android_kernel_motorola_sm6225/drivers/usb/gadget/inode.c
David Howells 454e2398be [PATCH] VFS: Permit filesystem to override root dentry on mount
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:45 -07:00

2119 lines
52 KiB
C

/*
* inode.c -- user mode filesystem api for usb gadget controllers
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// #define DEBUG /* data to help fault diagnosis */
// #define VERBOSE /* extra debug messages (success too) */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/uts.h>
#include <linux/wait.h>
#include <linux/compiler.h>
#include <asm/uaccess.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/moduleparam.h>
#include <linux/usb_gadgetfs.h>
#include <linux/usb_gadget.h>
/*
* The gadgetfs API maps each endpoint to a file descriptor so that you
* can use standard synchronous read/write calls for I/O. There's some
* O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
* drivers show how this works in practice. You can also use AIO to
* eliminate I/O gaps between requests, to help when streaming data.
*
* Key parts that must be USB-specific are protocols defining how the
* read/write operations relate to the hardware state machines. There
* are two types of files. One type is for the device, implementing ep0.
* The other type is for each IN or OUT endpoint. In both cases, the
* user mode driver must configure the hardware before using it.
*
* - First, dev_config() is called when /dev/gadget/$CHIP is configured
* (by writing configuration and device descriptors). Afterwards it
* may serve as a source of device events, used to handle all control
* requests other than basic enumeration.
*
* - Then either immediately, or after a SET_CONFIGURATION control request,
* ep_config() is called when each /dev/gadget/ep* file is configured
* (by writing endpoint descriptors). Afterwards these files are used
* to write() IN data or to read() OUT data. To halt the endpoint, a
* "wrong direction" request is issued (like reading an IN endpoint).
*
* Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
* not possible on all hardware. For example, precise fault handling with
* respect to data left in endpoint fifos after aborted operations; or
* selective clearing of endpoint halts, to implement SET_INTERFACE.
*/
#define DRIVER_DESC "USB Gadget filesystem"
#define DRIVER_VERSION "24 Aug 2004"
static const char driver_desc [] = DRIVER_DESC;
static const char shortname [] = "gadgetfs";
MODULE_DESCRIPTION (DRIVER_DESC);
MODULE_AUTHOR ("David Brownell");
MODULE_LICENSE ("GPL");
/*----------------------------------------------------------------------*/
#define GADGETFS_MAGIC 0xaee71ee7
#define DMA_ADDR_INVALID (~(dma_addr_t)0)
/* /dev/gadget/$CHIP represents ep0 and the whole device */
enum ep0_state {
/* DISBLED is the initial state.
*/
STATE_DEV_DISABLED = 0,
/* Only one open() of /dev/gadget/$CHIP; only one file tracks
* ep0/device i/o modes and binding to the controller. Driver
* must always write descriptors to initialize the device, then
* the device becomes UNCONNECTED until enumeration.
*/
STATE_OPENED,
/* From then on, ep0 fd is in either of two basic modes:
* - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
* - SETUP: read/write will transfer control data and succeed;
* or if "wrong direction", performs protocol stall
*/
STATE_UNCONNECTED,
STATE_CONNECTED,
STATE_SETUP,
/* UNBOUND means the driver closed ep0, so the device won't be
* accessible again (DEV_DISABLED) until all fds are closed.
*/
STATE_DEV_UNBOUND,
};
/* enough for the whole queue: most events invalidate others */
#define N_EVENT 5
struct dev_data {
spinlock_t lock;
atomic_t count;
enum ep0_state state;
struct usb_gadgetfs_event event [N_EVENT];
unsigned ev_next;
struct fasync_struct *fasync;
u8 current_config;
/* drivers reading ep0 MUST handle control requests (SETUP)
* reported that way; else the host will time out.
*/
unsigned usermode_setup : 1,
setup_in : 1,
setup_can_stall : 1,
setup_out_ready : 1,
setup_out_error : 1,
setup_abort : 1;
unsigned setup_wLength;
/* the rest is basically write-once */
struct usb_config_descriptor *config, *hs_config;
struct usb_device_descriptor *dev;
struct usb_request *req;
struct usb_gadget *gadget;
struct list_head epfiles;
void *buf;
wait_queue_head_t wait;
struct super_block *sb;
struct dentry *dentry;
/* except this scratch i/o buffer for ep0 */
u8 rbuf [256];
};
static inline void get_dev (struct dev_data *data)
{
atomic_inc (&data->count);
}
static void put_dev (struct dev_data *data)
{
if (likely (!atomic_dec_and_test (&data->count)))
return;
/* needs no more cleanup */
BUG_ON (waitqueue_active (&data->wait));
kfree (data);
}
static struct dev_data *dev_new (void)
{
struct dev_data *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return NULL;
dev->state = STATE_DEV_DISABLED;
atomic_set (&dev->count, 1);
spin_lock_init (&dev->lock);
INIT_LIST_HEAD (&dev->epfiles);
init_waitqueue_head (&dev->wait);
return dev;
}
/*----------------------------------------------------------------------*/
/* other /dev/gadget/$ENDPOINT files represent endpoints */
enum ep_state {
STATE_EP_DISABLED = 0,
STATE_EP_READY,
STATE_EP_DEFER_ENABLE,
STATE_EP_ENABLED,
STATE_EP_UNBOUND,
};
struct ep_data {
struct semaphore lock;
enum ep_state state;
atomic_t count;
struct dev_data *dev;
/* must hold dev->lock before accessing ep or req */
struct usb_ep *ep;
struct usb_request *req;
ssize_t status;
char name [16];
struct usb_endpoint_descriptor desc, hs_desc;
struct list_head epfiles;
wait_queue_head_t wait;
struct dentry *dentry;
struct inode *inode;
};
static inline void get_ep (struct ep_data *data)
{
atomic_inc (&data->count);
}
static void put_ep (struct ep_data *data)
{
if (likely (!atomic_dec_and_test (&data->count)))
return;
put_dev (data->dev);
/* needs no more cleanup */
BUG_ON (!list_empty (&data->epfiles));
BUG_ON (waitqueue_active (&data->wait));
BUG_ON (down_trylock (&data->lock) != 0);
kfree (data);
}
/*----------------------------------------------------------------------*/
/* most "how to use the hardware" policy choices are in userspace:
* mapping endpoint roles (which the driver needs) to the capabilities
* which the usb controller has. most of those capabilities are exposed
* implicitly, starting with the driver name and then endpoint names.
*/
static const char *CHIP;
/*----------------------------------------------------------------------*/
/* NOTE: don't use dev_printk calls before binding to the gadget
* at the end of ep0 configuration, or after unbind.
