drivers/macintosh/adb.c - kernel/msm-4.9 - Gitiles

 /*
  * Device driver for the Apple Desktop Bus
  * and the /dev/adb device on macintoshes.
  *
  * Copyright (C) 1996 Paul Mackerras.
  *
  * Modified to declare controllers as structures, added
  * client notification of bus reset and handles PowerBook
  * sleep, by Benjamin Herrenschmidt.
  *
  * To do:
  *
  * - /sys/bus/adb to list the devices and infos
  * - more /dev/adb to allow userland to receive the
  *   flow of auto-polling datas from a given device.
  * - move bus probe to a kernel thread
  */

 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/smp_lock.h>
 #include <linux/adb.h>
 #include <linux/cuda.h>
 #include <linux/pmu.h>
 #include <linux/notifier.h>
 #include <linux/wait.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/device.h>

 #include <asm/uaccess.h>
 #include <asm/semaphore.h>
 #ifdef CONFIG_PPC
 #include <asm/prom.h>
 #include <asm/machdep.h>
 #endif


 EXPORT_SYMBOL(adb_controller);
 EXPORT_SYMBOL(adb_client_list);

 extern struct adb_driver via_macii_driver;
 extern struct adb_driver via_maciisi_driver;
 extern struct adb_driver via_cuda_driver;
 extern struct adb_driver adb_iop_driver;
 extern struct adb_driver via_pmu_driver;
 extern struct adb_driver macio_adb_driver;

 static struct adb_driver *adb_driver_list[] = {
 #ifdef CONFIG_ADB_MACII
 	&via_macii_driver,
 #endif
 #ifdef CONFIG_ADB_MACIISI
 	&via_maciisi_driver,
 #endif
 #ifdef CONFIG_ADB_CUDA
 	&via_cuda_driver,
 #endif
 #ifdef CONFIG_ADB_IOP
 	&adb_iop_driver,
 #endif
 #if defined(CONFIG_ADB_PMU) || defined(CONFIG_ADB_PMU68K)
 	&via_pmu_driver,
 #endif
 #ifdef CONFIG_ADB_MACIO
 	&macio_adb_driver,
 #endif
 	NULL
 };

 static struct class *adb_dev_class;

 struct adb_driver *adb_controller;
 BLOCKING_NOTIFIER_HEAD(adb_client_list);
 static int adb_got_sleep;
 static int adb_inited;
 static pid_t adb_probe_task_pid;
 static DECLARE_MUTEX(adb_probe_mutex);
 static struct completion adb_probe_task_comp;
 static int sleepy_trackpad;
 static int autopoll_devs;
 int __adb_probe_sync;

 #ifdef CONFIG_PM
 static void adb_notify_sleep(struct pmu_sleep_notifier *self, int when);
 static struct pmu_sleep_notifier adb_sleep_notifier = {
 	adb_notify_sleep,
 	SLEEP_LEVEL_ADB,
 };
 #endif

 static int adb_scan_bus(void);
 static int do_adb_reset_bus(void);
 static void adbdev_init(void);
 static int try_handler_change(int, int);

 static struct adb_handler {
 	void (*handler)(unsigned char *, int, int);
 	int original_address;
 	int handler_id;
 	int busy;
 } adb_handler[16];

 /*
  * The adb_handler_sem mutex protects all accesses to the original_address
  * and handler_id fields of adb_handler[i] for all i, and changes to the
  * handler field.
  * Accesses to the handler field are protected by the adb_handler_lock
  * rwlock.  It is held across all calls to any handler, so that by the
  * time adb_unregister returns, we know that the old handler isn't being
  * called.
  */
 static DECLARE_MUTEX(adb_handler_sem);
 static DEFINE_RWLOCK(adb_handler_lock);

 #if 0
 static void printADBreply(struct adb_request *req)
 {
         int i;

         printk("adb reply (%d)", req->reply_len);
         for(i = 0; i < req->reply_len; i++)
                 printk(" %x", req->reply[i]);
         printk("\n");

 }
 #endif


 static __inline__ void adb_wait_ms(unsigned int ms)
 {
 	if (current->pid && adb_probe_task_pid &&
 	  adb_probe_task_pid == current->pid)
 		msleep(ms);
 	else
 		mdelay(ms);
 }

 static int adb_scan_bus(void)
 {
 	int i, highFree=0, noMovement;
 	int devmask = 0;
 	struct adb_request req;

 	/* assumes adb_handler[] is all zeroes at this point */
 	for (i = 1; i < 16; i++) {
 		/* see if there is anything at address i */
 		adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
                             (i << 4) | 0xf);
 		if (req.reply_len > 1)
 			/* one or more devices at this address */
 			adb_handler[i].original_address = i;
 		else if (i > highFree)
 			highFree = i;
 	}

 	/* Note we reset noMovement to 0 each time we move a device */
 	for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
 		for (i = 1; i < 16; i++) {
 			if (adb_handler[i].original_address == 0)
 				continue;
 			/*
 			 * Send a "talk register 3" command to address i
 			 * to provoke a collision if there is more than
 			 * one device at this address.
 			 */
 			adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 				    (i << 4) | 0xf);
 			/*
 			 * Move the device(s) which didn't detect a
 			 * collision to address `highFree'.  Hopefully
 			 * this only moves one device.
 			 */
 			adb_request(&req, NULL, ADBREQ_SYNC, 3,
 				    (i<< 4) | 0xb, (highFree | 0x60), 0xfe);
 			/*
 			 * See if anybody actually moved. This is suggested
 			 * by HW TechNote 01:
 			 *
 			 * http://developer.apple.com/technotes/hw/hw_01.html
 			 */
 			adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 				    (highFree << 4) | 0xf);
 			if (req.reply_len <= 1) continue;
 			/*
 			 * Test whether there are any device(s) left
 			 * at address i.
 			 */
 			adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 				    (i << 4) | 0xf);
 			if (req.reply_len > 1) {
 				/*
 				 * There are still one or more devices
 				 * left at address i.  Register the one(s)
 				 * we moved to `highFree', and find a new
 				 * value for highFree.
 				 */
 				adb_handler[highFree].original_address =
 					adb_handler[i].original_address;
 				while (highFree > 0 &&
 				       adb_handler[highFree].original_address)
 					highFree--;
 				if (highFree <= 0)
 					break;

 				noMovement = 0;
 			}
 			else {
 				/*
 				 * No devices left at address i; move the
 				 * one(s) we moved to `highFree' back to i.
 				 */
 				adb_request(&req, NULL, ADBREQ_SYNC, 3,
 					    (highFree << 4) | 0xb,
 					    (i | 0x60), 0xfe);
 			}
 		}
 	}

