1 files changed, 520 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/aspeed-vhub/ep0.c b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c
new file mode 100644
index 000000000..022b777b8
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c
@@ -0,0 +1,520 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
+ *
+ * ep0.c - Endpoint 0 handling
+ *
+ * Copyright 2017 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/dma-mapping.h>
+
+#include "vhub.h"
+
+int ast_vhub_reply(struct ast_vhub_ep *ep, char *ptr, int len)
+{
+	struct usb_request *req = &ep->ep0.req.req;
+	int rc;
+
+	if (WARN_ON(ep->d_idx != 0))
+		return std_req_stall;
+	if (WARN_ON(!ep->ep0.dir_in))
+		return std_req_stall;
+	if (WARN_ON(len > AST_VHUB_EP0_MAX_PACKET))
+		return std_req_stall;
+	if (WARN_ON(req->status == -EINPROGRESS))
+		return std_req_stall;
+
+	req->buf = ptr;
+	req->length = len;
+	req->complete = NULL;
+	req->zero = true;
+
+	/*
+	 * Call internal queue directly after dropping the lock. This is
+	 * safe to do as the reply is always the last thing done when
+	 * processing a SETUP packet, usually as a tail call
+	 */
+	spin_unlock(&ep->vhub->lock);
+	if (ep->ep.ops->queue(&ep->ep, req, GFP_ATOMIC))
+		rc = std_req_stall;
+	else
+		rc = std_req_data;
+	spin_lock(&ep->vhub->lock);
+	return rc;
+}
+
+int __ast_vhub_simple_reply(struct ast_vhub_ep *ep, int len, ...)
+{
+	u8 *buffer = ep->buf;
+	unsigned int i;
+	va_list args;
+
+	va_start(args, len);
+
+	/* Copy data directly into EP buffer */
+	for (i = 0; i < len; i++)
+		buffer[i] = va_arg(args, int);
+	va_end(args);
+
+	/* req->buf NULL means data is already there */
+	return ast_vhub_reply(ep, NULL, len);
+}
+
+void ast_vhub_ep0_handle_setup(struct ast_vhub_ep *ep)
+{
+	struct usb_ctrlrequest crq;
+	enum std_req_rc std_req_rc;
+	int rc = -ENODEV;
+
+	if (WARN_ON(ep->d_idx != 0))
+		return;
+
+	/*
+	 * Grab the setup packet from the chip and byteswap
+	 * interesting fields
+	 */
+	memcpy_fromio(&crq, ep->ep0.setup, sizeof(crq));
+
+	EPDBG(ep, "SETUP packet %02x/%02x/%04x/%04x/%04x [%s] st=%d\n",
+	      crq.bRequestType, crq.bRequest,
+	       le16_to_cpu(crq.wValue),
+	       le16_to_cpu(crq.wIndex),
+	       le16_to_cpu(crq.wLength),
+	       (crq.bRequestType & USB_DIR_IN) ? "in" : "out",
+	       ep->ep0.state);
+
+	/*
+	 * Check our state, cancel pending requests if needed
+	 *
+	 * Note: Under some circumstances, we can get a new setup
+	 * packet while waiting for the stall ack, just accept it.
+	 *
+	 * In any case, a SETUP packet in wrong state should have
+	 * reset the HW state machine, so let's just log, nuke
+	 * requests, move on.