*/
/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
#define xprintk(d,level,fmt,args...) \
printk(level "%s: " fmt , shortname , ## args)
#ifdef DEBUG
#define DBG(dev,fmt,args...) \
xprintk(dev , KERN_DEBUG , fmt , ## args)
#else
#define DBG(dev,fmt,args...) \
do { } while (0)
#endif /* DEBUG */
#ifdef VERBOSE
#define VDEBUG DBG
#else
#define VDEBUG(dev,fmt,args...) \
do { } while (0)
#endif /* DEBUG */
#define ERROR(dev,fmt,args...) \
xprintk(dev , KERN_ERR , fmt , ## args)
#define WARN(dev,fmt,args...) \
xprintk(dev , KERN_WARNING , fmt , ## args)
#define INFO(dev,fmt,args...) \
xprintk(dev , KERN_INFO , fmt , ## args)
/*----------------------------------------------------------------------*/
/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
*
* After opening, configure non-control endpoints. Then use normal
* stream read() and write() requests; and maybe ioctl() to get more
* precise FIFO status when recovering from cancellation.
*/
static void epio_complete (struct usb_ep *ep, struct usb_request *req)
{
struct ep_data *epdata = ep->driver_data;
if (!req->context)
return;
if (req->status)
epdata->status = req->status;
else
epdata->status = req->actual;
complete ((struct completion *)req->context);
}
/* tasklock endpoint, returning when it's connected.
* still need dev->lock to use epdata->ep.
*/
static int
get_ready_ep (unsigned f_flags, struct ep_data *epdata)
{
int val;
if (f_flags & O_NONBLOCK) {
if (down_trylock (&epdata->lock) != 0)
goto nonblock;
if (epdata->state != STATE_EP_ENABLED) {
up (&epdata->lock);
nonblock:
val = -EAGAIN;
} else
val = 0;
return val;
}
if ((val = down_interruptible (&epdata->lock)) < 0)
return val;
newstate:
switch (epdata->state) {
case STATE_EP_ENABLED:
break;
case STATE_EP_DEFER_ENABLE:
DBG (epdata->dev, "%s wait for host\n", epdata->name);
if ((val = wait_event_interruptible (epdata->wait,
epdata->state != STATE_EP_DEFER_ENABLE
|| epdata->dev->state == STATE_DEV_UNBOUND
)) < 0)
goto fail;
goto newstate;
// case STATE_EP_DISABLED: /* "can't happen" */
// case STATE_EP_READY: /* "can't happen" */
default: /* error! */
pr_debug ("%s: ep %p not available, state %d\n",
shortname, epdata, epdata->state);
// FALLTHROUGH
case STATE_EP_UNBOUND: /* clean disconnect */
val = -ENODEV;
fail:
up (&epdata->lock);
}
return val;
}
static ssize_t
ep_io (struct ep_data *epdata, void *buf, unsigned len)
{
DECLARE_COMPLETION (done);
int value;
spin_lock_irq (&epdata->dev->lock);
if (likely (epdata->ep != NULL)) {
struct usb_request *req = epdata->req;
req->context = &done;
req->complete = epio_complete;
req->buf = buf;
req->length = len;
value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
} else
value = -ENODEV;
spin_unlock_irq (&epdata->dev->lock);
if (likely (value == 0)) {
value = wait_event_interruptible (done.wait, done.done);
if (value != 0) {
spin_lock_irq (&epdata->dev->lock);
if (likely (epdata->ep != NULL)) {
DBG (epdata->dev, "%s i/o interrupted\n",
epdata->name);
usb_ep_dequeue (epdata->ep, epdata->req);
spin_unlock_irq (&epdata->dev->lock);
wait_event (done.wait, done.done);
if (epdata->status == -ECONNRESET)
epdata->status = -EINTR;
} else {
spin_unlock_irq (&epdata->dev->lock);
DBG (epdata->dev, "endpoint gone\n");
epdata->status = -ENODEV;
}
}
return epdata->status;
}
return value;
}
/* handle a synchronous OUT bulk/intr/iso transfer */
static ssize_t
ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
{
struct ep_data *data = fd->private_data;
void *kbuf;
ssize_t value;
if ((value = get_ready_ep (fd->f_flags, data)) < 0)
return value;
/* halt any endpoint by doing a "wrong direction" i/o call */
if (data->desc.bEndpointAddress & USB_DIR_IN) {
if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
== USB_ENDPOINT_XFER_ISOC)
return -EINVAL;
DBG (data->dev, "%s halt\n", data->name);
spin_lock_irq (&data->dev->lock);
if (likely (data->ep != NULL))
usb_ep_set_halt (data->ep);
spin_unlock_irq (&data->dev->lock);
up (&data->lock);
return -EBADMSG;
}
/* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
value = -ENOMEM;
kbuf = kmalloc (len, SLAB_KERNEL);
if (unlikely (!kbuf))
goto free1;
value = ep_io (data, kbuf, len);
VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
data->name, len, (int) value);
if (value >= 0 && copy_to_user (buf, kbuf, value))
value = -EFAULT;
free1:
up (&data->lock);
kfree (kbuf);
return value;
}
/* handle a synchronous IN bulk/intr/iso transfer */
static ssize_t
ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
{
struct ep_data *data = fd->private_data;
void *kbuf;
ssize_t value;
if ((value = get_ready_ep (fd->f_flags, data)) < 0)
return value;
/* halt any endpoint by doing a "wrong direction" i/o call */
if (!(data->desc.bEndpointAddress & USB_DIR_IN)) {
if ((data->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
== USB_ENDPOINT_XFER_ISOC)
return -EINVAL;
DBG (data->dev, "%s halt\n", data->name);
spin_lock_irq (&data->dev->lock);
if (likely (data->ep != NULL))
usb_ep_set_halt (data->ep);
spin_unlock_irq (&data->dev->lock);
up (&data->lock);
return -EBADMSG;
}
/* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
value = -ENOMEM;
kbuf = kmalloc (len, SLAB_KERNEL);
if (!kbuf)
goto free1;
if (copy_from_user (kbuf, buf, len)) {
value = -EFAULT;
goto free1;
}
value = ep_io (data, kbuf, len);
VDEBUG (data->dev, "%s write %zu IN, status %d\n",
data->name, len, (int) value);
free1:
up (&data->lock);
kfree (kbuf);
return value;
}
static int
ep_release (struct inode *inode, struct file *fd)
{
struct ep_data *data = fd->private_data;
/* clean up if this can be reopened */
if (data->state != STATE_EP_UNBOUND) {
data->state = STATE_EP_DISABLED;
data->desc.bDescriptorType = 0;
data->hs_desc.bDescriptorType = 0;
usb_ep_disable(data->ep);
}
put_ep (data);
return 0;
}
static int ep_ioctl (struct inode *inode, struct file *fd,
unsigned code, unsigned long value)
{
struct ep_data *data = fd->private_data;
int status;
if ((status = get_ready_ep (fd->f_flags, data)) < 0)
return status;
spin_lock_irq (&data->dev->lock);
