Staging: add princeton instruments usb camera driver

Adds the driver for the Princeton Instruments USB camera.

Needs a lot of work...

TODO:
- make checkpatch.pl clean
- coding style fixups (typedefs, etc.)
- get it to build properly
- audit ioctls
- remove ioctls if possible
- assign proper minor number
- remove dbg() macro
- lots of general cleanups
- review locking

Cc: Judd Montgomery <[e-mail]>
Cc: Jeff Frontz <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/Kconfig

···
 
 source "drivers/staging/rtl8187se/Kconfig"
 
+source "drivers/staging/rspiusb/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile

···
 obj-$(CONFIG_PANEL)		+= panel/
 obj-$(CONFIG_ALTERA_PCIE_CHDMA)	+= altpciechdma/
 obj-$(CONFIG_RTL8187SE)		+= rtl8187se/
+obj-$(CONFIG_USB_RSPI)		+= rspiusb/

drivers/staging/rspiusb/Kconfig

···
+config USB_RSPI
+	tristate "Princeton Instruments USB camera support"
+	default n
+	depends on USB && BROKEN
+	help
+	  This driver is for the Princeton Instruments USB camera device.

drivers/staging/rspiusb/Makefile

···
+obj-$(CONFIG_USB_RSPI)		+= rspiusb.o

drivers/staging/rspiusb/TODO

···
+This driver is for the Princeton Instruments USB camera.
+
+It needs lots of work to get it into the main drivers/usb/ subdirectory:
+
+Any patches to do any of the following changes are greatly appreciated:
+
+	- make checkpatch.pl clean
+	- coding style fixups (typedefs, etc.)
+	- get it to build properly
+	- audit ioctls
+	- remove ioctls if possible
+	- assign proper minor number
+	- remove dbg() macro
+	- lots of general cleanups
+	- review locking
+
+Please send patches to:
+	Greg Kroah-Hartman <[e-mail]>
+and CC:
+	Judd Montgomery <[e-mail]>
+	Jeff Frontz <[e-mail]>
+as they have this device and can test any needed changes.