+	 */
+	if (ep->ep0.state != ep0_state_token &&
+	    ep->ep0.state != ep0_state_stall) {
+		EPDBG(ep, "wrong state\n");
+		ast_vhub_nuke(ep, -EIO);
+	}
+
+	/* Calculate next state for EP0 */
+	ep->ep0.state = ep0_state_data;
+	ep->ep0.dir_in = !!(crq.bRequestType & USB_DIR_IN);
+
+	/* If this is the vHub, we handle requests differently */
+	std_req_rc = std_req_driver;
+	if (ep->dev == NULL) {
+		if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
+			std_req_rc = ast_vhub_std_hub_request(ep, &crq);
+		else if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
+			std_req_rc = ast_vhub_class_hub_request(ep, &crq);
+		else
+			std_req_rc = std_req_stall;
+	} else if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
+		std_req_rc = ast_vhub_std_dev_request(ep, &crq);
+
+	/* Act upon result */
+	switch(std_req_rc) {
+	case std_req_complete:
+		goto complete;
+	case std_req_stall:
+		goto stall;
+	case std_req_driver:
+		break;
+	case std_req_data:
+		return;
+	}
+
+	/* Pass request up to the gadget driver */
+	if (WARN_ON(!ep->dev))
+		goto stall;
+	if (ep->dev->driver) {
+		EPDBG(ep, "forwarding to gadget...\n");
+		spin_unlock(&ep->vhub->lock);
+		rc = ep->dev->driver->setup(&ep->dev->gadget, &crq);
+		spin_lock(&ep->vhub->lock);
+		EPDBG(ep, "driver returned %d\n", rc);
+	} else {
+		EPDBG(ep, "no gadget for request !\n");
+	}
+	if (rc >= 0)
+		return;
+
+ stall:
+	EPDBG(ep, "stalling\n");
+	writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
+	ep->ep0.state = ep0_state_stall;
+	ep->ep0.dir_in = false;
+	return;
+
+ complete:
+	EPVDBG(ep, "sending [in] status with no data\n");
+	writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+	ep->ep0.state = ep0_state_status;
+	ep->ep0.dir_in = false;
+}
+
+
+static void ast_vhub_ep0_do_send(struct ast_vhub_ep *ep,
+				 struct ast_vhub_req *req)
+{
+	unsigned int chunk;
+	u32 reg;
+
+	/* If this is a 0-length request, it's the gadget trying to
+	 * send a status on our behalf. We take it from here.
+	 */
+	if (req->req.length == 0)
+		req->last_desc = 1;
+
+	/* Are we done ? Complete request, otherwise wait for next interrupt */
+	if (req->last_desc >= 0) {
+		EPVDBG(ep, "complete send %d/%d\n",
+		       req->req.actual, req->req.length);
+		ep->ep0.state = ep0_state_status;
+		writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
+		ast_vhub_done(ep, req, 0);
+		return;
+	}
+
+	/*
+	 * Next chunk cropped to max packet size. Also check if this
+	 * is the last packet
+	 */
+	chunk = req->req.length - req->req.actual;
+	if (chunk > ep->ep.maxpacket)
+		chunk = ep->ep.maxpacket;
+	else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
+		req->last_desc = 1;
+
+	EPVDBG(ep, "send chunk=%d last=%d, req->act=%d mp=%d\n",
+	       chunk, req->last_desc, req->req.actual, ep->ep.maxpacket);
+
+	/*
+	 * Copy data if any (internal requests already have data
+	 * in the EP buffer)
+	 */
+	if (chunk && req->req.buf)
+		memcpy(ep->buf, req->req.buf + req->req.actual, chunk);
+
+	vhub_dma_workaround(ep->buf);
+
+	/* Remember chunk size and trigger send */
+	reg = VHUB_EP0_SET_TX_LEN(chunk);
+	writel(reg, ep->ep0.ctlstat);
+	writel(reg | VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+	req->req.actual += chunk;
+}
+
+static void ast_vhub_ep0_rx_prime(struct ast_vhub_ep *ep)
+{
+	EPVDBG(ep, "rx prime\n");
+
+	/* Prime endpoint for receiving data */
+	writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
+}
+
+static void ast_vhub_ep0_do_receive(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
+				    unsigned int len)
+{
+	unsigned int remain;
+	int rc = 0;
+
+	/* We are receiving... grab request */
+	remain = req->req.length - req->req.actual;
+
+	EPVDBG(ep, "receive got=%d remain=%d\n", len, remain);
