Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 896 insertions, 0 deletions

diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
new file mode 100644
index 000000000..76e98f0f7
--- /dev/null
+++ b/drivers/macintosh/adb.c
@@ -0,0 +1,896 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/signal.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 <linux/kthread.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+
+#include <linux/uaccess.h>
+#ifdef CONFIG_PPC
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#endif
+
+
+EXPORT_SYMBOL(adb_client_list);
+
+extern struct adb_driver via_macii_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 DEFINE_MUTEX(adb_mutex);
+static struct adb_driver *adb_driver_list[] = {
+#ifdef CONFIG_ADB_MACII
+	&via_macii_driver,
+#endif
+#ifdef CONFIG_ADB_CUDA
+	&via_cuda_driver,
+#endif
+#ifdef CONFIG_ADB_IOP
+	&adb_iop_driver,
+#endif
+#ifdef CONFIG_ADB_PMU
+	&via_pmu_driver,
+#endif
+#ifdef CONFIG_ADB_MACIO
+	&macio_adb_driver,
+#endif
+	NULL
+};
+
+static struct class *adb_dev_class;
+
+static struct adb_driver *adb_controller;
+BLOCKING_NOTIFIER_HEAD(adb_client_list);
+static int adb_got_sleep;
+static int adb_inited;
+static DEFINE_SEMAPHORE(adb_probe_mutex);
+static int sleepy_trackpad;
+static int autopoll_devs;
+int __adb_probe_sync;
+
+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_mutex 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 DEFINE_MUTEX(adb_handler_mutex);
+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 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. */
+	pr_debug("adb devices:\n");
+	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];
+		pr_debug(" [%d]: %d %x\n", i, adb_handler[i].original_address,
+			 adb_handler[i].handler_id);
+		devmask |= 1 << i;
+	}
+	return devmask;
+}
+
+/*
+ * This kernel task handles ADB probing. It dies once probing is
+ * completed.
+ */
+static int
+adb_probe_task(void *x)
+{
+	pr_debug("adb: starting probe task...\n");
+	do_adb_reset_bus();
+	pr_debug("adb: finished probe task...\n");
+
+	up(&adb_probe_mutex);
+
+	return 0;
+}
+
+static void
+__adb_probe_task(struct work_struct *bullshit)
+{
+	kthread_run(adb_probe_task, NULL, "kadbprobe");
+}
+
+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;
+}
+
+#ifdef CONFIG_PM
+/*
+ * notify clients before sleep
+ */
+static int __adb_suspend(struct platform_device *dev, pm_message_t state)
+{
+	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);
+
+	return 0;
+}
+
+static int adb_suspend(struct device *dev)
+{
+	return __adb_suspend(to_platform_device(dev), PMSG_SUSPEND);
+}
+
+static int adb_freeze(struct device *dev)
+{
+	return __adb_suspend(to_platform_device(dev), PMSG_FREEZE);
+}
+
+static int adb_poweroff(struct device *dev)
+{
+	return __adb_suspend(to_platform_device(dev), PMSG_HIBERNATE);
+}
+
+/*
+ * reset bus after sleep
+ */
+static int __adb_resume(struct platform_device *dev)
+{
+	adb_got_sleep = 0;
+	up(&adb_probe_mutex);
+	adb_reset_bus();
+
+	return 0;
+}
+
+static int adb_resume(struct device *dev)
+{
+	return __adb_resume(to_platform_device(dev));
+}
+#endif /* CONFIG_PM */
+
+static 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 &&
+	    adb_controller->init())
+		adb_controller = NULL;
+	if (adb_controller == NULL) {
+		pr_warn("Warning: no ADB interface detected\n");
+	} else {
+#ifdef CONFIG_PPC
+		if (of_machine_is_compatible("AAPL,PowerBook1998") ||
+			of_machine_is_compatible("PowerBook1,1"))
+			sleepy_trackpad = 1;
+#endif /* CONFIG_PPC */
+
+		adbdev_init();
+		adb_reset_bus();
+	}
+	return 0;
+}
+
+device_initcall(adb_init);
+
+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 */
+		msleep(500);
+	}
+
+	mutex_lock(&adb_handler_mutex);
+	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 */
+		msleep(1500);
+	}
+
+	if (!ret) {
+		autopoll_devs = adb_scan_bus();
+		if (adb_controller->autopoll)
+			adb_controller->autopoll(autopoll_devs);
+	}
+	mutex_unlock(&adb_handler_mutex);
+
+	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();
+}
+EXPORT_SYMBOL(adb_poll);
+
+static void adb_sync_req_done(struct adb_request *req)
+{
+	struct completion *comp = req->arg;
+
+	complete(comp);
+}
+
+int
+adb_request(struct adb_request *req, void (*done)(struct adb_request *),
+	    int flags, int nbytes, ...)
