup_buf;
+	*response = cpu_to_le16(status);
+
+	pdev->ep0_preq.request.length = sizeof(*response);
+	pdev->ep0_preq.request.buf = pdev->setup_buf;
+
+	return cdnsp_ep_enqueue(pdev->ep0_preq.pep, &pdev->ep0_preq);
+}
+
+static void cdnsp_enter_test_mode(struct cdnsp_device *pdev)
+{
+	u32 temp;
+
+	temp = readl(&pdev->active_port->regs->portpmsc) & ~GENMASK(31, 28);
+	temp |= PORT_TEST_MODE(pdev->test_mode);
+	writel(temp, &pdev->active_port->regs->portpmsc);
+}
+
+static int cdnsp_ep0_handle_feature_device(struct cdnsp_device *pdev,
+					   struct usb_ctrlrequest *ctrl,
+					   int set)
+{
+	enum usb_device_state state;
+	enum usb_device_speed speed;
+	u16 tmode;
+
+	state = pdev->gadget.state;
+	speed = pdev->gadget.speed;
+
+	switch (le16_to_cpu(ctrl->wValue)) {
+	case USB_DEVICE_REMOTE_WAKEUP:
+		pdev->may_wakeup = !!set;
+		break;
+	case USB_DEVICE_U1_ENABLE:
+		if (state != USB_STATE_CONFIGURED || speed < USB_SPEED_SUPER)
+			return -EINVAL;
+
+		pdev->u1_allowed = !!set;
+		break;
+	case USB_DEVICE_U2_ENABLE:
+		if (state != USB_STATE_CONFIGURED || speed < USB_SPEED_SUPER)
+			return -EINVAL;
+
+		pdev->u2_allowed = !!set;
+		break;
+	case USB_DEVICE_LTM_ENABLE:
+		return -EINVAL;
+	case USB_DEVICE_TEST_MODE:
+		if (state != USB_STATE_CONFIGURED || speed > USB_SPEED_HIGH)
+			return -EINVAL;
+
+		tmode = le16_to_cpu(ctrl->wIndex);
+
+		if (!set || (tmode & 0xff) != 0)
+			return -EINVAL;
+
+		tmode = tmode >> 8;
+
+		if (tmode > USB_TEST_FORCE_ENABLE || tmode < USB_TEST_J)
+			return -EINVAL;
+
+		pdev->test_mode = tmode;
+
+		/*
+		 * Test mode must be set before Status Stage but controller
+		 * will start testing sequence after Status Stage.
+		 */
+		cdnsp_enter_test_mode(pdev);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cdnsp_ep0_handle_feature_intf(struct cdnsp_device *pdev,
+					 struct usb_ctrlrequest *ctrl,
+					 int set)
+{
+	u16 wValue, wIndex;
+	int ret;
+
+	wValue = le16_to_cpu(ctrl->wValue);
+	wIndex = le16_to_cpu(ctrl->wIndex);
+
+	switch (wValue) {
+	case USB_INTRF_FUNC_SUSPEND:
+		ret = cdnsp_ep0_delegate_req(pdev, ctrl);
+		if (ret)
+			return ret;
+
+		/*
+		 * Remote wakeup is enabled when any function within a device
+		 * is enabled for function remote wakeup.
+		 */
+		if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
+			pdev->may_wakeup++;
+		else
+			if (pdev->may_wakeup > 0)
+				pdev->may_wakeup--;
+
+		return 0;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cdnsp_ep0_handle_feature_endpoint(struct cdnsp_device *pdev,
+					     struct usb_ctrlrequest *ctrl,
+					     int set)
+{
+	struct cdnsp_ep *pep;
+	u32 wValue;
+
+	wValue = le16_to_cpu(ctrl->wValue);
+	pep = &pdev->eps[cdnsp_w_index_to_ep_index(ctrl->wIndex)];
+
+	switch (wValue) {
+	case USB_ENDPOINT_HALT:
+		if (!set && (pep->ep_state & EP_WEDGE)) {
+			/* Resets Sequence Number */
+			cdnsp_halt_endpoint(pdev, pep, 0);
+			cdnsp_halt_endpoint(pdev, pep, 1);
+			break;
+		}
+
+		return cdnsp_halt_endpoint(pdev, pep, set);
+	default:
+		dev_warn(pdev->dev, "WARN Incorrect wValue %04x\n", wValue);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cdnsp_ep0_handle_feature(struct cdnsp_device *pdev,
+				    struct usb_ctrlrequest *ctrl,
+				    int set)
+{
+	switch (ctrl->bRequestType & USB_RECIP_MASK) {
+	case USB_RECIP_DEVICE:
+		return cdnsp_ep0_handle_feature_device(pdev, ctrl, set);
+	case USB_RECIP_INTERFACE:
+		return cdnsp_ep0_handle_feature_intf(pdev, ctrl, set);
+	case USB_RECIP_ENDPOINT:
+		return cdnsp_ep0_handle_feature_endpoint(pdev, ctrl, set);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int cdnsp_ep0_set_sel(struct cdnsp_device *pdev,
+			     struct usb_ctrlrequest *ctrl)
+{
+	enum usb_device_state state = pdev->gadget.state;
+	u16 wLength;
+
+	if (state == USB_STATE_DEFAULT)
+		return -EINVAL;
+
+	wLength = le16_to_cpu(ctrl->wLength);
+
+	if (wLength != 6) {
+		dev_err(pdev->dev, "Set SEL should be 6 bytes, got %d\n",
+			wLength);
+		return -EINVAL;
+	}
+
+	/*
+	 * To handle Set SEL we need to receive 6 bytes from Host. So let's
+	 * queue a usb_request for 6 bytes.
