/* * udc.c - ChipIdea UDC driver * * Copyright (C) 2008 Chipidea - MIPS Technologies, Inc. All rights reserved. * * Author: David Lopo * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "ci.h" #include "udc.h" #include "bits.h" #include "debug.h" /* control endpoint description */ static const struct usb_endpoint_descriptor ctrl_endpt_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .bmAttributes = USB_ENDPOINT_XFER_CONTROL, .wMaxPacketSize = cpu_to_le16(CTRL_PAYLOAD_MAX), }; static const struct usb_endpoint_descriptor ctrl_endpt_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_CONTROL, .wMaxPacketSize = cpu_to_le16(CTRL_PAYLOAD_MAX), }; /** * hw_ep_bit: calculates the bit number * @num: endpoint number * @dir: endpoint direction * * This function returns bit number */ static inline int hw_ep_bit(int num, int dir) { return num + (dir ? 16 : 0); } static inline int ep_to_bit(struct ci13xxx *ci, int n) { int fill = 16 - ci->hw_ep_max / 2; if (n >= ci->hw_ep_max / 2) n += fill; return n; } /** * hw_device_state: enables/disables interrupts (execute without interruption) * @dma: 0 => disable, !0 => enable and set dma engine * * This function returns an error code */ static int hw_device_state(struct ci13xxx *ci, u32 dma) { if (dma) { hw_write(ci, OP_ENDPTLISTADDR, ~0, dma); /* interrupt, error, port change, reset, sleep/suspend */ hw_write(ci, OP_USBINTR, ~0, USBi_UI|USBi_UEI|USBi_PCI|USBi_URI|USBi_SLI); } else { hw_write(ci, OP_USBINTR, ~0, 0); } return 0; } /** * hw_ep_flush: flush endpoint fifo (execute without interruption) * @num: endpoint number * @dir: endpoint direction * * This function returns an error code */ static int hw_ep_flush(struct ci13xxx *ci, int num, int dir) { int n = hw_ep_bit(num, dir); do { /* flush any pending transfer */ hw_write(ci, OP_ENDPTFLUSH, BIT(n), BIT(n)); while (hw_read(ci, OP_ENDPTFLUSH, BIT(n))) cpu_relax(); } while (hw_read(ci, OP_ENDPTSTAT, BIT(n))); return 0; } /** * hw_ep_disable: disables endpoint (execute without interruption) * @num: endpoint number * @dir: endpoint direction * * This function returns an error code */ static int hw_ep_disable(struct ci13xxx *ci, int num, int dir) { hw_ep_flush(ci, num, dir); hw_write(ci, OP_ENDPTCTRL + num, dir ? ENDPTCTRL_TXE : ENDPTCTRL_RXE, 0); return 0; } /** * hw_ep_enable: enables endpoint (execute without interruption) * @num: endpoint number * @dir: endpoint direction * @type: endpoint type * * This function returns an error code */ static int hw_ep_enable(struct ci13xxx *ci, int num, int dir, int type) { u32 mask, data; if (dir) { mask = ENDPTCTRL_TXT; /* type */ data = type << __ffs(mask); mask |= ENDPTCTRL_TXS; /* unstall */ mask |= ENDPTCTRL_TXR; /* reset data toggle */ data |= ENDPTCTRL_TXR; mask |= ENDPTCTRL_TXE; /* enable */ data |= ENDPTCTRL_TXE; } else { mask = ENDPTCTRL_RXT; /* type */ data = type << __ffs(mask); mask |= ENDPTCTRL_RXS; /* unstall */ mask |= ENDPTCTRL_RXR; /* reset data toggle */ data |= ENDPTCTRL_RXR; mask |= ENDPTCTRL_RXE; /* enable */ data |= ENDPTCTRL_RXE; } hw_write(ci, OP_ENDPTCTRL + num, mask, data); return 0; } /** * hw_ep_get_halt: return endpoint halt status * @num: endpoint number * @dir: endpoint direction * * This function returns 1 if endpoint halted */ static int hw_ep_get_halt(struct ci13xxx *ci, int num, int dir) { u32 mask = dir ? ENDPTCTRL_TXS : ENDPTCTRL_RXS; return hw_read(ci, OP_ENDPTCTRL + num, mask) ? 1 : 0; } /** * hw_test_and_clear_setup_status: test & clear setup status (execute without * interruption) * @n: endpoint number * * This function returns setup status */ static int hw_test_and_clear_setup_status(struct ci13xxx *ci, int n) { n = ep_to_bit(ci, n); return hw_test_and_clear(ci, OP_ENDPTSETUPSTAT, BIT(n)); } /** * hw_ep_prime: primes endpoint (execute without interruption) * @num: endpoint number * @dir: endpoint direction * @is_ctrl: true if control endpoint * * This function returns an error code */ static int hw_ep_prime(struct ci13xxx *ci, int num, int dir, int is_ctrl) { int n = hw_ep_bit(num, dir); if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num))) return -EAGAIN; hw_write(ci, OP_ENDPTPRIME, BIT(n), BIT(n)); while (hw_read(ci, OP_ENDPTPRIME, BIT(n))) cpu_relax(); if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num))) return -EAGAIN; /* status shoult be tested according with manual but it doesn't work */ return 0; } /** * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute * without interruption) * @num: endpoint number * @dir: endpoint direction * @value: true => stall, false => unstall * * This function returns an error code */ static int hw_ep_set_halt(struct ci13xxx *ci, int num, int dir, int value) { if (value != 0 && value != 1) return -EINVAL; do { enum ci13xxx_regs reg = OP_ENDPTCTRL + num; u32 mask_xs = dir ? ENDPTCTRL_TXS : ENDPTCTRL_RXS; u32 mask_xr = dir ? ENDPTCTRL_TXR : ENDPTCTRL_RXR; /* data toggle - reserved for EP0 but it's in ESS */ hw_write(ci, reg, mask_xs|mask_xr, value ? mask_xs : mask_xr); } while (value != hw_ep_get_halt(ci, num, dir)); return 0; } /** * hw_is_port_high_speed: test if port is high speed * * This function returns true if high speed port */ static int hw_port_is_high_speed(struct ci13xxx *ci) { return ci->hw_bank.lpm ? hw_read(ci, OP_DEVLC, DEVLC_PSPD) : hw_read(ci, OP_PORTSC, PORTSC_HSP); } /** * hw_read_intr_enable: returns interrupt enable register * * This function returns register data */ static u32 hw_read_intr_enable(struct ci13xxx *ci) { return hw_read(ci, OP_USBINTR, ~0); } /** * hw_read_intr_status: returns interrupt status register * * This function returns register data */ static u32 hw_read_intr_status(struct ci13xxx *ci) { return hw_read(ci, OP_USBSTS, ~0); } /** * hw_test_and_clear_complete: test & clear complete status (execute without * interruption) * @n: endpoint number * * This function returns complete status */ static int hw_test_and_clear_complete(struct ci13xxx *ci, int n) { n = ep_to_bit(ci, n); return hw_test_and_clear(ci, OP_ENDPTCOMPLETE, BIT(n)); } /** * hw_test_and_clear_intr_active: test & clear active interrupts (execute * without interruption) * * This function returns active interrutps */ static u32 hw_test_and_clear_intr_active(struct ci13xxx *ci) { u32 reg = hw_read_intr_status(ci) & hw_read_intr_enable(ci); hw_write(ci, OP_USBSTS, ~0, reg); return reg; } /** * hw_test_and_clear_setup_guard: test & clear setup guard (execute without * interruption) * * This function returns guard value */ static int hw_test_and_clear_setup_guard(struct ci13xxx *ci) { return hw_test_and_write(ci, OP_USBCMD, USBCMD_SUTW, 0); } /** * hw_test_and_set_setup_guard: test & set setup guard (execute without * interruption) * * This function returns guard value */ static int hw_test_and_set_setup_guard(struct ci13xxx *ci) { return hw_test_and_write(ci, OP_USBCMD, USBCMD_SUTW, USBCMD_SUTW); } /** * hw_usb_set_address: configures USB address (execute without interruption) * @value: new USB address * * This function explicitly sets the address, without the "USBADRA" (advance) * feature, which is not supported by older versions of the controller. */ static void hw_usb_set_address(struct ci13xxx *ci, u8 value) { hw_write(ci, OP_DEVICEADDR, DEVICEADDR_USBADR, value << __ffs(DEVICEADDR_USBADR)); } /** * hw_usb_reset: restart device after a bus reset (execute without * interruption) * * This function returns an error code */ static int hw_usb_reset(struct ci13xxx *ci) { hw_usb_set_address(ci, 0); /* ESS flushes only at end?!? */ hw_write(ci, OP_ENDPTFLUSH, ~0, ~0); /* clear setup token semaphores */ hw_write(ci, OP_ENDPTSETUPSTAT, 0, 0); /* clear complete status */ hw_write(ci, OP_ENDPTCOMPLETE, 0, 0); /* wait until all bits cleared */ while (hw_read(ci, OP_ENDPTPRIME, ~0)) udelay(10); /* not RTOS friendly */ /* reset all endpoints ? */ /* reset internal status and wait for further instructions no need to verify the port reset status (ESS does it) */ return 0; } /****************************************************************************** * UTIL block *****************************************************************************/ /** * _usb_addr: calculates endpoint address from direction & number * @ep: endpoint */ static inline u8 _usb_addr(struct ci13xxx_ep *ep) { return ((ep->dir == TX) ? USB_ENDPOINT_DIR_MASK : 0) | ep->num; } /** * _hardware_queue: configures a request at hardware level * @gadget: gadget * @mEp: endpoint * * This function returns an error code */ static int _hardware_enqueue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq) { struct ci13xxx *ci = mEp->ci; unsigned i; int ret = 0; unsigned length = mReq->req.length; /* don't queue twice */ if (mReq->req.status == -EALREADY) return -EALREADY; mReq->req.status = -EALREADY; if (mReq->req.zero && length && (length % mEp->ep.maxpacket == 0)) { mReq->zptr = dma_pool_alloc(mEp->td_pool, GFP_ATOMIC, &mReq->zdma); if (mReq->zptr == NULL) return -ENOMEM; memset(mReq->zptr, 0, sizeof(*mReq->zptr)); mReq->zptr->next = TD_TERMINATE; mReq->zptr->token = TD_STATUS_ACTIVE; if (!mReq->req.no_interrupt) mReq->zptr->token |= TD_IOC; } ret = usb_gadget_map_request(&ci->gadget, &mReq->req, mEp->dir); if (ret) return ret; /* * TD configuration * TODO - handle requests which spawns into several TDs */ memset(mReq->ptr, 0, sizeof(*mReq->ptr)); mReq->ptr->token = length << __ffs(TD_TOTAL_BYTES); mReq->ptr->token &= TD_TOTAL_BYTES; mReq->ptr->token |= TD_STATUS_ACTIVE; if (mReq->zptr) { mReq->ptr->next = mReq->zdma; } else { mReq->ptr->next = TD_TERMINATE; if (!mReq->req.no_interrupt) mReq->ptr->token |= TD_IOC; } mReq->ptr->page[0] = mReq->req.dma; for (i = 1; i < 5; i++) mReq->ptr->page[i] = (mReq->req.dma + i * CI13XXX_PAGE_SIZE) & ~TD_RESERVED_MASK; if (!list_empty(&mEp->qh.queue)) { struct ci13xxx_req *mReqPrev; int n = hw_ep_bit(mEp->num, mEp->dir); int tmp_stat; mReqPrev = list_entry(mEp->qh.queue.prev, struct ci13xxx_req, queue); if (mReqPrev->zptr) mReqPrev->zptr->next = mReq->dma & TD_ADDR_MASK; else mReqPrev->ptr->next = mReq->dma & TD_ADDR_MASK; wmb(); if (hw_read(ci, OP_ENDPTPRIME, BIT(n))) goto done; do { hw_write(ci, OP_USBCMD, USBCMD_ATDTW, USBCMD_ATDTW); tmp_stat = hw_read(ci, OP_ENDPTSTAT, BIT(n)); } while (!hw_read(ci, OP_USBCMD, USBCMD_ATDTW)); hw_write(ci, OP_USBCMD, USBCMD_ATDTW, 0); if (tmp_stat) goto done; } /* QH configuration */ mEp->qh.ptr->td.next = mReq->dma; /* TERMINATE = 0 */ mEp->qh.ptr->td.token &= ~TD_STATUS; /* clear status */ mEp->qh.ptr->cap |= QH_ZLT; wmb(); /* synchronize before ep prime */ ret = hw_ep_prime(ci, mEp->num, mEp->dir, mEp->type == USB_ENDPOINT_XFER_CONTROL); done: return ret; } /** * _hardware_dequeue: handles a request at hardware level * @gadget: gadget * @mEp: endpoint * * This function returns an error code */ static int _hardware_dequeue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq) { if (mReq->req.status != -EALREADY) return -EINVAL; if ((TD_STATUS_ACTIVE & mReq->ptr->token) != 0) return -EBUSY; if (mReq->zptr) { if ((TD_STATUS_ACTIVE & mReq->zptr->token) != 0) return -EBUSY; dma_pool_free(mEp->td_pool, mReq->zptr, mReq->zdma); mReq->zptr = NULL; } mReq->req.status = 0; usb_gadget_unmap_request(&mEp->ci->gadget, &mReq->req, mEp->dir); mReq->req.status = mReq->ptr->token & TD_STATUS; if ((TD_STATUS_HALTED & mReq->req.status) != 0) mReq->req.status = -1; else if ((TD_STATUS_DT_ERR & mReq->req.status) != 0) mReq->req.status = -1; else if ((TD_STATUS_TR_ERR & mReq->req.status) != 0) mReq->req.status = -1; mReq->req.actual = mReq->ptr->token & TD_TOTAL_BYTES; mReq->req.actual >>= __ffs(TD_TOTAL_BYTES); mReq->req.actual = mReq->req.length - mReq->req.actual; mReq->req.actual = mReq->req.status ? 0 : mReq->req.actual; return mReq->req.actual; } /** * _ep_nuke: dequeues all endpoint requests * @mEp: endpoint * * This function returns an error code * Caller must hold lock */ static int _ep_nuke(struct ci13xxx_ep *mEp) __releases(mEp->lock) __acquires(mEp->lock) { if (mEp == NULL) return -EINVAL; hw_ep_flush(mEp->ci, mEp->num, mEp->dir); while (!list_empty(&mEp->qh.queue)) { /* pop oldest request */ struct ci13xxx_req *mReq = \ list_entry(mEp->qh.queue.next, struct ci13xxx_req, queue); list_del_init(&mReq->queue); mReq->req.status = -ESHUTDOWN; if (mReq->req.complete != NULL) { spin_unlock(mEp->lock); mReq->req.complete(&mEp->ep, &mReq->req); spin_lock(mEp->lock); } } return 0; } /** * _gadget_stop_activity: stops all USB activity, flushes & disables all endpts * @gadget: gadget * * This function returns an error code */ static int _gadget_stop_activity(struct usb_gadget *gadget) { struct usb_ep *ep; struct ci13xxx *ci = container_of(gadget, struct ci13xxx, gadget); unsigned long flags; spin_lock_irqsave(&ci->lock, flags); ci->gadget.speed = USB_SPEED_UNKNOWN; ci->remote_wakeup = 0; ci->suspended = 0; spin_unlock_irqrestore(&ci->lock, flags); /* flush all endpoints */ gadget_for_each_ep(ep, gadget) { usb_ep_fifo_flush(ep); } usb_ep_fifo_flush(&ci->ep0out->ep); usb_ep_fifo_flush(&ci->ep0in->ep); if (ci->driver) ci->driver->disconnect(gadget); /* make sure to disable all endpoints */ gadget_for_each_ep(ep, gadget) { usb_ep_disable(ep); } if (ci->status != NULL) { usb_ep_free_request(&ci->ep0in->ep, ci->status); ci->status = NULL; } return 0; } /****************************************************************************** * ISR block *****************************************************************************/ /** * isr_reset_handler: USB reset interrupt handler * @ci: UDC device * * This function resets USB engine after a bus reset occurred */ static void isr_reset_handler(struct ci13xxx *ci) __releases(ci->lock) __acquires(ci->lock) { int retval; spin_unlock(&ci->lock); retval = _gadget_stop_activity(&ci->gadget); if (retval) goto done; retval = hw_usb_reset(ci); if (retval) goto done; ci->status = usb_ep_alloc_request(&ci->ep0in->ep, GFP_ATOMIC); if (ci->status == NULL) retval = -ENOMEM; done: spin_lock(&ci->lock); if (retval) dev_err(ci->dev, "error: %i\n", retval); } /** * isr_get_status_complete: get_status request complete function * @ep: endpoint * @req: request handled * * Caller must release lock */ static void isr_get_status_complete(struct usb_ep *ep, struct usb_request *req) { if (ep == NULL || req == NULL) return; kfree(req->buf); usb_ep_free_request(ep, req); } /** * isr_get_status_response: get_status request response * @ci: ci struct * @setup: setup request packet * * This function returns an error code */ static int isr_get_status_response(struct ci13xxx *ci, struct usb_ctrlrequest *setup) __releases(mEp->lock) __acquires(mEp->lock) { struct ci13xxx_ep *mEp = ci->ep0in; struct usb_request *req = NULL; gfp_t gfp_flags = GFP_ATOMIC; int dir, num, retval; if (mEp == NULL || setup == NULL) return -EINVAL; spin_unlock(mEp->lock); req = usb_ep_alloc_request(&mEp->ep, gfp_flags); spin_lock(mEp->lock); if (req == NULL) return -ENOMEM; req->complete = isr_get_status_complete; req->length = 2; req->buf = kzalloc(req->length, gfp_flags); if (req->buf == NULL) { retval = -ENOMEM; goto err_free_req; } if ((setup->bRequestType & USB_RECIP_MASK) == USB_RECIP_DEVICE) { /* Assume that device is bus powered for now. */ *(u16 *)req->buf = ci->remote_wakeup << 1; retval = 0; } else if ((setup->bRequestType & USB_RECIP_MASK) \ == USB_RECIP_ENDPOINT) { dir = (le16_to_cpu(setup->wIndex) & USB_ENDPOINT_DIR_MASK) ? TX : RX; num = le16_to_cpu(setup->wIndex) & USB_ENDPOINT_NUMBER_MASK; *(u16 *)req->buf = hw_ep_get_halt(ci, num, dir); } /* else do nothing; reserved for future use */ spin_unlock(mEp->lock); retval = usb_ep_queue(&mEp->ep, req, gfp_flags); spin_lock(mEp->lock); if (retval) goto err_free_buf; return 0; err_free_buf: kfree(req->buf); err_free_req: spin_unlock(mEp->lock); usb_ep_free_request(&mEp->ep, req); spin_lock(mEp->lock); return retval; } /** * isr_setup_status_complete: setup_status request complete function * @ep: endpoint * @req: request handled * * Caller must release lock. Put the port in test mode if test mode * feature is selected. */ static void isr_setup_status_complete(struct usb_ep *ep, struct usb_request *req) { struct ci13xxx *ci = req->context; unsigned long flags; if (ci->setaddr) { hw_usb_set_address(ci, ci->address); ci->setaddr = false; } spin_lock_irqsave(&ci->lock, flags); if (ci->test_mode) hw_port_test_set(ci, ci->test_mode); spin_unlock_irqrestore(&ci->lock, flags); } /** * isr_setup_status_phase: queues the status phase of a setup transation * @ci: ci struct * * This function returns an error code */ static int isr_setup_status_phase(struct ci13xxx *ci) __releases(mEp->lock) __acquires(mEp->lock) { int retval; struct ci13xxx_ep *mEp; mEp = (ci->ep0_dir == TX) ? ci->ep0out : ci->ep0in; ci->status->context = ci; ci->status->complete = isr_setup_status_complete; spin_unlock(mEp->lock); retval = usb_ep_queue(&mEp->ep, ci->status, GFP_ATOMIC); spin_lock(mEp->lock); return retval; } /** * isr_tr_complete_low: transaction complete low level handler * @mEp: endpoint * * This function returns an error code * Caller must hold lock */ static int isr_tr_complete_low(struct ci13xxx_ep *mEp) __releases(mEp->lock) __acquires(mEp->lock) { struct ci13xxx_req *mReq, *mReqTemp; struct ci13xxx_ep *mEpTemp = mEp; int retval = 0; list_for_each_entry_safe(mReq, mReqTemp, &mEp->qh.queue, queue) { retval = _hardware_dequeue(mEp, mReq); if (retval < 0) break; list_del_init(&mReq->queue); if (mReq->req.complete != NULL) { spin_unlock(mEp->lock); if ((mEp->type == USB_ENDPOINT_XFER_CONTROL) && mReq->req.length) mEpTemp = mEp->ci->ep0in; mReq->req.complete(&mEpTemp->ep, &mReq->req); spin_lock(mEp->lock); } } if (retval == -EBUSY) retval = 0; return retval; } /** * isr_tr_complete_handler: transaction complete interrupt handler * @ci: UDC descriptor * * This function handles traffic events */ static void isr_tr_complete_handler(struct ci13xxx *ci) __releases(ci->lock) __acquires(ci->lock) { unsigned i; u8 tmode = 0; for (i = 0; i < ci->hw_ep_max; i++) { struct ci13xxx_ep *mEp = &ci->ci13xxx_ep[i]; int type, num, dir, err = -EINVAL; struct usb_ctrlrequest req; if (mEp->ep.desc == NULL) continue; /* not configured */ if (hw_test_and_clear_complete(ci, i)) { err = isr_tr_complete_low(mEp); if (mEp->type == USB_ENDPOINT_XFER_CONTROL) { if (err > 0) /* needs status phase */ err = isr_setup_status_phase(ci); if (err < 0) { spin_unlock(&ci->lock); if (usb_ep_set_halt(&mEp->ep)) dev_err(ci->dev, "error: ep_set_halt\n"); spin_lock(&ci->lock); } } } if (mEp->type != USB_ENDPOINT_XFER_CONTROL || !hw_test_and_clear_setup_status(ci, i)) continue; if (i != 0) { dev_warn(ci->dev, "ctrl traffic at endpoint %d\n", i); continue; } /* * Flush data and handshake transactions of previous * setup packet. */ _ep_nuke(ci->ep0out); _ep_nuke(ci->ep0in); /* read_setup_packet */ do { hw_test_and_set_setup_guard(ci); memcpy(&req, &mEp->qh.ptr->setup, sizeof(req)); } while (!hw_test_and_clear_setup_guard(ci)); type = req.bRequestType; ci->ep0_dir = (type & USB_DIR_IN) ? TX : RX; switch (req.bRequest) { case USB_REQ_CLEAR_FEATURE: if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) && le16_to_cpu(req.wValue) == USB_ENDPOINT_HALT) { if (req.wLength != 0) break; num = le16_to_cpu(req.wIndex); dir = num & USB_ENDPOINT_DIR_MASK; num &= USB_ENDPOINT_NUMBER_MASK; if (dir) /* TX */ num += ci->hw_ep_max/2; if (!ci->ci13xxx_ep[num].wedge) { spin_unlock(&ci->lock); err = usb_ep_clear_halt( &ci->ci13xxx_ep[num].ep); spin_lock(&ci->lock); if (err) break; } err = isr_setup_status_phase(ci); } else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE) && le16_to_cpu(req.wValue) == USB_DEVICE_REMOTE_WAKEUP) { if (req.wLength != 0) break; ci->remote_wakeup = 0; err = isr_setup_status_phase(ci); } else { goto delegate; } break; case USB_REQ_GET_STATUS: if (type != (USB_DIR_IN|USB_RECIP_DEVICE) && type != (USB_DIR_IN|USB_RECIP_ENDPOINT) && type != (USB_DIR_IN|USB_RECIP_INTERFACE)) goto delegate; if (le16_to_cpu(req.wLength) != 2 || le16_to_cpu(req.wValue) != 0) break; err = isr_get_status_response(ci, &req); break; case USB_REQ_SET_ADDRESS: if (type != (USB_DIR_OUT|USB_RECIP_DEVICE)) goto delegate; if (le16_to_cpu(req.wLength) != 0 || le16_to_cpu(req.wIndex) != 0) break; ci->address = (u8)le16_to_cpu(req.wValue); ci->setaddr = true; err = isr_setup_status_phase(ci); break; case USB_REQ_SET_FEATURE: if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) && le16_to_cpu(req.wValue) == USB_ENDPOINT_HALT) { if (req.wLength != 0) break; num = le16_to_cpu(req.wIndex); dir = num & USB_ENDPOINT_DIR_MASK; num &= USB_ENDPOINT_NUMBER_MASK; if (dir) /* TX */ num += ci->hw_ep_max/2; spin_unlock(&ci->lock); err = usb_ep_set_halt(&ci->ci13xxx_ep[num].ep); spin_lock(&ci->lock); if (!err) isr_setup_status_phase(ci); } else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE)) { if (req.wLength != 0) break; switch (le16_to_cpu(req.wValue)) { case USB_DEVICE_REMOTE_WAKEUP: ci->remote_wakeup = 1; err = isr_setup_status_phase(ci); break; case USB_DEVICE_TEST_MODE: tmode = le16_to_cpu(req.wIndex) >> 8; switch (tmode) { case TEST_J: case TEST_K: case TEST_SE0_NAK: case TEST_PACKET: case TEST_FORCE_EN: ci->test_mode = tmode; err = isr_setup_status_phase( ci); break; default: break; } default: goto delegate; } } else { goto delegate; } break; default: delegate: if (req.wLength == 0) /* no data phase */ ci->ep0_dir = TX; spin_unlock(&ci->lock); err = ci->driver->setup(&ci->gadget, &req); spin_lock(&ci->lock); break; } if (err < 0) { spin_unlock(&ci->lock); if (usb_ep_set_halt(&mEp->ep)) dev_err(ci->dev, "error: ep_set_halt\n"); spin_lock(&ci->lock); } } } /****************************************************************************** * ENDPT block *****************************************************************************/ /** * ep_enable: configure endpoint, making it usable * * Check usb_ep_enable() at "usb_gadget.h" for details */ static int ep_enable(struct usb_ep *ep, const struct usb_endpoint_descriptor *desc) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); int retval = 0; unsigned long flags; if (ep == NULL || desc == NULL) return -EINVAL; spin_lock_irqsave(mEp->lock, flags); /* only internal SW should enable ctrl endpts */ mEp->ep.desc = desc; if (!list_empty(&mEp->qh.queue)) dev_warn(mEp->ci->dev, "enabling a non-empty endpoint!\n"); mEp->dir = usb_endpoint_dir_in(desc) ? TX : RX; mEp->num = usb_endpoint_num(desc); mEp->type = usb_endpoint_type(desc); mEp->ep.maxpacket = usb_endpoint_maxp(desc); mEp->qh.ptr->cap = 0; if (mEp->type == USB_ENDPOINT_XFER_CONTROL) mEp->qh.ptr->cap |= QH_IOS; else if (mEp->type == USB_ENDPOINT_XFER_ISOC) mEp->qh.ptr->cap &= ~QH_MULT; else mEp->qh.ptr->cap &= ~QH_ZLT; mEp->qh.ptr->cap |= (mEp->ep.maxpacket << __ffs(QH_MAX_PKT)) & QH_MAX_PKT; mEp->qh.ptr->td.next |= TD_TERMINATE; /* needed? */ /* * Enable endpoints in the HW other than ep0 as ep0 * is always enabled */ if (mEp->num) retval |= hw_ep_enable(mEp->ci, mEp->num, mEp->dir, mEp->type); spin_unlock_irqrestore(mEp->lock, flags); return retval; } /** * ep_disable: endpoint is no longer usable * * Check usb_ep_disable() at "usb_gadget.h" for details */ static int ep_disable(struct usb_ep *ep) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); int direction, retval = 0; unsigned long flags; if (ep == NULL) return -EINVAL; else if (mEp->ep.desc == NULL) return -EBUSY; spin_lock_irqsave(mEp->lock, flags); /* only internal SW should disable ctrl endpts */ direction = mEp->dir; do { retval |= _ep_nuke(mEp); retval |= hw_ep_disable(mEp->ci, mEp->num, mEp->dir); if (mEp->type == USB_ENDPOINT_XFER_CONTROL) mEp->dir = (mEp->dir == TX) ? RX : TX; } while (mEp->dir != direction); mEp->ep.desc = NULL; spin_unlock_irqrestore(mEp->lock, flags); return retval; } /** * ep_alloc_request: allocate a request object to use with this endpoint * * Check usb_ep_alloc_request() at "usb_gadget.h" for details */ static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); struct ci13xxx_req *mReq = NULL; if (ep == NULL) return NULL; mReq = kzalloc(sizeof(struct ci13xxx_req), gfp_flags); if (mReq != NULL) { INIT_LIST_HEAD(&mReq->queue); mReq->ptr = dma_pool_alloc(mEp->td_pool, gfp_flags, &mReq->dma); if (mReq->ptr == NULL) { kfree(mReq); mReq = NULL; } } return (mReq == NULL) ? NULL : &mReq->req; } /** * ep_free_request: frees a request object * * Check usb_ep_free_request() at "usb_gadget.h" for details */ static void ep_free_request(struct usb_ep *ep, struct usb_request *req) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); struct ci13xxx_req *mReq = container_of(req, struct ci13xxx_req, req); unsigned long flags; if (ep == NULL || req == NULL) { return; } else if (!list_empty(&mReq->queue)) { dev_err(mEp->ci->dev, "freeing queued request\n"); return; } spin_lock_irqsave(mEp->lock, flags); if (mReq->ptr) dma_pool_free(mEp->td_pool, mReq->ptr, mReq->dma); kfree(mReq); spin_unlock_irqrestore(mEp->lock, flags); } /** * ep_queue: queues (submits) an I/O request to an endpoint * * Check usb_ep_queue()* at usb_gadget.h" for details */ static int ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t __maybe_unused gfp_flags) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); struct ci13xxx_req *mReq = container_of(req, struct ci13xxx_req, req); struct ci13xxx *ci = mEp->ci; int retval = 0; unsigned long flags; if (ep == NULL || req == NULL || mEp->ep.desc == NULL) return -EINVAL; spin_lock_irqsave(mEp->lock, flags); if (mEp->type == USB_ENDPOINT_XFER_CONTROL) { if (req->length) mEp = (ci->ep0_dir == RX) ? ci->ep0out : ci->ep0in; if (!list_empty(&mEp->qh.queue)) { _ep_nuke(mEp); retval = -EOVERFLOW; dev_warn(mEp->ci->dev, "endpoint ctrl %X nuked\n", _usb_addr(mEp)); } } /* first nuke then test link, e.g. previous status has not sent */ if (!list_empty(&mReq->queue)) { retval = -EBUSY; dev_err(mEp->ci->dev, "request already in queue\n"); goto done; } if (req->length > 4 * CI13XXX_PAGE_SIZE) { req->length = 4 * CI13XXX_PAGE_SIZE; retval = -EMSGSIZE; dev_warn(mEp->ci->dev, "request length truncated\n"); } /* push request */ mReq->req.status = -EINPROGRESS; mReq->req.actual = 0; retval = _hardware_enqueue(mEp, mReq); if (retval == -EALREADY) retval = 0; if (!retval) list_add_tail(&mReq->queue, &mEp->qh.queue); done: spin_unlock_irqrestore(mEp->lock, flags); return retval; } /** * ep_dequeue: dequeues (cancels, unlinks) an I/O request from an endpoint * * Check usb_ep_dequeue() at "usb_gadget.h" for details */ static int ep_dequeue(struct usb_ep *ep, struct usb_request *req) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); struct ci13xxx_req *mReq = container_of(req, struct ci13xxx_req, req); unsigned long flags; if (ep == NULL || req == NULL || mReq->req.status != -EALREADY || mEp->ep.desc == NULL || list_empty(&mReq->queue) || list_empty(&mEp->qh.queue)) return -EINVAL; spin_lock_irqsave(mEp->lock, flags); hw_ep_flush(mEp->ci, mEp->num, mEp->dir); /* pop request */ list_del_init(&mReq->queue); usb_gadget_unmap_request(&mEp->ci->gadget, req, mEp->dir); req->status = -ECONNRESET; if (mReq->req.complete != NULL) { spin_unlock(mEp->lock); mReq->req.complete(&mEp->ep, &mReq->req); spin_lock(mEp->lock); } spin_unlock_irqrestore(mEp->lock, flags); return 0; } /** * ep_set_halt: sets the endpoint halt feature * * Check usb_ep_set_halt() at "usb_gadget.h" for details */ static int ep_set_halt(struct usb_ep *ep, int value) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); int direction, retval = 0; unsigned long flags; if (ep == NULL || mEp->ep.desc == NULL) return -EINVAL; spin_lock_irqsave(mEp->lock, flags); #ifndef STALL_IN /* g_file_storage MS compliant but g_zero fails chapter 9 compliance */ if (value && mEp->type == USB_ENDPOINT_XFER_BULK && mEp->dir == TX && !list_empty(&mEp->qh.queue)) { spin_unlock_irqrestore(mEp->lock, flags); return -EAGAIN; } #endif direction = mEp->dir; do { retval |= hw_ep_set_halt(mEp->ci, mEp->num, mEp->dir, value); if (!value) mEp->wedge = 0; if (mEp->type == USB_ENDPOINT_XFER_CONTROL) mEp->dir = (mEp->dir == TX) ? RX : TX; } while (mEp->dir != direction); spin_unlock_irqrestore(mEp->lock, flags); return retval; } /** * ep_set_wedge: sets the halt feature and ignores clear requests * * Check usb_ep_set_wedge() at "usb_gadget.h" for details */ static int ep_set_wedge(struct usb_ep *ep) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); unsigned long flags; if (ep == NULL || mEp->ep.desc == NULL) return -EINVAL; spin_lock_irqsave(mEp->lock, flags); mEp->wedge = 1; spin_unlock_irqrestore(mEp->lock, flags); return usb_ep_set_halt(ep); } /** * ep_fifo_flush: flushes contents of a fifo * * Check usb_ep_fifo_flush() at "usb_gadget.h" for details */ static void ep_fifo_flush(struct usb_ep *ep) { struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep); unsigned long flags; if (ep == NULL) { dev_err(mEp->ci->dev, "%02X: -EINVAL\n", _usb_addr(mEp)); return; } spin_lock_irqsave(mEp->lock, flags); hw_ep_flush(mEp->ci, mEp->num, mEp->dir); spin_unlock_irqrestore(mEp->lock, flags); } /** * Endpoint-specific part of the API to the USB controller hardware * Check "usb_gadget.h" for details */ static const struct usb_ep_ops usb_ep_ops = { .enable = ep_enable, .disable = ep_disable, .alloc_request = ep_alloc_request, .free_request = ep_free_request, .queue = ep_queue, .dequeue = ep_dequeue, .set_halt = ep_set_halt, .set_wedge = ep_set_wedge, .fifo_flush = ep_fifo_flush, }; /****************************************************************************** * GADGET block *****************************************************************************/ static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active) { struct ci13xxx *ci = container_of(_gadget, struct ci13xxx, gadget); unsigned long flags; int gadget_ready = 0; if (!