drivers/staging/rspiusb/rspiusb.c

···
+/*
+ * rspiusb.c
+ *
+ * Copyright (C) 2005, 2006 Princeton Instruments
+ *
+ * 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 version 2 of the License
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/completion.h>
+#include <linux/scatterlist.h>
+#include <linux/usb.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/ioctl.h>
+#include "rspiusb.h"
+
+#ifdef CONFIG_USB_DEBUG
+static int debug = 1;
+#else
+static int debug;
+#endif
+/* Use our own dbg macro */
+#undef dbg
+#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0)
+
+/* Version Information */
+#define DRIVER_VERSION "V1.0.1"
+#define DRIVER_AUTHOR  "Princeton Instruments"
+#define DRIVER_DESC    "PI USB2.0 Device Driver for Linux"
+
+/* Define these values to match your devices */
+#define VENDOR_ID   0x0BD7
+#define ST133_PID   0xA010
+#define PIXIS_PID   0xA026
+
+/* Get a minor range for your devices from the usb maintainer */
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+#define PIUSB_MINOR_BASE    0
+#else
+#define PIUSB_MINOR_BASE    192
+#endif
+
+/* prevent races between open() and disconnect() */
+static DECLARE_MUTEX(disconnect_sem);
+
+/* Structure to hold all of our device specific stuff */
+struct device_extension {
+	struct usb_device *udev;	/* save off the usb device pointer */
+	struct usb_interface *interface;	/* the interface for this device */
+	unsigned char minor;	/* the starting minor number for this device */
+	size_t bulk_in_size_returned;
+	int bulk_in_byte_trk;
+	struct urb ***PixelUrb;
+	int frameIdx;
+	int urbIdx;
+	unsigned int *maplist_numPagesMapped;
+	int open;		/* if the port is open or not */
+	int present;		/* if the device is not disconnected */
+	int userBufMapped;	/* has the user buffer been mapped? */
+	struct scatterlist **sgl;	/* scatter-gather list for user buffer */
+	unsigned int *sgEntries;
+	struct kref kref;
+	int gotPixelData;
+	int pendingWrite;
+	char **pendedPixelUrbs;
+	int iama;		/*PIXIS or ST133 */
+	int num_frames;		/* the number of frames that will fit in the user buffer */
+	int active_frame;
+	unsigned long frameSize;
+	struct semaphore sem;
+	//FX2 specific endpoints
+	unsigned int hEP[8];
+};
+#define to_pi_dev(d) container_of( d, struct device_extension, kref )
+
+static int MapUserBuffer(struct ioctl_struct *, struct device_extension *);
+static int UnMapUserBuffer(struct device_extension *);
+static int piusb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+		       unsigned long arg);
+static int piusb_output(struct ioctl_struct *, unsigned char *, int, struct device_extension *);
+static struct usb_driver piusb_driver;
+
+/* table of devices that work with this driver */
+static struct usb_device_id pi_device_table[] = {
+	{USB_DEVICE(VENDOR_ID, ST133_PID)},
+	{USB_DEVICE(VENDOR_ID, PIXIS_PID)},
+	{0, }			/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, pi_device_table);
+
+static int lastErr = 0;
+static int errCnt = 0;
+
+static void piusb_delete(struct kref *kref)
+{
+	struct device_extension *pdx = to_pi_dev(kref);
+
+	dev_dbg(&pdx->udev->dev, "%s\n", __func__);
+	usb_put_dev(pdx->udev);
+	kfree(pdx);
+}
+
+static int piusb_open(struct inode *inode, struct file *file)
+{
+	struct device_extension *pdx = NULL;
+	struct usb_interface *interface;
+	int subminor;
+	int retval = 0;
+
+	dbg("Piusb_Open()");
+	subminor = iminor(inode);
+	interface = usb_find_interface(&piusb_driver, subminor);
+	if (!interface) {
+		printk(KERN_ERR "%s - error, can't find device for minor %d\n",
+		       __func__, subminor);
+		retval = -ENODEV;
+		goto exit_no_device;
+	}
+
+	pdx = usb_get_intfdata(interface);
+	if (!pdx) {
+		retval = -ENODEV;
+		goto exit_no_device;
+	}
+	dbg("Alternate Setting = %d", interface->num_altsetting);
+
+	pdx->frameIdx = pdx->urbIdx = 0;
+	pdx->gotPixelData = 0;
+	pdx->pendingWrite = 0;
+	pdx->frameSize = 0;
+	pdx->num_frames = 0;
+	pdx->active_frame = 0;
+	pdx->bulk_in_byte_trk = 0;
+	pdx->userBufMapped = 0;
+	pdx->pendedPixelUrbs = NULL;
+	pdx->sgEntries = NULL;
+	pdx->sgl = NULL;
+	pdx->maplist_numPagesMapped = NULL;
+	pdx->PixelUrb = NULL;
+	pdx->bulk_in_size_returned = 0;
+	/* increment our usage count for the device */
+	kref_get(&pdx->kref);
+	/* save our object in the file's private structure */
+	file->private_data = pdx;
+      exit_no_device:
+	return retval;
+}
+
+static int piusb_release(struct inode *inode, struct file *file)
+{
+	struct device_extension *pdx;
+	int retval = 0;
+