if (likely (data->ep != NULL)) {
switch (code) {
case GADGETFS_FIFO_STATUS:
status = usb_ep_fifo_status (data->ep);
break;
case GADGETFS_FIFO_FLUSH:
usb_ep_fifo_flush (data->ep);
break;
case GADGETFS_CLEAR_HALT:
status = usb_ep_clear_halt (data->ep);
break;
default:
status = -ENOTTY;
}
} else
status = -ENODEV;
spin_unlock_irq (&data->dev->lock);
up (&data->lock);
return status;
}
/*----------------------------------------------------------------------*/
/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
struct kiocb_priv {
struct usb_request *req;
struct ep_data *epdata;
void *buf;
char __user *ubuf; /* NULL for writes */
unsigned actual;
};
static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
{
struct kiocb_priv *priv = iocb->private;
struct ep_data *epdata;
int value;
local_irq_disable();
epdata = priv->epdata;
// spin_lock(&epdata->dev->lock);
kiocbSetCancelled(iocb);
if (likely(epdata && epdata->ep && priv->req))
value = usb_ep_dequeue (epdata->ep, priv->req);
else
value = -EINVAL;
// spin_unlock(&epdata->dev->lock);
local_irq_enable();
aio_put_req(iocb);
return value;
}
static ssize_t ep_aio_read_retry(struct kiocb *iocb)
{
struct kiocb_priv *priv = iocb->private;
ssize_t status = priv->actual;
/* we "retry" to get the right mm context for this: */
status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
if (unlikely(0 != status))
status = -EFAULT;
else
status = priv->actual;
kfree(priv->buf);
kfree(priv);
return status;
}
static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
{
struct kiocb *iocb = req->context;
struct kiocb_priv *priv = iocb->private;
struct ep_data *epdata = priv->epdata;
/* lock against disconnect (and ideally, cancel) */
spin_lock(&epdata->dev->lock);
priv->req = NULL;
priv->epdata = NULL;
if (priv->ubuf == NULL
|| unlikely(req->actual == 0)
|| unlikely(kiocbIsCancelled(iocb))) {
kfree(req->buf);
kfree(priv);
iocb->private = NULL;
/* aio_complete() reports bytes-transferred _and_ faults */
if (unlikely(kiocbIsCancelled(iocb)))
aio_put_req(iocb);
else
aio_complete(iocb,
req->actual ? req->actual : req->status,
req->status);
} else {
/* retry() won't report both; so we hide some faults */
if (unlikely(0 != req->status))
DBG(epdata->dev, "%s fault %d len %d\n",
ep->name, req->status, req->actual);
priv->buf = req->buf;
priv->actual = req->actual;
kick_iocb(iocb);
}
spin_unlock(&epdata->dev->lock);
usb_ep_free_request(ep, req);
put_ep(epdata);
}
static ssize_t
ep_aio_rwtail(
struct kiocb *iocb,
char *buf,
size_t len,
struct ep_data *epdata,
char __user *ubuf
)
{
struct kiocb_priv *priv;
struct usb_request *req;
ssize_t value;
priv = kmalloc(sizeof *priv, GFP_KERNEL);
if (!priv) {
value = -ENOMEM;
fail:
kfree(buf);
return value;
}
iocb->private = priv;
priv->ubuf = ubuf;
value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
if (unlikely(value < 0)) {
kfree(priv);
goto fail;
}
iocb->ki_cancel = ep_aio_cancel;
get_ep(epdata);
priv->epdata = epdata;
priv->actual = 0;
/* each kiocb is coupled to one usb_request, but we can't
* allocate or submit those if the host disconnected.
*/
spin_lock_irq(&epdata->dev->lock);
if (likely(epdata->ep)) {
req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
if (likely(req)) {
priv->req = req;
req->buf = buf;
req->length = len;
req->complete = ep_aio_complete;
req->context = iocb;
value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
if (unlikely(0 != value))
usb_ep_free_request(epdata->ep, req);
} else
value = -EAGAIN;
} else
value = -ENODEV;
spin_unlock_irq(&epdata->dev->lock);
up(&epdata->lock);
if (unlikely(value)) {
kfree(priv);
put_ep(epdata);
} else
value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
return value;
}
static ssize_t
ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
{
struct ep_data *epdata = iocb->ki_filp->private_data;
char *buf;
if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
return -EINVAL;
buf = kmalloc(len, GFP_KERNEL);
if (unlikely(!buf))
return -ENOMEM;
iocb->ki_retry = ep_aio_read_retry;
return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
}
static ssize_t
ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
{
struct ep_data *epdata = iocb->ki_filp->private_data;
char *buf;
if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
return -EINVAL;
buf = kmalloc(len, GFP_KERNEL);
if (unlikely(!buf))
return -ENOMEM;
if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
kfree(buf);
return -EFAULT;
}
return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
}
/*----------------------------------------------------------------------*/
/* used after endpoint configuration */
static struct file_operations ep_io_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = ep_read,
.write = ep_write,
.ioctl = ep_ioctl,
.release = ep_release,
.aio_read = ep_aio_read,
.aio_write = ep_aio_write,
};
/* ENDPOINT INITIALIZATION
*
* fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
* status = write (fd, descriptors, sizeof descriptors)
*
* That write establishes the endpoint configuration, configuring
* the controller to process bulk, interrupt, or isochronous transfers
* at the right maxpacket size, and so on.
*
* The descriptors are message type 1, identified by a host order u32
* at the beginning of what's written. Descriptor order is: full/low
* speed descriptor, then optional high speed descriptor.
*/
static ssize_t
ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
{
struct ep_data *data = fd->private_data;
struct usb_ep *ep;
u32 tag;
int value;
if ((value = down_interruptible (&data->lock)) < 0)
return value;
if (data->state != STATE_EP_READY) {
value = -EL2HLT;
goto fail;
}
value = len;
if (len < USB_DT_ENDPOINT_SIZE + 4)
goto fail0;
/* we might need to change message format someday */
if (copy_from_user (&tag, buf, 4)) {
goto fail1;
}
if (tag != 1) {
DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
goto fail0;
}
buf += 4;
len -= 4;
/* NOTE: audio endpoint extensions not accepted here;
* just don't include the extra bytes.