(ci->platdata->flags & CI13XXX_PULLUP_ON_VBUS)) return -EOPNOTSUPP; spin_lock_irqsave(&ci->lock, flags); ci->vbus_active = is_active; if (ci->driver) gadget_ready = 1; spin_unlock_irqrestore(&ci->lock, flags); if (gadget_ready) { if (is_active) { pm_runtime_get_sync(&_gadget->dev); hw_device_reset(ci, USBMODE_CM_DC); hw_device_state(ci, ci->ep0out->qh.dma); } else { hw_device_state(ci, 0); if (ci->platdata->notify_event) ci->platdata->notify_event(ci, CI13XXX_CONTROLLER_STOPPED_EVENT); _gadget_stop_activity(&ci->gadget); pm_runtime_put_sync(&_gadget->dev); } } return 0; } static int ci13xxx_wakeup(struct usb_gadget *_gadget) { struct ci13xxx *ci = container_of(_gadget, struct ci13xxx, gadget); unsigned long flags; int ret = 0; spin_lock_irqsave(&ci->lock, flags); if (!ci->remote_wakeup) { ret = -EOPNOTSUPP; goto out; } if (!hw_read(ci, OP_PORTSC, PORTSC_SUSP)) { ret = -EINVAL; goto out; } hw_write(ci, OP_PORTSC, PORTSC_FPR, PORTSC_FPR); out: spin_unlock_irqrestore(&ci->lock, flags); return ret; } static int ci13xxx_vbus_draw(struct usb_gadget *_gadget, unsigned mA) { struct ci13xxx *ci = container_of(_gadget, struct ci13xxx, gadget); if (ci->transceiver) return usb_phy_set_power(ci->transceiver, mA); return -ENOTSUPP; } /* Change Data+ pullup status * this func is used by usb_gadget_connect/disconnet */ static int ci13xxx_pullup(struct usb_gadget *_gadget, int is_on) { struct ci13xxx *ci = container_of(_gadget, struct ci13xxx, gadget); if (is_on) hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS); else hw_write(ci, OP_USBCMD, USBCMD_RS, 0); return 0; } static int ci13xxx_start(struct usb_gadget *gadget, struct usb_gadget_driver *driver); static int ci13xxx_stop(struct usb_gadget *gadget, struct usb_gadget_driver *driver); /** * Device operations part of the API to the USB controller hardware, * which don't involve endpoints (or i/o) * Check "usb_gadget.h" for details */ static const struct usb_gadget_ops usb_gadget_ops = { .vbus_session = ci13xxx_vbus_session, .wakeup = ci13xxx_wakeup, .pullup = ci13xxx_pullup, .vbus_draw = ci13xxx_vbus_draw, .udc_start = ci13xxx_start, .udc_stop = ci13xxx_stop, }; static int init_eps(struct ci13xxx *ci) { int retval = 0, i, j; for (i = 0; i < ci->hw_ep_max/2; i++) for (j = RX; j <= TX; j++) { int k = i + j * ci->hw_ep_max/2; struct ci13xxx_ep *mEp = &ci->ci13xxx_ep[k]; scnprintf(mEp->name, sizeof(mEp->name), "ep%i%s", i, (j == TX) ? "in" : "out"); mEp->ci = ci; mEp->lock = &ci->lock; mEp->td_pool = ci->td_pool; mEp->ep.name = mEp->name; mEp->ep.ops = &usb_ep_ops; /* * for ep0: maxP defined in desc, for other * eps, maxP is set by epautoconfig() called * by gadget layer */ mEp->ep.maxpacket = (unsigned short)~0; INIT_LIST_HEAD(&mEp->qh.queue); mEp->qh.ptr = dma_pool_alloc(ci->qh_pool, GFP_KERNEL, &mEp->qh.dma); if (mEp->qh.ptr == NULL) retval = -ENOMEM; else memset(mEp->qh.ptr, 0, sizeof(*mEp->qh.ptr)); /* * set up shorthands for ep0 out and in endpoints, * don't add to gadget's ep_list */ if (i == 0) { if (j == RX) ci->ep0out = mEp; else ci->ep0in = mEp; mEp->ep.maxpacket = CTRL_PAYLOAD_MAX; continue; } list_add_tail(&mEp->ep.ep_list, &ci->gadget.ep_list); } return retval; } static void destroy_eps(struct ci13xxx *ci) { int i; for (i = 0; i < ci->hw_ep_max; i++) { struct ci13xxx_ep *mEp = &ci->ci13xxx_ep[i]; dma_pool_free(ci->qh_pool, mEp->qh.ptr, mEp->qh.dma); } } /** * ci13xxx_start: register a gadget driver * @gadget: our gadget * @driver: the driver being registered * * Interrupts are enabled here. */ static int ci13xxx_start(struct usb_gadget *gadget, struct usb_gadget_driver *driver) { struct ci13xxx *ci = container_of(gadget, struct ci13xxx, gadget); unsigned long flags; int retval = -ENOMEM; if (driver->disconnect == NULL) return -EINVAL; ci->ep0out->ep.desc = &ctrl_endpt_out_desc; retval = usb_ep_enable(&ci->ep0out->ep); if (retval) return retval; ci->ep0in->ep.desc = &ctrl_endpt_in_desc; retval = usb_ep_enable(&ci->ep0in->ep); if (retval) return retval; spin_lock_irqsave(&ci->lock, flags); ci->driver = driver; pm_runtime_get_sync(&ci->gadget.dev); if (ci->platdata->flags & CI13XXX_PULLUP_ON_VBUS) { if (ci->vbus_active) { if (ci->platdata->flags & CI13XXX_REGS_SHARED) hw_device_reset(ci, USBMODE_CM_DC); } else { pm_runtime_put_sync(&ci->gadget.dev); goto done; } } retval = hw_device_state(ci, ci->ep0out->qh.dma); if (retval) pm_runtime_put_sync(&ci->gadget.dev); done: spin_unlock_irqrestore(&ci->lock, flags); return retval; } /** * ci13xxx_stop: unregister a gadget driver */ static int ci13xxx_stop(struct usb_gadget *gadget, struct usb_gadget_driver *driver) { struct ci13xxx *ci = container_of(gadget, struct ci13xxx, gadget); unsigned long flags; spin_lock_irqsave(&ci->lock, flags); if (!