[PATCH] USB: gadgetfs minor updates

Gadgetfs updates:

 - Resolve a problem that came from a change in the API to AIO:
   kiocb->private type and size changed, but the name remained
   the same ... so GCC wouldn't report pending memory-corruption.

 - Probe the controller at runtime, eliminatingting config-specific
   defines which need to be updated for each new controller.  Rip
   out the old #defines.

 - Use newish APIs to let VBUS current be used to recharge
   batteries (or whatever).

 - Use no_llseek() ... endpoints are pure data streams.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/gadget/inode.c

 /*
  * inode.c -- user mode filesystem api for usb gadget controllers
  *
- * Copyright (C) 2003 David Brownell
+ * Copyright (C) 2003-2004 David Brownell
  * Copyright (C) 2003 Agilent Technologies
  *
  * This program is free software; you can redistribute it and/or modify
@@ -71,7 +71,7 @@
  */
 
 #define	DRIVER_DESC	"USB Gadget filesystem"
-#define	DRIVER_VERSION	"18 Nov 2003"
+#define	DRIVER_VERSION	"24 Aug 2004"
 
 static const char driver_desc [] = DRIVER_DESC;
 static const char shortname [] = "gadgetfs";
@@ -229,41 +229,12 @@ static void put_ep (struct ep_data *data)
 /*----------------------------------------------------------------------*/
 
 /* most "how to use the hardware" policy choices are in userspace:
- * mapping endpoint roles the driver needs to the capabilities that
- * the usb controller exposes.
+ * 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.
  */
 
-#ifdef	CONFIG_USB_GADGET_DUMMY_HCD
-/* act (mostly) like a net2280 */
-#define CONFIG_USB_GADGET_NET2280
-#endif
-
-#ifdef	CONFIG_USB_GADGET_NET2280
-#define CHIP			"net2280"
-#define HIGHSPEED
-#endif
-
-#ifdef	CONFIG_USB_GADGET_PXA2XX
-#define CHIP			"pxa2xx_udc"
-/* earlier hardware doesn't have UDCCFR, races set_{config,interface} */
-#warning works best with pxa255 or newer
-#endif
-
-#ifdef	CONFIG_USB_GADGET_GOKU
-#define CHIP			"goku_udc"
-#endif
-
-#ifdef	CONFIG_USB_GADGET_OMAP
-#define CHIP			"omap_udc"
-#endif
-
-#ifdef	CONFIG_USB_GADGET_SA1100
-#define CHIP			"sa1100"
-#endif
-
-#ifdef CONFIG_USB_GADGET_LH7A40X
-#define CHIP			"lh7a40x_udc"
-#endif
+static const char *CHIP;
 
 /*----------------------------------------------------------------------*/
 
@@ -562,7 +533,7 @@ struct kiocb_priv {
 
 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 {
-	struct kiocb_priv	*priv = (void *) &iocb->private;
+	struct kiocb_priv	*priv = iocb->private;
 	struct ep_data		*epdata;
 	int			value;
 
@@ -583,7 +554,7 @@ static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 
 static long ep_aio_read_retry(struct kiocb *iocb)
 {
-	struct kiocb_priv	*priv = (void *) &iocb->private;
+	struct kiocb_priv	*priv = iocb->private;
 	int			status = priv->actual;
 
 	/* we "retry" to get the right mm context for this: */
@@ -593,6 +564,7 @@ static long ep_aio_read_retry(struct kiocb *iocb)
 	else
 		status = priv->actual;
 	kfree(priv->buf);
+	kfree(priv);
 	aio_put_req(iocb);
 	return status;
 }
@@ -600,7 +572,7 @@ static long ep_aio_read_retry(struct kiocb *iocb)
 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 {
 	struct kiocb		*iocb = req->context;
-	struct kiocb_priv	*priv = (void *) &iocb->private;
+	struct kiocb_priv	*priv = iocb->private;
 	struct ep_data		*epdata = priv->epdata;
 
 	/* lock against disconnect (and ideally, cancel) */
@@ -611,6 +583,8 @@ static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 			|| unlikely(0 == req->actual)
 			|| unlikely(kiocbIsCancelled(iocb))) {
 		kfree(req->buf);
+		kfree(priv);
+		iocb->private = 0;
 		/* aio_complete() reports bytes-transferred _and_ faults */
 		if (unlikely(kiocbIsCancelled(iocb)))
 			aio_put_req(iocb);
@@ -635,17 +609,33 @@ static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 }
 
 static ssize_t
-ep_aio_rwtail(struct kiocb *iocb, char *buf, size_t len, struct ep_data *epdata)
+ep_aio_rwtail(
+	struct kiocb	*iocb,
+	char		*buf,
+	size_t		len,
+	struct ep_data	*epdata,
+	char __user	*ubuf
+)
 {
 	struct kiocb_priv	*priv = (void *) &iocb->private;
 	struct usb_request	*req;
 	ssize_t			value;
 