+
+	/* Are we getting more than asked ? */
+	if (len > remain) {
+		EPDBG(ep, "receiving too much (ovf: %d) !\n",
+		      len - remain);
+		len = remain;
+		rc = -EOVERFLOW;
+	}
+	if (len && req->req.buf)
+		memcpy(req->req.buf + req->req.actual, ep->buf, len);
+	req->req.actual += len;
+
+	/* Done ? */
+	if (len < ep->ep.maxpacket || len == remain) {
+		ep->ep0.state = ep0_state_status;
+		writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+		ast_vhub_done(ep, req, rc);
+	} else
+		ast_vhub_ep0_rx_prime(ep);
+}
+
+void ast_vhub_ep0_handle_ack(struct ast_vhub_ep *ep, bool in_ack)
+{
+	struct ast_vhub_req *req;
+	struct ast_vhub *vhub = ep->vhub;
+	struct device *dev = &vhub->pdev->dev;
+	bool stall = false;
+	u32 stat;
+
+	/* Read EP0 status */
+	stat = readl(ep->ep0.ctlstat);
+
+	/* Grab current request if any */
+	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
+
+	EPVDBG(ep, "ACK status=%08x,state=%d is_in=%d in_ack=%d req=%p\n",
+		stat, ep->ep0.state, ep->ep0.dir_in, in_ack, req);
+
+	switch(ep->ep0.state) {
+	case ep0_state_token:
+		/* There should be no request queued in that state... */
+		if (req) {
+			dev_warn(dev, "request present while in TOKEN state\n");
+			ast_vhub_nuke(ep, -EINVAL);
+		}
+		dev_warn(dev, "ack while in TOKEN state\n");
+		stall = true;
+		break;
+	case ep0_state_data:
+		/* Check the state bits corresponding to our direction */
+		if ((ep->ep0.dir_in && (stat & VHUB_EP0_TX_BUFF_RDY)) ||
+		    (!ep->ep0.dir_in && (stat & VHUB_EP0_RX_BUFF_RDY)) ||
+		    (ep->ep0.dir_in != in_ack)) {
+			/* In that case, ignore interrupt */
+			dev_warn(dev, "irq state mismatch");
+			break;
+		}
+		/*
+		 * We are in data phase and there's no request, something is
+		 * wrong, stall
+		 */
+		if (!req) {
+			dev_warn(dev, "data phase, no request\n");
+			stall = true;
+			break;
+		}
+
+		/* We have a request, handle data transfers */
+		if (ep->ep0.dir_in)
+			ast_vhub_ep0_do_send(ep, req);
+		else
+			ast_vhub_ep0_do_receive(ep, req, VHUB_EP0_RX_LEN(stat));
+		return;
+	case ep0_state_status:
+		/* Nuke stale requests */
+		if (req) {
+			dev_warn(dev, "request present while in STATUS state\n");
+			ast_vhub_nuke(ep, -EINVAL);
+		}
+
+		/*
+		 * If the status phase completes with the wrong ack, stall
+		 * the endpoint just in case, to abort whatever the host
+		 * was doing.
+		 */
+		if (ep->ep0.dir_in == in_ack) {
+			dev_warn(dev, "status direction mismatch\n");
+			stall = true;
+		}
+		break;
+	case ep0_state_stall:
+		/*
+		 * There shouldn't be any request left, but nuke just in case
+		 * otherwise the stale request will block subsequent ones
+		 */
+		ast_vhub_nuke(ep, -EIO);
+		break;
+	}
+
+	/* Reset to token state or stall */
+	if (stall) {
+		writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
+		ep->ep0.state = ep0_state_stall;
+	} else
+		ep->ep0.state = ep0_state_token;
+}
+
+static int ast_vhub_ep0_queue(struct usb_ep* u_ep, struct usb_request *u_req,
+			      gfp_t gfp_flags)
+{
+	struct ast_vhub_req *req = to_ast_req(u_req);
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	struct device *dev = &vhub->pdev->dev;
+	unsigned long flags;
+
+	/* Paranoid cheks */
+	if (!u_req || (!u_req->complete && !req->internal)) {
+		dev_warn(dev, "Bogus EP0 request ! u_req=%p\n", u_req);
+		if (u_req) {
+			dev_warn(dev, "complete=%p internal=%d\n",
+				 u_req->complete, req->internal);
+		}
+		return -EINVAL;
+	}
+
+	/* Not endpoint 0 ? */
+	if (WARN_ON(ep->d_idx != 0))
+		return -EINVAL;
+
+	/* Disabled device */
+	if (ep->dev && !ep->dev->enabled)
+		return -ESHUTDOWN;
+
+	/* Data, no buffer and not internal ? */
+	if (u_req->length && !u_req->buf && !req->internal) {
+		dev_warn(dev, "Request with no buffer !\n");