 	/* Now fill in the handler_id field of the adb_handler entries. */
 	printk(KERN_DEBUG "adb devices:");
 	for (i = 1; i < 16; i++) {
 		if (adb_handler[i].original_address == 0)
 			continue;
 		adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 			    (i << 4) | 0xf);
 		adb_handler[i].handler_id = req.reply[2];
 		printk(" [%d]: %d %x", i, adb_handler[i].original_address,
 		       adb_handler[i].handler_id);
 		devmask |= 1 << i;
 	}
 	printk("\n");
 	return devmask;
 }

 /*
  * This kernel task handles ADB probing. It dies once probing is
  * completed.
  */
 static int
 adb_probe_task(void *x)
 {
 	sigset_t blocked;

 	strcpy(current->comm, "kadbprobe");

 	sigfillset(&blocked);
 	sigprocmask(SIG_BLOCK, &blocked, NULL);
 	flush_signals(current);

 	printk(KERN_INFO "adb: starting probe task...\n");
 	do_adb_reset_bus();
 	printk(KERN_INFO "adb: finished probe task...\n");

 	adb_probe_task_pid = 0;
 	up(&adb_probe_mutex);

 	return 0;
 }

 static void
 __adb_probe_task(struct work_struct *bullshit)
 {
 	adb_probe_task_pid = kernel_thread(adb_probe_task, NULL, SIGCHLD | CLONE_KERNEL);
 }

 static DECLARE_WORK(adb_reset_work, __adb_probe_task);

 int
 adb_reset_bus(void)
 {
 	if (__adb_probe_sync) {
 		do_adb_reset_bus();
 		return 0;
 	}

 	down(&adb_probe_mutex);
 	schedule_work(&adb_reset_work);
 	return 0;
 }

 int __init adb_init(void)
 {
 	struct adb_driver *driver;
 	int i;

 #ifdef CONFIG_PPC32
 	if (!machine_is(chrp) && !machine_is(powermac))
 		return 0;
 #endif
 #ifdef CONFIG_MAC
 	if (!MACH_IS_MAC)
 		return 0;
 #endif

 	/* xmon may do early-init */
 	if (adb_inited)
 		return 0;
 	adb_inited = 1;

 	adb_controller = NULL;

 	i = 0;
 	while ((driver = adb_driver_list[i++]) != NULL) {
 		if (!driver->probe()) {
 			adb_controller = driver;
 			break;
 		}
 	}
 	if ((adb_controller == NULL) || adb_controller->init()) {
 		printk(KERN_WARNING "Warning: no ADB interface detected\n");
 		adb_controller = NULL;
 	} else {
 #ifdef CONFIG_PM
 		pmu_register_sleep_notifier(&adb_sleep_notifier);
 #endif /* CONFIG_PM */
 #ifdef CONFIG_PPC
 		if (machine_is_compatible("AAPL,PowerBook1998") ||
 			machine_is_compatible("PowerBook1,1"))
 			sleepy_trackpad = 1;
 #endif /* CONFIG_PPC */
 		init_completion(&adb_probe_task_comp);
 		adbdev_init();
 		adb_reset_bus();
 	}
 	return 0;
 }

 __initcall(adb_init);

 #ifdef CONFIG_PM
 /*
  * notify clients before sleep and reset bus afterwards
  */
 void
 adb_notify_sleep(struct pmu_sleep_notifier *self, int when)
 {
 	switch (when) {
 	case PBOOK_SLEEP_REQUEST:
 		adb_got_sleep = 1;
 		/* We need to get a lock on the probe thread */
 		down(&adb_probe_mutex);
 		/* Stop autopoll */
 		if (adb_controller->autopoll)
 			adb_controller->autopoll(0);
 		blocking_notifier_call_chain(&adb_client_list,
 			ADB_MSG_POWERDOWN, NULL);
 		break;
 	case PBOOK_WAKE:
 		adb_got_sleep = 0;
 		up(&adb_probe_mutex);
 		adb_reset_bus();
 		break;
 	}
 }
 #endif /* CONFIG_PM */

 static int
 do_adb_reset_bus(void)
 {
 	int ret;

 	if (adb_controller == NULL)
 		return -ENXIO;

 	if (adb_controller->autopoll)
 		adb_controller->autopoll(0);

 	blocking_notifier_call_chain(&adb_client_list,
 		ADB_MSG_PRE_RESET, NULL);

 	if (sleepy_trackpad) {
 		/* Let the trackpad settle down */
 		adb_wait_ms(500);
 	}

 	down(&adb_handler_sem);
 	write_lock_irq(&adb_handler_lock);
 	memset(adb_handler, 0, sizeof(adb_handler));
 	write_unlock_irq(&adb_handler_lock);

 	/* That one is still a bit synchronous, oh well... */
 	if (adb_controller->reset_bus)
 		ret = adb_controller->reset_bus();
 	else
 		ret = 0;

 	if (sleepy_trackpad) {
 		/* Let the trackpad settle down */
 		adb_wait_ms(1500);
 	}

 	if (!ret) {
 		autopoll_devs = adb_scan_bus();
 		if (adb_controller->autopoll)
 			adb_controller->autopoll(autopoll_devs);
 	}
 	up(&adb_handler_sem);

 	blocking_notifier_call_chain(&adb_client_list,
 		ADB_MSG_POST_RESET, NULL);

 	return ret;
 }

 void
 adb_poll(void)
 {
 	if ((adb_controller == NULL)||(adb_controller->poll == NULL))
 		return;
 	adb_controller->poll();
 }

 static void
 adb_probe_wakeup(struct adb_request *req)
 {
 	complete(&adb_probe_task_comp);
 }

