Merge tag 'staging-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging tree update from Greg Kroah-Hartman:
 "Here's the big staging tree merge for 3.9-rc1

  Lots of cleanups and updates for drivers all through the staging tree.
  We are pretty much "code neutral" here, adding just about as many
  lines as we removed.

  All of these have been in linux-next for a while."

* tag 'staging-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (804 commits)
  staging: comedi: vmk80xx: wait for URBs to complete
  staging: comedi: drivers: addi-data: hwdrv_apci3200.c: Add a missing semicolon
  staging: et131x: Update TODO list
  staging: et131x: Remove assignment of skb->dev
  staging: wlan-ng: hfa384x.h: fix for error reported by smatch
  staging/zache checkpatch ERROR: spaces prohibited around that
  staging/ozwpan: Mark read only parameters and structs as const
  staging/ozwpan: Remove empty and unused function oz_cdev_heartbeat
  staging/ozwpan: Mark local functions as static (fix sparse warnings)
  staging/ozwpan: Add missing header includes
  staging/usbip: Mark local functions as static (fix sparse warnings)
  staging/xgifb: Remove duplicated code in loops.
  staging/xgifb: Consolidate return paths
  staging/xgifb: Remove code without effect
  staging/xgifb: Remove unnecessary casts
  staging/xgifb: Consolidate if/else if with identical code branches
  staging: vt6656: replaced custom TRUE definition with true
  staging: vt6656: replaced custom FALSE definition with false
  staging: vt6656: replace custom BOOL definition with bool
  staging/rtl8187se: Mark functions as static to silence sparse
  ...

6 files changed, 867 insertions, 0 deletions

diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig
index 8390dca..69616ae 100644
--- a/drivers/platform/Kconfig
+++ b/drivers/platform/Kconfig
@@ -1,3 +1,7 @@
 if X86
 source "drivers/platform/x86/Kconfig"
 endif
+if GOLDFISH
+source "drivers/platform/goldfish/Kconfig"
+endif
+
diff --git a/drivers/platform/Makefile b/drivers/platform/Makefile
index b17c16c..8a44a4c 100644
--- a/drivers/platform/Makefile
+++ b/drivers/platform/Makefile
@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_X86)		+= x86/
 obj-$(CONFIG_OLPC)		+= olpc/
+obj-$(CONFIG_GOLDFISH)		+= goldfish/
diff --git a/drivers/platform/goldfish/Kconfig b/drivers/platform/goldfish/Kconfig
new file mode 100644
index 0000000..635ef25
--- /dev/null
+++ b/drivers/platform/goldfish/Kconfig
@@ -0,0 +1,5 @@
+config GOLDFISH_PIPE
+	tristate "Goldfish virtual device for QEMU pipes"
+	---help---
+	  This is a virtual device to drive the QEMU pipe interface used by
+	  the Goldfish Android Virtual Device.
diff --git a/drivers/platform/goldfish/Makefile b/drivers/platform/goldfish/Makefile
new file mode 100644
index 0000000..a002239
--- /dev/null
+++ b/drivers/platform/goldfish/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for Goldfish platform specific drivers
+#
+obj-$(CONFIG_GOLDFISH)	+=	pdev_bus.o
+obj-$(CONFIG_GOLDFISH_PIPE)	+= goldfish_pipe.o
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
new file mode 100644
index 0000000..4f5aa831
--- /dev/null
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -0,0 +1,612 @@
+/*
+ * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2012 Intel, Inc.
+ * Copyright (C) 2013 Intel, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+/* This source file contains the implementation of a special device driver
+ * that intends to provide a *very* fast communication channel between the
+ * guest system and the QEMU emulator.
+ *
+ * Usage from the guest is simply the following (error handling simplified):
+ *
+ *    int  fd = open("/dev/qemu_pipe",O_RDWR);
+ *    .... write() or read() through the pipe.
+ *
+ * This driver doesn't deal with the exact protocol used during the session.