+	dbg("Piusb_Release()");
+	pdx = (struct device_extension *)file->private_data;
+	if (pdx == NULL) {
+		dbg("%s - object is NULL", __func__);
+		return -ENODEV;
+	}
+	/* decrement the count on our device */
+	kref_put(&pdx->kref, piusb_delete);
+	return retval;
+}
+
+/**
+ *	piusb_ioctl
+ */
+static int piusb_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+		       unsigned long arg)
+{
+	struct device_extension *pdx;
+	char dummyCtlBuf[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+	unsigned long devRB = 0;
+	int i = 0;
+	int err = 0;
+	int retval = 0;
+	struct ioctl_struct ctrl;
+	unsigned char *uBuf;
+	int numbytes = 0;
+	unsigned short controlData = 0;
+
+	pdx = (struct device_extension *)file->private_data;
+	/* verify that the device wasn't unplugged */
+	if (!pdx->present) {
+		dbg("No Device Present\n");
+		return -ENODEV;
+	}
+	/* fill in your device specific stuff here */
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		err = !access_ok(VERIFY_WRITE, (void __user *)arg, _IOC_SIZE(cmd));
+	else if (_IOC_DIR(cmd) & _IOC_WRITE)
+		err = !access_ok(VERIFY_READ, (void __user *)arg, _IOC_SIZE(cmd));
+	if (err) {
+		dev_err(&pdx->udev->dev, "return with error = %d\n", err);
+		return -EFAULT;
+	}
+	switch (cmd) {
+	case PIUSB_GETVNDCMD:
+		if (copy_from_user
+		    (&ctrl, (void __user *)arg, sizeof(struct ioctl_struct)))
+			info("copy_from_user failed\n");
+		dbg("%s %x\n", "Get Vendor Command = ", ctrl.cmd);
+		retval =
+		    usb_control_msg(pdx->udev, usb_rcvctrlpipe(pdx->udev, 0),
+				    ctrl.cmd, USB_DIR_IN, 0, 0, &devRB,
+				    ctrl.numbytes, HZ * 10);
+		if (ctrl.cmd == 0xF1) {
+			dbg("FW Version returned from HW = %ld.%ld",
+			    (devRB >> 8), (devRB & 0xFF));
+		}
+		return devRB;
+	case PIUSB_SETVNDCMD:
+		if (copy_from_user
+		    (&ctrl, (void __user *)arg, sizeof(struct ioctl_struct)))
+			info("copy_from_user failed\n");
+//            dbg( "%s %x", "Set Vendor Command = ",ctrl.cmd );
+		controlData = ctrl.pData[0];
+		controlData |= (ctrl.pData[1] << 8);
+//            dbg( "%s %d", "Vendor Data =",controlData );
+		retval = usb_control_msg(pdx->udev, usb_sndctrlpipe(pdx->udev, 0), ctrl.cmd, (USB_DIR_OUT | USB_TYPE_VENDOR),	/* | USB_RECIP_ENDPOINT), */
+					 controlData,
+					 0,
+					 &dummyCtlBuf, ctrl.numbytes, HZ * 10);
+		return retval;
+		break;
+	case PIUSB_ISHIGHSPEED:
+		return ((pdx->udev->speed == USB_SPEED_HIGH) ? 1 : 0);
+		break;
+	case PIUSB_WRITEPIPE:
+		if (copy_from_user(&ctrl, (void __user *)arg, _IOC_SIZE(cmd)))
+			info("copy_from_user WRITE_DUMMY failed\n");
+		if (!access_ok(VERIFY_READ, ctrl.pData, ctrl.numbytes)) {
+			dbg("can't access pData");
+			return 0;
+		}
+		piusb_output(&ctrl, ctrl.pData /*uBuf */ , ctrl.numbytes, pdx);
+		return ctrl.numbytes;
+		break;
+	case PIUSB_USERBUFFER:
+		if (copy_from_user
+		    (&ctrl, (void __user *)arg, sizeof(struct ioctl_struct)))
+			info("copy_from_user failed\n");
+		return MapUserBuffer((struct ioctl_struct *) & ctrl, pdx);
+		break;
+	case PIUSB_UNMAP_USERBUFFER:
+		UnMapUserBuffer(pdx);
+		return 0;
+		break;
+	case PIUSB_READPIPE:
+		if (copy_from_user
+		    (&ctrl, (void __user *)arg, sizeof(struct ioctl_struct)))
+			info("copy_from_user failed\n");
+		switch (ctrl.endpoint) {
+		case 0:	//ST133 Pixel Data or PIXIS IO
+			if (pdx->iama == PIXIS_PID) {
+				unsigned int numToRead = 0;
+				unsigned int totalRead = 0;
+				uBuf = kmalloc(ctrl.numbytes, GFP_KERNEL);
+				if (!uBuf) {
+					dbg("Alloc for uBuf failed");
+					return 0;
+				}
+				numbytes = ctrl.numbytes;
+				numToRead = numbytes;
+				dbg("numbytes to read = %d", numbytes);
+				dbg("endpoint # %d", ctrl.endpoint);
+				if (copy_from_user(uBuf, ctrl.pData, numbytes))
+					dbg("copying ctrl.pData to dummyBuf failed");
+				do {
+					i = usb_bulk_msg(pdx->udev, pdx->hEP[ctrl.endpoint], (uBuf + totalRead), (numToRead > 64) ? 64 : numToRead, &numbytes, HZ * 10);	//EP0 can only handle 64 bytes at a time
+					if (i) {
+						dbg("CMD = %s, Address = 0x%02X", ((uBuf[3] == 0x02) ? "WRITE" : "READ"), uBuf[1]);
+						dbg("Number of bytes Attempted to read = %d", (int)ctrl.numbytes);
+						dbg("Blocking ReadI/O Failed with status %d", i);
+						kfree(uBuf);
+						return -1;
+					} else {
+						dbg("Pixis EP0 Read %d bytes",
+						    numbytes);
+						totalRead += numbytes;
+						numToRead -= numbytes;
+					}
+				}
+				while (numToRead);
+				memcpy(ctrl.pData, uBuf, totalRead);
+				dbg("Total Bytes Read from PIXIS EP0 = %d",