 /* Static request used during probe */
 static struct adb_request adb_sreq;
 static unsigned long adb_sreq_lock; // Use semaphore ! */

 int
 adb_request(struct adb_request *req, void (*done)(struct adb_request *),
 	    int flags, int nbytes, ...)
 {
 	va_list list;
 	int i, use_sreq;
 	int rc;

 	if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
 		return -ENXIO;
 	if (nbytes < 1)
 		return -EINVAL;
 	if (req == NULL && (flags & ADBREQ_NOSEND))
 		return -EINVAL;

 	if (req == NULL) {
 		if (test_and_set_bit(0,&adb_sreq_lock)) {
 			printk("adb.c: Warning: contention on static request !\n");
 			return -EPERM;
 		}
 		req = &adb_sreq;
 		flags |= ADBREQ_SYNC;
 		use_sreq = 1;
 	} else
 		use_sreq = 0;
 	req->nbytes = nbytes+1;
 	req->done = done;
 	req->reply_expected = flags & ADBREQ_REPLY;
 	req->data[0] = ADB_PACKET;
 	va_start(list, nbytes);
 	for (i = 0; i < nbytes; ++i)
 		req->data[i+1] = va_arg(list, int);
 	va_end(list);

 	if (flags & ADBREQ_NOSEND)
 		return 0;

 	/* Synchronous requests send from the probe thread cause it to
 	 * block. Beware that the "done" callback will be overriden !
 	 */
 	if ((flags & ADBREQ_SYNC) &&
 	    (current->pid && adb_probe_task_pid &&
 	    adb_probe_task_pid == current->pid)) {
 		req->done = adb_probe_wakeup;
 		rc = adb_controller->send_request(req, 0);
 		if (rc || req->complete)
 			goto bail;
 		wait_for_completion(&adb_probe_task_comp);
 		rc = 0;
 		goto bail;
 	}

 	rc = adb_controller->send_request(req, flags & ADBREQ_SYNC);
 bail:
 	if (use_sreq)
 		clear_bit(0, &adb_sreq_lock);

 	return rc;
 }

  /* Ultimately this should return the number of devices with
     the given default id.
     And it does it now ! Note: changed behaviour: This function
     will now register if default_id _and_ handler_id both match
     but handler_id can be left to 0 to match with default_id only.
     When handler_id is set, this function will try to adjust
     the handler_id id it doesn't match. */
 int
 adb_register(int default_id, int handler_id, struct adb_ids *ids,
 	     void (*handler)(unsigned char *, int, int))
 {
 	int i;

 	down(&adb_handler_sem);
 	ids->nids = 0;
 	for (i = 1; i < 16; i++) {
 		if ((adb_handler[i].original_address == default_id) &&
 		    (!handler_id || (handler_id == adb_handler[i].handler_id) ||
 		    try_handler_change(i, handler_id))) {
 			if (adb_handler[i].handler != 0) {
 				printk(KERN_ERR
 				       "Two handlers for ADB device %d\n",
 				       default_id);
 				continue;
 			}
 			write_lock_irq(&adb_handler_lock);
 			adb_handler[i].handler = handler;
 			write_unlock_irq(&adb_handler_lock);
 			ids->id[ids->nids++] = i;
 		}
 	}
 	up(&adb_handler_sem);
 	return ids->nids;
 }

 int
 adb_unregister(int index)
 {
 	int ret = -ENODEV;

 	down(&adb_handler_sem);
 	write_lock_irq(&adb_handler_lock);
 	if (adb_handler[index].handler) {
 		while(adb_handler[index].busy) {
 			write_unlock_irq(&adb_handler_lock);
 			yield();
 			write_lock_irq(&adb_handler_lock);
 		}
 		ret = 0;
 		adb_handler[index].handler = NULL;
 	}
 	write_unlock_irq(&adb_handler_lock);
 	up(&adb_handler_sem);
 	return ret;
 }

 void
 adb_input(unsigned char *buf, int nb, int autopoll)
 {
 	int i, id;
 	static int dump_adb_input = 0;
 	unsigned long flags;

 	void (*handler)(unsigned char *, int, int);

 	/* We skip keystrokes and mouse moves when the sleep process
 	 * has been started. We stop autopoll, but this is another security
 	 */
 	if (adb_got_sleep)
 		return;

 	id = buf[0] >> 4;
 	if (dump_adb_input) {
 		printk(KERN_INFO "adb packet: ");
 		for (i = 0; i < nb; ++i)
 			printk(" %x", buf[i]);
 		printk(", id = %d\n", id);
 	}
 	write_lock_irqsave(&adb_handler_lock, flags);
 	handler = adb_handler[id].handler;
 	if (handler != NULL)
 		adb_handler[id].busy = 1;
 	write_unlock_irqrestore(&adb_handler_lock, flags);
 	if (handler != NULL) {
 		(*handler)(buf, nb, autopoll);
 		wmb();
 		adb_handler[id].busy = 0;
 	}

 }

 /* Try to change handler to new_id. Will return 1 if successful. */
 static int try_handler_change(int address, int new_id)
 {
 	struct adb_request req;

 	if (adb_handler[address].handler_id == new_id)
 	    return 1;
 	adb_request(&req, NULL, ADBREQ_SYNC, 3,
 	    ADB_WRITEREG(address, 3), address | 0x20, new_id);
 	adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 	    ADB_READREG(address, 3));
 	if (req.reply_len < 2)
 	    return 0;
 	if (req.reply[2] != new_id)
 	    return 0;
 	adb_handler[address].handler_id = req.reply[2];

 	return 1;
 }

 int
 adb_try_handler_change(int address, int new_id)
 {
 	int ret;

 	down(&adb_handler_sem);
 	ret = try_handler_change(address, new_id);
 	up(&adb_handler_sem);
 	return ret;
 }

 int
 adb_get_infos(int address, int *original_address, int *handler_id)
 {
 	down(&adb_handler_sem);
 	*original_address = adb_handler[address].original_address;
 	*handler_id = adb_handler[address].handler_id;
 	up(&adb_handler_sem);

 	return (*original_address != 0);
 }


 /*
  * /dev/adb device driver.
  */

 #define ADB_MAJOR	56	/* major number for /dev/adb */

 struct adbdev_state {
 	spinlock_t	lock;
 	atomic_t	n_pending;
 	struct adb_request *completed;
   	wait_queue_head_t wait_queue;
 	int		inuse;
 };

 static void adb_write_done(struct adb_request *req)
 {
 	struct adbdev_state *state = (struct adbdev_state *) req->arg;
 	unsigned long flags;

