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