*/
/* full/low speed descriptor, then high speed */
if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
goto fail1;
}
if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
|| data->desc.bDescriptorType != USB_DT_ENDPOINT)
goto fail0;
if (len != USB_DT_ENDPOINT_SIZE) {
if (len != 2 * USB_DT_ENDPOINT_SIZE)
goto fail0;
if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
USB_DT_ENDPOINT_SIZE)) {
goto fail1;
}
if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
|| data->hs_desc.bDescriptorType
!= USB_DT_ENDPOINT) {
DBG(data->dev, "config %s, bad hs length or type\n",
data->name);
goto fail0;
}
}
value = len;
spin_lock_irq (&data->dev->lock);
if (data->dev->state == STATE_DEV_UNBOUND) {
value = -ENOENT;
goto gone;
} else if ((ep = data->ep) == NULL) {
value = -ENODEV;
goto gone;
}
switch (data->dev->gadget->speed) {
case USB_SPEED_LOW:
case USB_SPEED_FULL:
value = usb_ep_enable (ep, &data->desc);
if (value == 0)
data->state = STATE_EP_ENABLED;
break;
#ifdef CONFIG_USB_GADGET_DUALSPEED
case USB_SPEED_HIGH:
/* fails if caller didn't provide that descriptor... */
value = usb_ep_enable (ep, &data->hs_desc);
if (value == 0)
data->state = STATE_EP_ENABLED;
break;
#endif
default:
DBG (data->dev, "unconnected, %s init deferred\n",
data->name);
data->state = STATE_EP_DEFER_ENABLE;
}
if (value == 0)
fd->f_op = &ep_io_operations;
gone:
spin_unlock_irq (&data->dev->lock);
if (value < 0) {
fail:
data->desc.bDescriptorType = 0;
data->hs_desc.bDescriptorType = 0;
}
up (&data->lock);
return value;
fail0:
value = -EINVAL;
goto fail;
fail1:
value = -EFAULT;
goto fail;
}
static int
ep_open (struct inode *inode, struct file *fd)
{
struct ep_data *data = inode->u.generic_ip;
int value = -EBUSY;
if (down_interruptible (&data->lock) != 0)
return -EINTR;
spin_lock_irq (&data->dev->lock);
if (data->dev->state == STATE_DEV_UNBOUND)
value = -ENOENT;
else if (data->state == STATE_EP_DISABLED) {
value = 0;
data->state = STATE_EP_READY;
get_ep (data);
fd->private_data = data;
VDEBUG (data->dev, "%s ready\n", data->name);
} else
DBG (data->dev, "%s state %d\n",
data->name, data->state);
spin_unlock_irq (&data->dev->lock);
up (&data->lock);
return value;
}
/* used before endpoint configuration */
static struct file_operations ep_config_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = ep_open,
.write = ep_config,
.release = ep_release,
};
/*----------------------------------------------------------------------*/
/* EP0 IMPLEMENTATION can be partly in userspace.
*
* Drivers that use this facility receive various events, including
* control requests the kernel doesn't handle. Drivers that don't
* use this facility may be too simple-minded for real applications.
*/
static inline void ep0_readable (struct dev_data *dev)
{
wake_up (&dev->wait);
kill_fasync (&dev->fasync, SIGIO, POLL_IN);
}
static void clean_req (struct usb_ep *ep, struct usb_request *req)
{
struct dev_data *dev = ep->driver_data;
if (req->buf != dev->rbuf) {
usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
req->buf = dev->rbuf;
req->dma = DMA_ADDR_INVALID;
}
req->complete = epio_complete;
dev->setup_out_ready = 0;
}
static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
{
struct dev_data *dev = ep->driver_data;
int free = 1;
/* for control OUT, data must still get to userspace */
if (!dev->setup_in) {
dev->setup_out_error = (req->status != 0);
if (!dev->setup_out_error)
free = 0;
dev->setup_out_ready = 1;
ep0_readable (dev);
} else if (dev->state == STATE_SETUP)
dev->state = STATE_CONNECTED;
/* clean up as appropriate */
if (free && req->buf != &dev->rbuf)
clean_req (ep, req);
req->complete = epio_complete;
}
static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
{
struct dev_data *dev = ep->driver_data;
if (dev->setup_out_ready) {
DBG (dev, "ep0 request busy!\n");
return -EBUSY;
}
if (len > sizeof (dev->rbuf))
req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
if (req->buf == 0) {
req->buf = dev->rbuf;
return -ENOMEM;
}
req->complete = ep0_complete;
req->length = len;
req->zero = 0;
return 0;
}
static ssize_t
ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
{
struct dev_data *dev = fd->private_data;
ssize_t retval;
enum ep0_state state;
spin_lock_irq (&dev->lock);
/* report fd mode change before acting on it */
if (dev->setup_abort) {
dev->setup_abort = 0;
retval = -EIDRM;
goto done;
}
/* control DATA stage */
if ((state = dev->state) == STATE_SETUP) {
if (dev->setup_in) { /* stall IN */
VDEBUG(dev, "ep0in stall\n");
(void) usb_ep_set_halt (dev->gadget->ep0);
retval = -EL2HLT;
dev->state = STATE_CONNECTED;
} else if (len == 0) { /* ack SET_CONFIGURATION etc */
struct usb_ep *ep = dev->gadget->ep0;
struct usb_request *req = dev->req;
if ((retval = setup_req (ep, req, 0)) == 0)
retval = usb_ep_queue (ep, req, GFP_ATOMIC);
dev->state = STATE_CONNECTED;
/* assume that was SET_CONFIGURATION */
if (dev->current_config) {
unsigned power;
#ifdef CONFIG_USB_GADGET_DUALSPEED
if (dev->gadget->speed == USB_SPEED_HIGH)
power = dev->hs_config->bMaxPower;
else
#endif
power = dev->config->bMaxPower;
usb_gadget_vbus_draw(dev->gadget, 2 * power);
}
} else { /* collect OUT data */
if ((fd->f_flags & O_NONBLOCK) != 0
&& !dev->setup_out_ready) {
retval = -EAGAIN;
goto done;
}
spin_unlock_irq (&dev->lock);
retval = wait_event_interruptible (dev->wait,
dev->setup_out_ready != 0);
/* FIXME state could change from under us */
spin_lock_irq (&dev->lock);
if (retval)
goto done;
if (dev->setup_out_error)
retval = -EIO;
else {
len = min (len, (size_t)dev->req->actual);
// FIXME don't call this with the spinlock held ...
if (copy_to_user (buf, &dev->req->buf, len))
retval = -EFAULT;
clean_req (dev->gadget->ep0, dev->req);
/* NOTE userspace can't yet choose to stall */
}
}
goto done;
}
/* else normal: return event data */
if (len < sizeof dev->event [0]) {
retval = -EINVAL;
goto done;
}
len -= len % sizeof (struct usb_gadgetfs_event);
dev->usermode_setup = 1;
scan:
/* return queued events right away */
if (dev->ev_next != 0) {
unsigned i, n;
int tmp = dev->ev_next;
len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
n = len / sizeof (struct usb_gadgetfs_event);
/* ep0 can't deliver events when STATE_SETUP */
for (i = 0; i < n; i++) {
if (dev->event [i].type == GADGETFS_SETUP) {
len = i + 1;
len *= sizeof (struct usb_gadgetfs_event);
n = 0;
break;
}
}
spin_unlock_irq (&dev->lock);
if (copy_to_user (buf, &dev->event, len))
retval = -EFAULT;
else
retval = len;
if (len > 0) {
len /= sizeof (struct usb_gadgetfs_event);
/* NOTE this doesn't guard against broken drivers;
* concurrent ep0 readers may lose events.