 	if (!req->complete) {
 		req->reply_len = 0;
 		req->complete = 1;
 	}
 	spin_lock_irqsave(&state->lock, flags);
 	atomic_dec(&state->n_pending);
 	if (!state->inuse) {
 		kfree(req);
 		if (atomic_read(&state->n_pending) == 0) {
 			spin_unlock_irqrestore(&state->lock, flags);
 			kfree(state);
 			return;
 		}
 	} else {
 		struct adb_request **ap = &state->completed;
 		while (*ap != NULL)
 			ap = &(*ap)->next;
 		req->next = NULL;
 		*ap = req;
 		wake_up_interruptible(&state->wait_queue);
 	}
 	spin_unlock_irqrestore(&state->lock, flags);
 }

 static int
 do_adb_query(struct adb_request *req)
 {
 	int	ret = -EINVAL;

 	switch(req->data[1])
 	{
 	case ADB_QUERY_GETDEVINFO:
 		if (req->nbytes < 3)
 			break;
 		down(&adb_handler_sem);
 		req->reply[0] = adb_handler[req->data[2]].original_address;
 		req->reply[1] = adb_handler[req->data[2]].handler_id;
 		up(&adb_handler_sem);
 		req->complete = 1;
 		req->reply_len = 2;
 		adb_write_done(req);
 		ret = 0;
 		break;
 	}
 	return ret;
 }

 static int adb_open(struct inode *inode, struct file *file)
 {
 	struct adbdev_state *state;

 	if (iminor(inode) > 0 || adb_controller == NULL)
 		return -ENXIO;
 	state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
 	if (state == 0)
 		return -ENOMEM;
 	file->private_data = state;
 	spin_lock_init(&state->lock);
 	atomic_set(&state->n_pending, 0);
 	state->completed = NULL;
 	init_waitqueue_head(&state->wait_queue);
 	state->inuse = 1;

 	return 0;
 }

 static int adb_release(struct inode *inode, struct file *file)
 {
 	struct adbdev_state *state = file->private_data;
 	unsigned long flags;

 	lock_kernel();
 	if (state) {
 		file->private_data = NULL;
 		spin_lock_irqsave(&state->lock, flags);
 		if (atomic_read(&state->n_pending) == 0
 		    && state->completed == NULL) {
 			spin_unlock_irqrestore(&state->lock, flags);
 			kfree(state);
 		} else {
 			state->inuse = 0;
 			spin_unlock_irqrestore(&state->lock, flags);
 		}
 	}
 	unlock_kernel();
 	return 0;
 }

 static ssize_t adb_read(struct file *file, char __user *buf,
 			size_t count, loff_t *ppos)
 {
 	int ret = 0;
 	struct adbdev_state *state = file->private_data;
 	struct adb_request *req;
 	wait_queue_t wait = __WAITQUEUE_INITIALIZER(wait,current);
 	unsigned long flags;

 	if (count < 2)
 		return -EINVAL;
 	if (count > sizeof(req->reply))
 		count = sizeof(req->reply);
 	if (!access_ok(VERIFY_WRITE, buf, count))
 		return -EFAULT;

 	req = NULL;
 	spin_lock_irqsave(&state->lock, flags);
 	add_wait_queue(&state->wait_queue, &wait);
 	current->state = TASK_INTERRUPTIBLE;

 	for (;;) {
 		req = state->completed;
 		if (req != NULL)
 			state->completed = req->next;
 		else if (atomic_read(&state->n_pending) == 0)
 			ret = -EIO;
 		if (req != NULL || ret != 0)
 			break;

 		if (file->f_flags & O_NONBLOCK) {
 			ret = -EAGAIN;
 			break;
 		}
 		if (signal_pending(current)) {
 			ret = -ERESTARTSYS;
 			break;
 		}
 		spin_unlock_irqrestore(&state->lock, flags);
 		schedule();
 		spin_lock_irqsave(&state->lock, flags);
 	}

 	current->state = TASK_RUNNING;
 	remove_wait_queue(&state->wait_queue, &wait);
 	spin_unlock_irqrestore(&state->lock, flags);

 	if (ret)
 		return ret;

 	ret = req->reply_len;
 	if (ret > count)
 		ret = count;
 	if (ret > 0 && copy_to_user(buf, req->reply, ret))
 		ret = -EFAULT;

 	kfree(req);
 	return ret;
 }

 static ssize_t adb_write(struct file *file, const char __user *buf,
 			 size_t count, loff_t *ppos)
 {
 	int ret/*, i*/;
 	struct adbdev_state *state = file->private_data;
 	struct adb_request *req;

 	if (count < 2 || count > sizeof(req->data))
 		return -EINVAL;
 	if (adb_controller == NULL)
 		return -ENXIO;
 	if (!access_ok(VERIFY_READ, buf, count))
 		return -EFAULT;

 	req = kmalloc(sizeof(struct adb_request),
 					     GFP_KERNEL);
 	if (req == NULL)
 		return -ENOMEM;

 	req->nbytes = count;
 	req->done = adb_write_done;
 	req->arg = (void *) state;
 	req->complete = 0;

 	ret = -EFAULT;
 	if (copy_from_user(req->data, buf, count))
 		goto out;

 	atomic_inc(&state->n_pending);

 	/* If a probe is in progress or we are sleeping, wait for it to complete */
 	down(&adb_probe_mutex);

 	/* Queries are special requests sent to the ADB driver itself */
 	if (req->data[0] == ADB_QUERY) {
 		if (count > 1)
 			ret = do_adb_query(req);
 		else
 			ret = -EINVAL;
 		up(&adb_probe_mutex);
 	}
 	/* Special case for ADB_BUSRESET request, all others are sent to
 	   the controller */
 	else if ((req->data[0] == ADB_PACKET)&&(count > 1)
 		&&(req->data[1] == ADB_BUSRESET)) {
 		ret = do_adb_reset_bus();
 		up(&adb_probe_mutex);
 		atomic_dec(&state->n_pending);
 		if (ret == 0)
 			ret = count;
 		goto out;
 	} else {
 		req->reply_expected = ((req->data[1] & 0xc) == 0xc);
 		if (adb_controller && adb_controller->send_request)
 			ret = adb_controller->send_request(req, 0);
 		else
 			ret = -ENXIO;
 		up(&adb_probe_mutex);
 	}

 	if (ret != 0) {
 		atomic_dec(&state->n_pending);
 		goto out;
 	}
 	return count;

 out:
 	kfree(req);
 	return ret;
 }

 static const struct file_operations adb_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.read		= adb_read,
 	.write		= adb_write,
 	.open		= adb_open,
 	.release	= adb_release,
 };

 static void
 adbdev_init(void)
 {
 	if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
 		printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
 		return;
 	}

 	adb_dev_class = class_create(THIS_MODULE, "adb");
 	if (IS_ERR(adb_dev_class))
 		return;
 	class_device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
 }
	/*
	* Device driver for the Apple Desktop Bus
	* and the /dev/adb device on macintoshes.
	*
	* Copyright (C) 1996 Paul Mackerras.
	*
	* Modified to declare controllers as structures, added
	* client notification of bus reset and handles PowerBook
	* sleep, by Benjamin Herrenschmidt.
	*
	* To do:
	*
	* - /sys/bus/adb to list the devices and infos
	* - more /dev/adb to allow userland to receive the
	* flow of auto-polling datas from a given device.
	* - move bus probe to a kernel thread
	*/