-	value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
-	if (unlikely(value < 0)) {
+	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);
@@ -675,9 +665,10 @@ ep_aio_rwtail(struct kiocb *iocb, char *buf, size_t len, struct ep_data *epdata)
 
 	up(&epdata->lock);
 
-	if (unlikely(value))
+	if (unlikely(value)) {
+		kfree(priv);
 		put_ep(epdata);
-	else
+	} else
 		value = -EIOCBQUEUED;
 	return value;
 }
@@ -685,7 +676,6 @@ ep_aio_rwtail(struct kiocb *iocb, char *buf, size_t len, struct ep_data *epdata)
 static ssize_t
 ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 {
-	struct kiocb_priv	*priv = (void *) &iocb->private;
 	struct ep_data		*epdata = iocb->ki_filp->private_data;
 	char			*buf;
 
@@ -695,8 +685,7 @@ ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
 	if (unlikely(!buf))
 		return -ENOMEM;
 	iocb->ki_retry = ep_aio_read_retry;
-	priv->ubuf = ubuf;
-	return ep_aio_rwtail(iocb, buf, len, epdata);
+	return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
 }
 
 static ssize_t
@@ -714,7 +703,7 @@ ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 		kfree(buf);
 		return -EFAULT;
 	}
-	return ep_aio_rwtail(iocb, buf, len, epdata);
+	return ep_aio_rwtail(iocb, buf, len, epdata, 0);
 }
 
 /*----------------------------------------------------------------------*/
@@ -722,6 +711,8 @@ ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
 /* 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,
@@ -878,6 +869,8 @@ ep_open (struct inode *inode, struct file *fd)
 /* 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,
@@ -984,6 +977,18 @@ ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 				retval = usb_ep_queue (ep, req, GFP_ATOMIC);
 			dev->state = STATE_CONNECTED;
 
+			/* assume that was SET_CONFIGURATION */
+			if (dev->current_config) {
+				unsigned power;
+#ifdef	HIGHSPEED
+				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) {
@@ -1234,6 +1239,8 @@ static int dev_ioctl (struct inode *inode, struct file *fd,
 /* 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,
@@ -1410,19 +1417,25 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 		if (0 == (u8) ctrl->wValue) {
 			value = 0;
 			dev->current_config = 0;
+			usb_gadget_vbus_draw(gadget, 8 /* mA */ );
 			// user mode expected to disable endpoints
 		} else {
-			u8	config;
+			u8	config, power;
 #ifdef	HIGHSPEED
-			if (gadget->speed == USB_SPEED_HIGH)
+			if (gadget->speed == USB_SPEED_HIGH) {
 				config = dev->hs_config->bConfigurationValue;
-			else
+				power = dev->hs_config->bMaxPower;
+			} else
 #endif
+			{
 				config = dev->config->bConfigurationValue;
+				power = dev->config->bMaxPower;
+			}
 
 			if (config == (u8) ctrl->wValue) {
 				value = 0;
 				dev->current_config = config;
+				usb_gadget_vbus_draw(gadget, 2 * power);
 			}
 		}
 
@@ -1640,8 +1653,8 @@ gadgetfs_bind (struct usb_gadget *gadget)
 	if (!dev)
 		return -ESRCH;
 	if (0 != strcmp (CHIP, gadget->name)) {
-		printk (KERN_ERR "%s expected " CHIP " controller not %s\n",
-			shortname, gadget->name);
+		printk (KERN_ERR "%s expected %s controller not %s\n",
+			shortname, CHIP, gadget->name);
 		return -ENODEV;
 	}
 
@@ -1731,6 +1744,26 @@ static struct usb_gadget_driver gadgetfs_driver = {
 
 /*----------------------------------------------------------------------*/
 
+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)
@@ -1767,6 +1800,7 @@ static int is_valid_config (struct usb_config_descriptor *config)
 		&& 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 */
 }
 
@@ -1885,6 +1919,8 @@ dev_open (struct inode *inode, struct file *fd)
 
 static struct file_operations dev_init_operations = {
 	.owner =	THIS_MODULE,
+	.llseek =	no_llseek,
+
 	.open =		dev_open,
 	.write =	dev_config,
 	.fasync =	ep0_fasync,
@@ -1980,6 +2016,11 @@ gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
 	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;