// SPDX-License-Identifier: GPL-2.0+ /* * f_printer.c - USB printer function driver * * Copied from drivers/usb/gadget/legacy/printer.c, * which was: * * printer.c -- Printer gadget driver * * Copyright (C) 2003-2005 David Brownell * Copyright (C) 2006 Craig W. Nadler */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "u_printer.h" #define PRINTER_MINORS 4 #define GET_DEVICE_ID 0 #define GET_PORT_STATUS 1 #define SOFT_RESET 2 static int major, minors; static struct class *usb_gadget_class; static DEFINE_IDA(printer_ida); static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */ /*-------------------------------------------------------------------------*/ struct printer_dev { spinlock_t lock; /* lock this structure */ /* lock buffer lists during read/write calls */ struct mutex lock_printer_io; struct usb_gadget *gadget; s8 interface; struct usb_ep *in_ep, *out_ep; struct list_head rx_reqs; /* List of free RX structs */ struct list_head rx_reqs_active; /* List of Active RX xfers */ struct list_head rx_buffers; /* List of completed xfers */ /* wait until there is data to be read. */ wait_queue_head_t rx_wait; struct list_head tx_reqs; /* List of free TX structs */ struct list_head tx_reqs_active; /* List of Active TX xfers */ /* Wait until there are write buffers available to use. */ wait_queue_head_t tx_wait; /* Wait until all write buffers have been sent. */ wait_queue_head_t tx_flush_wait; struct usb_request *current_rx_req; size_t current_rx_bytes; u8 *current_rx_buf; u8 printer_status; u8 reset_printer; int minor; struct cdev printer_cdev; u8 printer_cdev_open; wait_queue_head_t wait; unsigned q_len; char *pnp_string; /* We don't own memory! */ struct usb_function function; }; static inline struct printer_dev *func_to_printer(struct usb_function *f) { return container_of(f, struct printer_dev, function); } /*-------------------------------------------------------------------------*/ /* * DESCRIPTORS ... most are static, but strings and (full) configuration * descriptors are built on demand. */ /* holds our biggest descriptor */ #define USB_DESC_BUFSIZE 256 #define USB_BUFSIZE 8192 static struct usb_interface_descriptor intf_desc = { .bLength = sizeof(intf_desc), .bDescriptorType = USB_DT_INTERFACE, .bNumEndpoints = 2, .bInterfaceClass = USB_CLASS_PRINTER, .bInterfaceSubClass = 1, /* Printer Sub-Class */ .bInterfaceProtocol = 2, /* Bi-Directional */ .iInterface = 0 }; static struct usb_endpoint_descriptor fs_ep_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_BULK }; static struct usb_endpoint_descriptor fs_ep_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .bmAttributes = USB_ENDPOINT_XFER_BULK }; static struct usb_descriptor_header *fs_printer_function[] = { (struct usb_descriptor_header *) &intf_desc, (struct usb_descriptor_header *) &fs_ep_in_desc, (struct usb_descriptor_header *) &fs_ep_out_desc, NULL }; /* * usb 2.0 devices need to expose both high speed and full speed * descriptors, unless they only run at full speed. */ static struct usb_endpoint_descriptor hs_ep_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512) }; static struct usb_endpoint_descriptor hs_ep_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512) }; static struct usb_descriptor_header *hs_printer_function[] = { (struct usb_descriptor_header *) &intf_desc, (struct usb_descriptor_header *) &hs_ep_in_desc, (struct usb_descriptor_header *) &hs_ep_out_desc, NULL }; /* * Added endpoint descriptors for 3.0 devices */ static struct usb_endpoint_descriptor ss_ep_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(1024), }; static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = { .bLength = sizeof(ss_ep_in_comp_desc), .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, }; static struct usb_endpoint_descriptor ss_ep_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(1024), }; static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = { .bLength = sizeof(ss_ep_out_comp_desc), .