	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/mm.h>
	#include <linux/sched.h>
	#include <linux/smp_lock.h>
	#include <linux/adb.h>
	#include <linux/cuda.h>
	#include <linux/pmu.h>
	#include <linux/notifier.h>
	#include <linux/wait.h>
	#include <linux/init.h>
	#include <linux/delay.h>
	#include <linux/spinlock.h>
	#include <linux/completion.h>
	#include <linux/device.h>

	#include <asm/uaccess.h>
	#include <asm/semaphore.h>
	#ifdef CONFIG_PPC
	#include <asm/prom.h>
	#include <asm/machdep.h>
	#endif


	EXPORT_SYMBOL(adb_controller);
	EXPORT_SYMBOL(adb_client_list);

	extern struct adb_driver via_macii_driver;
	extern struct adb_driver via_maciisi_driver;
	extern struct adb_driver via_cuda_driver;
	extern struct adb_driver adb_iop_driver;
	extern struct adb_driver via_pmu_driver;
	extern struct adb_driver macio_adb_driver;

	static struct adb_driver *adb_driver_list[] = {
	#ifdef CONFIG_ADB_MACII
	&via_macii_driver,
	#endif
	#ifdef CONFIG_ADB_MACIISI
	&via_maciisi_driver,
	#endif
	#ifdef CONFIG_ADB_CUDA
	&via_cuda_driver,
	#endif
	#ifdef CONFIG_ADB_IOP
	&adb_iop_driver,
	#endif
	#if defined(CONFIG_ADB_PMU) \|\| defined(CONFIG_ADB_PMU68K)
	&via_pmu_driver,
	#endif
	#ifdef CONFIG_ADB_MACIO
	&macio_adb_driver,
	#endif
	NULL
	};

	static struct class *adb_dev_class;

	struct adb_driver *adb_controller;
	BLOCKING_NOTIFIER_HEAD(adb_client_list);
	static int adb_got_sleep;
	static int adb_inited;
	static pid_t adb_probe_task_pid;
	static DECLARE_MUTEX(adb_probe_mutex);
	static struct completion adb_probe_task_comp;
	static int sleepy_trackpad;
	static int autopoll_devs;
	int __adb_probe_sync;

	#ifdef CONFIG_PM
	static void adb_notify_sleep(struct pmu_sleep_notifier *self, int when);
	static struct pmu_sleep_notifier adb_sleep_notifier = {
	adb_notify_sleep,
	SLEEP_LEVEL_ADB,
	};
	#endif

	static int adb_scan_bus(void);
	static int do_adb_reset_bus(void);
	static void adbdev_init(void);
	static int try_handler_change(int, int);

	static struct adb_handler {
	void (handler)(unsigned char , int, int);
	int original_address;
	int handler_id;
	int busy;
	} adb_handler[16];

	/*
	* The adb_handler_sem mutex protects all accesses to the original_address
	* and handler_id fields of adb_handler[i] for all i, and changes to the
	* handler field.
	* Accesses to the handler field are protected by the adb_handler_lock
	* rwlock. It is held across all calls to any handler, so that by the
	* time adb_unregister returns, we know that the old handler isn't being
	* called.
	*/
	static DECLARE_MUTEX(adb_handler_sem);
	static DEFINE_RWLOCK(adb_handler_lock);

	#if 0
	static void printADBreply(struct adb_request *req)
	{
	int i;

	printk("adb reply (%d)", req->reply_len);
	for(i = 0; i < req->reply_len; i++)
	printk(" %x", req->reply[i]);
	printk("\n");

	}
	#endif


	static __inline__ void adb_wait_ms(unsigned int ms)
	{
	if (current->pid && adb_probe_task_pid &&
	adb_probe_task_pid == current->pid)
	msleep(ms);
	else
	mdelay(ms);
	}

	static int adb_scan_bus(void)
	{
	int i, highFree=0, noMovement;
	int devmask = 0;
	struct adb_request req;

	/* assumes adb_handler[] is all zeroes at this point */
	for (i = 1; i < 16; i++) {
	/* see if there is anything at address i */
	adb_request(&req, NULL, ADBREQ_SYNC \| ADBREQ_REPLY, 1,
	(i << 4) \| 0xf);
	if (req.reply_len > 1)
	/* one or more devices at this address */
	adb_handler[i].original_address = i;
	else if (i > highFree)
	highFree = i;
	}

	/* Note we reset noMovement to 0 each time we move a device */
	for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
	for (i = 1; i < 16; i++) {
	if (adb_handler[i].original_address == 0)
	continue;
	/*
	* Send a "talk register 3" command to address i
	* to provoke a collision if there is more than
	* one device at this address.
	*/
	adb_request(&req, NULL, ADBREQ_SYNC \| ADBREQ_REPLY, 1,
	(i << 4) \| 0xf);
	/*
	* Move the device(s) which didn't detect a
	* collision to address `highFree'. Hopefully
	* this only moves one device.
	*/
	adb_request(&req, NULL, ADBREQ_SYNC, 3,
	(i<< 4) \| 0xb, (highFree \| 0x60), 0xfe);
	/*
	* See if anybody actually moved. This is suggested
	* by HW TechNote 01:
	*
	* http://developer.apple.com/technotes/hw/hw_01.html
	*/
	adb_request(&req, NULL, ADBREQ_SYNC \| ADBREQ_REPLY, 1,
	(highFree << 4) \| 0xf);
	if (req.reply_len <= 1) continue;
	/*
	* Test whether there are any device(s) left
	* at address i.
	*/
	adb_request(&req, NULL, ADBREQ_SYNC \| ADBREQ_REPLY, 1,
	(i << 4) \| 0xf);
	if (req.reply_len > 1) {
	/*
	* There are still one or more devices
	* left at address i. Register the one(s)
	* we moved to `highFree', and find a new
	* value for highFree.
	*/
	adb_handler[highFree].original_address =
	adb_handler[i].original_address;
	while (highFree > 0 &&
	adb_handler[highFree].original_address)
	highFree--;
	if (highFree <= 0)
	break;

	noMovement = 0;
	}
	else {
	/*
	* No devices left at address i; move the
	* one(s) we moved to `highFree' back to i.
	*/
	adb_request(&req, NULL, ADBREQ_SYNC, 3,
	(highFree << 4) \| 0xb,
	(i \| 0x60), 0xfe);
	}
	}
	}