+				    totalRead);
+				ctrl.numbytes = totalRead;
+				if (copy_to_user
+				    ((struct ioctl_struct *) arg, &ctrl,
+				     sizeof(struct ioctl_struct)))
+					dbg("copy_to_user failed in IORB");
+				kfree(uBuf);
+				return ctrl.numbytes;
+			} else	//ST133 Pixel Data
+			{
+				if (!pdx->gotPixelData)
+					return 0;
+				else {
+					pdx->gotPixelData = 0;
+					ctrl.numbytes =
+					    pdx->bulk_in_size_returned;
+					pdx->bulk_in_size_returned -=
+					    pdx->frameSize;
+					for (i = 0; i < pdx->maplist_numPagesMapped[pdx->active_frame]; i++)
+						SetPageDirty(pdx->sgl[pdx->active_frame][i].page_link);
+					pdx->active_frame =
+					    ((pdx->active_frame +
+					      1) % pdx->num_frames);
+					return ctrl.numbytes;
+				}
+			}
+			break;
+		case 1:	//ST133IO
+		case 4:	//PIXIS IO
+			uBuf = kmalloc(ctrl.numbytes, GFP_KERNEL);
+			if (!uBuf) {
+				dbg("Alloc for uBuf failed");
+				return 0;
+			}
+			numbytes = ctrl.numbytes;
+//                                      dbg( "numbytes to read = %d", numbytes );
+			if (copy_from_user(uBuf, ctrl.pData, numbytes))
+				dbg("copying ctrl.pData to dummyBuf failed");
+			i = usb_bulk_msg(pdx->udev, pdx->hEP[ctrl.endpoint],
+					 uBuf, numbytes, &numbytes, HZ * 10);
+			if (i) {
+				dbg("Blocking ReadI/O Failed with status %d",
+				    i);
+				kfree(uBuf);
+				return -1;
+			} else {
+				ctrl.numbytes = numbytes;
+				memcpy(ctrl.pData, uBuf, numbytes);
+				if (copy_to_user
+				    ((struct ioctl_struct *) arg, &ctrl,
+				     sizeof(struct ioctl_struct)))
+					dbg("copy_to_user failed in IORB");
+				kfree(uBuf);
+				return ctrl.numbytes;
+			}
+			break;
+
+		case 2:	//PIXIS Ping
+		case 3:	//PIXIS Pong
+			if (!pdx->gotPixelData)
+				return 0;
+			else {
+				pdx->gotPixelData = 0;
+				ctrl.numbytes = pdx->bulk_in_size_returned;
+				pdx->bulk_in_size_returned -= pdx->frameSize;
+				for (i = 0;
+				     i <
+				     pdx->maplist_numPagesMapped[pdx->
+								 active_frame];
+				     i++)
+					SetPageDirty(pdx->sgl[pdx->active_frame][i].page_link);
+				pdx->active_frame =
+				    ((pdx->active_frame + 1) % pdx->num_frames);
+				return ctrl.numbytes;
+			}
+			break;
+		}
+		break;
+	case PIUSB_WHATCAMERA:
+		return pdx->iama;
+	case PIUSB_SETFRAMESIZE:
+		dbg("PIUSB_SETFRAMESIZE");
+		if (copy_from_user
+		    (&ctrl, (void __user *)arg, sizeof(struct ioctl_struct)))
+			info("copy_from_user failed\n");
+		pdx->frameSize = ctrl.numbytes;
+		pdx->num_frames = ctrl.numFrames;
+		if (!pdx->sgl)
+			pdx->sgl =
+			    kmalloc(sizeof(struct scatterlist *) *
+				    pdx->num_frames, GFP_KERNEL);
+		if (!pdx->sgEntries)
+			pdx->sgEntries =
+			    kmalloc(sizeof(unsigned int) * pdx->num_frames,
+				    GFP_KERNEL);
+		if (!pdx->PixelUrb)
+			pdx->PixelUrb =
+			    kmalloc(sizeof(struct urb **) * pdx->num_frames,
+				    GFP_KERNEL);
+		if (!pdx->maplist_numPagesMapped)
+			pdx->maplist_numPagesMapped =
+			    vmalloc(sizeof(unsigned int) * pdx->num_frames);
+		if (!pdx->pendedPixelUrbs)
+			pdx->pendedPixelUrbs =
+			    kmalloc(sizeof(char *) * pdx->num_frames,
+				    GFP_KERNEL);
+		return 0;
+	default:
+		dbg("%s\n", "No IOCTL found");
+		break;
+
+	}
+	/* return that we did not understand this ioctl call */
+	dbg("Returning -ENOTTY");
+	return -ENOTTY;
+}
+
+static void piusb_write_bulk_callback(struct urb *urb)
+{
+	struct device_extension *pdx = urb->context;
+	int status = urb->status;
+
+	/* sync/async unlink faults aren't errors */
+	if (status && !(status == -ENOENT || status == -ECONNRESET))
+		dev_dbg(&urb->dev->dev,
+			"%s - nonzero write bulk status received: %d",
+			__func__, status);
+
+	pdx->pendingWrite = 0;
+	usb_buffer_free(urb->dev, urb->transfer_buffer_length,
+			urb->transfer_buffer, urb->transfer_dma);
+}
+
+int piusb_output(struct ioctl_struct * io, unsigned char *uBuf, int len,
+		 struct device_extension *pdx)
+{
+	struct urb *urb = NULL;
+	int err = 0;
+	unsigned char *kbuf = NULL;
+
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (urb != NULL) {
+		kbuf =
+		    usb_buffer_alloc(pdx->udev, len, GFP_KERNEL,
+				     &urb->transfer_dma);
+		if (!kbuf) {
+			info("buffer_alloc failed\n");
+			return -ENOMEM;
+		}
+		memcpy(kbuf, uBuf, len);
+		usb_fill_bulk_urb(urb, pdx->udev, pdx->hEP[io->endpoint], kbuf,
+				  len, piusb_write_bulk_callback, pdx);
+		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+		err = usb_submit_urb(urb, GFP_KERNEL);
+		if (err) {
+			dev_err(&pdx->udev->dev,