(ci->platdata->flags & CI13XXX_PULLUP_ON_VBUS) || ci->vbus_active) { hw_device_state(ci, 0); if (ci->platdata->notify_event) ci->platdata->notify_event(ci, CI13XXX_CONTROLLER_STOPPED_EVENT); ci->driver = NULL; spin_unlock_irqrestore(&ci->lock, flags); _gadget_stop_activity(&ci->gadget); spin_lock_irqsave(&ci->lock, flags); pm_runtime_put(&ci->gadget.dev); } spin_unlock_irqrestore(&ci->lock, flags); return 0; } /****************************************************************************** * BUS block *****************************************************************************/ /** * udc_irq: ci interrupt handler * * This function returns IRQ_HANDLED if the IRQ has been handled * It locks access to registers */ static irqreturn_t udc_irq(struct ci13xxx *ci) { irqreturn_t retval; u32 intr; if (ci == NULL) return IRQ_HANDLED; spin_lock(&ci->lock); if (ci->platdata->flags & CI13XXX_REGS_SHARED) { if (hw_read(ci, OP_USBMODE, USBMODE_CM) != USBMODE_CM_DC) { spin_unlock(&ci->lock); return IRQ_NONE; } } intr = hw_test_and_clear_intr_active(ci); if (intr) { /* order defines priority - do NOT change it */ if (USBi_URI & intr) isr_reset_handler(ci); if (USBi_PCI & intr) { ci->gadget.speed = hw_port_is_high_speed(ci) ? USB_SPEED_HIGH : USB_SPEED_FULL; if (ci->suspended && ci->driver->resume) { spin_unlock(&ci->lock); ci->driver->resume(&ci->gadget); spin_lock(&ci->lock); ci->suspended = 0; } } if (USBi_UI & intr) isr_tr_complete_handler(ci); if (USBi_SLI & intr) { if (ci->gadget.speed != USB_SPEED_UNKNOWN && ci->driver->suspend) { ci->suspended = 1; spin_unlock(&ci->lock); ci->driver->suspend(&ci->gadget); spin_lock(&ci->lock); } } retval = IRQ_HANDLED; } else { retval = IRQ_NONE; } spin_unlock(&ci->lock); return retval; } /** * udc_release: driver release function * @dev: device * * Currently does nothing */ static void udc_release(struct device *dev) { } /** * udc_start: initialize gadget role * @ci: chipidea controller */ static int udc_start(struct ci13xxx *ci) { struct device *dev = ci->dev; int retval = 0; spin_lock_init(&ci->lock); ci->gadget.ops = &usb_gadget_ops; ci->gadget.speed = USB_SPEED_UNKNOWN; ci->gadget.max_speed = USB_SPEED_HIGH; ci->gadget.is_otg = 0; ci->gadget.name = ci->platdata->name; INIT_LIST_HEAD(&ci->gadget.ep_list); dev_set_name(&ci->gadget.dev, "gadget"); ci->gadget.dev.dma_mask = dev->dma_mask; ci->gadget.dev.coherent_dma_mask = dev->coherent_dma_mask; ci->gadget.dev.parent = dev; ci->gadget.dev.release = udc_release; /* alloc resources */ ci->qh_pool = dma_pool_create("ci13xxx_qh", dev, sizeof(struct ci13xxx_qh), 64, CI13XXX_PAGE_SIZE); if (ci->qh_pool == NULL) return -ENOMEM; ci->td_pool = dma_pool_create("ci13xxx_td", dev, sizeof(struct ci13xxx_td), 64, CI13XXX_PAGE_SIZE); if (ci->td_pool == NULL) { retval = -ENOMEM; goto free_qh_pool; } retval = init_eps(ci); if (retval) goto free_pools; ci->gadget.ep0 = &ci->ep0in->ep; if (ci->global_phy) ci->transceiver = usb_get_phy(USB_PHY_TYPE_USB2); if (ci->platdata->flags & CI13XXX_REQUIRE_TRANSCEIVER) { if (ci->transceiver == NULL) { retval = -ENODEV; goto destroy_eps; } } if (!(ci->platdata->flags & CI13XXX_REGS_SHARED)) { retval = hw_device_reset(ci, USBMODE_CM_DC); if (retval) goto put_transceiver; } retval = device_register(&ci->gadget.dev); if (retval) { put_device(&ci->gadget.dev); goto put_transceiver; } if (!IS_ERR_OR_NULL(ci->transceiver)) { retval = otg_set_peripheral(ci->transceiver->otg, &ci->gadget); if (retval) goto unreg_device; } retval = usb_add_gadget_udc(dev, &ci->gadget); if (retval) goto remove_trans; pm_runtime_no_callbacks(&ci->gadget.dev); pm_runtime_enable(&ci->gadget.dev); return retval; remove_trans: if (!IS_ERR_OR_NULL(ci->transceiver)) { otg_set_peripheral(ci->transceiver->otg, NULL); if (ci->global_phy) usb_put_phy(ci->transceiver); } dev_err(dev, "error = %i\n", retval); unreg_device: device_unregister(&ci->gadget.dev); put_transceiver: if (!IS_ERR_OR_NULL(ci->transceiver) && ci->global_phy) usb_put_phy(ci->transceiver); destroy_eps: destroy_eps(ci); free_pools: dma_pool_destroy(ci->td_pool); free_qh_pool: dma_pool_destroy(ci->qh_pool); return retval; } /** * udc_remove: parent remove must call this to remove UDC * * No interrupts active, the IRQ has been released */ static void udc_stop(struct ci13xxx *ci) { if (ci == NULL) return; usb_del_gadget_udc(&ci->gadget); destroy_eps(ci); dma_pool_destroy(ci->td_pool); dma_pool_destroy(ci->qh_pool); if (!IS_ERR_OR_NULL(ci->transceiver)) { otg_set_peripheral(ci->transceiver->otg, NULL); if (ci->global_phy) usb_put_phy(ci->transceiver); } device_unregister(&ci->gadget.dev); /* my kobject is dynamic, I swear! */ memset(&ci->gadget, 0, sizeof(ci->gadget)); } /** * ci_hdrc_gadget_init - initialize device related bits * ci: the controller * * This function enables the gadget role, if the device is "device capable". */ int ci_hdrc_gadget_init(struct ci13xxx *ci) { struct ci_role_driver *rdrv; if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC)) return -ENXIO; rdrv = devm_kzalloc(ci->dev, sizeof(struct ci_role_driver), GFP_KERNEL); if (!rdrv) return -ENOMEM; rdrv->start = udc_start; rdrv->stop = udc_stop; rdrv->irq = udc_irq; rdrv->name = "gadget"; ci->roles[CI_ROLE_GADGET] = rdrv; return 0; }