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, }; static struct usb_descriptor_header *ss_printer_function[] = { (struct usb_descriptor_header *) &intf_desc, (struct usb_descriptor_header *) &ss_ep_in_desc, (struct usb_descriptor_header *) &ss_ep_in_comp_desc, (struct usb_descriptor_header *) &ss_ep_out_desc, (struct usb_descriptor_header *) &ss_ep_out_comp_desc, NULL }; /* maxpacket and other transfer characteristics vary by speed. */ static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget, struct usb_endpoint_descriptor *fs, struct usb_endpoint_descriptor *hs, struct usb_endpoint_descriptor *ss) { switch (gadget->speed) { case USB_SPEED_SUPER: return ss; case USB_SPEED_HIGH: return hs; default: return fs; } } /*-------------------------------------------------------------------------*/ static struct usb_request * printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags) { struct usb_request *req; req = usb_ep_alloc_request(ep, gfp_flags); if (req != NULL) { req->length = len; req->buf = kmalloc(len, gfp_flags); if (req->buf == NULL) { usb_ep_free_request(ep, req); return NULL; } } return req; } static void printer_req_free(struct usb_ep *ep, struct usb_request *req) { if (ep != NULL && req != NULL) { kfree(req->buf); usb_ep_free_request(ep, req); } } /*-------------------------------------------------------------------------*/ static void rx_complete(struct usb_ep *ep, struct usb_request *req) { struct printer_dev *dev = ep->driver_data; int status = req->status; unsigned long flags; spin_lock_irqsave(&dev->lock, flags); list_del_init(&req->list); /* Remode from Active List */ switch (status) { /* normal completion */ case 0: if (req->actual > 0) { list_add_tail(&req->list, &dev->rx_buffers); DBG(dev, "G_Printer : rx length %d\n", req->actual); } else { list_add(&req->list, &dev->rx_reqs); } break; /* software-driven interface shutdown */ case -ECONNRESET: /* unlink */ case -ESHUTDOWN: /* disconnect etc */ VDBG(dev, "rx shutdown, code %d\n", status); list_add(&req->list, &dev->rx_reqs); break; /* for hardware automagic (such as pxa) */ case -ECONNABORTED: /* endpoint reset */ DBG(dev, "rx %s reset\n", ep->name); list_add(&req->list, &dev->rx_reqs); break; /* data overrun */ case -EOVERFLOW: fallthrough; default: DBG(dev, "rx status %d\n", status); list_add(&req->list, &dev->rx_reqs); break; } wake_up_interruptible(&dev->rx_wait); spin_unlock_irqrestore(&dev->lock, flags); } static void tx_complete(struct usb_ep *ep, struct usb_request *req) { struct printer_dev *dev = ep->driver_data; switch (req->status) { default: VDBG(dev, "tx err %d\n", req->status); fallthrough; case -ECONNRESET: /* unlink */ case -ESHUTDOWN: /* disconnect etc */ break; case 0: break; } spin_lock(&dev->lock); /* Take the request struct off the active list and put it on the * free list. */ list_del_init(&req->list); list_add(&req->list, &dev->tx_reqs); wake_up_interruptible(&dev->tx_wait); if (likely(list_empty(&dev->tx_reqs_active))) wake_up_interruptible(&dev->tx_flush_wait); spin_unlock(&dev->lock); } /*-------------------------------------------------------------------------*/ static int printer_open(struct inode *inode, struct file *fd) { struct printer_dev *dev; unsigned long flags; int ret = -EBUSY; dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev); spin_lock_irqsave(&dev->lock, flags); if (dev->interface < 0) { spin_unlock_irqrestore(&dev->lock, flags); return -ENODEV; } if (!dev->printer_cdev_open) { dev->printer_cdev_open = 1; fd->private_data = dev; ret = 0; /* Change the printer status to show that it's on-line. */ dev->printer_status |= PRINTER_SELECTED; } spin_unlock_irqrestore(&dev->lock, flags); DBG(dev, "printer_open returned %x\n", ret); return ret; } static int printer_close(struct inode *inode, struct file *fd) { struct printer_dev *dev = fd->private_data; unsigned long flags; spin_lock_irqsave(&dev->lock, flags); dev->printer_cdev_open = 0; fd->private_data = NULL; /* Change printer status to show that the printer is off-line. */ dev->printer_status &= ~PRINTER_SELECTED; spin_unlock_irqrestore(&dev->lock, flags); DBG(dev, "printer_close\n"); return 0; } /* This function must be called with interrupts turned off. */ static void setup_rx_reqs(struct printer_dev *dev) { struct usb_request *req; while (likely(!list_empty(&dev->rx_reqs))) { int error; req = container_of(dev->rx_reqs.next, struct usb_request, list); list_del_init(&req->list); /* The USB Host sends us whatever amount of data it wants to * so we always set the length field to the full USB_BUFSIZE. * If the