*/
spin_lock_irq (&dev->lock);
dev->ev_next -= len;
if (dev->ev_next != 0)
memmove (&dev->event, &dev->event [len],
sizeof (struct usb_gadgetfs_event)
* (tmp - len));
if (n == 0)
dev->state = STATE_SETUP;
spin_unlock_irq (&dev->lock);
}
return retval;
}
if (fd->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
goto done;
}
switch (state) {
default:
DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
retval = -ESRCH;
break;
case STATE_UNCONNECTED:
case STATE_CONNECTED:
spin_unlock_irq (&dev->lock);
DBG (dev, "%s wait\n", __FUNCTION__);
/* wait for events */
retval = wait_event_interruptible (dev->wait,
dev->ev_next != 0);
if (retval < 0)
return retval;
spin_lock_irq (&dev->lock);
goto scan;
}
done:
spin_unlock_irq (&dev->lock);
return retval;
}
static struct usb_gadgetfs_event *
next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
{
struct usb_gadgetfs_event *event;
unsigned i;
switch (type) {
/* these events purge the queue */
case GADGETFS_DISCONNECT:
if (dev->state == STATE_SETUP)
dev->setup_abort = 1;
// FALL THROUGH
case GADGETFS_CONNECT:
dev->ev_next = 0;
break;
case GADGETFS_SETUP: /* previous request timed out */
case GADGETFS_SUSPEND: /* same effect */
/* these events can't be repeated */
for (i = 0; i != dev->ev_next; i++) {
if (dev->event [i].type != type)
continue;
DBG (dev, "discard old event %d\n", type);
dev->ev_next--;
if (i == dev->ev_next)
break;
/* indices start at zero, for simplicity */
memmove (&dev->event [i], &dev->event [i + 1],
sizeof (struct usb_gadgetfs_event)
* (dev->ev_next - i));
}
break;
default:
BUG ();
}
event = &dev->event [dev->ev_next++];
BUG_ON (dev->ev_next > N_EVENT);
VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
memset (event, 0, sizeof *event);
event->type = type;
return event;
}
static ssize_t
ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
{
struct dev_data *dev = fd->private_data;
ssize_t retval = -ESRCH;
spin_lock_irq (&dev->lock);
/* report fd mode change before acting on it */
if (dev->setup_abort) {
dev->setup_abort = 0;
retval = -EIDRM;
/* data and/or status stage for control request */
} else if (dev->state == STATE_SETUP) {
/* IN DATA+STATUS caller makes len <= wLength */
if (dev->setup_in) {
retval = setup_req (dev->gadget->ep0, dev->req, len);
if (retval == 0) {
spin_unlock_irq (&dev->lock);
if (copy_from_user (dev->req->buf, buf, len))
retval = -EFAULT;
else {
if (len < dev->setup_wLength)
dev->req->zero = 1;
retval = usb_ep_queue (
dev->gadget->ep0, dev->req,
GFP_KERNEL);
}
if (retval < 0) {
spin_lock_irq (&dev->lock);
clean_req (dev->gadget->ep0, dev->req);
spin_unlock_irq (&dev->lock);
} else
retval = len;
return retval;
}
/* can stall some OUT transfers */
} else if (dev->setup_can_stall) {
VDEBUG(dev, "ep0out stall\n");
(void) usb_ep_set_halt (dev->gadget->ep0);
retval = -EL2HLT;
dev->state = STATE_CONNECTED;
} else {
DBG(dev, "bogus ep0out stall!\n");
}
} else
DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);
spin_unlock_irq (&dev->lock);
return retval;
}
static int
ep0_fasync (int f, struct file *fd, int on)
{
struct dev_data *dev = fd->private_data;
// caller must F_SETOWN before signal delivery happens
VDEBUG (dev, "%s %s\n", __FUNCTION__, on ? "on" : "off");
return fasync_helper (f, fd, on, &dev->fasync);
}
static struct usb_gadget_driver gadgetfs_driver;
static int
dev_release (struct inode *inode, struct file *fd)
{
struct dev_data *dev = fd->private_data;
/* closing ep0 === shutdown all */
usb_gadget_unregister_driver (&gadgetfs_driver);
/* at this point "good" hardware has disconnected the
* device from USB; the host won't see it any more.
* alternatively, all host requests will time out.
*/
fasync_helper (-1, fd, 0, &dev->fasync);
kfree (dev->buf);
dev->buf = NULL;
put_dev (dev);
/* other endpoints were all decoupled from this device */
dev->state = STATE_DEV_DISABLED;
return 0;
}
static int dev_ioctl (struct inode *inode, struct file *fd,
unsigned code, unsigned long value)
{
struct dev_data *dev = fd->private_data;
struct usb_gadget *gadget = dev->gadget;
if (gadget->ops->ioctl)
return gadget->ops->ioctl (gadget, code, value);
return -ENOTTY;
}
/* used after device configuration */
static struct file_operations ep0_io_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = ep0_read,
.write = ep0_write,
.fasync = ep0_fasync,
// .poll = ep0_poll,
.ioctl = dev_ioctl,
.release = dev_release,
};
/*----------------------------------------------------------------------*/
/* The in-kernel gadget driver handles most ep0 issues, in particular
* enumerating the single configuration (as provided from user space).
*
* Unrecognized ep0 requests may be handled in user space.
*/
#ifdef CONFIG_USB_GADGET_DUALSPEED
static void make_qualifier (struct dev_data *dev)
{
struct usb_qualifier_descriptor qual;
struct usb_device_descriptor *desc;
qual.bLength = sizeof qual;
qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
qual.bcdUSB = __constant_cpu_to_le16 (0x0200);
desc = dev->dev;
qual.bDeviceClass = desc->bDeviceClass;
qual.bDeviceSubClass = desc->bDeviceSubClass;
qual.bDeviceProtocol = desc->bDeviceProtocol;
/* assumes ep0 uses the same value for both speeds ... */
qual.bMaxPacketSize0 = desc->bMaxPacketSize0;
qual.bNumConfigurations = 1;
qual.bRESERVED = 0;
memcpy (dev->rbuf, &qual, sizeof qual);
}
#endif
static int
config_buf (struct dev_data *dev, u8 type, unsigned index)
{
int len;
#ifdef CONFIG_USB_GADGET_DUALSPEED
int hs;
#endif
/* only one configuration */
if (index > 0)
return -EINVAL;
#ifdef CONFIG_USB_GADGET_DUALSPEED
hs = (dev->gadget->speed == USB_SPEED_HIGH);
if (type == USB_DT_OTHER_SPEED_CONFIG)
hs = !hs;
if (hs) {
dev->req->buf = dev->hs_config;
len = le16_to_cpup (&dev->hs_config->wTotalLength);
} else
#endif
{
dev->req->buf = dev->config;
len = le16_to_cpup (&dev->config->wTotalLength);
}
((u8 *)dev->req->buf) [1] = type;
return len;
}
static int
gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
{
struct dev_data *dev = get_gadget_data (gadget);
struct usb_request *req = dev->req;
int value = -EOPNOTSUPP;
struct usb_gadgetfs_event *event;
u16 w_value = le16_to_cpu(ctrl->wValue);
u16 w_length = le16_to_cpu(ctrl->wLength);
spin_lock (&dev->lock);
dev->setup_abort = 0;
if (dev->state == STATE_UNCONNECTED) {
struct usb_ep *ep;
struct ep_data *data;
dev->state = STATE_CONNECTED;
dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
#ifdef CONFIG_USB_GADGET_DUALSPEED
if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
ERROR (dev, "no high speed config??\n");
return -EINVAL;
}
#endif /* CONFIG_USB_GADGET_DUALSPEED */
INFO (dev, "connected\n");
event = next_event (dev, GADGETFS_CONNECT);
event->u.speed = gadget->speed;
ep0_readable (dev);
list_for_each_entry (ep, &gadget->ep_list, ep_list) {
data = ep->driver_data;
/* ... down_trylock (&data->lock) ... */
if (data->state != STATE_EP_DEFER_ENABLE)
continue;
#ifdef CONFIG_USB_GADGET_DUALSPEED
if (gadget->speed == USB_SPEED_HIGH)
value = usb_ep_enable (ep, &data->hs_desc);
else
#endif /* CONFIG_USB_GADGET_DUALSPEED */
value = usb_ep_enable (ep, &data->desc);
if (value) {
ERROR (dev, "deferred %s enable --> %d\n",
data->name, value);
continue;
}
data->state = STATE_EP_ENABLED;
wake_up (&data->wait);
DBG (dev, "woke up %s waiters\n", data->name);
}
/* host may have given up waiting for response. we can miss control
* requests handled lower down (device/endpoint status and features);
* then ep0_{read,write} will report the wrong status. controller
* driver will have aborted pending i/o.