+ * It is intended to be as simple as something like:
+ *
+ *    // do this _just_ after opening the fd to connect to a specific
+ *    // emulator service.
+ *    const char*  msg = "<pipename>";
+ *    if (write(fd, msg, strlen(msg)+1) < 0) {
+ *       ... could not connect to <pipename> service
+ *       close(fd);
+ *    }
+ *
+ *    // after this, simply read() and write() to communicate with the
+ *    // service. Exact protocol details left as an exercise to the reader.
+ *
+ * This driver is very fast because it doesn't copy any data through
+ * intermediate buffers, since the emulator is capable of translating
+ * guest user addresses into host ones.
+ *
+ * Note that we must however ensure that each user page involved in the
+ * exchange is properly mapped during a transfer.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/miscdevice.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+/*
+ * IMPORTANT: The following constants must match the ones used and defined
+ * in external/qemu/hw/goldfish_pipe.c in the Android source tree.
+ */
+
+/* pipe device registers */
+#define PIPE_REG_COMMAND		0x00  /* write: value = command */
+#define PIPE_REG_STATUS			0x04  /* read */
+#define PIPE_REG_CHANNEL		0x08  /* read/write: channel id */
+#define PIPE_REG_SIZE			0x0c  /* read/write: buffer size */
+#define PIPE_REG_ADDRESS		0x10  /* write: physical address */
+#define PIPE_REG_WAKES			0x14  /* read: wake flags */
+#define PIPE_REG_PARAMS_ADDR_LOW	0x18  /* read/write: batch data address */
+#define PIPE_REG_PARAMS_ADDR_HIGH	0x1c  /* read/write: batch data address */
+#define PIPE_REG_ACCESS_PARAMS		0x20  /* write: batch access */
+
+/* list of commands for PIPE_REG_COMMAND */
+#define CMD_OPEN			1  /* open new channel */
+#define CMD_CLOSE			2  /* close channel (from guest) */
+#define CMD_POLL			3  /* poll read/write status */
+
+/* List of bitflags returned in status of CMD_POLL command */
+#define PIPE_POLL_IN			(1 << 0)
+#define PIPE_POLL_OUT			(1 << 1)
+#define PIPE_POLL_HUP			(1 << 2)
+
+/* The following commands are related to write operations */
+#define CMD_WRITE_BUFFER	4  /* send a user buffer to the emulator */
+#define CMD_WAKE_ON_WRITE	5  /* tell the emulator to wake us when writing
+				     is possible */
+
+/* The following commands are related to read operations, they must be
+ * listed in the same order than the corresponding write ones, since we
+ * will use (CMD_READ_BUFFER - CMD_WRITE_BUFFER) as a special offset
+ * in goldfish_pipe_read_write() below.
+ */
+#define CMD_READ_BUFFER        6  /* receive a user buffer from the emulator */
+#define CMD_WAKE_ON_READ       7  /* tell the emulator to wake us when reading
+				   * is possible */
+
+/* Possible status values used to signal errors - see goldfish_pipe_error_convert */
+#define PIPE_ERROR_INVAL       -1
+#define PIPE_ERROR_AGAIN       -2
+#define PIPE_ERROR_NOMEM       -3
+#define PIPE_ERROR_IO          -4
+
+/* Bit-flags used to signal events from the emulator */
+#define PIPE_WAKE_CLOSED       (1 << 0)  /* emulator closed pipe */
+#define PIPE_WAKE_READ         (1 << 1)  /* pipe can now be read from */
+#define PIPE_WAKE_WRITE        (1 << 2)  /* pipe can now be written to */
+
+struct access_params {
+	u32 channel;
+	u32 size;
+	u32 address;
+	u32 cmd;
+	u32 result;
+	/* reserved for future extension */
+	u32 flags;
+};
+
+/* The global driver data. Holds a reference to the i/o page used to
+ * communicate with the emulator, and a wake queue for blocked tasks
+ * waiting to be awoken.