	/* Now fill in the handler_id field of the adb_handler entries. */
	printk(KERN_DEBUG "adb devices:");
	for (i = 1; i < 16; i++) {
	if (adb_handler[i].original_address == 0)
	continue;
	adb_request(&req, NULL, ADBREQ_SYNC \| ADBREQ_REPLY, 1,
	(i << 4) \| 0xf);
	adb_handler[i].handler_id = req.reply[2];
	printk(" [%d]: %d %x", i, adb_handler[i].original_address,
	adb_handler[i].handler_id);
	devmask \|= 1 << i;
	}
	printk("\n");
	return devmask;
	}

	/*
	* This kernel task handles ADB probing. It dies once probing is
	* completed.
	*/
	static int
	adb_probe_task(void *x)
	{
	sigset_t blocked;

	strcpy(current->comm, "kadbprobe");

	sigfillset(&blocked);
	sigprocmask(SIG_BLOCK, &blocked, NULL);
	flush_signals(current);

	printk(KERN_INFO "adb: starting probe task...\n");
	do_adb_reset_bus();
	printk(KERN_INFO "adb: finished probe task...\n");

	adb_probe_task_pid = 0;
	up(&adb_probe_mutex);

	return 0;
	}

	static void
	__adb_probe_task(struct work_struct *bullshit)
	{
	adb_probe_task_pid = kernel_thread(adb_probe_task, NULL, SIGCHLD \| CLONE_KERNEL);
	}

	static DECLARE_WORK(adb_reset_work, __adb_probe_task);

	int
	adb_reset_bus(void)
	{
	if (__adb_probe_sync) {
	do_adb_reset_bus();
	return 0;
	}

	down(&adb_probe_mutex);
	schedule_work(&adb_reset_work);
	return 0;
	}

	int __init adb_init(void)
	{
	struct adb_driver *driver;
	int i;

	#ifdef CONFIG_PPC32
	if (!machine_is(chrp) && !machine_is(powermac))
	return 0;
	#endif
	#ifdef CONFIG_MAC
	if (!MACH_IS_MAC)
	return 0;
	#endif

	/* xmon may do early-init */
	if (adb_inited)
	return 0;
	adb_inited = 1;

	adb_controller = NULL;

	i = 0;
	while ((driver = adb_driver_list[i++]) != NULL) {
	if (!driver->probe()) {
	adb_controller = driver;
	break;
	}
	}
	if ((adb_controller == NULL) \|\| adb_controller->init()) {
	printk(KERN_WARNING "Warning: no ADB interface detected\n");
	adb_controller = NULL;
	} else {
	#ifdef CONFIG_PM
	pmu_register_sleep_notifier(&adb_sleep_notifier);
	#endif /* CONFIG_PM */
	#ifdef CONFIG_PPC
	if (machine_is_compatible("AAPL,PowerBook1998") \|\|
	machine_is_compatible("PowerBook1,1"))
	sleepy_trackpad = 1;
	#endif /* CONFIG_PPC */
	init_completion(&adb_probe_task_comp);
	adbdev_init();
	adb_reset_bus();
	}
	return 0;
	}

	__initcall(adb_init);

	#ifdef CONFIG_PM
	/*
	* notify clients before sleep and reset bus afterwards
	*/
	void
	adb_notify_sleep(struct pmu_sleep_notifier *self, int when)
	{
	switch (when) {
	case PBOOK_SLEEP_REQUEST:
	adb_got_sleep = 1;
	/* We need to get a lock on the probe thread */
	down(&adb_probe_mutex);
	/* Stop autopoll */
	if (adb_controller->autopoll)
	adb_controller->autopoll(0);
	blocking_notifier_call_chain(&adb_client_list,
	ADB_MSG_POWERDOWN, NULL);
	break;
	case PBOOK_WAKE:
	adb_got_sleep = 0;
	up(&adb_probe_mutex);
	adb_reset_bus();
	break;
	}
	}
	#endif /* CONFIG_PM */

	static int
	do_adb_reset_bus(void)
	{
	int ret;

	if (adb_controller == NULL)
	return -ENXIO;

	if (adb_controller->autopoll)
	adb_controller->autopoll(0);

	blocking_notifier_call_chain(&adb_client_list,
	ADB_MSG_PRE_RESET, NULL);

	if (sleepy_trackpad) {
	/* Let the trackpad settle down */
	adb_wait_ms(500);
	}

	down(&adb_handler_sem);
	write_lock_irq(&adb_handler_lock);
	memset(adb_handler, 0, sizeof(adb_handler));
	write_unlock_irq(&adb_handler_lock);

	/* That one is still a bit synchronous, oh well... */
	if (adb_controller->reset_bus)
	ret = adb_controller->reset_bus();
	else
	ret = 0;

	if (sleepy_trackpad) {
	/* Let the trackpad settle down */
	adb_wait_ms(1500);
	}

	if (!ret) {
	autopoll_devs = adb_scan_bus();
	if (adb_controller->autopoll)
	adb_controller->autopoll(autopoll_devs);
	}
	up(&adb_handler_sem);

	blocking_notifier_call_chain(&adb_client_list,
	ADB_MSG_POST_RESET, NULL);

	return ret;
	}

	void
	adb_poll(void)
	{
	if ((adb_controller == NULL)\|\|(adb_controller->poll == NULL))
	return;
	adb_controller->poll();
	}

	static void
	adb_probe_wakeup(struct adb_request *req)
	{
	complete(&adb_probe_task_comp);
	}