amount of data is more than the read() caller asked * for it will be stored in the request buffer until it is * asked for by read(). */ req->length = USB_BUFSIZE; req->complete = rx_complete; /* here, we unlock, and only unlock, to avoid deadlock. */ spin_unlock(&dev->lock); error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC); spin_lock(&dev->lock); if (error) { DBG(dev, "rx submit --> %d\n", error); list_add(&req->list, &dev->rx_reqs); break; } /* if the req is empty, then add it into dev->rx_reqs_active. */ else if (list_empty(&req->list)) list_add(&req->list, &dev->rx_reqs_active); } } static ssize_t printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr) { struct printer_dev *dev = fd->private_data; unsigned long flags; size_t size; size_t bytes_copied; struct usb_request *req; /* This is a pointer to the current USB rx request. */ struct usb_request *current_rx_req; /* This is the number of bytes in the current rx buffer. */ size_t current_rx_bytes; /* This is a pointer to the current rx buffer. */ u8 *current_rx_buf; if (len == 0) return -EINVAL; DBG(dev, "printer_read trying to read %d bytes\n", (int)len); mutex_lock(&dev->lock_printer_io); spin_lock_irqsave(&dev->lock, flags); if (dev->interface < 0) { spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); return -ENODEV; } /* We will use this flag later to check if a printer reset happened * after we turn interrupts back on. */ dev->reset_printer = 0; setup_rx_reqs(dev); bytes_copied = 0; current_rx_req = dev->current_rx_req; current_rx_bytes = dev->current_rx_bytes; current_rx_buf = dev->current_rx_buf; dev->current_rx_req = NULL; dev->current_rx_bytes = 0; dev->current_rx_buf = NULL; /* Check if there is any data in the read buffers. Please note that * current_rx_bytes is the number of bytes in the current rx buffer. * If it is zero then check if there are any other rx_buffers that * are on the completed list. We are only out of data if all rx * buffers are empty. */ if ((current_rx_bytes == 0) && (likely(list_empty(&dev->rx_buffers)))) { /* Turn interrupts back on before sleeping. */ spin_unlock_irqrestore(&dev->lock, flags); /* * If no data is available check if this is a NON-Blocking * call or not. */ if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) { mutex_unlock(&dev->lock_printer_io); return -EAGAIN; } /* Sleep until data is available */ wait_event_interruptible(dev->rx_wait, (likely(!list_empty(&dev->rx_buffers)))); spin_lock_irqsave(&dev->lock, flags); } /* We have data to return then copy it to the caller's buffer.*/ while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers))) && len) { if (current_rx_bytes == 0) { req = container_of(dev->rx_buffers.next, struct usb_request, list); list_del_init(&req->list); if (req->actual && req->buf) { current_rx_req = req; current_rx_bytes = req->actual; current_rx_buf = req->buf; } else { list_add(&req->list, &dev->rx_reqs); continue; } } /* Don't leave irqs off while doing memory copies */ spin_unlock_irqrestore(&dev->lock, flags); if (len > current_rx_bytes) size = current_rx_bytes; else size = len; size -= copy_to_user(buf, current_rx_buf, size); bytes_copied += size; len -= size; buf += size; spin_lock_irqsave(&dev->lock, flags); /* We've disconnected or reset so return. */ if (dev->reset_printer) { list_add(¤t_rx_req->list, &dev->rx_reqs); spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); return -EAGAIN; } /* If we not returning all the data left in this RX request * buffer then adjust the amount of data left in the buffer. * Othewise if we are done with this RX request buffer then * requeue it to get any incoming data from the USB host. */ if (size < current_rx_bytes) { current_rx_bytes -= size; current_rx_buf += size; } else { list_add(¤t_rx_req->list, &dev->rx_reqs); current_rx_bytes = 0; current_rx_buf = NULL; current_rx_req = NULL; } } dev->current_rx_req = current_rx_req; dev->current_rx_bytes = current_rx_bytes; dev->current_rx_buf = current_rx_buf; spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied); if (bytes_copied) return bytes_copied; else return -EAGAIN; } static ssize_t printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr) { struct printer_dev *dev = fd->private_data; unsigned long flags; size_t size; /* Amount