+ */
+struct goldfish_pipe_dev {
+	spinlock_t lock;
+	unsigned char __iomem *base;
+	struct access_params *aps;
+	int irq;
+};
+
+static struct goldfish_pipe_dev   pipe_dev[1];
+
+/* This data type models a given pipe instance */
+struct goldfish_pipe {
+	struct goldfish_pipe_dev *dev;
+	struct mutex lock;
+	unsigned long flags;
+	wait_queue_head_t wake_queue;
+};
+
+
+/* Bit flags for the 'flags' field */
+enum {
+	BIT_CLOSED_ON_HOST = 0,  /* pipe closed by host */
+	BIT_WAKE_ON_WRITE  = 1,  /* want to be woken on writes */
+	BIT_WAKE_ON_READ   = 2,  /* want to be woken on reads */
+};
+
+
+static u32 goldfish_cmd_status(struct goldfish_pipe *pipe, u32 cmd)
+{ 
+	unsigned long flags;
+	u32 status;
+	struct goldfish_pipe_dev *dev = pipe->dev;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	writel((u32)pipe, dev->base + PIPE_REG_CHANNEL);
+	writel(cmd, dev->base + PIPE_REG_COMMAND);
+	status = readl(dev->base + PIPE_REG_STATUS);
+	spin_unlock_irqrestore(&dev->lock, flags);
+	return status;
+}
+
+static void goldfish_cmd(struct goldfish_pipe *pipe, u32 cmd)
+{ 
+	unsigned long flags;
+	struct goldfish_pipe_dev *dev = pipe->dev;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	writel((u32)pipe, dev->base + PIPE_REG_CHANNEL);
+	writel(cmd, dev->base + PIPE_REG_COMMAND);
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+/* This function converts an error code returned by the emulator through
+ * the PIPE_REG_STATUS i/o register into a valid negative errno value.
+ */
+static int goldfish_pipe_error_convert(int status)
+{
+	switch (status) {
+	case PIPE_ERROR_AGAIN:
+		return -EAGAIN;
+	case PIPE_ERROR_NOMEM:
+		return -ENOMEM;
+	case PIPE_ERROR_IO:
+		return -EIO;
+	default:
+		return -EINVAL;
+	}
+}
+
+/*
+ * Notice: QEMU will return 0 for un-known register access, indicating
+ * param_acess is supported or not
+ */
+static int valid_batchbuffer_addr(struct goldfish_pipe_dev *dev,
+				  struct access_params *aps)
+{
+	u32 aph, apl;
+	u64 paddr;
+	aph = readl(dev->base + PIPE_REG_PARAMS_ADDR_HIGH);
+	apl = readl(dev->base + PIPE_REG_PARAMS_ADDR_LOW);
+
+	paddr = ((u64)aph << 32) | apl;
+	if (paddr != (__pa(aps)))
+		return 0;
+	return 1;
+}
+
+/* 0 on success */
+static int setup_access_params_addr(struct platform_device *pdev,
+					struct goldfish_pipe_dev *dev)
+{
+	u64 paddr;
+	struct access_params *aps;
+
+	aps = devm_kzalloc(&pdev->dev, sizeof(struct access_params), GFP_KERNEL);
+	if (!aps)
+		return -1;
+
+	/* FIXME */
+	paddr = __pa(aps);
+	writel((u32)(paddr >> 32), dev->base + PIPE_REG_PARAMS_ADDR_HIGH);
+	writel((u32)paddr, dev->base + PIPE_REG_PARAMS_ADDR_LOW);
+
+	if (valid_batchbuffer_addr(dev, aps)) {
+		dev->aps = aps;
+		return 0;
+	} else
+		return -1;
+}
+
+/* A value that will not be set by qemu emulator */
+#define INITIAL_BATCH_RESULT (0xdeadbeaf)
+static int access_with_param(struct goldfish_pipe_dev *dev, const int cmd,
+				unsigned long address, unsigned long avail,
+				struct goldfish_pipe *pipe, int *status)
+{
+	struct access_params *aps = dev->aps;
+
+	if (aps == NULL)
+		return -1;
+
+	aps->result = INITIAL_BATCH_RESULT;
+	aps->channel = (unsigned long)pipe;
+	aps->size = avail;
+	aps->address = address;
+	aps->cmd = cmd;
+	writel(cmd, dev->base + PIPE_REG_ACCESS_PARAMS);
+	/*
+	 * If the aps->result has not changed, that means
+	 * that the batch command failed
+	 */
+	if (aps->result == INITIAL_BATCH_RESULT)
+		return -1;
+	*status = aps->result;
+	return 0;
+}
+
+/* This function is used for both reading from and writing to a given
+ * pipe.