	/* Static request used during probe */
	static struct adb_request adb_sreq;
	static unsigned long adb_sreq_lock; // Use semaphore ! */

	int
	adb_request(struct adb_request req, void (done)(struct adb_request *),
	int flags, int nbytes, ...)
	{
	va_list list;
	int i, use_sreq;
	int rc;

	if ((adb_controller == NULL) \|\| (adb_controller->send_request == NULL))
	return -ENXIO;
	if (nbytes < 1)
	return -EINVAL;
	if (req == NULL && (flags & ADBREQ_NOSEND))
	return -EINVAL;

	if (req == NULL) {
	if (test_and_set_bit(0,&adb_sreq_lock)) {
	printk("adb.c: Warning: contention on static request !\n");
	return -EPERM;
	}
	req = &adb_sreq;
	flags \|= ADBREQ_SYNC;
	use_sreq = 1;
	} else
	use_sreq = 0;
	req->nbytes = nbytes+1;
	req->done = done;
	req->reply_expected = flags & ADBREQ_REPLY;
	req->data[0] = ADB_PACKET;
	va_start(list, nbytes);
	for (i = 0; i < nbytes; ++i)
	req->data[i+1] = va_arg(list, int);
	va_end(list);

	if (flags & ADBREQ_NOSEND)
	return 0;

	/* Synchronous requests send from the probe thread cause it to
	* block. Beware that the "done" callback will be overriden !
	*/
	if ((flags & ADBREQ_SYNC) &&
	(current->pid && adb_probe_task_pid &&
	adb_probe_task_pid == current->pid)) {
	req->done = adb_probe_wakeup;
	rc = adb_controller->send_request(req, 0);
	if (rc \|\| req->complete)
	goto bail;
	wait_for_completion(&adb_probe_task_comp);
	rc = 0;
	goto bail;
	}

	rc = adb_controller->send_request(req, flags & ADBREQ_SYNC);
	bail:
	if (use_sreq)
	clear_bit(0, &adb_sreq_lock);

	return rc;
	}

	/* Ultimately this should return the number of devices with
	the given default id.
	And it does it now ! Note: changed behaviour: This function
	will now register if default_id _and_ handler_id both match
	but handler_id can be left to 0 to match with default_id only.
	When handler_id is set, this function will try to adjust
	the handler_id id it doesn't match. */
	int
	adb_register(int default_id, int handler_id, struct adb_ids *ids,
	void (handler)(unsigned char , int, int))
	{
	int i;

	down(&adb_handler_sem);
	ids->nids = 0;
	for (i = 1; i < 16; i++) {
	if ((adb_handler[i].original_address == default_id) &&
	(!handler_id \|\| (handler_id == adb_handler[i].handler_id) \|\|
	try_handler_change(i, handler_id))) {
	if (adb_handler[i].handler != 0) {
	printk(KERN_ERR
	"Two handlers for ADB device %d\n",
	default_id);
	continue;
	}
	write_lock_irq(&adb_handler_lock);
	adb_handler[i].handler = handler;
	write_unlock_irq(&adb_handler_lock);
	ids->id[ids->nids++] = i;
	}
	}
	up(&adb_handler_sem);
	return ids->nids;
	}

	int
	adb_unregister(int index)
	{
	int ret = -ENODEV;

	down(&adb_handler_sem);
	write_lock_irq(&adb_handler_lock);
	if (adb_handler[index].handler) {
	while(adb_handler[index].busy) {
	write_unlock_irq(&adb_handler_lock);
	yield();
	write_lock_irq(&adb_handler_lock);
	}
	ret = 0;
	adb_handler[index].handler = NULL;
	}
	write_unlock_irq(&adb_handler_lock);
	up(&adb_handler_sem);
	return ret;
	}

	void
	adb_input(unsigned char *buf, int nb, int autopoll)
	{
	int i, id;
	static int dump_adb_input = 0;
	unsigned long flags;

	void (handler)(unsigned char , int, int);

	/* We skip keystrokes and mouse moves when the sleep process
	* has been started. We stop autopoll, but this is another security
	*/
	if (adb_got_sleep)
	return;

	id = buf[0] >> 4;
	if (dump_adb_input) {
	printk(KERN_INFO "adb packet: ");
	for (i = 0; i < nb; ++i)
	printk(" %x", buf[i]);
	printk(", id = %d\n", id);
	}
	write_lock_irqsave(&adb_handler_lock, flags);
	handler = adb_handler[id].handler;
	if (handler != NULL)
	adb_handler[id].busy = 1;
	write_unlock_irqrestore(&adb_handler_lock, flags);
	if (handler != NULL) {
	(*handler)(buf, nb, autopoll);
	wmb();
	adb_handler[id].busy = 0;
	}

	}

	/* Try to change handler to new_id. Will return 1 if successful. */
	static int try_handler_change(int address, int new_id)
	{
	struct adb_request req;

	if (adb_handler[address].handler_id == new_id)
	return 1;
	adb_request(&req, NULL, ADBREQ_SYNC, 3,
	ADB_WRITEREG(address, 3), address \| 0x20, new_id);
	adb_request(&req, NULL, ADBREQ_SYNC \| ADBREQ_REPLY, 1,
	ADB_READREG(address, 3));
	if (req.reply_len < 2)
	return 0;
	if (req.reply[2] != new_id)
	return 0;
	adb_handler[address].handler_id = req.reply[2];

	return 1;
	}

	int
	adb_try_handler_change(int address, int new_id)
	{
	int ret;

	down(&adb_handler_sem);
	ret = try_handler_change(address, new_id);
	up(&adb_handler_sem);
	return ret;
	}

	int
	adb_get_infos(int address, int original_address, int handler_id)
	{
	down(&adb_handler_sem);
	*original_address = adb_handler[address].original_address;
	*handler_id = adb_handler[address].handler_id;
	up(&adb_handler_sem);

	return (*original_address != 0);
	}


	/*
	* /dev/adb device driver.
	*/

	#define ADB_MAJOR 56 /* major number for /dev/adb */

	struct adbdev_state {
	spinlock_t lock;
	atomic_t n_pending;
	struct adb_request *completed;
	wait_queue_head_t wait_queue;
	int inuse;
	};

	static void adb_write_done(struct adb_request *req)
	{
	struct adbdev_state state = (struct adbdev_state ) req->arg;
	unsigned long flags;

