/**************************************************************************** * drivers/bch/bchdev_driver.c * * Copyright (C) 2008-2009, 2014-2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "bch.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static int bch_open(FAR struct file *filep); static int bch_close(FAR struct file *filep); static off_t bch_seek(FAR struct file *filep, off_t offset, int whence); static ssize_t bch_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t bch_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int bch_ioctl(FAR struct file *filep, int cmd, unsigned long arg); static int bch_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup); #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int bch_unlink(FAR struct inode *inode); #endif /**************************************************************************** * Public Data ****************************************************************************/ const struct file_operations bch_fops = { bch_open, /* open */ bch_close, /* close */ bch_read, /* read */ bch_write, /* write */ bch_seek, /* seek */ bch_ioctl, /* ioctl */ bch_poll /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , bch_unlink /* unlink */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: bch_poll ****************************************************************************/ static int bch_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup) { if (setup) { fds->revents |= (fds->events & (POLLIN | POLLOUT)); if (fds->revents != 0) { nxsem_post(fds->sem); } } return OK; } /**************************************************************************** * Name: bch_open * * Description: Open the block device * ****************************************************************************/ static int bch_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct bchlib_s *bch; int ret = OK; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; /* Increment the reference count */ bchlib_semtake(bch); if (bch->refs == MAX_OPENCNT) { ret = -EMFILE; } else { bch->refs++; } bchlib_semgive(bch); return ret; } /**************************************************************************** * Name: bch_close * * Description: close the block device * ****************************************************************************/ static int bch_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct bchlib_s *bch; int ret = OK; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; /* Flush any dirty pages remaining in the cache */ bchlib_semtake(bch); (void)bchlib_flushsector(bch); /* Decrement the reference count (I don't use bchlib_decref() because I * want the entire close operation to be atomic wrt other driver * operations. */ if (bch->refs == 0) { ret = -EIO; } else { bch->refs--; /* If the reference count decremented to zero AND if the character * driver has been unlinked, then teardown the BCH device now. */ if (bch->refs == 0 && bch->unlinked) { /* Tear the driver down now. */ ret = bchlib_teardown((FAR void *)bch); /* bchlib_teardown() would only fail if there are outstanding * references on the device. Since we know that is not true, it * should not fail at all. */ DEBUGASSERT(ret >= 0); if (ret >= 0) { /* Return without releasing the stale semaphore */ return OK; } } } bchlib_semgive(bch); return ret; } /**************************************************************************** * Name: bch_seek ****************************************************************************/ static off_t bch_seek(FAR struct file *filep, off_t offset, int whence) { FAR struct inode *inode = filep->f_inode; FAR struct bchlib_s *bch; off_t newpos; int ret; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; bchlib_semtake(bch); /* Determine the new, requested file position */ switch (whence) { case SEEK_CUR: newpos = filep->f_pos + offset; break; case SEEK_SET: newpos = offset; break; case SEEK_END: newpos = bch->sectsize * bch->nsectors + offset; break; default: /* Return EINVAL if the whence argument is invalid */ bchlib_semgive(bch); return -EINVAL; } /* Opengroup.org: * * "The lseek() function shall allow the file offset to be set beyond the end * of the existing data in the file. If data is later written at this point, * subsequent reads of data in the gap shall return bytes with the value 0 * until data is actually written into the gap." * * We can conform to the first part, but not the second. But return EINVAL if * * "...the resulting file offset would be negative for a regular file, block * special file, or directory." */ if (newpos >= 0) { filep->f_pos = newpos; ret = newpos; } else { ret = -EINVAL; } bchlib_semgive(bch); return ret; } /**************************************************************************** * Name: bch_read ****************************************************************************/ static ssize_t bch_read(FAR struct file *filep, FAR char *buffer, size_t len) { FAR struct inode *inode = filep->f_inode; FAR struct bchlib_s *bch; int ret; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; bchlib_semtake(bch); ret = bchlib_read(bch, buffer, filep->f_pos, len); if (ret > 0) { filep->f_pos += len; } bchlib_semgive(bch); return ret; } /**************************************************************************** * Name: bch_write ****************************************************************************/ static ssize_t bch_write(FAR struct file *filep, FAR const char *buffer, size_t len) { FAR struct inode *inode = filep->f_inode; FAR struct bchlib_s *bch; int ret = -EACCES; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; if (!bch->readonly) { bchlib_semtake(bch); ret = bchlib_write(bch, buffer, filep->f_pos, len); if (ret > 0) { filep->f_pos += len; } bchlib_semgive(bch); } return ret; } /**************************************************************************** * Name: bch_ioctl * * Description: * Handle IOCTL commands * ****************************************************************************/ static int bch_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct inode *inode = filep->f_inode; FAR struct bchlib_s *bch; int ret = -ENOTTY; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; /* Process the call according to the command */ switch (cmd) { /* This isa request to get the private data structure */ case DIOC_GETPRIV: { FAR struct bchlib_s **bchr = (FAR struct bchlib_s **)((uintptr_t)arg); bchlib_semtake(bch); if (!bchr || bch->refs == MAX_OPENCNT) { ret = -EINVAL; } else { bch->refs++; *bchr = bch; ret = OK; } bchlib_semgive(bch); } break; /* This is a required to return the geometry of the underlying block * driver. */ case BIOC_GEOMETRY: { FAR struct geometry *geo = (FAR struct geometry *)((uintptr_t)arg); DEBUGASSERT(geo != NULL && bch->inode && bch->inode->u.i_bops && bch->inode->u.i_bops->geometry); ret = bch->inode->u.i_bops->geometry(bch->inode, geo); if (ret < 0) { ferr("ERROR: geometry failed: %d\n", -ret); } else if (!geo->geo_available) { ferr("ERROR: geometry failed: %d\n", -ret); ret = -ENODEV; } } break; #ifdef CONFIG_BCH_ENCRYPTION /* This is a request to set the encryption key? */ case DIOC_SETKEY: { memcpy(bch->key, (FAR void *)arg, CONFIG_BCH_ENCRYPTION_KEY_SIZE); ret = OK; } break; #endif /* Otherwise, pass the IOCTL command on to the contained block driver. */ default: { FAR struct inode *bchinode = bch->inode; /* Does the block driver support the ioctl method? */ if (bchinode->u.i_bops->ioctl != NULL) { ret = bchinode->u.i_bops->ioctl(bchinode, cmd, arg); } } break; } return ret; } /**************************************************************************** * Name: bch_unlink * * Handle unlinking of the BCH device * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int bch_unlink(FAR struct inode *inode) { FAR struct bchlib_s *bch; int ret = OK; DEBUGASSERT(inode && inode->i_private); bch = (FAR struct bchlib_s *)inode->i_private; /* Get exclusive access to the BCH device */ bchlib_semtake(bch); /* Indicate that the driver has been unlinked */ bch->unlinked = true; /* If there are no open references to the drvier then teardown the BCH * device now. */ if (bch->refs == 0) { /* Tear the driver down now. */ ret = bchlib_teardown((FAR void *)bch); /* bchlib_teardown() would only fail if there are outstanding * references on the device. Since we know that is not true, it * should not fail at all. */ DEBUGASSERT(ret >= 0); if (ret >= 0) { /* Return without releasing the stale semaphore */ return OK; } } bchlib_semgive(bch); return ret; } #endif /**************************************************************************** * Public Functions ****************************************************************************/