+ */
+static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
+				    size_t bufflen, int is_write)
+{
+	unsigned long irq_flags;
+	struct goldfish_pipe *pipe = filp->private_data;
+	struct goldfish_pipe_dev *dev = pipe->dev;
+	const int cmd_offset = is_write ? 0
+					: (CMD_READ_BUFFER - CMD_WRITE_BUFFER);
+	unsigned long address, address_end;
+	int ret = 0;
+
+	/* If the emulator already closed the pipe, no need to go further */
+	if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
+		return -EIO;
+
+	/* Null reads or writes succeeds */
+	if (unlikely(bufflen) == 0)
+		return 0;
+
+	/* Check the buffer range for access */
+	if (!access_ok(is_write ? VERIFY_WRITE : VERIFY_READ,
+			buffer, bufflen))
+		return -EFAULT;
+
+	/* Serialize access to the pipe */
+	if (mutex_lock_interruptible(&pipe->lock))
+		return -ERESTARTSYS;
+
+	address = (unsigned long)(void *)buffer;
+	address_end = address + bufflen;
+
+	while (address < address_end) {
+		unsigned long  page_end = (address & PAGE_MASK) + PAGE_SIZE;
+		unsigned long  next     = page_end < address_end ? page_end
+								 : address_end;
+		unsigned long  avail    = next - address;
+		int status, wakeBit;
+
+		/* Ensure that the corresponding page is properly mapped */
+		/* FIXME: this isn't safe or sufficient - use get_user_pages */
+		if (is_write) {
+			char c;
+			/* Ensure that the page is mapped and readable */
+			if (__get_user(c, (char __user *)address)) {
+				if (!ret)
+					ret = -EFAULT;
+				break;
+			}
+		} else {
+			/* Ensure that the page is mapped and writable */
+			if (__put_user(0, (char __user *)address)) {
+				if (!ret)
+					ret = -EFAULT;
+				break;
+			}
+		}
+
+		/* Now, try to transfer the bytes in the current page */
+		spin_lock_irqsave(&dev->lock, irq_flags);
+		if (access_with_param(dev, CMD_WRITE_BUFFER + cmd_offset,
+				address, avail, pipe, &status)) {
+			writel((u32)pipe, dev->base + PIPE_REG_CHANNEL);
+			writel(avail, dev->base + PIPE_REG_SIZE);
+			writel(address, dev->base + PIPE_REG_ADDRESS);
+			writel(CMD_WRITE_BUFFER + cmd_offset,
+					dev->base + PIPE_REG_COMMAND);
+			status = readl(dev->base + PIPE_REG_STATUS);
+		}
+		spin_unlock_irqrestore(&dev->lock, irq_flags);
+
+		if (status > 0) { /* Correct transfer */
+			ret += status;
+			address += status;
+			continue;
+		}
+
+		if (status == 0)  /* EOF */
+			break;
+
+		/* An error occured. If we already transfered stuff, just
+		* return with its count. We expect the next call to return
+		* an error code */
+		if (ret > 0)
+			break;
+
+		/* If the error is not PIPE_ERROR_AGAIN, or if we are not in
+		* non-blocking mode, just return the error code.