+{
+	va_list list;
+	int i;
+	int rc;
+	struct completion comp;
+
+	if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
+		return -ENXIO;
+	if (nbytes < 1)
+		return -EINVAL;
+
+	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 block using an on-stack completion */
+	if (flags & ADBREQ_SYNC) {
+		WARN_ON(done);
+		req->done = adb_sync_req_done;
+		req->arg = &comp;
+		init_completion(&comp);
+	}
+
+	rc = adb_controller->send_request(req, 0);
+
+	if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
+		wait_for_completion(&comp);
+
+	return rc;
+}
+EXPORT_SYMBOL(adb_request);
+
+ /* 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;
+
+	mutex_lock(&adb_handler_mutex);
+	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) {
+				pr_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;
+		}
+	}
+	mutex_unlock(&adb_handler_mutex);
+	return ids->nids;
+}
+EXPORT_SYMBOL(adb_register);
+
+int
+adb_unregister(int index)
+{
+	int ret = -ENODEV;
+
+	mutex_lock(&adb_handler_mutex);
+	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);
+	mutex_unlock(&adb_handler_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(adb_unregister);
+
+void
+adb_input(unsigned char *buf, int nb, int autopoll)
+{
+	int i, id;
+	static int dump_adb_input;
+	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) {
+		pr_info("adb packet: ");
+		for (i = 0; i < nb; ++i)
+			pr_cont(" %x", buf[i]);
+		pr_cont(", 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;
+
+	mutex_lock(&adb_handler_mutex);
+	ret = try_handler_change(address, new_id);
+	mutex_unlock(&adb_handler_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(adb_try_handler_change);
+
+int
+adb_get_infos(int address, int *original_address, int *handler_id)
+{
+	mutex_lock(&adb_handler_mutex);
+	*original_address = adb_handler[address].original_address;
+	*handler_id = adb_handler[address].handler_id;
+	mutex_unlock(&adb_handler_mutex);
+
+	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;
+		mutex_lock(&adb_handler_mutex);
+		req->reply[0] = adb_handler[req->data[2]].original_address;
+		req->reply[1] = adb_handler[req->data[2]].handler_id;
+		mutex_unlock(&adb_handler_mutex);
+		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;
+	int ret = 0;
+
+	mutex_lock(&adb_mutex);
+	if (iminor(inode) > 0 || adb_controller == NULL) {
+		ret = -ENXIO;
+		goto out;
+	}
+	state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
+	if (state == 0) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	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;
+
+out:
+	mutex_unlock(&adb_mutex);
+	return ret;
+}
+
+static int adb_release(struct inode *inode, struct file *file)
+{
+	struct adbdev_state *state = file->private_data;
+	unsigned long flags;
+
+	mutex_lock(&adb_mutex);
+	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);
+		}
+	}
+	mutex_unlock(&adb_mutex);
+	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;
+	DECLARE_WAITQUEUE(wait, current);
+	unsigned long flags;
+
+	if (count < 2)
+		return -EINVAL;
+	if (count > sizeof(req->reply))
+		count = sizeof(req->reply);
+
+	req = NULL;
+	spin_lock_irqsave(&state->lock, flags);
+	add_wait_queue(&state->wait_queue, &wait);
+	set_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);
+	}
+
+	set_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;
+
+	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,
+};
+
+#ifdef CONFIG_PM
+static const struct dev_pm_ops adb_dev_pm_ops = {
+	.suspend = adb_suspend,
+	.resume = adb_resume,
+	/* Hibernate hooks */
+	.freeze = adb_freeze,
+	.thaw = adb_resume,
+	.poweroff = adb_poweroff,
+	.restore = adb_resume,
+};
+#endif
+
+static struct platform_driver adb_pfdrv = {
+	.driver = {
+		.name = "adb",
+#ifdef CONFIG_PM
+		.pm = &adb_dev_pm_ops,
+#endif
+	},
+};
+
+static struct platform_device adb_pfdev = {
+	.name = "adb",
+};
+
+static int __init
+adb_dummy_probe(struct platform_device *dev)
+{
+	if (dev == &adb_pfdev)
+		return 0;
+	return -ENODEV;
+}
+
+static void __init
+adbdev_init(void)
+{
+	if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
+		pr_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;
+	device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
+
+	platform_device_register(&adb_pfdev);
+	platform_driver_probe(&adb_pfdrv, adb_dummy_probe);
+}