// SPDX-License-Identifier: GPL-2.0+
/*
* aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
*
* ep0.c - Endpoint 0 handling
*
* Copyright 2017 IBM Corporation
*/
#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/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;
}
/* Hardware return wrong data len */
if (len < ep->ep.maxpacket && len != remain) {
EPDBG(ep, "using expected data len instead\n");
len = remain;
}
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;
}
}
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