+				"WRITE ERROR:submit urb error = %d\n", err);
+		}
+		pdx->pendingWrite = 1;
+		usb_free_urb(urb);
+	}
+	return -EINPROGRESS;
+}
+
+static int UnMapUserBuffer(struct device_extension *pdx)
+{
+	int i = 0;
+	int k = 0;
+	unsigned int epAddr;
+	for (k = 0; k < pdx->num_frames; k++) {
+		dbg("Killing Urbs for Frame %d", k);
+		for (i = 0; i < pdx->sgEntries[k]; i++) {
+			usb_kill_urb(pdx->PixelUrb[k][i]);
+			usb_free_urb(pdx->PixelUrb[k][i]);
+			pdx->pendedPixelUrbs[k][i] = 0;
+		}
+		dbg("Urb error count = %d", errCnt);
+		errCnt = 0;
+		dbg("Urbs free'd and Killed for Frame %d", k);
+	}
+
+	for (k = 0; k < pdx->num_frames; k++) {
+		if (pdx->iama == PIXIS_PID)	//if so, which EP should we map this frame to
+		{
+			if (k % 2)	//check to see if this should use EP4(PONG)
+			{
+				epAddr = pdx->hEP[3];	//PONG, odd frames
+			} else {
+				epAddr = pdx->hEP[2];	//PING, even frames and zero
+			}
+		} else		//ST133 only has 1 endpoint for Pixel data transfer
+		{
+			epAddr = pdx->hEP[0];
+		}
+		usb_buffer_unmap_sg(pdx->udev, epAddr, pdx->sgl[k],
+				    pdx->maplist_numPagesMapped[k]);
+		for (i = 0; i < pdx->maplist_numPagesMapped[k]; i++) {
+			page_cache_release(pdx->sgl[k][i].page_link);
+		}
+		kfree(pdx->sgl[k]);
+		kfree(pdx->PixelUrb[k]);
+		kfree(pdx->pendedPixelUrbs[k]);
+		pdx->sgl[k] = NULL;
+		pdx->PixelUrb[k] = NULL;
+		pdx->pendedPixelUrbs[k] = NULL;
+	}
+	kfree(pdx->sgEntries);
+	vfree(pdx->maplist_numPagesMapped);
+	pdx->sgEntries = NULL;
+	pdx->maplist_numPagesMapped = NULL;
+	kfree(pdx->sgl);
+	kfree(pdx->pendedPixelUrbs);
+	kfree(pdx->PixelUrb);
+	pdx->sgl = NULL;
+	pdx->pendedPixelUrbs = NULL;
+	pdx->PixelUrb = NULL;
+	return 0;
+}
+
+static void piusb_readPIXEL_callback(struct urb *urb)
+{
+	int i = 0;
+	struct device_extension *pdx = urb->context;
+	int status = urb->status;
+
+	if (status && !(status == -ENOENT || status == -ECONNRESET)) {
+		dbg("%s - nonzero read bulk status received: %d", __func__,
+		    status);
+		dbg("Error in read EP2 callback");
+		dbg("FrameIndex = %d", pdx->frameIdx);
+		dbg("Bytes received before problem occurred = %d",
+		    pdx->bulk_in_byte_trk);
+		dbg("Urb Idx = %d", pdx->urbIdx);
+		pdx->pendedPixelUrbs[pdx->frameIdx][pdx->urbIdx] = 0;
+	} else {
+		pdx->bulk_in_byte_trk += urb->actual_length;
+		{
+			i = usb_submit_urb(urb, GFP_ATOMIC);	//resubmit the URB
+			if (i) {
+				errCnt++;
+				if (i != lastErr) {
+					dbg("submit urb in callback failed with error code %d", i);
+					lastErr = i;
+				}
+			} else {
+				pdx->urbIdx++;	//point to next URB when we callback
+				if (pdx->bulk_in_byte_trk >= pdx->frameSize) {
+					pdx->bulk_in_size_returned =
+					    pdx->bulk_in_byte_trk;
+					pdx->bulk_in_byte_trk = 0;
+					pdx->gotPixelData = 1;
+					pdx->frameIdx =
+					    ((pdx->frameIdx +
+					      1) % pdx->num_frames);
+					pdx->urbIdx = 0;
+				}
+			}
+		}
+	}
+}
+
+/* MapUserBuffer(
+	inputs:
+	struct ioctl_struct *io - structure containing user address, frame #, and size
+	struct device_extension *pdx - the PIUSB device extension
+	returns:
+	int - status of the task
+	Notes:
+	MapUserBuffer maps a buffer passed down through an ioctl.  The user buffer is Page Aligned by the app
+	and then passed down.  The function get_free_pages(...) does the actual mapping of the buffer from user space to
+	kernel space.  From there a scatterlist is created from all the pages.  The next function called is to usb_buffer_map_sg
+	which allocated DMA addresses for each page, even coalescing them if possible.  The DMA address is placed in the scatterlist
+	structure.  The function returns the number of DMA addresses.  This may or may not be equal to the number of pages that
+	the user buffer uses.  We then build an URB for each DMA address and then submit them.
+*/
+//int MapUserBuffer( unsigned long uaddr, unsigned long numbytes, unsigned long frameInfo, struct device_extension *pdx )
+static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
+{
+	unsigned long uaddr;
+	unsigned long numbytes;
+	int frameInfo;		//which frame we're mapping
+	unsigned int epAddr = 0;
+	unsigned long count = 0;
+	int i = 0;
+	int k = 0;
+	int err = 0;
+	struct page **maplist_p;
+	int numPagesRequired;
+	frameInfo = io->numFrames;
+	uaddr = (unsigned long)io->pData;
+	numbytes = io->numbytes;
+
+	if (pdx->iama == PIXIS_PID)	//if so, which EP should we map this frame to
+	{
+		if (frameInfo % 2)	//check to see if this should use EP4(PONG)
+		{