+		*/
+		if (status != PIPE_ERROR_AGAIN ||
+			(filp->f_flags & O_NONBLOCK) != 0) {
+			ret = goldfish_pipe_error_convert(status);
+			break;
+		}
+
+		/* We will have to wait until more data/space is available.
+		* First, mark the pipe as waiting for a specific wake signal.
+		*/
+		wakeBit = is_write ? BIT_WAKE_ON_WRITE : BIT_WAKE_ON_READ;
+		set_bit(wakeBit, &pipe->flags);
+
+		/* Tell the emulator we're going to wait for a wake event */
+		goldfish_cmd(pipe, CMD_WAKE_ON_WRITE + cmd_offset);
+
+		/* Unlock the pipe, then wait for the wake signal */
+		mutex_unlock(&pipe->lock);
+
+		while (test_bit(wakeBit, &pipe->flags)) {
+			if (wait_event_interruptible(
+					pipe->wake_queue,
+					!test_bit(wakeBit, &pipe->flags)))
+				return -ERESTARTSYS;
+
+			if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
+				return -EIO;
+		}
+
+		/* Try to re-acquire the lock */
+		if (mutex_lock_interruptible(&pipe->lock))
+			return -ERESTARTSYS;
+
+		/* Try the transfer again */
+		continue;
+	}
+	mutex_unlock(&pipe->lock);
+	return ret;
+}
+
+static ssize_t goldfish_pipe_read(struct file *filp, char __user *buffer,
+			      size_t bufflen, loff_t *ppos)
+{
+	return goldfish_pipe_read_write(filp, buffer, bufflen, 0);
+}
+
+static ssize_t goldfish_pipe_write(struct file *filp,
+				const char __user *buffer, size_t bufflen,
+				loff_t *ppos)
+{
+	return goldfish_pipe_read_write(filp, (char __user *)buffer,
+								bufflen, 1);
+}
+
+
+static unsigned int goldfish_pipe_poll(struct file *filp, poll_table *wait)
+{
+	struct goldfish_pipe *pipe = filp->private_data;
+	unsigned int mask = 0;
+	int status;
+
+	mutex_lock(&pipe->lock);
+
+	poll_wait(filp, &pipe->wake_queue, wait);
+
+	status = goldfish_cmd_status(pipe, CMD_POLL);
+
+	mutex_unlock(&pipe->lock);
+
+	if (status & PIPE_POLL_IN)
+		mask |= POLLIN | POLLRDNORM;
+
+	if (status & PIPE_POLL_OUT)
+		mask |= POLLOUT | POLLWRNORM;
+
+	if (status & PIPE_POLL_HUP)
+		mask |= POLLHUP;
+
+	if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
+		mask |= POLLERR;
+
+	return mask;
+}
+
+static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id)
+{
+	struct goldfish_pipe_dev *dev = dev_id;
+	unsigned long irq_flags;
+	int count = 0;
+
+	/* We're going to read from the emulator a list of (channel,flags)
+	* pairs corresponding to the wake events that occured on each
+	* blocked pipe (i.e. channel).