of data in a TX request. */ size_t bytes_copied = 0; struct usb_request *req; int value; DBG(dev, "printer_write trying to send %d bytes\n", (int)len); if (len == 0) return -EINVAL; mutex_lock(&dev->lock_printer_io); spin_lock_irqsave(&dev->lock, flags); if (dev->interface < 0) { spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); return -ENODEV; } /* Check if a printer reset happens while we have interrupts on */ dev->reset_printer = 0; /* Check if there is any available write buffers */ if (likely(list_empty(&dev->tx_reqs))) { /* Turn interrupts back on before sleeping. */ spin_unlock_irqrestore(&dev->lock, flags); /* * If write buffers are available check if this is * a NON-Blocking call or not. */ if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) { mutex_unlock(&dev->lock_printer_io); return -EAGAIN; } /* Sleep until a write buffer is available */ wait_event_interruptible(dev->tx_wait, (likely(!list_empty(&dev->tx_reqs)))); spin_lock_irqsave(&dev->lock, flags); } while (likely(!list_empty(&dev->tx_reqs)) && len) { if (len > USB_BUFSIZE) size = USB_BUFSIZE; else size = len; req = container_of(dev->tx_reqs.next, struct usb_request, list); list_del_init(&req->list); req->complete = tx_complete; req->length = size; /* Check if we need to send a zero length packet. */ if (len > size) /* They will be more TX requests so no yet. */ req->zero = 0; else /* If the data amount is not a multiple of the * maxpacket size then send a zero length packet. */ req->zero = ((len % dev->in_ep->maxpacket) == 0); /* Don't leave irqs off while doing memory copies */ spin_unlock_irqrestore(&dev->lock, flags); if (copy_from_user(req->buf, buf, size)) { list_add(&req->list, &dev->tx_reqs); mutex_unlock(&dev->lock_printer_io); return bytes_copied; } bytes_copied += size; len -= size; buf += size; spin_lock_irqsave(&dev->lock, flags); /* We've disconnected or reset so free the req and buffer */ if (dev->reset_printer) { list_add(&req->list, &dev->tx_reqs); spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); return -EAGAIN; } list_add(&req->list, &dev->tx_reqs_active); /* here, we unlock, and only unlock, to avoid deadlock. */ spin_unlock(&dev->lock); value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC); spin_lock(&dev->lock); if (value) { list_del(&req->list); list_add(&req->list, &dev->tx_reqs); spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); return -EAGAIN; } } spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied); if (bytes_copied) return bytes_copied; else return -EAGAIN; } static int printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync) { struct printer_dev *dev = fd->private_data; struct inode *inode = file_inode(fd); unsigned long flags; int tx_list_empty; inode_lock(inode); spin_lock_irqsave(&dev->lock, flags); if (dev->interface < 0) { spin_unlock_irqrestore(&dev->lock, flags); inode_unlock(inode); return -ENODEV; } tx_list_empty = (likely(list_empty(&dev->tx_reqs))); spin_unlock_irqrestore(&dev->lock, flags); if (!tx_list_empty) { /* Sleep until all data has been sent */ wait_event_interruptible(dev->tx_flush_wait, (likely(list_empty(&dev->tx_reqs_active)))); } inode_unlock(inode); return 0; } static __poll_t printer_poll(struct file *fd, poll_table *wait) { struct printer_dev *dev = fd->private_data; unsigned long flags; __poll_t status = 0; mutex_lock(&dev->lock_printer_io); spin_lock_irqsave(&dev->lock, flags); if (dev->interface < 0) { spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); return EPOLLERR | EPOLLHUP; } setup_rx_reqs(dev); spin_unlock_irqrestore(&dev->lock, flags); mutex_unlock(&dev->lock_printer_io); poll_wait(fd, &dev->rx_wait, wait); poll_wait(fd, &dev->tx_wait, wait); spin_lock_irqsave(&dev->lock, flags); if (likely(!list_empty(&dev->tx_reqs))) status |= EPOLLOUT | EPOLLWRNORM; if (likely(dev->current_rx_bytes) || likely(!list_empty(&dev->rx_buffers))) status |= EPOLLIN | EPOLLRDNORM; spin_unlock_irqrestore(&dev->lock, flags); return status; } static long printer_ioctl(struct file *fd, unsigned int code, unsigned long arg) { struct printer_dev *dev = fd->private_data; unsigned long flags; int status = 0; DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg); /* handle ioctls */ spin_lock_irqsave(&dev->lock, flags); if (dev->interface < 0) { spin_unlock_irqrestore(&dev->lock, flags); return -ENODEV; } switch (code) { case GADGET_GET_PRINTER_STATUS: status = (int)dev->printer_status; break; case GADGET_SET_PRINTER_STATUS: dev->printer_status = (u8)arg; break; default: /* could not handle ioctl */ DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n", code); status = -ENOTTY; } spin_unlock_irqrestore(&dev->lock, flags); return status; } /* used after endpoint configuration */ static const struct file_operations printer_io_operations = { .owner = THIS_MODULE, .open = printer_open, .read = printer_read, .write = printer_write, .fsync = printer_fsync, .poll = printer_poll, .unlocked_ioctl = printer_ioctl, .release = printer_close, .llseek = noop_llseek, }; /*-------------------------------------------------------------------------*/ static int set_printer_interface(struct printer_dev *dev) { int result = 0; dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc, &ss_ep_in_desc); dev->in_ep->driver_data = dev; dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc, &hs_ep_out_desc, &ss_ep_out_desc); dev->out_ep->driver_data = dev; result = usb_ep_enable(dev->in_ep); if (result != 0) { DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result); goto done; } result = usb_ep_enable(dev->out_ep); if (result != 0) { DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result); goto done; } done: /* on error, disable any endpoints */ if (result != 0) { (void) usb_ep_disable(dev->in_ep); (void) usb_ep_disable(dev->out_ep); dev->in_ep->desc = NULL; dev->out_ep->desc = NULL; } /* caller is responsible for cleanup on error */ return result; } static void printer_reset_interface(struct printer_dev *dev) { unsigned long flags; if (dev->interface < 0) return; DBG(dev, "%s\n", __func__); if (dev->in_ep->desc) usb_ep_disable(dev->in_ep); if (dev->out_ep->desc) usb_ep_disable(dev->out_ep); spin_lock_irqsave(&dev->lock, flags); dev->in_ep->desc = NULL; dev->out_ep->desc = NULL; dev->interface = -1; spin_unlock_irqrestore(&dev->lock, flags); } /* Change our operational Interface. */ static int set_interface(struct printer_dev *dev, unsigned number) { int result = 0; /* Free the current interface */ printer_reset_interface(dev); result = set_printer_interface(dev); if (result) printer_reset_interface(dev); else dev->interface = number; if (!result) INFO(dev, "Using interface %x\n", number); return result; } static void printer_soft_reset(struct printer_dev *dev) { struct usb_request *req; INFO(dev, "Received Printer Reset Request\n"); if (usb_ep_disable(dev->in_ep)) DBG(dev, "Failed to disable USB in_ep\n"); if (usb_ep_disable(dev->out_ep)) DBG(dev, "Failed to disable USB out_ep\n"); if (dev->current_rx_req != NULL) { list_add(&dev->current_rx_req->list, &dev->rx_reqs); dev->current_rx_req = NULL; } dev->current_rx_bytes = 0; dev->current_rx_buf = NULL; dev->reset_printer = 1; while (likely(!(list_empty(&dev->rx_buffers)))) { req = container_of(dev->rx_buffers.next, struct usb_request, list); list_del_init(&req->list); list_add(&req->list, &dev->rx_reqs); } while (likely(!(list_empty(&dev->rx_reqs_active)))) { req = container_of(dev->rx_buffers.next, struct usb_request, list); list_del_init(&req->list); list_add(&req->list, &dev->rx_reqs); } while (likely(!(list_empty(&dev->tx_reqs_active)))) { req = container_of(dev->tx_reqs_active.next, struct usb_request, list); list_del_init(&req->list); list_add(&req->list, &dev->tx_reqs); } if (usb_ep_enable(dev->in_ep)) DBG(dev, "Failed to enable USB in_ep\n"); if (usb_ep_enable(dev->out_ep)) DBG(dev, "Failed to enable USB out_ep\n"); wake_up_interruptible(&dev->rx_wait); wake_up_interruptible(&dev->tx_wait); wake_up_interruptible(&dev->tx_flush_wait); } /*-------------------------------------------------------------------------*/ static bool gprinter_req_match(struct usb_function *f, const struct usb_ctrlrequest *ctrl, bool config0) { struct printer_dev *dev = func_to_printer(f); u16 w_index = le16_to_cpu(ctrl->wIndex); u16 w_value = le16_to_cpu(ctrl->wValue); u16 w_length = le16_to_cpu(ctrl->wLength); if (config0) return false; if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE || (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) return false; switch (ctrl->bRequest) { case GET_DEVICE_ID: w_index >>= 8; if (USB_DIR_IN & ctrl->bRequestType) break; return false; case GET_PORT_STATUS: if (!w_value && w_length == 1 && (USB_DIR_IN & ctrl->bRequestType)) break; return false; case SOFT_RESET: if (!w_value && !w_length && !