+			epAddr = pdx->hEP[3];	//PONG, odd frames
+		} else {
+			epAddr = pdx->hEP[2];	//PING, even frames and zero
+		}
+		dbg("Pixis Frame #%d: EP=%d", frameInfo,
+		    (epAddr == pdx->hEP[2]) ? 2 : 4);
+	} else			//ST133 only has 1 endpoint for Pixel data transfer
+	{
+		epAddr = pdx->hEP[0];
+		dbg("ST133 Frame #%d: EP=2", frameInfo);
+	}
+	count = numbytes;
+	dbg("UserAddress = 0x%08lX", uaddr);
+	dbg("numbytes = %d", (int)numbytes);
+	//number of pages to map the entire user space DMA buffer
+	numPagesRequired =
+	    ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
+	dbg("Number of pages needed = %d", numPagesRequired);
+	maplist_p = vmalloc(numPagesRequired * sizeof(struct page));	//, GFP_ATOMIC);
+	if (!maplist_p) {
+		dbg("Can't Allocate Memory for maplist_p");
+		return -ENOMEM;
+	}
+	//map the user buffer to kernel memory
+	down_write(&current->mm->mmap_sem);
+	pdx->maplist_numPagesMapped[frameInfo] = get_user_pages(current, current->mm, (uaddr & PAGE_MASK), numPagesRequired, WRITE, 0,	//Don't Force
+								maplist_p,
+								NULL);
+	up_write(&current->mm->mmap_sem);
+	dbg("Number of pages mapped = %d",
+	    pdx->maplist_numPagesMapped[frameInfo]);
+	for (i = 0; i < pdx->maplist_numPagesMapped[frameInfo]; i++)
+		flush_dcache_page(maplist_p[i]);
+	if (!pdx->maplist_numPagesMapped[frameInfo]) {
+		dbg("get_user_pages() failed");
+		vfree(maplist_p);
+		return -ENOMEM;
+	}
+	//need to create a scatterlist that spans each frame that can fit into the mapped buffer
+	pdx->sgl[frameInfo] =
+	    kmalloc((pdx->maplist_numPagesMapped[frameInfo] *
+		     sizeof(struct scatterlist)), GFP_ATOMIC);
+	if (!pdx->sgl[frameInfo]) {
+		vfree(maplist_p);
+		dbg("can't allocate mem for sgl");
+		return -ENOMEM;
+	}
+	pdx->sgl[frameInfo][0].page_link = maplist_p[0];
+	pdx->sgl[frameInfo][0].offset = uaddr & ~PAGE_MASK;
+	if (pdx->maplist_numPagesMapped[frameInfo] > 1) {
+		pdx->sgl[frameInfo][0].length =
+		    PAGE_SIZE - pdx->sgl[frameInfo][0].offset;
+		count -= pdx->sgl[frameInfo][0].length;
+		for (k = 1; k < pdx->maplist_numPagesMapped[frameInfo]; k++) {
+			pdx->sgl[frameInfo][k].offset = 0;
+			pdx->sgl[frameInfo][k].page_link = maplist_p[k];
+			pdx->sgl[frameInfo][k].length =
+			    (count < PAGE_SIZE) ? count : PAGE_SIZE;
+			count -= PAGE_SIZE;	//example had PAGE_SIZE here;
+		}
+	} else {
+		pdx->sgl[frameInfo][0].length = count;
+	}
+	pdx->sgEntries[frameInfo] =
+	    usb_buffer_map_sg(pdx->udev, epAddr, pdx->sgl[frameInfo],
+			      pdx->maplist_numPagesMapped[frameInfo]);
+	dbg("number of sgEntries = %d", pdx->sgEntries[frameInfo]);
+	pdx->userBufMapped = 1;
+	vfree(maplist_p);
+	//Create and Send the URB's for each s/g entry
+	pdx->PixelUrb[frameInfo] =
+	    kmalloc(pdx->sgEntries[frameInfo] * sizeof(struct urb *),
+		    GFP_KERNEL);
+	if (!pdx->PixelUrb[frameInfo]) {
+		dbg("Can't Allocate Memory for Urb");
+		return -ENOMEM;
+	}
+	for (i = 0; i < pdx->sgEntries[frameInfo]; i++) {
+		pdx->PixelUrb[frameInfo][i] = usb_alloc_urb(0, GFP_KERNEL);	//0 because we're using BULK transfers
+		usb_fill_bulk_urb(pdx->PixelUrb[frameInfo][i],
+				  pdx->udev,
+				  epAddr,
+				  (dma_addr_t *) sg_dma_address(&pdx->
+								sgl[frameInfo]
+								[i]),
+				  sg_dma_len(&pdx->sgl[frameInfo][i]),
+				  piusb_readPIXEL_callback, (void *)pdx);
+		pdx->PixelUrb[frameInfo][i]->transfer_dma =
+		    sg_dma_address(&pdx->sgl[frameInfo][i]);
+		pdx->PixelUrb[frameInfo][i]->transfer_flags =
+		    URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT;
+	}
+	pdx->PixelUrb[frameInfo][--i]->transfer_flags &= ~URB_NO_INTERRUPT;	//only interrupt when last URB completes
+	pdx->pendedPixelUrbs[frameInfo] =
+	    kmalloc((pdx->sgEntries[frameInfo] * sizeof(char)), GFP_KERNEL);
+	if (!pdx->pendedPixelUrbs[frameInfo])
+		dbg("Can't allocate Memory for pendedPixelUrbs");
+	for (i = 0; i < pdx->sgEntries[frameInfo]; i++) {
+		err = usb_submit_urb(pdx->PixelUrb[frameInfo][i], GFP_ATOMIC);
+		if (err) {
+			dbg("%s %d\n", "submit urb error =", err);
+			pdx->pendedPixelUrbs[frameInfo][i] = 0;
+			return err;
+		} else
+			pdx->pendedPixelUrbs[frameInfo][i] = 1;;
+	}
+	return 0;
+}
+
+static struct file_operations piusb_fops = {
+	.owner = THIS_MODULE,
+	.ioctl = piusb_ioctl,
+	.open = piusb_open,
+	.release = piusb_release,
+};
+
+static struct usb_class_driver piusb_class = {
+	.name = "usb/rspiusb%d",
+	.fops = &piusb_fops,
+	.minor_base = PIUSB_MINOR_BASE,
+};
+
+/**
+ *	piusb_probe
+ *
+ *	Called by the usb core when a new device is connected that it thinks