+	 */
+	pdev->ep0_preq.request.length = 6;
+	pdev->ep0_preq.request.buf = pdev->setup_buf;
+
+	return cdnsp_ep_enqueue(pdev->ep0_preq.pep, &pdev->ep0_preq);
+}
+
+static int cdnsp_ep0_set_isoch_delay(struct cdnsp_device *pdev,
+				     struct usb_ctrlrequest *ctrl)
+{
+	if (le16_to_cpu(ctrl->wIndex) || le16_to_cpu(ctrl->wLength))
+		return -EINVAL;
+
+	pdev->gadget.isoch_delay = le16_to_cpu(ctrl->wValue);
+
+	return 0;
+}
+
+static int cdnsp_ep0_std_request(struct cdnsp_device *pdev,
+				 struct usb_ctrlrequest *ctrl)
+{
+	int ret;
+
+	switch (ctrl->bRequest) {
+	case USB_REQ_GET_STATUS:
+		ret = cdnsp_ep0_handle_status(pdev, ctrl);
+		break;
+	case USB_REQ_CLEAR_FEATURE:
+		ret = cdnsp_ep0_handle_feature(pdev, ctrl, 0);
+		break;
+	case USB_REQ_SET_FEATURE:
+		ret = cdnsp_ep0_handle_feature(pdev, ctrl, 1);
+		break;
+	case USB_REQ_SET_ADDRESS:
+		ret = cdnsp_ep0_set_address(pdev, ctrl);
+		break;
+	case USB_REQ_SET_CONFIGURATION:
+		ret = cdnsp_ep0_set_config(pdev, ctrl);
+		break;
+	case USB_REQ_SET_SEL:
+		ret = cdnsp_ep0_set_sel(pdev, ctrl);
+		break;
+	case USB_REQ_SET_ISOCH_DELAY:
+		ret = cdnsp_ep0_set_isoch_delay(pdev, ctrl);
+		break;
+	case USB_REQ_SET_INTERFACE:
+		/*
+		 * Add request into pending list to block sending status stage
+		 * by libcomposite.
+		 */
+		list_add_tail(&pdev->ep0_preq.list,
+			      &pdev->ep0_preq.pep->pending_list);
+
+		ret = cdnsp_ep0_delegate_req(pdev, ctrl);
+		if (ret == -EBUSY)
+			ret = 0;
+
+		list_del(&pdev->ep0_preq.list);
+		break;
+	default:
+		ret = cdnsp_ep0_delegate_req(pdev, ctrl);
+		break;
+	}
+
+	return ret;
+}
+
+void cdnsp_setup_analyze(struct cdnsp_device *pdev)
+{
+	struct usb_ctrlrequest *ctrl = &pdev->setup;
+	int ret = 0;
+	__le16 len;
+
+	if (!pdev->gadget_driver)
+		goto out;
+
+	if (pdev->gadget.state == USB_STATE_NOTATTACHED) {
+		dev_err(pdev->dev, "ERR: Setup detected in unattached state\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Restore the ep0 to Stopped/Running state. */
+	if (pdev->eps[0].ep_state & EP_HALTED)
+		cdnsp_halt_endpoint(pdev, &pdev->eps[0], 0);
+
+	/*
+	 * Finishing previous SETUP transfer by removing request from
+	 * list and informing upper layer
+	 */
+	if (!list_empty(&pdev->eps[0].pending_list)) {
+		struct cdnsp_request	*req;
+
+		req = next_request(&pdev->eps[0].pending_list);
+		cdnsp_ep_dequeue(&pdev->eps[0], req);
+	}
+
+	len = le16_to_cpu(ctrl->wLength);
+	if (!len) {
+		pdev->three_stage_setup = false;
+		pdev->ep0_expect_in = false;
+	} else {
+		pdev->three_stage_setup = true;
+		pdev->ep0_expect_in = !!(ctrl->bRequestType & USB_DIR_IN);
+	}
+
+	if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
+		ret = cdnsp_ep0_std_request(pdev, ctrl);
+	else
+		ret = cdnsp_ep0_delegate_req(pdev, ctrl);
+
+	if (!len)
+		pdev->ep0_stage = CDNSP_STATUS_STAGE;
+
+	if (ret == USB_GADGET_DELAYED_STATUS)
+		return;
+out:
+	if (ret < 0)
+		cdnsp_ep0_stall(pdev);
+	else if (pdev->ep0_stage == CDNSP_STATUS_STAGE)
+		cdnsp_status_stage(pdev);
+}