diff options
Diffstat (limited to 'drivers/staging/ccg/f_fs.c')
| -rw-r--r-- | drivers/staging/ccg/f_fs.c | 2455 |
1 files changed, 2455 insertions, 0 deletions
diff --git a/drivers/staging/ccg/f_fs.c b/drivers/staging/ccg/f_fs.c new file mode 100644 index 000000000000..8adc79d1b402 --- /dev/null +++ b/drivers/staging/ccg/f_fs.c @@ -0,0 +1,2455 @@ +/* + * f_fs.c -- user mode file system API for USB composite function controllers + * + * Copyright (C) 2010 Samsung Electronics + * Author: Michal Nazarewicz <mina86@mina86.com> + * + * Based on inode.c (GadgetFS) which was: + * Copyright (C) 2003-2004 David Brownell + * Copyright (C) 2003 Agilent Technologies + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + + +/* #define DEBUG */ +/* #define VERBOSE_DEBUG */ + +#include <linux/blkdev.h> +#include <linux/pagemap.h> +#include <linux/export.h> +#include <linux/hid.h> +#include <asm/unaligned.h> + +#include <linux/usb/composite.h> +#include <linux/usb/functionfs.h> + + +#define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ + + +/* Debugging ****************************************************************/ + +#ifdef VERBOSE_DEBUG +# define pr_vdebug pr_debug +# define ffs_dump_mem(prefix, ptr, len) \ + print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len) +#else +# define pr_vdebug(...) do { } while (0) +# define ffs_dump_mem(prefix, ptr, len) do { } while (0) +#endif /* VERBOSE_DEBUG */ + +#define ENTER() pr_vdebug("%s()\n", __func__) + + +/* The data structure and setup file ****************************************/ + +enum ffs_state { + /* + * Waiting for descriptors and strings. + * + * In this state no open(2), read(2) or write(2) on epfiles + * may succeed (which should not be the problem as there + * should be no such files opened in the first place). + */ + FFS_READ_DESCRIPTORS, + FFS_READ_STRINGS, + + /* + * We've got descriptors and strings. We are or have called + * functionfs_ready_callback(). functionfs_bind() may have + * been called but we don't know. + * + * This is the only state in which operations on epfiles may + * succeed. + */ + FFS_ACTIVE, + + /* + * All endpoints have been closed. This state is also set if + * we encounter an unrecoverable error. The only + * unrecoverable error is situation when after reading strings + * from user space we fail to initialise epfiles or + * functionfs_ready_callback() returns with error (<0). + * + * In this state no open(2), read(2) or write(2) (both on ep0 + * as well as epfile) may succeed (at this point epfiles are + * unlinked and all closed so this is not a problem; ep0 is + * also closed but ep0 file exists and so open(2) on ep0 must + * fail). + */ + FFS_CLOSING +}; + + +enum ffs_setup_state { + /* There is no setup request pending. */ + FFS_NO_SETUP, + /* + * User has read events and there was a setup request event + * there. The next read/write on ep0 will handle the + * request. + */ + FFS_SETUP_PENDING, + /* + * There was event pending but before user space handled it + * some other event was introduced which canceled existing + * setup. If this state is set read/write on ep0 return + * -EIDRM. This state is only set when adding event. + */ + FFS_SETUP_CANCELED +}; + + + +struct ffs_epfile; +struct ffs_function; + +struct ffs_data { + struct usb_gadget *gadget; + + /* + * Protect access read/write operations, only one read/write + * at a time. As a consequence protects ep0req and company. + * While setup request is being processed (queued) this is + * held. + */ + struct mutex mutex; + + /* + * Protect access to endpoint related structures (basically + * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for + * endpoint zero. + */ + spinlock_t eps_lock; + + /* + * XXX REVISIT do we need our own request? Since we are not + * handling setup requests immediately user space may be so + * slow that another setup will be sent to the gadget but this + * time not to us but another function and then there could be + * a race. Is that the case? Or maybe we can use cdev->req + * after all, maybe we just need some spinlock for that? + */ + struct usb_request *ep0req; /* P: mutex */ + struct completion ep0req_completion; /* P: mutex */ + int ep0req_status; /* P: mutex */ + + /* reference counter */ + atomic_t ref; + /* how many files are opened (EP0 and others) */ + atomic_t opened; + + /* EP0 state */ + enum ffs_state state; + + /* + * Possible transitions: + * + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock + * happens only in ep0 read which is P: mutex + * + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock + * happens only in ep0 i/o which is P: mutex + * + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock + * + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg + */ + enum ffs_setup_state setup_state; + +#define FFS_SETUP_STATE(ffs) \ + ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \ + FFS_SETUP_CANCELED, FFS_NO_SETUP)) + + /* Events & such. */ + struct { + u8 types[4]; + unsigned short count; + /* XXX REVISIT need to update it in some places, or do we? */ + unsigned short can_stall; + struct usb_ctrlrequest setup; + + wait_queue_head_t waitq; + } ev; /* the whole structure, P: ev.waitq.lock */ + + /* Flags */ + unsigned long flags; +#define FFS_FL_CALL_CLOSED_CALLBACK 0 +#define FFS_FL_BOUND 1 + + /* Active function */ + struct ffs_function *func; + + /* + * Device name, write once when file system is mounted. + * Intended for user to read if she wants. + */ + const char *dev_name; + /* Private data for our user (ie. gadget). Managed by user. */ + void *private_data; + + /* filled by __ffs_data_got_descs() */ + /* + * Real descriptors are 16 bytes after raw_descs (so you need + * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the + * first full speed descriptor). raw_descs_length and + * raw_fs_descs_length do not have those 16 bytes added. + */ + const void *raw_descs; + unsigned raw_descs_length; + unsigned raw_fs_descs_length; + unsigned fs_descs_count; + unsigned hs_descs_count; + + unsigned short strings_count; + unsigned short interfaces_count; + unsigned short eps_count; + unsigned short _pad1; + + /* filled by __ffs_data_got_strings() */ + /* ids in stringtabs are set in functionfs_bind() */ + const void *raw_strings; + struct usb_gadget_strings **stringtabs; + + /* + * File system's super block, write once when file system is + * mounted. + */ + struct super_block *sb; + + /* File permissions, written once when fs is mounted */ + struct ffs_file_perms { + umode_t mode; + uid_t uid; + gid_t gid; + } file_perms; + + /* + * The endpoint files, filled by ffs_epfiles_create(), + * destroyed by ffs_epfiles_destroy(). + */ + struct ffs_epfile *epfiles; +}; + +/* Reference counter handling */ +static void ffs_data_get(struct ffs_data *ffs); +static void ffs_data_put(struct ffs_data *ffs); +/* Creates new ffs_data object. */ +static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc)); + +/* Opened counter handling. */ +static void ffs_data_opened(struct ffs_data *ffs); +static void