adb.c

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		flags |= ADBREQ_SYNC;
	}
	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;

	return adb_controller->send_request(req, flags & ADBREQ_SYNC);
}

 /* 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, struct pt_regs *, int))
{
	int i;

	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) || 
		    adb_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;
			}
			adb_handler[i].handler = handler;
			ids->id[ids->nids++] = i;
		}
	}
	return ids->nids;
}

int
adb_unregister(int index)
{
	if (!adb_handler[index].handler)
		return -ENODEV;
	adb_handler[index].handler = 0;
	return 0;
}

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

	/* 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);
	}
	if (adb_handler[id].handler != 0) {
		(*adb_handler[id].handler)(buf, nb, regs, autopoll);
	}
}

/* Try to change handler to new_id. Will return 1 if successful */
int
adb_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_get_infos(int address, int *original_address, int *handler_id)
{
	*original_address = adb_handler[address].original_address;
	*handler_id = adb_handler[address].handler_id;
	
	return (*original_address != 0);
}


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

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

extern void adbdev_init(void);

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

	if (MINOR(inode->i_rdev) > 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 long long adb_lseek(struct file *file, loff_t offset, int origin)
{
	return -ESPIPE;
}

static ssize_t adb_read(struct file *file, char *buf,
			size_t count, loff_t *ppos)
{
	int ret;
	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);
	ret = verify_area(VERIFY_WRITE, buf, count);
	if (ret)
		return ret;

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

	for (;;) {
		spin_lock_irqsave(&state->lock, flags);
		req = state->completed;
		if (req != NULL)
			state->completed = req->next;
		else if (atomic_read(&state->n_pending) == 0)
			ret = -EIO;
		spin_unlock_irqrestore(&state->lock, flags);
		if (req != NULL || ret != 0)
			break;
		
		if (file->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			break;
		}
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
		schedule();
	}

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

	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 *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;
	ret = verify_area(VERIFY_READ, buf, count);
	if (ret)
		return ret;

	req = (struct adb_request *) 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 (adb_controller == NULL) return -ENXIO;

	/* Special case for ADB_BUSRESET request, all others are sent to
	   the controller */
	if ((req->data[0] == ADB_PACKET)&&(count > 1)
		&&(req->data[1] == ADB_BUSRESET)) {
		ret = adb_reset_bus();
		atomic_dec(&state->n_pending);
		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;
	}

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

out:
	kfree(req);
	return ret;
}

static struct file_operations adb_fops = {
	llseek:		adb_lseek,
	read:		adb_read,
	write:		adb_write,
	open:		adb_open,
	release:	adb_release,
};

void adbdev_init()
{
#ifdef CONFIG_PPC
	if ( (_machine != _MACH_chrp) && (_machine != _MACH_Pmac) )
		return;
#endif
#ifdef CONFIG_MAC
	if (!MACH_IS_MAC)
		return;
#endif

	if (devfs_register_chrdev(ADB_MAJOR, "adb", &adb_fops))
		printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
	else
		devfs_register (NULL, "adb", DEVFS_FL_DEFAULT,
				ADB_MAJOR, 0,
				S_IFCHR | S_IRUSR | S_IWUSR,
				&adb_fops, NULL);
}