+ *	this driver might be interested in.
+ */
+static int piusb_probe(struct usb_interface *interface,
+		       const struct usb_device_id *id)
+{
+	struct device_extension *pdx = NULL;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	int i;
+	int retval = -ENOMEM;
+
+	dev_dbg(&interface->dev, "%s - Looking for PI USB Hardware", __func__);
+
+	pdx = kzalloc(sizeof(struct device_extension), GFP_KERNEL);
+	if (pdx == NULL) {
+		dev_err(&interface->dev, "Out of memory\n");
+		goto error;
+	}
+	kref_init(&pdx->kref);
+	pdx->udev = usb_get_dev(interface_to_usbdev(interface));
+	pdx->interface = interface;
+	iface_desc = interface->cur_altsetting;
+
+	/* See if the device offered us matches what we can accept */
+	if ((pdx->udev->descriptor.idVendor != VENDOR_ID)
+	    || ((pdx->udev->descriptor.idProduct != PIXIS_PID)
+		&& (pdx->udev->descriptor.idProduct != ST133_PID))) {
+		return -ENODEV;
+	}
+	pdx->iama = pdx->udev->descriptor.idProduct;
+
+	if (debug) {
+		if (pdx->udev->descriptor.idProduct == PIXIS_PID)
+			dbg("PIUSB:Pixis Camera Found");
+		else
+			dbg("PIUSB:ST133 USB Controller Found");
+		if (pdx->udev->speed == USB_SPEED_HIGH)
+			dbg("Highspeed(USB2.0) Device Attached");
+		else
+			dbg("Lowspeed (USB1.1) Device Attached");
+
+		dbg("NumEndpoints in Configuration: %d",
+		    iface_desc->desc.bNumEndpoints);
+	}
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+		if (debug) {
+			dbg("Endpoint[%d]->bDescriptorType = %d", i,
+			    endpoint->bDescriptorType);
+			dbg("Endpoint[%d]->bEndpointAddress = 0x%02X", i,
+			    endpoint->bEndpointAddress);
+			dbg("Endpoint[%d]->bbmAttributes = %d", i,
+			    endpoint->bmAttributes);
+			dbg("Endpoint[%d]->MaxPacketSize = %d\n", i,
+			    endpoint->wMaxPacketSize);
+		}
+		if ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+		    USB_ENDPOINT_XFER_BULK) {
+			if (endpoint->bEndpointAddress & USB_DIR_IN)
+				pdx->hEP[i] =
+				    usb_rcvbulkpipe(pdx->udev,
+						    endpoint->bEndpointAddress);
+			else
+				pdx->hEP[i] =
+				    usb_sndbulkpipe(pdx->udev,
+						    endpoint->bEndpointAddress);
+		}
+	}
+	usb_set_intfdata(interface, pdx);
+	retval = usb_register_dev(interface, &piusb_class);
+	if (retval) {
+		err("Not able to get a minor for this device.");
+		usb_set_intfdata(interface, NULL);
+		goto error;
+	}
+	pdx->present = 1;
+
+	/* we can register the device now, as it is ready */
+	pdx->minor = interface->minor;
+	/* let the user know what node this device is now attached to */
+	dbg("PI USB2.0 device now attached to piusb-%d", pdx->minor);
+	return 0;
+
+      error:
+	if (pdx)
+		kref_put(&pdx->kref, piusb_delete);
+	return retval;
+}
+
+/**
+ *	piusb_disconnect
+ *
+ *	Called by the usb core when the device is removed from the system.
+ *
+ *	This routine guarantees that the driver will not submit any more urbs
+ *	by clearing pdx->udev.  It is also supposed to terminate any currently
+ *	active urbs.  Unfortunately, usb_bulk_msg(), used in piusb_read(), does
+ *	not provide any way to do this.  But at least we can cancel an active
+ *	write.
+ */
+static void piusb_disconnect(struct usb_interface *interface)
+{
+	struct device_extension *pdx;
+	int minor = interface->minor;
+	lock_kernel();
+	pdx = usb_get_intfdata(interface);
+	usb_set_intfdata(interface, NULL);
+	/* give back our minor */
+	usb_deregister_dev(interface, &piusb_class);
+	unlock_kernel();
+	/* prevent device read, write and ioctl */
+	pdx->present = 0;
+	kref_put(&pdx->kref, piusb_delete);
+	dbg("PI USB2.0 device #%d now disconnected\n", minor);
+}
+
+static struct usb_driver piusb_driver = {
+	.name = "sub",
+	.probe = piusb_probe,
+	.disconnect = piusb_disconnect,
+	.id_table = pi_device_table,
+};
+
+/**
+ *	piusb_init
+ */
+static int __init piusb_init(void)
+{
+	int result;
+	/* register this driver with the USB subsystem */
+	result = usb_register(&piusb_driver);
+	if (result) {
+		printk(KERN_ERR KBUILD_MODNAME
+		       ": usb_register failed. Error number %d\n", result);
+		return result;
+	}
+	printk(KERN_INFO KBUILD_MODNAME ":%s: %s\n", DRIVER_DESC,
+	       DRIVER_VERSION);
+	return 0;
+}
+
+/**
+ *	piusb_exit
+ */
+static void __exit piusb_exit(void)
+{
+	/* deregister this driver with the USB subsystem */
+	usb_deregister(&piusb_driver);
+}
+
+module_init(piusb_init);
+module_exit(piusb_exit);
+
+/* Module parameters */
+module_param(debug, int, 0);
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL v2");