ffs_data_closed(struct ffs_data *ffs); + +/* Called with ffs->mutex held; take over ownership of data. */ +static int __must_check +__ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); +static int __must_check +__ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); + + +/* The function structure ***************************************************/ + +struct ffs_ep; + +struct ffs_function { + struct usb_configuration *conf; + struct usb_gadget *gadget; + struct ffs_data *ffs; + + struct ffs_ep *eps; + u8 eps_revmap[16]; + short *interfaces_nums; + + struct usb_function function; +}; + + +static struct ffs_function *ffs_func_from_usb(struct usb_function *f) +{ + return container_of(f, struct ffs_function, function); +} + +static void ffs_func_free(struct ffs_function *func); + +static void ffs_func_eps_disable(struct ffs_function *func); +static int __must_check ffs_func_eps_enable(struct ffs_function *func); + +static int ffs_func_bind(struct usb_configuration *, + struct usb_function *); +static void ffs_func_unbind(struct usb_configuration *, + struct usb_function *); +static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); +static void ffs_func_disable(struct usb_function *); +static int ffs_func_setup(struct usb_function *, + const struct usb_ctrlrequest *); +static void ffs_func_suspend(struct usb_function *); +static void ffs_func_resume(struct usb_function *); + + +static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); +static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); + + +/* The endpoints structures *************************************************/ + +struct ffs_ep { + struct usb_ep *ep; /* P: ffs->eps_lock */ + struct usb_request *req; /* P: epfile->mutex */ + + /* [0]: full speed, [1]: high speed */ + struct usb_endpoint_descriptor *descs[2]; + + u8 num; + + int status; /* P: epfile->mutex */ +}; + +struct ffs_epfile { + /* Protects ep->ep and ep->req. */ + struct mutex mutex; + wait_queue_head_t wait; + + struct ffs_data *ffs; + struct ffs_ep *ep; /* P: ffs->eps_lock */ + + struct dentry *dentry; + + char name[5]; + + unsigned char in; /* P: ffs->eps_lock */ + unsigned char isoc; /* P: ffs->eps_lock */ + + unsigned char _pad; +}; + +static int __must_check ffs_epfiles_create(struct ffs_data *ffs); +static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count); + +static struct inode *__must_check +ffs_sb_create_file(struct super_block *sb, const char *name, void *data, + const struct file_operations *fops, + struct dentry **dentry_p); + + +/* Misc helper functions ****************************************************/ + +static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) + __attribute__((warn_unused_result, nonnull)); +static char *ffs_prepare_buffer(const char * __user buf, size_t len) + __attribute__((warn_unused_result, nonnull)); + + +/* Control file aka ep0 *****************************************************/ + +static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct ffs_data *ffs = req->context; + + complete_all(&ffs->ep0req_completion); +} + +static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) +{ + struct usb_request *req = ffs->ep0req; + int ret; + + req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); + + spin_unlock_irq(&ffs->ev.waitq.lock); + + req->buf = data; + req->length = len; + + /* + * UDC layer requires to provide a buffer even for ZLP, but should + * not use it at all. Let's provide some poisoned pointer to catch + * possible bug in the driver. + */ + if (req->buf == NULL) + req->buf = (void *)0xDEADBABE; + + INIT_COMPLETION(ffs->ep0req_completion); + + ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); + if (unlikely(ret < 0)) + return ret; + + ret = wait_for_completion_interruptible(&ffs->ep0req_completion); + if (unlikely(ret)) { + usb_ep_dequeue(ffs->gadget->ep0, req); + return -EINTR; + } + + ffs->setup_state = FFS_NO_SETUP; + return ffs->ep0req_status; +} + +static int __ffs_ep0_stall(struct ffs_data *ffs) +{ + if (ffs->ev.can_stall) { + pr_vdebug("ep0 stall\n"); + usb_ep_set_halt(ffs->gadget->ep0); + ffs->setup_state = FFS_NO_SETUP; + return -EL2HLT; + } else { + pr_debug("bogus ep0 stall!\n"); + return -ESRCH; + } +} + +static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, + size_t len, loff_t *ptr) +{ + struct ffs_data *ffs = file->private_data; + ssize_t ret; + char *data; + + ENTER(); + + /* Fast check if setup was canceled */ + if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) + return -EIDRM; + + /* Acquire mutex */ + ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); + if (unlikely(ret < 0)) + return ret; + + /* Check state */ + switch (ffs->state) { + case FFS_READ_DESCRIPTORS: + case FFS_READ_STRINGS: + /* Copy data */ + if (unlikely(len < 16)) { + ret = -EINVAL; + break; + } + + data = ffs_prepare_buffer(buf, len); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + + /* Handle data */ + if (ffs->state == FFS_READ_DESCRIPTORS) { + pr_info("read descriptors\n"); + ret = __ffs_data_got_descs(ffs, data, len); + if (unlikely(ret < 0)) + break; + + ffs->state = FFS_READ_STRINGS; + ret = len; + } else { + pr_info("read strings\n"); + ret = __ffs_data_got_strings(ffs, data, len); + if (unlikely(ret < 0)) + break; + + ret = ffs_epfiles_create(ffs); + if (unlikely(ret)) { + ffs->state = FFS_CLOSING; + break; + } + + ffs->state = FFS_ACTIVE; + mutex_unlock(&ffs->mutex); + + ret = functionfs_ready_callback(ffs); + if (unlikely(ret < 0)) { + ffs->state = FFS_CLOSING; + return ret; + } + + set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); + return len; + } + break; + + case FFS_ACTIVE: + data = NULL; + /* + * We're called from user space, we can use _irq + * rather then _irqsave + */ + spin_lock_irq(&ffs->ev.waitq.lock); + switch (FFS_SETUP_STATE(ffs)) { + case FFS_SETUP_CANCELED: + ret = -EIDRM; + goto done_spin; + + case FFS_NO_SETUP: + ret = -ESRCH; + goto done_spin; + + case FFS_SETUP_PENDING: + break; + } + + /* FFS_SETUP_PENDING */ + if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { + spin_unlock_irq(&ffs->ev.waitq.lock); + ret = __ffs_ep0_stall(ffs); + break; + } + + /* FFS_SETUP_PENDING and not stall */ + len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); + + spin_unlock_irq(&ffs->ev.waitq.lock); + + data = ffs_prepare_buffer(buf, len); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + + spin_lock_irq(&ffs->ev.waitq.lock); + + /* + * We are guaranteed to be still in FFS_ACTIVE state + * but the state of setup could have changed from + * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need + * to check for that. If that happened we copied data + * from user space in vain but it's unlikely. + * + * For sure we are not in FFS_NO_SETUP since this is + * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP + * transition can be performed and it's protected by + * mutex. + */ + if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) { + ret = -EIDRM; +done_spin: + spin_unlock_irq(&ffs->ev.waitq.lock); + } else { + /* unlocks spinlock */ + ret = __ffs_ep0_queue_wait(ffs, data, len); + } + kfree(data); + break; + + default: + ret = -EBADFD; + break; + } + + mutex_unlock(&ffs->mutex); + return ret; +} + +static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, + size_t n) +{ + /* + * We are holding ffs->ev.waitq.lock and ffs->mutex and we need + * to release them. + */ + struct usb_functionfs_event events[n]; + unsigned i = 0; + + memset(events, 0, sizeof events); + + do { + events[i].type = ffs->ev.types[i]; + if (events[i].type == FUNCTIONFS_SETUP) { + events[i].u.setup = ffs->ev.setup; + ffs->setup_state = FFS_SETUP_PENDING; + } + } while (++i < n); + + if (n < ffs->ev.count) { + ffs->ev.count -= n; + memmove(ffs->ev.types, ffs->ev.types + n, + ffs->ev.count * sizeof *ffs->ev.types); + } else { + ffs->ev.count = 0; + } + + spin_unlock_irq(&ffs->ev.waitq.lock); + mutex_unlock(&ffs->mutex); + + return unlikely(__copy_to_user(buf, events, sizeof events)) + ? -EFAULT : sizeof events; +} + +static ssize_t ffs_ep0_read(struct file *file, char __user *buf, + size_t len, loff_t *ptr) +{ + struct ffs_data *ffs = file->private_data; + char *data = NULL; + size_t n; + int ret; + + ENTER(); + + /* Fast check if setup was canceled */ + if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) + return -EIDRM; + + /* Acquire mutex */ + ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); + if (unlikely(ret < 0)) + return ret; + + /* Check state */ + if (ffs->state != FFS_ACTIVE) { + ret = -EBADFD; + goto done_mutex; + } + + /* + * We're called from user space, we can use _irq rather then + * _irqsave + */ + spin_lock_irq(&ffs->ev.waitq.lock); + + switch (FFS_SETUP_STATE(ffs)) { + case FFS_SETUP_CANCELED: + ret = -EIDRM; + break; + + case FFS_NO_SETUP: + n = len / sizeof(struct usb_functionfs_event); + if (unlikely(!n)) { + ret = -EINVAL; + break; + } + + if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { + ret = -EAGAIN; + break; + } + + if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, + ffs->ev.count)) { + ret = -EINTR; + break; + } + + return __ffs_ep0_read_events(ffs, buf, + min(n, (size_t)ffs->ev.count)); + + case FFS_SETUP_PENDING: + if (ffs->ev.setup.bRequestType & USB_DIR_IN) { + spin_unlock_irq(&ffs->ev.waitq.lock); + ret = __ffs_ep0_stall(ffs); + goto done_mutex; + } + + len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); + + spin_unlock_irq(&ffs->ev.waitq.lock); + + if (likely(len)) { + data = kmalloc(len, GFP_KERNEL); + if (unlikely(!data)) { + ret = -ENOMEM; + goto done_mutex; + } + } + + spin_lock_irq(&ffs->ev.waitq.lock); + + /* See ffs_ep0_write() */ + if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) { + ret = -EIDRM; + break; + } + + /* unlocks spinlock */ + ret = __ffs_ep0_queue_wait(ffs, data, len); + if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len))) + ret = -EFAULT; + goto done_mutex; + + default: + ret = -EBADFD; + break; + } + + spin_unlock_irq(&ffs->ev.waitq.lock); +done_mutex: + mutex_unlock(&ffs->mutex); + kfree(data); + return ret; +} + +static int ffs_ep0_open(struct inode *inode, struct file *file) +{ + struct ffs_data *ffs = inode->i_private; + + ENTER(); + + if (unlikely(ffs->state == FFS_CLOSING)) + return -EBUSY; + + file->private_data = ffs; + ffs_data_opened(ffs); + + return 0; +} + +static int ffs_ep0_release(struct inode *inode, struct file *file) +{ + struct ffs_data *ffs = file->private_data; + + ENTER(); + + ffs_data_closed(ffs); + + return 0; +} + +static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) +{ + struct ffs_data *ffs = file->private_data; + struct usb_gadget *gadget = ffs->gadget; + long ret; + + ENTER(); + + if (code == FUNCTIONFS_INTERFACE_REVMAP) { + struct ffs_function *func = ffs->func; + ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; + } else if (gadget && gadget->ops->ioctl) { + ret = gadget->ops->ioctl(gadget, code, value); + } else { + ret = -ENOTTY; + } + + return ret; +} + +static const struct file_operations ffs_ep0_operations = { + .owner = THIS_MODULE, + .llseek = no_llseek, + + .open = ffs_ep0_open, + .write = ffs_ep0_write, + .read = ffs_ep0_read, + .release = ffs_ep0_release, + .unlocked_ioctl = ffs_ep0_ioctl, +}; + + +/* "Normal" endpoints operations ********************************************/ + +static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) +{ + ENTER(); + if (likely(req->context)) { + struct ffs_ep *ep = _ep->driver_data; + ep->status = req->status ? req->status : req->actual; + complete(req->context); + } +} + +static ssize_t ffs_epfile_io(struct file *file, + char __user *buf, size_t len, int read) +{ + struct ffs_epfile *epfile = file->private_data; + struct ffs_ep *ep; + char *data = NULL; + ssize_t ret; + int halt; + + goto first_try; + do { + spin_unlock_irq(&epfile->ffs->eps_lock); + mutex_unlock(&epfile->mutex); + +first_try: + /* Are we still active? */ + if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) { + ret = -ENODEV; + goto error; + } + + /* Wait for endpoint to be enabled */ + ep = epfile->ep; + if (!ep) { + if (file->f_flags & O_NONBLOCK) { + ret = -EAGAIN; + goto error; + } + + if (wait_event_interruptible(epfile->wait, + (ep = epfile->ep))) { + ret = -EINTR; + goto error; + } + } + + /* Do we halt? */ + halt = !read == !epfile->in; + if (halt && epfile->isoc) { + ret = -EINVAL; + goto error; + } + + /* Allocate & copy */ + if (!halt && !data) { + data = kzalloc(len, GFP_KERNEL); + if (unlikely(!data)) + return -ENOMEM; + + if (!read && + unlikely(__copy_from_user(data, buf, len))) { + ret = -EFAULT; + goto error; + } + } + + /* We will be using request */ + ret = ffs_mutex_lock(&epfile->mutex, + file->f_flags & O_NONBLOCK); + if (unlikely(ret)) + goto error; + + /* + * We're called from user space, we can use _irq rather then + * _irqsave + */ + spin_lock_irq(&epfile->ffs->eps_lock); + + /* + * While we were acquiring mutex endpoint got disabled + * or changed? + */ + } while (unlikely(epfile->ep != ep)); + + /* Halt */ + if (unlikely(halt)) { + if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep)) + usb_ep_set_halt(ep->ep); + spin_unlock_irq(&epfile->ffs->eps_lock); + ret = -EBADMSG; + } else { + /* Fire the request */ + DECLARE_COMPLETION_ONSTACK(done); + + struct usb_request *req = ep->req; + req->context = &done; + req->complete = ffs_epfile_io_complete; + req->buf = data; + req->length = len; + + ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); + + spin_unlock_irq(&epfile->ffs->eps_lock); + + if (unlikely(ret < 0)) { + /* nop */ + } else if (unlikely(wait_for_completion_interruptible(&done))) { + ret = -EINTR; + usb_ep_dequeue(ep->ep, req); + } else { + ret = ep->status; + if (read && ret > 0 && + unlikely(copy_to_user(buf, data, ret))) + ret = -EFAULT; + } + } + + mutex_unlock(&epfile->mutex); +error: + kfree(data); + return ret; +} + +static ssize_t +ffs_epfile_write(struct file *file, const char __user *buf, size_t len, + loff_t *ptr) +{ + ENTER(); + + return ffs_epfile_io(file, (char __user *)buf, len, 0); +} + +static ssize_t +ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr) +{ + ENTER(); + + return ffs_epfile_io(file, buf, len, 1); +} + +static int +ffs_epfile_open(struct inode *inode, struct file *file) +{ + struct ffs_epfile *epfile = inode->i_private; + + ENTER(); + + if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) + return -ENODEV; + + file->private_data = epfile; + ffs_data_opened(epfile->ffs); + + return 0; +} + +static int +ffs_epfile_release(struct inode *inode, struct file *file) +{ + struct ffs_epfile *epfile = inode->i_private; + + ENTER(); + + ffs_data_closed(epfile->ffs); + + return 0; +} + +static long ffs_epfile_ioctl(struct file *file, unsigned code, + unsigned long value) +{ + struct ffs_epfile *epfile = file->private_data; + int ret; + + ENTER(); + + if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) + return -ENODEV; + + spin_lock_irq(&epfile->ffs->eps_lock); + if (likely(epfile->ep)) { + switch (code) { + case FUNCTIONFS_FIFO_STATUS: + ret = usb_ep_fifo_status(epfile->ep->ep); + break; + case FUNCTIONFS_FIFO_FLUSH: + usb_ep_fifo_flush(epfile->ep->ep); + ret = 0; + break; + case FUNCTIONFS_CLEAR_HALT: + ret = usb_ep_clear_halt(epfile->ep->ep); + break; + case FUNCTIONFS_ENDPOINT_REVMAP: + ret = epfile->ep->num; + break; + default: + ret = -ENOTTY; + } + } else { + ret = -ENODEV; + } + spin_unlock_irq(&epfile->ffs->eps_lock); + + return ret; +} + +static const struct file_operations ffs_epfile_operations = { + .owner = THIS_MODULE, + .llseek = no_llseek, + + .open = ffs_epfile_open, + .write = ffs_epfile_write, + .read = ffs_epfile_read, + .release = ffs_epfile_release, + .unlocked_ioctl = ffs_epfile_ioctl, +}; + + +/* File system and super block operations ***********************************/ + +/* + * Mounting the file system creates a controller file, used first for + * function configuration then later for event monitoring. + */ + +static struct inode *__must_check +ffs_sb_make_inode(struct super_block *sb, void *data, + const struct file_operations *fops, + const struct inode_operations *iops, + struct ffs_file_perms *perms) +{ + struct inode *inode; + + ENTER(); + + inode = new_inode(sb); + + if (likely(inode)) { + struct timespec current_time = CURRENT_TIME; + + inode->i_ino = get_next_ino(); + inode->i_mode = perms->mode; + inode->i_uid = perms->uid; + inode->i_gid = perms->gid; + inode->i_atime = current_time; + inode->i_mtime = current_time; + inode->i_ctime = current_time; + inode->i_private = data; + if (fops) + inode->i_fop = fops; + if (iops) + inode->i_op = iops; + } + + return inode; +} + +/* Create "regular" file */ +static struct inode *ffs_sb_create_file(struct super_block *sb, + const char *name, void *data, + const struct file_operations *fops, + struct dentry **dentry_p) +{ + struct ffs_data *ffs = sb->s_fs_info; + struct dentry *dentry; + struct inode *inode; + + ENTER(); + + dentry = d_alloc_name(sb->s_root, name); + if (unlikely(!dentry)) + return NULL; + + inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); + if (unlikely(!inode)) { + dput(dentry); + return NULL; + } + + d_add(dentry, inode); + if (dentry_p) + *dentry_p = dentry; + + return inode; +} + +/* Super block */ +static const struct super_operations ffs_sb_operations = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +struct ffs_sb_fill_data { + struct ffs_file_perms perms; + umode_t root_mode; + const char *dev_name; + union { + /* set by ffs_fs_mount(), read by ffs_sb_fill() */ + void *private_data; + /* set by ffs_sb_fill(), read by ffs_fs_mount */ + struct ffs_data *ffs_data; + }; +}; + +static int ffs_sb_fill(struct super_block *sb, void *_data, int silent) +{ + struct ffs_sb_fill_data *data = _data; + struct inode *inode; + struct ffs_data *ffs; + + ENTER(); + + /* Initialise data */ + ffs = ffs_data_new(); + if (unlikely(!ffs)) + goto Enomem; + + ffs->sb = sb; + ffs->dev_name = kstrdup(data->dev_name, GFP_KERNEL); + if (unlikely(!ffs->dev_name)) + goto Enomem; + ffs->file_perms = data->perms; + ffs->private_data = data->private_data; + + /* used by the caller of this function */ + data->ffs_data = ffs; + + sb->s_fs_info = ffs; + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = FUNCTIONFS_MAGIC; + sb->s_op = &ffs_sb_operations; + sb->s_time_gran = 1; + + /* Root inode */ + data->perms.mode = data->root_mode; + inode = ffs_sb_make_inode(sb, NULL, + &simple_dir_operations, + &simple_dir_inode_operations, + &data->perms); + sb->s_root = d_make_root(inode); + if (unlikely(!sb->s_root)) + goto Enomem; + + /* EP0 file */ + if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs, + &ffs_ep0_operations, NULL))) + goto Enomem; + + return 0; + +Enomem: + return -ENOMEM; +} + +static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts) +{ + ENTER(); + + if (!opts || !*opts) + return 0; + + for (;;) { + char *end, *eq, *comma; + unsigned long value; + + /* Option limit */ + comma = strchr(opts, ','); + if (comma) + *comma = 0; + + /* Value limit */ + eq = strchr(opts, '='); + if (unlikely(!eq)) { + pr_err("'=' missing in %s\n", opts); + return -EINVAL; + } + *eq = 0; + + /* Parse value */ + value = simple_strtoul(eq + 1, &end, 0); + if (unlikely(*end != ',' && *end != 0)) { + pr_err("%s: invalid value: %s\n", opts, eq + 1); + return -EINVAL; + } + + /* Interpret option */ + switch (eq - opts) { + case 5: + if (!memcmp(opts, "rmode", 5)) + data->root_mode = (value & 0555) | S_IFDIR; + else if (!memcmp(opts, "fmode", 5)) + data->perms.mode = (value & 0666) | S_IFREG; + else + goto invalid; + break; + + case 4: + if (!memcmp(opts, "mode", 4)) { + data->root_mode = (value & 0555) | S_IFDIR; + data->perms.mode = (value & 0666) | S_IFREG; + } else { + goto invalid; + } + break; + + case 3: + if (!memcmp(opts, "uid", 3)) + data->perms.uid = value; + else if (!memcmp(opts, "gid", 3)) + data->perms.gid = value; + else + goto invalid; + break; + + default: +invalid: + pr_err("%s: invalid option\n", opts); + return -EINVAL; + } + + /* Next iteration */ + if (!comma) + break; + opts = comma + 1; + } + + return 0; +} + +/* "mount -t functionfs dev_name /dev/function" ends up here */ + +static struct dentry * +ffs_fs_mount(struct file_system_type *t, int flags, + const char *dev_name, void *opts) +{ + struct ffs_sb_fill_data data = { + .perms = { + .mode = S_IFREG | 0600, + .uid = 0, + .gid = 0 + }, + .root_mode = S_IFDIR | 0500, + }; + struct dentry *rv; + int ret; + void *ffs_dev; + + ENTER(); + + ret = ffs_fs_parse_opts(&data, opts); + if (unlikely(ret < 0)) + return ERR_PTR(ret); + + ffs_dev = functionfs_acquire_dev_callback(dev_name); + if (IS_ERR(ffs_dev)) + return ffs_dev; + + data.dev_name = dev_name; + data.private_data = ffs_dev; + rv = mount_nodev(t, flags, &data, ffs_sb_fill); + + /* data.ffs_data is set by ffs_sb_fill */ + if (IS_ERR(rv)) + functionfs_release_dev_callback(data.ffs_data); + + return rv; +} + +static void +ffs_fs_kill_sb(struct super_block *sb) +{ + ENTER(); + + kill_litter_super(sb); + if (sb->s_fs_info) { + functionfs_release_dev_callback(sb->s_fs_info); + ffs_data_put(sb->s_fs_info); + } +} + +static struct