+		return -EINVAL;
+	}
+
+	EPVDBG(ep, "enqueue req @%p\n", req);
+	EPVDBG(ep, "  l=%d zero=%d noshort=%d is_in=%d\n",
+	       u_req->length, u_req->zero,
+	       u_req->short_not_ok, ep->ep0.dir_in);
+
+	/* Initialize request progress fields */
+	u_req->status = -EINPROGRESS;
+	u_req->actual = 0;
+	req->last_desc = -1;
+	req->active = false;
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* EP0 can only support a single request at a time */
+	if (!list_empty(&ep->queue) ||
+	    ep->ep0.state == ep0_state_token ||
+	    ep->ep0.state == ep0_state_stall) {
+		dev_warn(dev, "EP0: Request in wrong state\n");
+	        EPVDBG(ep, "EP0: list_empty=%d state=%d\n",
+		       list_empty(&ep->queue), ep->ep0.state);
+		spin_unlock_irqrestore(&vhub->lock, flags);
+		return -EBUSY;
+	}
+
+	/* Add request to list and kick processing if empty */
+	list_add_tail(&req->queue, &ep->queue);
+
+	if (ep->ep0.dir_in) {
+		/* IN request, send data */
+		ast_vhub_ep0_do_send(ep, req);
+	} else if (u_req->length == 0) {
+		/* 0-len request, send completion as rx */
+		EPVDBG(ep, "0-length rx completion\n");
+		ep->ep0.state = ep0_state_status;
+		writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+		ast_vhub_done(ep, req, 0);
+	} else {
+		/* OUT request, start receiver */
+		ast_vhub_ep0_rx_prime(ep);
+	}
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	return 0;
+}
+
+static int ast_vhub_ep0_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
+{
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	struct ast_vhub_req *req;
+	unsigned long flags;
+	int rc = -EINVAL;
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* Only one request can be in the queue */
+	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
+
+	/* Is it ours ? */
+	if (req && u_req == &req->req) {
+		EPVDBG(ep, "dequeue req @%p\n", req);
+
+		/*
+		 * We don't have to deal with "active" as all
+		 * DMAs go to the EP buffers, not the request.
+		 */
+		ast_vhub_done(ep, req, -ECONNRESET);
+
+		/* We do stall the EP to clean things up in HW */
+		writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
+		ep->ep0.state = ep0_state_status;
+		ep->ep0.dir_in = false;
+		rc = 0;
+	}
+	spin_unlock_irqrestore(&vhub->lock, flags);
+	return rc;
+}
+
+
+static const struct usb_ep_ops ast_vhub_ep0_ops = {
+	.queue		= ast_vhub_ep0_queue,
+	.dequeue	= ast_vhub_ep0_dequeue,
+	.alloc_request	= ast_vhub_alloc_request,
+	.free_request	= ast_vhub_free_request,
+};
+
+void ast_vhub_reset_ep0(struct ast_vhub_dev *dev)
+{
+	struct ast_vhub_ep *ep = &dev->ep0;
+
+	ast_vhub_nuke(ep, -EIO);
+	ep->ep0.state = ep0_state_token;
+}
+
+
+void ast_vhub_init_ep0(struct ast_vhub *vhub, struct ast_vhub_ep *ep,
+		       struct ast_vhub_dev *dev)
+{
+	memset(ep, 0, sizeof(*ep));
+
+	INIT_LIST_HEAD(&ep->ep.ep_list);
+	INIT_LIST_HEAD(&ep->queue);
+	ep->ep.ops = &ast_vhub_ep0_ops;
+	ep->ep.name = "ep0";
+	ep->ep.caps.type_control = true;
+	usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EP0_MAX_PACKET);
+	ep->d_idx = 0;
+	ep->dev = dev;
+	ep->vhub = vhub;
+	ep->ep0.state = ep0_state_token;
+	INIT_LIST_HEAD(&ep->ep0.req.queue);
+	ep->ep0.req.internal = true;
+
+	/* Small difference between vHub and devices */
+	if (dev) {
+		ep->ep0.ctlstat = dev->regs + AST_VHUB_DEV_EP0_CTRL;
+		ep->ep0.setup = vhub->regs +
+			AST_VHUB_SETUP0 + 8 * (dev->index + 1);
+		ep->buf = vhub->ep0_bufs +
+			AST_VHUB_EP0_MAX_PACKET * (dev->index + 1);
+		ep->buf_dma = vhub->ep0_bufs_dma +
+			AST_VHUB_EP0_MAX_PACKET * (dev->index + 1);
+	} else {
+		ep->ep0.ctlstat = vhub->regs + AST_VHUB_EP0_CTRL;
+		ep->ep0.setup = vhub->regs + AST_VHUB_SETUP0;
+		ep->buf = vhub->ep0_bufs;
+		ep->buf_dma = vhub->ep0_bufs_dma;
+	}
+}