(USB_DIR_IN & ctrl->bRequestType)) break; fallthrough; default: return false; } return w_index == dev->interface; } /* * The setup() callback implements all the ep0 functionality that's not * handled lower down. */ static int printer_func_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { struct printer_dev *dev = func_to_printer(f); struct usb_composite_dev *cdev = f->config->cdev; struct usb_request *req = cdev->req; u8 *buf = req->buf; int value = -EOPNOTSUPP; u16 wIndex = le16_to_cpu(ctrl->wIndex); u16 wValue = le16_to_cpu(ctrl->wValue); u16 wLength = le16_to_cpu(ctrl->wLength); DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n", ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength); switch (ctrl->bRequestType&USB_TYPE_MASK) { case USB_TYPE_CLASS: switch (ctrl->bRequest) { case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */ /* Only one printer interface is supported. */ if ((wIndex>>8) != dev->interface) break; if (!dev->pnp_string) { value = 0; break; } value = strlen(dev->pnp_string); buf[0] = (value >> 8) & 0xFF; buf[1] = value & 0xFF; memcpy(buf + 2, dev->pnp_string, value); DBG(dev, "1284 PNP String: %x %s\n", value, dev->pnp_string); break; case GET_PORT_STATUS: /* Get Port Status */ /* Only one printer interface is supported. */ if (wIndex != dev->interface) break; buf[0] = dev->printer_status; value = min_t(u16, wLength, 1); break; case SOFT_RESET: /* Soft Reset */ /* Only one printer interface is supported. */ if (wIndex != dev->interface) break; printer_soft_reset(dev); value = 0; break; default: goto unknown; } break; default: unknown: VDBG(dev, "unknown ctrl req%02x.%02x v%04x i%04x l%d\n", ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength); break; } /* host either stalls (value < 0) or reports success */ if (value >= 0) { req->length = value; req->zero = value < wLength; value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); if (value < 0) { ERROR(dev, "%s:%d Error!\n", __func__, __LINE__); req->status = 0; } } return value; } static int printer_func_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_gadget *gadget = c->cdev->gadget; struct printer_dev *dev = func_to_printer(f); struct device *pdev; struct usb_composite_dev *cdev = c->cdev; struct usb_ep *in_ep; struct usb_ep *out_ep = NULL; struct usb_request *req; dev_t devt; int id; int ret; u32 i; id = usb_interface_id(c, f); if (id < 0) return id; intf_desc.bInterfaceNumber = id; /* finish hookup to lower layer ... */ dev->gadget = gadget; /* all we really need is bulk IN/OUT */ in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc); if (!in_ep) { autoconf_fail: dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n", cdev->gadget->name); return -ENODEV; } out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc); if (!out_ep) goto autoconf_fail; /* assumes that all endpoints are dual-speed */ hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress; hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress; ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress; ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress; ret = usb_assign_descriptors(f, fs_printer_function, hs_printer_function, ss_printer_function, NULL); if (ret) return ret; dev->in_ep = in_ep; dev->out_ep = out_ep; ret = -ENOMEM; for (i = 0; i < dev->q_len; i++) { req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL); if (!req) goto fail_tx_reqs; list_add(&req->list, &dev->tx_reqs); } for (i = 0; i < dev->q_len; i++) { req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL); if (!req) goto fail_rx_reqs; list_add(&req->list, &dev->rx_reqs); } /* Setup the sysfs files for the printer gadget. */ devt = MKDEV(major, dev->minor); pdev = device_create(usb_gadget_class, NULL, devt, NULL, "g_printer%d", dev->minor); if (IS_ERR(pdev)) { ERROR(dev, "Failed to create device: g_printer\n"); ret = PTR_ERR(pdev); goto fail_rx_reqs; } /* * Register a character device as an interface to a user mode * program that handles the printer specific