drivers/staging/rspiusb/rspiusb.h

···
+#ifndef __RSPIUSB_H
+#define __RSPIUSB_H
+
+#define PIUSB_MAGIC		'm'
+#define PIUSB_IOCTL_BASE	192
+#define PIUSB_GETVNDCMD		_IOR(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 1, struct ioctl_struct)
+#define PIUSB_SETVNDCMD		_IOW(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 2, struct ioctl_struct)
+#define PIUSB_WRITEPIPE		_IOW(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 3, struct ioctl_struct)
+#define PIUSB_READPIPE		_IOR(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 4, struct ioctl_struct)
+#define PIUSB_SETFRAMESIZE	_IOW(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 5, struct ioctl_struct)
+#define PIUSB_WHATCAMERA	_IO(PIUSB_MAGIC,  PIUSB_IOCTL_BASE + 6)
+#define PIUSB_USERBUFFER	_IOW(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 7, struct ioctl_struct)
+#define PIUSB_ISHIGHSPEED	_IO(PIUSB_MAGIC,  PIUSB_IOCTL_BASE + 8)
+#define PIUSB_UNMAP_USERBUFFER	_IOW(PIUSB_MAGIC, PIUSB_IOCTL_BASE + 9, struct ioctl_struct)
+
+struct ioctl_struct {
+	unsigned char cmd;
+	unsigned long numbytes;
+	unsigned char dir;	//1=out;0=in
+	int endpoint;
+	int numFrames;
+	unsigned char *pData;
+};
+
+#endif