*/
} else if (dev->state == STATE_SETUP)
dev->setup_abort = 1;
req->buf = dev->rbuf;
req->dma = DMA_ADDR_INVALID;
req->context = NULL;
value = -EOPNOTSUPP;
switch (ctrl->bRequest) {
case USB_REQ_GET_DESCRIPTOR:
if (ctrl->bRequestType != USB_DIR_IN)
goto unrecognized;
switch (w_value >> 8) {
case USB_DT_DEVICE:
value = min (w_length, (u16) sizeof *dev->dev);
req->buf = dev->dev;
break;
#ifdef CONFIG_USB_GADGET_DUALSPEED
case USB_DT_DEVICE_QUALIFIER:
if (!dev->hs_config)
break;
value = min (w_length, (u16)
sizeof (struct usb_qualifier_descriptor));
make_qualifier (dev);
break;
case USB_DT_OTHER_SPEED_CONFIG:
// FALLTHROUGH
#endif
case USB_DT_CONFIG:
value = config_buf (dev,
w_value >> 8,
w_value & 0xff);
if (value >= 0)
value = min (w_length, (u16) value);
break;
case USB_DT_STRING:
goto unrecognized;
default: // all others are errors
break;
}
break;
/* currently one config, two speeds */
case USB_REQ_SET_CONFIGURATION:
if (ctrl->bRequestType != 0)
break;
if (0 == (u8) w_value) {
value = 0;
dev->current_config = 0;
usb_gadget_vbus_draw(gadget, 8 /* mA */ );
// user mode expected to disable endpoints
} else {
u8 config, power;
#ifdef CONFIG_USB_GADGET_DUALSPEED
if (gadget->speed == USB_SPEED_HIGH) {
config = dev->hs_config->bConfigurationValue;
power = dev->hs_config->bMaxPower;
} else
#endif
{
config = dev->config->bConfigurationValue;
power = dev->config->bMaxPower;
}
if (config == (u8) w_value) {
value = 0;
dev->current_config = config;
usb_gadget_vbus_draw(gadget, 2 * power);
}
}
/* report SET_CONFIGURATION like any other control request,
* except that usermode may not stall this. the next
* request mustn't be allowed start until this finishes:
* endpoints and threads set up, etc.
*
* NOTE: older PXA hardware (before PXA 255: without UDCCFR)
* has bad/racey automagic that prevents synchronizing here.
* even kernel mode drivers often miss them.
*/
if (value == 0) {
INFO (dev, "configuration #%d\n", dev->current_config);
if (dev->usermode_setup) {
dev->setup_can_stall = 0;
goto delegate;
}
}
break;
#ifndef CONFIG_USB_GADGETFS_PXA2XX
/* PXA automagically handles this request too */
case USB_REQ_GET_CONFIGURATION:
if (ctrl->bRequestType != 0x80)
break;
*(u8 *)req->buf = dev->current_config;
value = min (w_length, (u16) 1);
break;
#endif
default:
unrecognized:
VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
dev->usermode_setup ? "delegate" : "fail",
ctrl->bRequestType, ctrl->bRequest,
w_value, le16_to_cpu(ctrl->wIndex), w_length);
/* if there's an ep0 reader, don't stall */
if (dev->usermode_setup) {
dev->setup_can_stall = 1;
delegate:
dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
? 1 : 0;
dev->setup_wLength = w_length;
dev->setup_out_ready = 0;
dev->setup_out_error = 0;
value = 0;
/* read DATA stage for OUT right away */
if (unlikely (!dev->setup_in && w_length)) {
value = setup_req (gadget->ep0, dev->req,
w_length);
if (value < 0)
break;
value = usb_ep_queue (gadget->ep0, dev->req,
GFP_ATOMIC);
if (value < 0) {
clean_req (gadget->ep0, dev->req);
break;
}
/* we can't currently stall these */
dev->setup_can_stall = 0;
}
/* state changes when reader collects event */
event = next_event (dev, GADGETFS_SETUP);
event->u.setup = *ctrl;
ep0_readable (dev);
spin_unlock (&dev->lock);
return 0;
}
}
/* proceed with data transfer and status phases? */
if (value >= 0 && dev->state != STATE_SETUP) {
req->length = value;
req->zero = value < w_length;
value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
if (value < 0) {
DBG (dev, "ep_queue --> %d\n", value);
req->status = 0;
}
}
/* device stalls when value < 0 */
spin_unlock (&dev->lock);
return value;
}
static void destroy_ep_files (struct dev_data *dev)
{
struct list_head *entry, *tmp;
DBG (dev, "%s %d\n", __FUNCTION__, dev->state);
/* dev->state must prevent interference */
restart:
spin_lock_irq (&dev->lock);
list_for_each_safe (entry, tmp, &dev->epfiles) {
struct ep_data *ep;
struct inode *parent;
struct dentry *dentry;
/* break link to FS */
ep = list_entry (entry, struct ep_data, epfiles);
list_del_init (&ep->epfiles);
dentry = ep->dentry;
ep->dentry = NULL;
parent = dentry->d_parent->d_inode;
/* break link to controller */
if (ep->state == STATE_EP_ENABLED)
(void) usb_ep_disable (ep->ep);
ep->state = STATE_EP_UNBOUND;
usb_ep_free_request (ep->ep, ep->req);
ep->ep = NULL;
wake_up (&ep->wait);
put_ep (ep);
spin_unlock_irq (&dev->lock);
/* break link to dcache */
mutex_lock (&parent->i_mutex);
d_delete (dentry);
dput (dentry);
mutex_unlock (&parent->i_mutex);
/* fds may still be open */
goto restart;
}
spin_unlock_irq (&dev->lock);
}
static struct inode *
gadgetfs_create_file (struct super_block *sb, char const *name,
void *data, const struct file_operations *fops,
struct dentry **dentry_p);
static int activate_ep_files (struct dev_data *dev)
{
struct usb_ep *ep;
struct ep_data *data;
gadget_for_each_ep (ep, dev->gadget) {
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