+	*/
+	spin_lock_irqsave(&dev->lock, irq_flags);
+	for (;;) {
+		/* First read the channel, 0 means the end of the list */
+		struct goldfish_pipe *pipe;
+		unsigned long wakes;
+		unsigned long channel = readl(dev->base + PIPE_REG_CHANNEL);
+
+		if (channel == 0)
+			break;
+
+		/* Convert channel to struct pipe pointer + read wake flags */
+		wakes = readl(dev->base + PIPE_REG_WAKES);
+		pipe  = (struct goldfish_pipe *)(ptrdiff_t)channel;
+
+		/* Did the emulator just closed a pipe? */
+		if (wakes & PIPE_WAKE_CLOSED) {
+			set_bit(BIT_CLOSED_ON_HOST, &pipe->flags);
+			wakes |= PIPE_WAKE_READ | PIPE_WAKE_WRITE;
+		}
+		if (wakes & PIPE_WAKE_READ)
+			clear_bit(BIT_WAKE_ON_READ, &pipe->flags);
+		if (wakes & PIPE_WAKE_WRITE)
+			clear_bit(BIT_WAKE_ON_WRITE, &pipe->flags);
+
+		wake_up_interruptible(&pipe->wake_queue);
+		count++;
+	}
+	spin_unlock_irqrestore(&dev->lock, irq_flags);
+
+	return (count == 0) ? IRQ_NONE : IRQ_HANDLED;
+}
+
+/**
+ *	goldfish_pipe_open	-	open a channel to the AVD
+ *	@inode: inode of device
+ *	@file: file struct of opener
+ *
+ *	Create a new pipe link between the emulator and the use application.
+ *	Each new request produces a new pipe.
+ *
+ *	Note: we use the pipe ID as a mux. All goldfish emulations are 32bit
+ *	right now so this is fine. A move to 64bit will need this addressing
+ */
+static int goldfish_pipe_open(struct inode *inode, struct file *file)
+{
+	struct goldfish_pipe *pipe;
+	struct goldfish_pipe_dev *dev = pipe_dev;
+	int32_t status;
+
+	/* Allocate new pipe kernel object */
+	pipe = kzalloc(sizeof(*pipe), GFP_KERNEL);
+	if (pipe == NULL)
+		return -ENOMEM;
+
+	pipe->dev = dev;
+	mutex_init(&pipe->lock);
+	init_waitqueue_head(&pipe->wake_queue);
+
+	/*
+	 * Now, tell the emulator we're opening a new pipe. We use the
+	 * pipe object's address as the channel identifier for simplicity.
+	 */
+
+	status = goldfish_cmd_status(pipe, CMD_OPEN);
+	if (status < 0) {
+		kfree(pipe);
+		return status;
+	}
+
+	/* All is done, save the pipe into the file's private data field */
+	file->private_data = pipe;
+	return 0;
+}
+
+static int goldfish_pipe_release(struct inode *inode, struct file *filp)
+{
+	struct goldfish_pipe *pipe = filp->private_data;
+
+	/* The guest is closing the channel, so tell the emulator right now */
+	goldfish_cmd(pipe, CMD_CLOSE);
+	kfree(pipe);
+	filp->private_data = NULL;
+	return 0;
+}
+
+static const struct file_operations goldfish_pipe_fops = {
+	.owner = THIS_MODULE,
+	.read = goldfish_pipe_read,
+	.write = goldfish_pipe_write,
+	.poll = goldfish_pipe_poll,
+	.open = goldfish_pipe_open,
+	.release = goldfish_pipe_release,
+};
+
+static struct miscdevice goldfish_pipe_device = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "goldfish_pipe",
+	.fops = &goldfish_pipe_fops,
+};
+
+static int goldfish_pipe_probe(struct platform_device *pdev)
+{
+	int err;
+	struct resource *r;
+	struct goldfish_pipe_dev *dev = pipe_dev;
+
+	/* not thread safe, but this should not happen */
+	WARN_ON(dev->base != NULL);
+
+	spin_lock_init(&dev->lock);
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r == NULL || resource_size(r) < PAGE_SIZE) {
+		dev_err(&pdev->dev, "can't allocate i/o page\n");
+		return -EINVAL;
+	}
+	dev->base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
+	if (dev->base == NULL) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		return -EINVAL;
+	}
+