file_system_type ffs_fs_type = { + .owner = THIS_MODULE, + .name = "functionfs", + .mount = ffs_fs_mount, + .kill_sb = ffs_fs_kill_sb, +}; + + +/* Driver's main init/cleanup functions *************************************/ + +static int functionfs_init(void) +{ + int ret; + + ENTER(); + + ret = register_filesystem(&ffs_fs_type); + if (likely(!ret)) + pr_info("file system registered\n"); + else + pr_err("failed registering file system (%d)\n", ret); + + return ret; +} + +static void functionfs_cleanup(void) +{ + ENTER(); + + pr_info("unloading\n"); + unregister_filesystem(&ffs_fs_type); +} + + +/* ffs_data and ffs_function construction and destruction code **************/ + +static void ffs_data_clear(struct ffs_data *ffs); +static void ffs_data_reset(struct ffs_data *ffs); + +static void ffs_data_get(struct ffs_data *ffs) +{ + ENTER(); + + atomic_inc(&ffs->ref); +} + +static void ffs_data_opened(struct ffs_data *ffs) +{ + ENTER(); + + atomic_inc(&ffs->ref); + atomic_inc(&ffs->opened); +} + +static void ffs_data_put(struct ffs_data *ffs) +{ + ENTER(); + + if (unlikely(atomic_dec_and_test(&ffs->ref))) { + pr_info("%s(): freeing\n", __func__); + ffs_data_clear(ffs); + BUG_ON(waitqueue_active(&ffs->ev.waitq) || + waitqueue_active(&ffs->ep0req_completion.wait)); + kfree(ffs->dev_name); + kfree(ffs); + } +} + +static void ffs_data_closed(struct ffs_data *ffs) +{ + ENTER(); + + if (atomic_dec_and_test(&ffs->opened)) { + ffs->state = FFS_CLOSING; + ffs_data_reset(ffs); + } + + ffs_data_put(ffs); +} + +static struct ffs_data *ffs_data_new(void) +{ + struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); + if (unlikely(!ffs)) + return 0; + + ENTER(); + + atomic_set(&ffs->ref, 1); + atomic_set(&ffs->opened, 0); + ffs->state = FFS_READ_DESCRIPTORS; + mutex_init(&ffs->mutex); + spin_lock_init(&ffs->eps_lock); + init_waitqueue_head(&ffs->ev.waitq); + init_completion(&ffs->ep0req_completion); + + /* XXX REVISIT need to update it in some places, or do we? */ + ffs->ev.can_stall = 1; + + return ffs; +} + +static void ffs_data_clear(struct ffs_data *ffs) +{ + ENTER(); + + if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags)) + functionfs_closed_callback(ffs); + + BUG_ON(ffs->gadget); + + if (ffs->epfiles) + ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count); + + kfree(ffs->raw_descs); + kfree(ffs->raw_strings); + kfree(ffs->stringtabs); +} + +static void ffs_data_reset(struct ffs_data *ffs) +{ + ENTER(); + + ffs_data_clear(ffs); + + ffs->epfiles = NULL; + ffs->raw_descs = NULL; + ffs->raw_strings = NULL; + ffs->stringtabs = NULL; + + ffs->raw_descs_length = 0; + ffs->raw_fs_descs_length = 0; + ffs->fs_descs_count = 0; + ffs->hs_descs_count = 0; + + ffs->strings_count = 0; + ffs->interfaces_count = 0; + ffs->eps_count = 0; + + ffs->ev.count = 0; + + ffs->state = FFS_READ_DESCRIPTORS; + ffs->setup_state = FFS_NO_SETUP; + ffs->flags = 0; +} + + +static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) +{ + struct usb_gadget_strings **lang; + int first_id; + + ENTER(); + + if (WARN_ON(ffs->state != FFS_ACTIVE + || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) + return -EBADFD; + + first_id = usb_string_ids_n(cdev, ffs->strings_count); + if (unlikely(first_id < 0)) + return first_id; + + ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); + if (unlikely(!ffs->ep0req)) + return -ENOMEM; + ffs->ep0req->complete = ffs_ep0_complete; + ffs->ep0req->context = ffs; + + lang = ffs->stringtabs; + for (lang = ffs->stringtabs; *lang; ++lang) { + struct usb_string *str = (*lang)->strings; + int id = first_id; + for (; str->s; ++id, ++str) + str->id = id; + } + + ffs->gadget = cdev->gadget; + ffs_data_get(ffs); + return 0; +} + +static void functionfs_unbind(struct ffs_data *ffs) +{ + ENTER(); + + if (!WARN_ON(!ffs->gadget)) { + usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); + ffs->ep0req = NULL; + ffs->gadget = NULL; + ffs_data_put(ffs); + clear_bit(FFS_FL_BOUND, &ffs->flags); + } +} + +static int ffs_epfiles_create(struct ffs_data *ffs) +{ + struct ffs_epfile *epfile, *epfiles; + unsigned i, count; + + ENTER(); + + count = ffs->eps_count; + epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); + if (!epfiles) + return -ENOMEM; + + epfile = epfiles; + for (i = 1; i <= count; ++i, ++epfile) { + epfile->ffs = ffs; + mutex_init(&epfile->mutex); + init_waitqueue_head(&epfile->wait); + sprintf(epfiles->name, "ep%u", i); + if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile, + &ffs_epfile_operations, + &epfile->dentry))) { + ffs_epfiles_destroy(epfiles, i - 1); + return -ENOMEM; + } + } + + ffs->epfiles = epfiles; + return 0; +} + +static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) +{ + struct ffs_epfile *epfile = epfiles; + + ENTER(); + + for (; count; --count, ++epfile) { + BUG_ON(mutex_is_locked(&epfile->mutex) || + waitqueue_active(&epfile->wait)); + if (epfile->dentry) { + d_delete(epfile->dentry); + dput(epfile->dentry); + epfile->dentry = NULL; + } + } + + kfree(epfiles); +} + +static int functionfs_bind_config(struct usb_composite_dev *cdev, + struct usb_configuration *c, + struct ffs_data *ffs) +{ + struct ffs_function *func; + int ret; + + ENTER(); + + func = kzalloc(sizeof *func, GFP_KERNEL); + if (unlikely(!func)) + return -ENOMEM; + + func->function.name = "Function FS Gadget"; + func->function.strings = ffs->stringtabs; + + func->function.bind = ffs_func_bind; + func->function.unbind = ffs_func_unbind; + func->function.set_alt = ffs_func_set_alt; + func->function.disable = ffs_func_disable; + func->function.setup = ffs_func_setup; + func->function.suspend = ffs_func_suspend; + func->function.resume = ffs_func_resume; + + func->conf = c; + func->gadget = cdev->gadget; + func->ffs = ffs; + ffs_data_get(ffs); + + ret = usb_add_function(c, &func->function); + if (unlikely(ret)) + ffs_func_free(func); + + return ret; +} + +static void ffs_func_free(struct ffs_function *func) +{ + struct ffs_ep *ep = func->eps; + unsigned count = func->ffs->eps_count; + unsigned long flags; + + ENTER(); + + /* cleanup after autoconfig */ + spin_lock_irqsave(&func->ffs->eps_lock, flags); + do { + if (ep->ep && ep->req) + usb_ep_free_request(ep->ep, ep->req); + ep->req = NULL; + ++ep; + } while (--count); + spin_unlock_irqrestore(&func->ffs->eps_lock, flags); + + ffs_data_put(func->ffs); + + kfree(func->eps); + /* + * eps and interfaces_nums are allocated in the same chunk so + * only one free is required. Descriptors are also allocated + * in the same chunk. + */ + + kfree(func); +} + +static void ffs_func_eps_disable(struct ffs_function *func) +{ + struct ffs_ep *ep = func->eps; + struct ffs_epfile *epfile = func->ffs->epfiles; + unsigned count = func->ffs->eps_count; + unsigned long flags; + + spin_lock_irqsave(&func->ffs->eps_lock, flags); + do { + /* pending requests get nuked */ + if (likely(ep->ep)) + usb_ep_disable(ep->ep); + epfile->ep = NULL; + + ++ep; + ++epfile; + } while (--count); + spin_unlock_irqrestore(&func->ffs->eps_lock, flags); +} + +static int ffs_func_eps_enable(struct ffs_function *func) +{ + struct ffs_data *ffs = func->ffs; + struct ffs_ep *ep = func->eps; + struct ffs_epfile *epfile = ffs->epfiles; + unsigned count = ffs->eps_count; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&func->ffs->eps_lock, flags); + do { + struct usb_endpoint_descriptor *ds; + ds = ep->descs[ep->descs[1] ? 