goto enomem0;
data->state = STATE_EP_DISABLED;
init_MUTEX (&data->lock);
init_waitqueue_head (&data->wait);
strncpy (data->name, ep->name, sizeof (data->name) - 1);
atomic_set (&data->count, 1);
data->dev = dev;
get_dev (dev);
data->ep = ep;
ep->driver_data = data;
data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
if (!data->req)
goto enomem1;
data->inode = gadgetfs_create_file (dev->sb, data->name,
data, &ep_config_operations,
&data->dentry);
if (!data->inode)
goto enomem2;
list_add_tail (&data->epfiles, &dev->epfiles);
}
return 0;
enomem2:
usb_ep_free_request (ep, data->req);
enomem1:
put_dev (dev);
kfree (data);
enomem0:
DBG (dev, "%s enomem\n", __FUNCTION__);
destroy_ep_files (dev);
return -ENOMEM;
}
static void
gadgetfs_unbind (struct usb_gadget *gadget)
{
struct dev_data *dev = get_gadget_data (gadget);
DBG (dev, "%s\n", __FUNCTION__);
spin_lock_irq (&dev->lock);
dev->state = STATE_DEV_UNBOUND;
spin_unlock_irq (&dev->lock);
destroy_ep_files (dev);
gadget->ep0->driver_data = NULL;
set_gadget_data (gadget, NULL);
/* we've already been disconnected ... no i/o is active */
if (dev->req)
usb_ep_free_request (gadget->ep0, dev->req);
DBG (dev, "%s done\n", __FUNCTION__);
put_dev (dev);
}
static struct dev_data *the_device;
static int
gadgetfs_bind (struct usb_gadget *gadget)
{
struct dev_data *dev = the_device;
if (!dev)
return -ESRCH;
if (0 != strcmp (CHIP, gadget->name)) {
printk (KERN_ERR "%s expected %s controller not %s\n",
shortname, CHIP, gadget->name);
return -ENODEV;
}
set_gadget_data (gadget, dev);
dev->gadget = gadget;
gadget->ep0->driver_data = dev;
dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
/* preallocate control response and buffer */
dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
if (!dev->req)
goto enomem;
dev->req->context = NULL;
dev->req->complete = epio_complete;
if (activate_ep_files (dev) < 0)
goto enomem;
INFO (dev, "bound to %s driver\n", gadget->name);
dev->state = STATE_UNCONNECTED;
get_dev (dev);
return 0;
enomem:
gadgetfs_unbind (gadget);
return -ENOMEM;
}
static void
gadgetfs_disconnect (struct usb_gadget *gadget)
{
struct dev_data *dev = get_gadget_data (gadget);
if (dev->state == STATE_UNCONNECTED) {
DBG (dev, "already unconnected\n");
return;
}
dev->state = STATE_UNCONNECTED;
INFO (dev, "disconnected\n");
spin_lock (&dev->lock);
next_event (dev, GADGETFS_DISCONNECT);
ep0_readable (dev);
spin_unlock (&dev->lock);
}
static void
gadgetfs_suspend (struct usb_gadget *gadget)
{
struct dev_data *dev = get_gadget_data (gadget);
INFO (dev, "suspended from state %d\n", dev->state);
spin_lock (&dev->lock);
switch (dev->state) {
case STATE_SETUP: // VERY odd... host died??
case STATE_CONNECTED:
case STATE_UNCONNECTED:
next_event (dev, GADGETFS_SUSPEND);
ep0_readable (dev);
/* FALLTHROUGH */
default:
break;
}
spin_unlock (&dev->lock);
}
static struct usb_gadget_driver gadgetfs_driver = {
#ifdef CONFIG_USB_GADGET_DUALSPEED
.speed = USB_SPEED_HIGH,
#else
.speed = USB_SPEED_FULL,
#endif
.function = (char *) driver_desc,
.bind = gadgetfs_bind,
.unbind = gadgetfs_unbind,
.setup = gadgetfs_setup,
.disconnect = gadgetfs_disconnect,
.suspend = gadgetfs_suspend,
.driver = {
.name = (char *) shortname,
},
};
/*----------------------------------------------------------------------*/
static void gadgetfs_nop(struct usb_gadget *arg) { }
static int gadgetfs_probe (struct usb_gadget *gadget)
{
CHIP = gadget->name;
return -EISNAM;
}
static struct usb_gadget_driver probe_driver = {
.speed = USB_SPEED_HIGH,
.bind = gadgetfs_probe,
.unbind = gadgetfs_nop,
.setup = (void *)gadgetfs_nop,
.disconnect = gadgetfs_nop,
.driver = {
.name = "nop",
},
};
/* DEVICE INITIALIZATION
*
* fd = open ("/dev/gadget/$CHIP", O_RDWR)
* status = write (fd, descriptors, sizeof descriptors)
*
* That write establishes the device configuration, so the kernel can
* bind to the controller ... guaranteeing it can handle enumeration
* at all necessary speeds. Descriptor order is:
*
* . message tag (u32, host order) ... for now, must be zero; it
* would change to support features like multi-config devices
* . full/low speed config ... all wTotalLength bytes (with interface,
* class, altsetting, endpoint, and other descriptors)
* . high speed config ... all descriptors, for high speed operation;
* this one's optional except for high-speed hardware
* . device descriptor
*
* Endpoints are not yet enabled. Drivers may want to immediately
* initialize them, using the /dev/gadget/ep* files that are available
* as soon as the kernel sees the configuration, or they can wait
* until device configuration and interface altsetting changes create
* the need to configure (or unconfigure) them.
*
* After initialization, the device stays active for as long as that
* $CHIP file is open. Events may then be read from that descriptor,
* such as configuration notifications. More complex drivers will handle
* some control requests in user space.