	if (!req->complete) {
	req->reply_len = 0;
	req->complete = 1;
	}
	spin_lock_irqsave(&state->lock, flags);
	atomic_dec(&state->n_pending);
	if (!state->inuse) {
	kfree(req);
	if (atomic_read(&state->n_pending) == 0) {
	spin_unlock_irqrestore(&state->lock, flags);
	kfree(state);
	return;
	}
	} else {
	struct adb_request **ap = &state->completed;
	while (*ap != NULL)
	ap = &(*ap)->next;
	req->next = NULL;
	*ap = req;
	wake_up_interruptible(&state->wait_queue);
	}
	spin_unlock_irqrestore(&state->lock, flags);
	}

	static int
	do_adb_query(struct adb_request *req)
	{
	int ret = -EINVAL;

	switch(req->data[1])
	{
	case ADB_QUERY_GETDEVINFO:
	if (req->nbytes < 3)
	break;
	down(&adb_handler_sem);
	req->reply[0] = adb_handler[req->data[2]].original_address;
	req->reply[1] = adb_handler[req->data[2]].handler_id;
	up(&adb_handler_sem);
	req->complete = 1;
	req->reply_len = 2;
	adb_write_done(req);
	ret = 0;
	break;
	}
	return ret;
	}

	static int adb_open(struct inode inode, struct file file)
	{
	struct adbdev_state *state;

	if (iminor(inode) > 0 \|\| adb_controller == NULL)
	return -ENXIO;
	state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
	if (state == 0)
	return -ENOMEM;
	file->private_data = state;
	spin_lock_init(&state->lock);
	atomic_set(&state->n_pending, 0);
	state->completed = NULL;
	init_waitqueue_head(&state->wait_queue);
	state->inuse = 1;

	return 0;
	}

	static int adb_release(struct inode inode, struct file file)
	{
	struct adbdev_state *state = file->private_data;
	unsigned long flags;

	lock_kernel();
	if (state) {
	file->private_data = NULL;
	spin_lock_irqsave(&state->lock, flags);
	if (atomic_read(&state->n_pending) == 0
	&& state->completed == NULL) {
	spin_unlock_irqrestore(&state->lock, flags);
	kfree(state);
	} else {
	state->inuse = 0;
	spin_unlock_irqrestore(&state->lock, flags);
	}
	}
	unlock_kernel();
	return 0;
	}

	static ssize_t adb_read(struct file file, char __user buf,
	size_t count, loff_t *ppos)
	{
	int ret = 0;
	struct adbdev_state *state = file->private_data;
	struct adb_request *req;
	wait_queue_t wait = __WAITQUEUE_INITIALIZER(wait,current);
	unsigned long flags;

	if (count < 2)
	return -EINVAL;
	if (count > sizeof(req->reply))
	count = sizeof(req->reply);
	if (!access_ok(VERIFY_WRITE, buf, count))
	return -EFAULT;

	req = NULL;
	spin_lock_irqsave(&state->lock, flags);
	add_wait_queue(&state->wait_queue, &wait);
	current->state = TASK_INTERRUPTIBLE;

	for (;;) {
	req = state->completed;
	if (req != NULL)
	state->completed = req->next;
	else if (atomic_read(&state->n_pending) == 0)
	ret = -EIO;
	if (req != NULL \|\| ret != 0)
	break;

	if (file->f_flags & O_NONBLOCK) {
	ret = -EAGAIN;
	break;
	}
	if (signal_pending(current)) {
	ret = -ERESTARTSYS;
	break;
	}
	spin_unlock_irqrestore(&state->lock, flags);
	schedule();
	spin_lock_irqsave(&state->lock, flags);
	}

	current->state = TASK_RUNNING;
	remove_wait_queue(&state->wait_queue, &wait);
	spin_unlock_irqrestore(&state->lock, flags);

	if (ret)
	return ret;

	ret = req->reply_len;
	if (ret > count)
	ret = count;
	if (ret > 0 && copy_to_user(buf, req->reply, ret))
	ret = -EFAULT;

	kfree(req);
	return ret;
	}

	static ssize_t adb_write(struct file file, const char __user buf,
	size_t count, loff_t *ppos)
	{
	int ret/, i/;
	struct adbdev_state *state = file->private_data;
	struct adb_request *req;

	if (count < 2 \|\| count > sizeof(req->data))
	return -EINVAL;
	if (adb_controller == NULL)
	return -ENXIO;
	if (!access_ok(VERIFY_READ, buf, count))
	return -EFAULT;

	req = kmalloc(sizeof(struct adb_request),
	GFP_KERNEL);
	if (req == NULL)
	return -ENOMEM;

	req->nbytes = count;
	req->done = adb_write_done;
	req->arg = (void *) state;
	req->complete = 0;

	ret = -EFAULT;
	if (copy_from_user(req->data, buf, count))
	goto out;

	atomic_inc(&state->n_pending);

	/* If a probe is in progress or we are sleeping, wait for it to complete */
	down(&adb_probe_mutex);

	/* Queries are special requests sent to the ADB driver itself */
	if (req->data[0] == ADB_QUERY) {
	if (count > 1)
	ret = do_adb_query(req);
	else
	ret = -EINVAL;
	up(&adb_probe_mutex);
	}
	/* Special case for ADB_BUSRESET request, all others are sent to
	the controller */
	else if ((req->data[0] == ADB_PACKET)&&(count > 1)
	&&(req->data[1] == ADB_BUSRESET)) {
	ret = do_adb_reset_bus();
	up(&adb_probe_mutex);
	atomic_dec(&state->n_pending);
	if (ret == 0)
	ret = count;
	goto out;
	} else {
	req->reply_expected = ((req->data[1] & 0xc) == 0xc);
	if (adb_controller && adb_controller->send_request)
	ret = adb_controller->send_request(req, 0);
	else
	ret = -ENXIO;
	up(&adb_probe_mutex);
	}

	if (ret != 0) {
	atomic_dec(&state->n_pending);
	goto out;
	}
	return count;

	out:
	kfree(req);
	return ret;
	}

	static const struct file_operations adb_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.read = adb_read,
	.write = adb_write,
	.open = adb_open,
	.release = adb_release,
	};

	static void
	adbdev_init(void)
	{
	if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
	printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
	return;
	}

	adb_dev_class = class_create(THIS_MODULE, "adb");
	if (IS_ERR(adb_dev_class))
	return;
	class_device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
	}