functionality. */ cdev_init(&dev->printer_cdev, &printer_io_operations); dev->printer_cdev.owner = THIS_MODULE; ret = cdev_add(&dev->printer_cdev, devt, 1); if (ret) { ERROR(dev, "Failed to open char device\n"); goto fail_cdev_add; } return 0; fail_cdev_add: device_destroy(usb_gadget_class, devt); fail_rx_reqs: while (!list_empty(&dev->rx_reqs)) { req = container_of(dev->rx_reqs.next, struct usb_request, list); list_del(&req->list); printer_req_free(dev->out_ep, req); } fail_tx_reqs: while (!list_empty(&dev->tx_reqs)) { req = container_of(dev->tx_reqs.next, struct usb_request, list); list_del(&req->list); printer_req_free(dev->in_ep, req); } return ret; } static int printer_func_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { struct printer_dev *dev = func_to_printer(f); int ret = -ENOTSUPP; if (!alt) ret = set_interface(dev, intf); return ret; } static void printer_func_disable(struct usb_function *f) { struct printer_dev *dev = func_to_printer(f); DBG(dev, "%s\n", __func__); printer_reset_interface(dev); } static inline struct f_printer_opts *to_f_printer_opts(struct config_item *item) { return container_of(to_config_group(item), struct f_printer_opts, func_inst.group); } static void printer_attr_release(struct config_item *item) { struct f_printer_opts *opts = to_f_printer_opts(item); usb_put_function_instance(&opts->func_inst); } static struct configfs_item_operations printer_item_ops = { .release = printer_attr_release, }; static ssize_t f_printer_opts_pnp_string_show(struct config_item *item, char *page) { struct f_printer_opts *opts = to_f_printer_opts(item); int result = 0; mutex_lock(&opts->lock); if (!opts->pnp_string) goto unlock; result = strlcpy(page, opts->pnp_string, PAGE_SIZE); if (result >= PAGE_SIZE) { result = PAGE_SIZE; } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) { page[result++] = '\n'; page[result] = '\0'; } unlock: mutex_unlock(&opts->lock); return result; } static ssize_t f_printer_opts_pnp_string_store(struct config_item *item, const char *page, size_t len) { struct f_printer_opts *opts = to_f_printer_opts(item); char *new_pnp; int result; mutex_lock(&opts->lock); new_pnp = kstrndup(page, len, GFP_KERNEL); if (!new_pnp) { result = -ENOMEM; goto unlock; } if (opts->pnp_string_allocated) kfree(opts->pnp_string); opts->pnp_string_allocated = true; opts->pnp_string = new_pnp; result = len; unlock: mutex_unlock(&opts->lock); return result; } CONFIGFS_ATTR(f_printer_opts_, pnp_string); static ssize_t f_printer_opts_q_len_show(struct config_item *item, char *page) { struct f_printer_opts *opts = to_f_printer_opts(item); int result; mutex_lock(&opts->lock); result = sprintf(page, "%d\n", opts->q_len); mutex_unlock(&opts->lock); return result; } static ssize_t f_printer_opts_q_len_store(struct config_item *item, const char *page, size_t len) { struct f_printer_opts *opts = to_f_printer_opts(item); int ret; u16 num; mutex_lock(&opts->lock); if (opts->refcnt) { ret = -EBUSY; goto end; } ret = kstrtou16(page, 0, &num); if (ret) goto end; opts->q_len = (unsigned)num; ret = len; end: mutex_unlock(&opts->lock); return ret; } CONFIGFS_ATTR(f_printer_opts_, q_len); static struct configfs_attribute *printer_attrs[] = { &f_printer_opts_attr_pnp_string, &f_printer_opts_attr_q_len, NULL, }; static const struct config_item_type printer_func_type = { .ct_item_ops = &printer_item_ops, .ct_attrs = printer_attrs, .ct_owner = THIS_MODULE, }; static inline int gprinter_get_minor(void) { int ret; ret = ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL); if (ret >= PRINTER_MINORS) { ida_simple_remove(&printer_ida, ret); ret = -ENODEV; } return ret; } static inline void gprinter_put_minor(int minor) { ida_simple_remove(&printer_ida, minor); } static int gprinter_setup(int); static void gprinter_cleanup(void); static void gprinter_free_inst(struct usb_function_instance *f) { struct f_printer_opts *opts; opts = container_of(f, struct f_printer_opts, func_inst); mutex_lock(&printer_ida_lock); gprinter_put_minor(opts->minor); if (ida_is_empty(&printer_ida)) gprinter_cleanup(); mutex_unlock(&printer_ida_lock); if (opts->pnp_string_allocated) kfree(opts->pnp_string); kfree(opts); } static struct usb_function_instance *gprinter_alloc_inst(void) { struct f_printer_opts *opts; struct