*/
static int is_valid_config (struct usb_config_descriptor *config)
{
return config->bDescriptorType == USB_DT_CONFIG
&& config->bLength == USB_DT_CONFIG_SIZE
&& config->bConfigurationValue != 0
&& (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
&& (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
/* FIXME if gadget->is_otg, _must_ include an otg descriptor */
/* FIXME check lengths: walk to end */
}
static ssize_t
dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
{
struct dev_data *dev = fd->private_data;
ssize_t value = len, length = len;
unsigned total;
u32 tag;
char *kbuf;
if (dev->state != STATE_OPENED)
return -EEXIST;
if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
return -EINVAL;
/* we might need to change message format someday */
if (copy_from_user (&tag, buf, 4))
return -EFAULT;
if (tag != 0)
return -EINVAL;
buf += 4;
length -= 4;
kbuf = kmalloc (length, SLAB_KERNEL);
if (!kbuf)
return -ENOMEM;
if (copy_from_user (kbuf, buf, length)) {
kfree (kbuf);
return -EFAULT;
}
spin_lock_irq (&dev->lock);
value = -EINVAL;
if (dev->buf)
goto fail;
dev->buf = kbuf;
/* full or low speed config */
dev->config = (void *) kbuf;
total = le16_to_cpup (&dev->config->wTotalLength);
if (!is_valid_config (dev->config) || total >= length)
goto fail;
kbuf += total;
length -= total;
/* optional high speed config */
if (kbuf [1] == USB_DT_CONFIG) {
dev->hs_config = (void *) kbuf;
total = le16_to_cpup (&dev->hs_config->wTotalLength);
if (!is_valid_config (dev->hs_config) || total >= length)
goto fail;
kbuf += total;
length -= total;
}
/* could support multiple configs, using another encoding! */
/* device descriptor (tweaked for paranoia) */
if (length != USB_DT_DEVICE_SIZE)
goto fail;
dev->dev = (void *)kbuf;
if (dev->dev->bLength != USB_DT_DEVICE_SIZE
|| dev->dev->bDescriptorType != USB_DT_DEVICE
|| dev->dev->bNumConfigurations != 1)
goto fail;
dev->dev->bNumConfigurations = 1;
dev->dev->bcdUSB = __constant_cpu_to_le16 (0x0200);
/* triggers gadgetfs_bind(); then we can enumerate. */
spin_unlock_irq (&dev->lock);
value = usb_gadget_register_driver (&gadgetfs_driver);
if (value != 0) {
kfree (dev->buf);
dev->buf = NULL;
} else {
/* at this point "good" hardware has for the first time
* let the USB the host see us. alternatively, if users
* unplug/replug that will clear all the error state.
*
* note: everything running before here was guaranteed
* to choke driver model style diagnostics. from here
* on, they can work ... except in cleanup paths that
* kick in after the ep0 descriptor is closed.
*/
fd->f_op = &ep0_io_operations;
value = len;
}
return value;
fail:
spin_unlock_irq (&dev->lock);
pr_debug ("%s: %s fail %Zd, %p\n", shortname, __FUNCTION__, value, dev);
kfree (dev->buf);
dev->buf = NULL;
return value;
}
static int
dev_open (struct inode *inode, struct file *fd)
{
struct dev_data *dev = inode->u.generic_ip;
int value = -EBUSY;
if (dev->state == STATE_DEV_DISABLED) {
dev->ev_next = 0;
dev->state = STATE_OPENED;
fd->private_data = dev;
get_dev (dev);
value = 0;
}
return value;
}
static struct file_operations dev_init_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = dev_open,
.write = dev_config,
.fasync = ep0_fasync,
.ioctl = dev_ioctl,
.release = dev_release,
};
/*----------------------------------------------------------------------*/
/* FILESYSTEM AND SUPERBLOCK OPERATIONS
*
* Mounting the filesystem creates a controller file, used first for
* device configuration then later for event monitoring.
*/
/* FIXME PAM etc could set this security policy without mount options
* if epfiles inherited ownership and permissons from ep0 ...
*/
static unsigned default_uid;
static unsigned default_gid;
static unsigned default_perm = S_IRUSR | S_IWUSR;
module_param (default_uid, uint, 0644);
module_param (default_gid, uint, 0644);
module_param (default_perm, uint, 0644);
static struct inode *
gadgetfs_make_inode (struct super_block *sb,
void *data, const struct file_operations *fops,
int mode)
{
struct inode *inode = new_inode (sb);
if (inode) {
inode->i_mode = mode;
inode->i_uid = default_uid;
inode->i_gid = default_gid;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime
= CURRENT_TIME;
inode->u.generic_ip = data;
inode->i_fop = fops;
}
return inode;
}
/* creates in fs root directory, so non-renamable and non-linkable.
* so inode and dentry are paired, until device reconfig.
*/
static struct inode *
gadgetfs_create_file (struct super_block *sb, char const *name,
void *data, const struct file_operations *fops,
struct dentry **dentry_p)
{
struct dentry *dentry;
struct inode *inode;
dentry = d_alloc_name(sb->s_root, name);
if (!dentry)
return NULL;
inode = gadgetfs_make_inode (sb, data, fops,
S_IFREG | (default_perm & S_IRWXUGO));
if (!inode) {
dput(dentry);
return NULL;
}
d_add (dentry, inode);
*dentry_p = dentry;
return inode;
}
static struct super_operations gadget_fs_operations = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
static int
gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
{
struct inode *inode;
struct dentry *d;
struct dev_data *dev;
if (the_device)
return -ESRCH;
/* fake probe to determine $CHIP */
(void) usb_gadget_register_driver (&probe_driver);
if (!CHIP)
return -ENODEV;
/* superblock */
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = GADGETFS_MAGIC;
sb->s_op = &gadget_fs_operations;
sb->s_time_gran = 1;
/* root inode */
inode = gadgetfs_make_inode (sb,
NULL, &simple_dir_operations,
S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode)
goto enomem0;
inode->i_op = &simple_dir_inode_operations;
if (!(d = d_alloc_root (inode)))
goto enomem1;
sb->s_root = d;
/* the ep0 file is named after the controller we expect;
* user mode code can use it for sanity checks, like we do.
*/
dev = dev_new ();
if (!dev)
goto enomem2;
dev->sb = sb;
if (!gadgetfs_create_file (sb, CHIP,
dev, &dev_init_operations,
&dev->dentry))
goto enomem3;
/* other endpoint files are available after hardware setup,
* from binding to a controller.
*/
the_device = dev;
return 0;
enomem3:
put_dev (dev);
enomem2:
dput (d);
enomem1:
iput (inode);
enomem0:
return -ENOMEM;
}
/* "mount -t gadgetfs path /dev/gadget" ends up here */
static int
gadgetfs_get_sb (struct file_system_type *t, int flags,
const char *path, void *opts, struct vfsmount *mnt)
{
return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
}
static void
gadgetfs_kill_sb (struct super_block *sb)
{
kill_litter_super (sb);
if (the_device) {
put_dev (the_device);
the_device = NULL;
}
}
/*----------------------------------------------------------------------*/
static struct file_system_type gadgetfs_type = {
.owner = THIS_MODULE,
.name = shortname,
.get_sb = gadgetfs_get_sb,
.kill_sb = gadgetfs_kill_sb,
};
/*----------------------------------------------------------------------*/
static int __init init (void)
{
int status;
status = register_filesystem (&gadgetfs_type);
if (status == 0)
pr_info ("%s: %s, version " DRIVER_VERSION "\n",
shortname, driver_desc);
return status;
}
module_init (init);
static void __exit cleanup (void)
{
pr_debug ("unregister %s\n", shortname);
unregister_filesystem (&gadgetfs_type);
}
module_exit (cleanup);