1 : 0]; + + ep->ep->driver_data = ep; + ep->ep->desc = ds; + ret = usb_ep_enable(ep->ep); + if (likely(!ret)) { + epfile->ep = ep; + epfile->in = usb_endpoint_dir_in(ds); + epfile->isoc = usb_endpoint_xfer_isoc(ds); + } else { + break; + } + + wake_up(&epfile->wait); + + ++ep; + ++epfile; + } while (--count); + spin_unlock_irqrestore(&func->ffs->eps_lock, flags); + + return ret; +} + + +/* Parsing and building descriptors and strings *****************************/ + +/* + * This validates if data pointed by data is a valid USB descriptor as + * well as record how many interfaces, endpoints and strings are + * required by given configuration. Returns address after the + * descriptor or NULL if data is invalid. + */ + +enum ffs_entity_type { + FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT +}; + +typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, + u8 *valuep, + struct usb_descriptor_header *desc, + void *priv); + +static int __must_check ffs_do_desc(char *data, unsigned len, + ffs_entity_callback entity, void *priv) +{ + struct usb_descriptor_header *_ds = (void *)data; + u8 length; + int ret; + + ENTER(); + + /* At least two bytes are required: length and type */ + if (len < 2) { + pr_vdebug("descriptor too short\n"); + return -EINVAL; + } + + /* If we have at least as many bytes as the descriptor takes? */ + length = _ds->bLength; + if (len < length) { + pr_vdebug("descriptor longer then available data\n"); + return -EINVAL; + } + +#define __entity_check_INTERFACE(val) 1 +#define __entity_check_STRING(val) (val) +#define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) +#define __entity(type, val) do { \ + pr_vdebug("entity " #type "(%02x)\n", (val)); \ + if (unlikely(!__entity_check_ ##type(val))) { \ + pr_vdebug("invalid entity's value\n"); \ + return -EINVAL; \ + } \ + ret = entity(FFS_ ##type, &val, _ds, priv); \ + if (unlikely(ret < 0)) { \ + pr_debug("entity " #type "(%02x); ret = %d\n", \ + (val), ret); \ + return ret; \ + } \ + } while (0) + + /* Parse descriptor depending on type. */ + switch (_ds->bDescriptorType) { + case USB_DT_DEVICE: + case USB_DT_CONFIG: + case USB_DT_STRING: + case USB_DT_DEVICE_QUALIFIER: + /* function can't have any of those */ + pr_vdebug("descriptor reserved for gadget: %d\n", + _ds->bDescriptorType); + return -EINVAL; + + case USB_DT_INTERFACE: { + struct usb_interface_descriptor *ds = (void *)_ds; + pr_vdebug("interface descriptor\n"); + if (length != sizeof *ds) + goto inv_length; + + __entity(INTERFACE, ds->bInterfaceNumber); + if (ds->iInterface) + __entity(STRING, ds->iInterface); + } + break; + + case USB_DT_ENDPOINT: { + struct usb_endpoint_descriptor *ds = (void *)_ds; + pr_vdebug("endpoint descriptor\n"); + if (length != USB_DT_ENDPOINT_SIZE && + length != USB_DT_ENDPOINT_AUDIO_SIZE) + goto inv_length; + __entity(ENDPOINT, ds->bEndpointAddress); + } + break; + + case HID_DT_HID: + pr_vdebug("hid descriptor\n"); + if (length != sizeof(struct hid_descriptor)) + goto inv_length; + break; + + case USB_DT_OTG: + if (length != sizeof(struct usb_otg_descriptor)) + goto inv_length; + break; + + case USB_DT_INTERFACE_ASSOCIATION: { + struct usb_interface_assoc_descriptor *ds = (void *)_ds; + pr_vdebug("interface association descriptor\n"); + if (length != sizeof *ds) + goto inv_length; + if (ds->iFunction) + __entity(STRING, ds->iFunction); + } + break; + + case USB_DT_OTHER_SPEED_CONFIG: + case USB_DT_INTERFACE_POWER: + case USB_DT_DEBUG: + case USB_DT_SECURITY: + case USB_DT_CS_RADIO_CONTROL: + /* TODO */ + pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); + return -EINVAL; + + default: + /* We should never be here */ + pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); + return -EINVAL; + +inv_length: + pr_vdebug("invalid length: %d (descriptor %d)\n", + _ds->bLength, _ds->bDescriptorType); + return -EINVAL; + } + +#undef __entity +#undef __entity_check_DESCRIPTOR +#undef __entity_check_INTERFACE +#undef __entity_check_STRING +#undef __entity_check_ENDPOINT + + return length; +} + +static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, + ffs_entity_callback entity, void *priv) +{ + const unsigned _len = len; + unsigned long num = 0; + + ENTER(); + + for (;;) { + int ret; + + if (num == count) + data = NULL; + + /* Record "descriptor" entity */ + ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); + if (unlikely(ret < 0)) { + pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", + num, ret); + return ret; + } + + if (!data) + return _len - len; + + ret = ffs_do_desc(data, len, entity, priv); + if (unlikely(ret < 0)) { + pr_debug("%s returns %d\n", __func__, ret); + return ret; + } + + len -= ret; + data += ret; + ++num; + } +} + +static int __ffs_data_do_entity(enum ffs_entity_type type, + u8 *valuep, struct usb_descriptor_header *desc, + void *priv) +{ + struct ffs_data *ffs = priv; + + ENTER(); + + switch (type) { + case FFS_DESCRIPTOR: + break; + + case FFS_INTERFACE: + /* + * Interfaces are indexed from zero so if we + * encountered interface "n" then there are at least + * "n+1" interfaces. + */ + if (*valuep >= ffs->interfaces_count) + ffs->interfaces_count = *valuep + 1; + break; + + case FFS_STRING: + /* + * Strings are indexed from 1 (0 is magic ;) reserved + * for languages list or some such) + */ + if (*valuep > ffs->strings_count) + ffs->strings_count = *valuep; + break; + + case FFS_ENDPOINT: + /* Endpoints are indexed from 1 as well. */ + if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count) + ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK); + break; + } + + return 0; +} + +static int __ffs_data_got_descs(struct ffs_data *ffs, + char *const _data, size_t len) +{ + unsigned fs_count, hs_count; + int fs_len, ret = -EINVAL; + char *data = _data; + + ENTER(); + + if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC || + get_unaligned_le32(data + 4) != len)) + goto error; + fs_count = get_unaligned_le32(data + 8); + hs_count = get_unaligned_le32(data + 12); + + if (!fs_count && !hs_count) + goto einval; + + data += 16; + len -= 16; + + if (likely(fs_count)) { + fs_len = ffs_do_descs(fs_count, data, len, + __ffs_data_do_entity, ffs); + if (unlikely(fs_len < 0)) { + ret = fs_len; + goto error; + } + + data += fs_len; + len -= fs_len; + } else { + fs_len = 0; + } + + if (likely(hs_count)) { + ret = ffs_do_descs(hs_count, data, len, + __ffs_data_do_entity, ffs); + if (unlikely(ret < 0)) + goto error; + } else { + ret = 0; + } + + if (unlikely(len != ret)) + goto einval; + + ffs->raw_fs_descs_length = fs_len; + ffs->raw_descs_length = fs_len + ret; + ffs->raw_descs = _data; + ffs->fs_descs_count = fs_count; + ffs->hs_descs_count = hs_count; + + return 0; + +einval: + ret = -EINVAL; +error: + kfree(_data); + return ret; +} + +static int __ffs_data_got_strings(struct ffs_data *ffs, + char *const _data, size_t len) +{ + u32 str_count, needed_count, lang_count; + struct usb_gadget_strings **stringtabs, *t; + struct usb_string *strings, *s; + const char *data = _data; + + ENTER(); + + if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || + get_unaligned_le32(data + 4) != len)) + goto error; + str_count = get_unaligned_le32(data + 8); + lang_count = get_unaligned_le32(data + 12); + + /* if one is zero the other must be zero */ + if (unlikely(!str_count != !lang_count)) + goto error; + + /* Do we have at least as many strings as descriptors need? */ + needed_count = ffs->strings_count; + if (unlikely(str_count < needed_count)) + goto error; + + /* + * If we don't need any strings just return and free all + * memory. + */ + if (!needed_count) { + kfree(_data); + return 0; + } + + /* Allocate everything in one chunk so there's less maintenance. */ + { + struct { + struct usb_gadget_strings *stringtabs[lang_count + 1]; + struct usb_gadget_strings stringtab[lang_count]; + struct usb_string strings[lang_count*(needed_count+1)]; + } *d; + unsigned i = 0; + + d = kmalloc(sizeof *d, GFP_KERNEL); + if (unlikely(!d)) { + kfree(_data); + return -ENOMEM; + } + + stringtabs = d->stringtabs; + t = d->stringtab; + i = lang_count; + do { + *stringtabs++ = t++; + } while (--i); + *stringtabs = NULL; + + stringtabs = d->stringtabs; + t = d->stringtab; + s = d->strings; + strings = s; + } + + /* For each language */ + data += 16; + len -= 16; + + do { /* lang_count > 0 so we can use do-while */ + unsigned needed = needed_count; + + if (unlikely(len < 3)) + goto error_free; + t->language = get_unaligned_le16(data); + t->strings = s; + ++t; + + data += 2; + len -= 2; + + /* For each string */ + do { /* str_count > 0 so we can use do-while */ + size_t length = strnlen(data, len); + + if (unlikely(length == len)) + goto error_free; + + /* + * User may provide more strings then we need, + * if that's the case we simply ignore the + * rest + */ + if (likely(needed)) { + /* + * s->id will be set while adding + * function to configuration so for + * now just leave garbage here. + */ + s->s = data; + --needed; + ++s; + } + + data += length + 1; + len -= length + 1; + } while (--str_count); + + s->id = 0; /* terminator */ + s->s = NULL; + ++s; + + } while (--lang_count); + + /* Some garbage left? */ + if (unlikely(len)) + goto error_free; + + /* Done! */ + ffs->stringtabs = stringtabs; + ffs->raw_strings = _data; + + return 0; + +error_free: + kfree(stringtabs); +error: + kfree(_data); + return -EINVAL; +} + + +/* Events handling and management *******************************************/ + +static void __ffs_event_add(struct ffs_data *ffs, + enum usb_functionfs_event_type type) +{ + enum usb_functionfs_event_type rem_type1, rem_type2 = type; + int neg = 0; + + /* + * Abort any unhandled setup + * + * We do not need to worry about some cmpxchg() changing value + * of ffs->setup_state without holding the lock because when + * state is FFS_SETUP_PENDING cmpxchg() in several places in + * the source does nothing. + */ + if (ffs->setup_state == FFS_SETUP_PENDING) + ffs->setup_state = FFS_SETUP_CANCELED; + + switch (type) { + case FUNCTIONFS_RESUME: + rem_type2 = FUNCTIONFS_SUSPEND; + /* FALL THROUGH */ + case FUNCTIONFS_SUSPEND: + case FUNCTIONFS_SETUP: + rem_type1 = type; + /* Discard all similar events */ + break; + + case FUNCTIONFS_BIND: + case FUNCTIONFS_UNBIND: + case FUNCTIONFS_DISABLE: + case FUNCTIONFS_ENABLE: + /* Discard everything other then power management. */ + rem_type1 = FUNCTIONFS_SUSPEND; + rem_type2 = FUNCTIONFS_RESUME; + neg = 1; + break; + + default: + BUG(); + } + + { + u8 *ev = ffs->ev.types, *out = ev; + unsigned n = ffs->ev.count; + for (; n; --n, ++ev) + if ((*ev == rem_type1 || *ev == rem_type2) == neg) + *out++ = *ev; + else + pr_vdebug("purging event %d\n", *ev); + ffs->ev.count = out - ffs->ev.types; + } + + pr_vdebug("adding event %d\n", type); + ffs->ev.types[ffs->ev.count++] = type; + wake_up_locked(&ffs->ev.waitq); +} + +static void ffs_event_add(struct ffs_data *ffs, + enum usb_functionfs_event_type type) +{ + unsigned long flags; + spin_lock_irqsave(&ffs->ev.waitq.lock, flags); + __ffs_event_add(ffs, type); + spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); +} + + +/* Bind/unbind USB function hooks *******************************************/ + +static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, + struct usb_descriptor_header *desc, + void *priv) +{ + struct usb_endpoint_descriptor *ds = (void *)desc; + struct ffs_function *func = priv; + struct ffs_ep *ffs_ep; + + /* + * If hs_descriptors is not NULL then we are reading hs + * descriptors now + */ + const int isHS = func->function.hs_descriptors != NULL; + unsigned idx; + + if (type != FFS_DESCRIPTOR) + return 0; + + if (isHS) + func->function.hs_descriptors[(long)valuep] = desc; + else + func->function.descriptors[(long)valuep] = desc; + + if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) + return 0; + + idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1; + ffs_ep = func->eps + idx; + + if (unlikely(ffs_ep->descs[isHS])) { + pr_vdebug("two %sspeed descriptors for EP %d\n", + isHS ? "high" : "full", + ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); + return -EINVAL; + } + ffs_ep->descs[isHS] = ds; + + ffs_dump_mem(": Original ep desc", ds, ds->bLength); + if (ffs_ep->ep) { + ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; + if (!ds->wMaxPacketSize) + ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; + } else { + struct usb_request *req; + struct usb_ep *ep; + + pr_vdebug("autoconfig\n"); + ep = usb_ep_autoconfig(func->gadget, ds); + if (unlikely(!ep)) + return -ENOTSUPP; + ep->driver_data = func->eps + idx; + + req = usb_ep_alloc_request(ep, GFP_KERNEL); + if (unlikely(!req)) + return -ENOMEM; + + ffs_ep->ep = ep; + ffs_ep->req = req; + func->eps_revmap[ds->bEndpointAddress & + USB_ENDPOINT_NUMBER_MASK] = idx + 1; + } + ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); + + return 0; +} + +static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, + struct usb_descriptor_header *desc, + void *priv) +{ + struct ffs_function *func = priv; + unsigned idx; + u8 newValue; + + switch (type) { + default: + case FFS_DESCRIPTOR: + /* Handled in previous pass by __ffs_func_bind_do_descs() */ + return 0; + + case FFS_INTERFACE: + idx = *valuep; + if (func->interfaces_nums[idx] < 0) { + int id = usb_interface_id(func->conf, &func->function); + if (unlikely(id < 0)) + return id; + func->interfaces_nums[idx] = id; + } + newValue = func->interfaces_nums[idx]; + break; + + case FFS_STRING: + /* String' IDs are allocated when fsf_data is bound to cdev */ + newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; + break; + + case FFS_ENDPOINT: + /* + * USB_DT_ENDPOINT are handled in + * __ffs_func_bind_do_descs(). + */ + if (desc->bDescriptorType == USB_DT_ENDPOINT) + return 0; + + idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; + if (unlikely(!func->eps[idx].ep)) + return -EINVAL; + + { + struct usb_endpoint_descriptor **descs; + descs = func->eps[idx].descs; + newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; + } + break; + } + + pr_vdebug("%02x -> %02x\n", *valuep, newValue); + *valuep = newValue; + return 0; +} + +static int ffs_func_bind(struct usb_configuration *c, + struct usb_function *f) +{ + struct ffs_function *func = ffs_func_from_usb(f); + struct ffs_data *ffs = func->ffs; + + const int full = !!func->ffs->fs_descs_count; + const int high = gadget_is_dualspeed(func->gadget) && + func->ffs->hs_descs_count; + + int ret; + + /* Make it a single chunk, less management later on */ + struct { + struct ffs_ep eps[ffs->eps_count]; + struct usb_descriptor_header + *fs_descs[full ? ffs->fs_descs_count + 1 : 0]; + struct usb_descriptor_header + *hs_descs[high ? ffs->hs_descs_count + 1 : 0]; + short inums[ffs->interfaces_count]; + char raw_descs[high ? ffs->raw_descs_length + : ffs->raw_fs_descs_length]; + } *data; + + ENTER(); + + /* Only high speed but not supported by gadget? */ + if (unlikely(!(full | high))) + return -ENOTSUPP; + + /* Allocate */ + data = kmalloc(sizeof *data, GFP_KERNEL); + if (unlikely(!data)) + return -ENOMEM; + + /* Zero */ + memset(data->eps, 0, sizeof data->eps); + memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs); + memset(data->inums, 0xff, sizeof data->inums); + for (ret = ffs->eps_count; ret; --ret) + data->eps[ret].num = -1; + + /* Save pointers */ + func->eps = data->eps; + func->interfaces_nums = data->inums; + + /* + * Go through all the endpoint descriptors and allocate + * endpoints first, so that later we can rewrite the endpoint + * numbers without worrying that it may be described later on. + */ + if (likely(full)) { + func->function.descriptors = data->fs_descs; + ret = ffs_do_descs(ffs->fs_descs_count, + data->raw_descs, + sizeof data->raw_descs, + __ffs_func_bind_do_descs, func); + if (unlikely(ret < 0)) + goto error; + } else { + ret = 0; + } + + if (likely(high)) { + func->function.hs_descriptors = data->hs_descs; + ret = ffs_do_descs(ffs->hs_descs_count, + data->raw_descs + ret, + (sizeof data->raw_descs) - ret, + __ffs_func_bind_do_descs, func); + } + + /* + * Now handle interface numbers allocation and interface and + * endpoint numbers rewriting. We can do that in one go + * now. + */ + ret = ffs_do_descs(ffs->fs_descs_count + + (high ? ffs->hs_descs_count : 0), + data->raw_descs, sizeof data->raw_descs, + __ffs_func_bind_do_nums, func); + if (unlikely(ret < 0)) + goto error; + + /* And we're done */ + ffs_event_add(ffs, FUNCTIONFS_BIND); + return 0; + +error: + /* XXX Do we need to release all claimed endpoints here? */ + return ret; +} + + +/* Other USB function hooks *************************************************/ + +static void ffs_func_unbind(struct usb_configuration *c, + struct usb_function *f) +{ + struct ffs_function *func = ffs_func_from_usb(f); + struct ffs_data *ffs = func->ffs; + + ENTER(); + + if (ffs->func == func) { + ffs_func_eps_disable(func); + ffs->func = NULL; + } + + ffs_event_add(ffs, FUNCTIONFS_UNBIND); + + ffs_func_free(func); +} + +static int ffs_func_set_alt(struct usb_function *f, + unsigned interface, unsigned alt) +{ + struct ffs_function *func = ffs_func_from_usb(f); + struct ffs_data *ffs = func->ffs; + int ret = 0, intf; + + if (alt != (unsigned)-1) { + intf = ffs_func_revmap_intf(func, interface); + if (unlikely(intf < 0)) + return intf; + } + + if (ffs->func) + ffs_func_eps_disable(ffs->func); + + if (ffs->state != FFS_ACTIVE) + return -ENODEV; + + if (alt == (unsigned)-1) { + ffs->func = NULL; + ffs_event_add(ffs, FUNCTIONFS_DISABLE); + return 0; + } + + ffs->func = func; + ret = ffs_func_eps_enable(func); + if (likely(ret >= 0)) + ffs_event_add(ffs, FUNCTIONFS_ENABLE); + return ret; +} + +static void ffs_func_disable(struct usb_function *f) +{ + ffs_func_set_alt(f, 0, (unsigned)-1); +} + +static int ffs_func_setup(struct usb_function *f, + const struct usb_ctrlrequest *creq) +{ + struct ffs_function *func = ffs_func_from_usb(f); + struct ffs_data *ffs = func->ffs; + unsigned long flags; + int ret; + + ENTER(); + + pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); + pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); + pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); + pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); + pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); + + /* + * Most requests directed to interface go through here + * (notable exceptions are set/get interface) so we need to + * handle them. All other either handled by composite or + * passed to usb_configuration->setup() (if one is set). No + * matter, we will handle requests directed to endpoint here + * as well (as it's straightforward) but what to do with any + * other request? + */ + if (ffs->state != FFS_ACTIVE) + return -ENODEV; + + switch (creq->bRequestType & USB_RECIP_MASK) { + case USB_RECIP_INTERFACE: + ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); + if (unlikely(ret < 0)) + return ret; + break; + + case USB_RECIP_ENDPOINT: + ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); + if (unlikely(ret < 0)) + return ret; + break; + + default: + return -EOPNOTSUPP; + } + + spin_lock_irqsave(&ffs->ev.waitq.lock, flags); + ffs->ev.setup = *creq; + ffs->ev.setup.wIndex = cpu_to_le16(ret); + __ffs_event_add(ffs, FUNCTIONFS_SETUP); + spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); + + return 0; +} + +static void ffs_func_suspend(struct usb_function *f) +{ + ENTER(); + ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); +} + +static void ffs_func_resume(struct usb_function *f) +{ + ENTER(); + ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); +} + + +/* Endpoint and interface numbers reverse mapping ***************************/ + +static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) +{ + num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; + return num ? num : -EDOM; +} + +static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) +{ + short *nums = func->interfaces_nums; + unsigned count = func->ffs->interfaces_count; + + for (; count; --count, ++nums) { + if (*nums >= 0 && *nums == intf) + return nums - func->interfaces_nums; + } + + return -EDOM; +} + + +/* Misc helper functions ****************************************************/ + +static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) +{ + return nonblock + ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN + : mutex_lock_interruptible(mutex); +} + +static char *ffs_prepare_buffer(const char * __user buf, size_t len) +{ + char *data; + + if (unlikely(!len)) + return NULL; + + data = kmalloc(len, GFP_KERNEL); + if (unlikely(!data)) + return ERR_PTR(-ENOMEM); + + if (unlikely(__copy_from_user(data, buf, len))) { + kfree(data); + return ERR_PTR(-EFAULT); + } + + pr_vdebug("Buffer from user space:\n"); + ffs_dump_mem("", data, len); + + return data; +} |