usb_function_instance *ret; int status = 0; opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); mutex_init(&opts->lock); opts->func_inst.free_func_inst = gprinter_free_inst; ret = &opts->func_inst; mutex_lock(&printer_ida_lock); if (ida_is_empty(&printer_ida)) { status = gprinter_setup(PRINTER_MINORS); if (status) { ret = ERR_PTR(status); kfree(opts); goto unlock; } } opts->minor = gprinter_get_minor(); if (opts->minor < 0) { ret = ERR_PTR(opts->minor); kfree(opts); if (ida_is_empty(&printer_ida)) gprinter_cleanup(); goto unlock; } config_group_init_type_name(&opts->func_inst.group, "", &printer_func_type); unlock: mutex_unlock(&printer_ida_lock); return ret; } static void gprinter_free(struct usb_function *f) { struct printer_dev *dev = func_to_printer(f); struct f_printer_opts *opts; opts = container_of(f->fi, struct f_printer_opts, func_inst); kfree(dev); mutex_lock(&opts->lock); --opts->refcnt; mutex_unlock(&opts->lock); } static void printer_func_unbind(struct usb_configuration *c, struct usb_function *f) { struct printer_dev *dev; struct usb_request *req; dev = func_to_printer(f); device_destroy(usb_gadget_class, MKDEV(major, dev->minor)); /* Remove Character Device */ cdev_del(&dev->printer_cdev); /* we must already have been disconnected ... no i/o may be active */ WARN_ON(!list_empty(&dev->tx_reqs_active)); WARN_ON(!list_empty(&dev->rx_reqs_active)); /* Free all memory for this driver. */ while (!list_empty(&dev->tx_reqs)) { req = container_of(dev->tx_reqs.next, struct usb_request, list); list_del(&req->list); printer_req_free(dev->in_ep, req); } if (dev->current_rx_req != NULL) printer_req_free(dev->out_ep, dev->current_rx_req); while (!list_empty(&dev->rx_reqs)) { req = container_of(dev->rx_reqs.next, struct usb_request, list); list_del(&req->list); printer_req_free(dev->out_ep, req); } while (!list_empty(&dev->rx_buffers)) { req = container_of(dev->rx_buffers.next, struct usb_request, list); list_del(&req->list); printer_req_free(dev->out_ep, req); } usb_free_all_descriptors(f); } static struct usb_function *gprinter_alloc(struct usb_function_instance *fi) { struct printer_dev *dev; struct f_printer_opts *opts; opts = container_of(fi, struct f_printer_opts, func_inst); mutex_lock(&opts->lock); if (opts->minor >= minors) { mutex_unlock(&opts->lock); return ERR_PTR(-ENOENT); } dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) { mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); } ++opts->refcnt; dev->minor = opts->minor; dev->pnp_string = opts->pnp_string; dev->q_len = opts->q_len; mutex_unlock(&opts->lock); dev->function.name = "printer"; dev->function.bind = printer_func_bind; dev->function.setup = printer_func_setup; dev->function.unbind = printer_func_unbind; dev->function.set_alt = printer_func_set_alt; dev->function.disable = printer_func_disable; dev->function.req_match = gprinter_req_match; dev->function.free_func = gprinter_free; INIT_LIST_HEAD(&dev->tx_reqs); INIT_LIST_HEAD(&dev->rx_reqs); INIT_LIST_HEAD(&dev->rx_buffers); INIT_LIST_HEAD(&dev->tx_reqs_active); INIT_LIST_HEAD(&dev->rx_reqs_active); spin_lock_init(&dev->lock); mutex_init(&dev->lock_printer_io); init_waitqueue_head(&dev->rx_wait); init_waitqueue_head(&dev->tx_wait); init_waitqueue_head(&dev->tx_flush_wait); dev->interface = -1; dev->printer_cdev_open = 0; dev->printer_status = PRINTER_NOT_ERROR; dev->current_rx_req = NULL; dev->current_rx_bytes = 0; dev->current_rx_buf = NULL; return &dev->function; } DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Craig Nadler"); static int gprinter_setup(int count) { int status; dev_t devt; usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget"); if (IS_ERR(usb_gadget_class)) { status = PTR_ERR(usb_gadget_class); usb_gadget_class = NULL; pr_err("unable to create usb_gadget class %d\n", status); return status; } status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget"); if (status) { pr_err("alloc_chrdev_region %d\n", status); class_destroy(usb_gadget_class); usb_gadget_class = NULL; return status; } major = MAJOR(devt); minors = count; return status; } static void gprinter_cleanup(void) { if (major) { unregister_chrdev_region(MKDEV(major, 0), minors); major = minors = 0; } class_destroy(usb_gadget_class); usb_gadget_class = NULL; }