+	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (r == NULL) {
+		err = -EINVAL;
+		goto error;
+	}
+	dev->irq = r->start;
+
+	err = devm_request_irq(&pdev->dev, dev->irq, goldfish_pipe_interrupt,
+				IRQF_SHARED, "goldfish_pipe", dev);
+	if (err) {
+		dev_err(&pdev->dev, "unable to allocate IRQ\n");
+		goto error;
+	}
+
+	err = misc_register(&goldfish_pipe_device);
+	if (err) {
+		dev_err(&pdev->dev, "unable to register device\n");
+		goto error;
+	}
+	setup_access_params_addr(pdev, dev);
+	return 0;
+
+error:
+	dev->base = NULL;
+	return err;
+}
+
+static int goldfish_pipe_remove(struct platform_device *pdev)
+{
+	struct goldfish_pipe_dev *dev = pipe_dev;
+	misc_deregister(&goldfish_pipe_device);
+	dev->base = NULL;
+	return 0;
+}
+
+static struct platform_driver goldfish_pipe = {
+	.probe = goldfish_pipe_probe,
+	.remove = goldfish_pipe_remove,
+	.driver = {
+		.name = "goldfish_pipe"
+	}
+};
+
+module_platform_driver(goldfish_pipe);
+MODULE_AUTHOR("David Turner <digit@google.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/platform/goldfish/pdev_bus.c b/drivers/platform/goldfish/pdev_bus.c
new file mode 100644
index 0000000..92cc4cf
--- /dev/null
+++ b/drivers/platform/goldfish/pdev_bus.c
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (C) 2011 Intel, Inc.
+ * Copyright (C) 2013 Intel, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#define PDEV_BUS_OP_DONE        (0x00)
+#define PDEV_BUS_OP_REMOVE_DEV  (0x04)
+#define PDEV_BUS_OP_ADD_DEV     (0x08)
+
+#define PDEV_BUS_OP_INIT        (0x00)
+
+#define PDEV_BUS_OP             (0x00)
+#define PDEV_BUS_GET_NAME       (0x04)
+#define PDEV_BUS_NAME_LEN       (0x08)
+#define PDEV_BUS_ID             (0x0c)
+#define PDEV_BUS_IO_BASE        (0x10)
+#define PDEV_BUS_IO_SIZE        (0x14)
+#define PDEV_BUS_IRQ            (0x18)
+#define PDEV_BUS_IRQ_COUNT      (0x1c)
+
+struct pdev_bus_dev {
+	struct list_head list;
+	struct platform_device pdev;
+	struct resource resources[0];
+};
+
+static void goldfish_pdev_worker(struct work_struct *work);
+
+static void __iomem *pdev_bus_base;
+static unsigned long pdev_bus_addr;
+static unsigned long pdev_bus_len;
+static u32 pdev_bus_irq;
+static LIST_HEAD(pdev_bus_new_devices);
+static LIST_HEAD(pdev_bus_registered_devices);
+static LIST_HEAD(pdev_bus_removed_devices);
+static DECLARE_WORK(pdev_bus_worker, goldfish_pdev_worker);
+
+
+static void goldfish_pdev_worker(struct work_struct *work)
+{
+	int ret;
+	struct pdev_bus_dev *pos, *n;
+
+	list_for_each_entry_safe(pos, n, &pdev_bus_removed_devices, list) {
+		list_del(&pos->list);
+		platform_device_unregister(&pos->pdev);
+		kfree(pos);
+	}
+	list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
+		list_del(&pos->list);
+		ret = platform_device_register(&pos->pdev);
+		if (ret)
+			pr_err("goldfish_pdev_worker failed to register device, %s\n",
+								pos->pdev.name);
+		list_add_tail(&pos->list, &pdev_bus_registered_devices);
+	}
+}
+
+static void goldfish_pdev_remove(void)
+{
+	struct pdev_bus_dev *pos, *n;
+	u32 base;
+
+	base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
+
+	list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
+		if (pos->resources[0].start == base) {
+			list_del(&pos->list);
+			kfree(pos);
+			return;
+		}
+	}
+	list_for_each_entry_safe(pos, n, &pdev_bus_registered_devices, list) {
+		if (pos->resources[0].start == base) {
+			list_del(&pos->list);
+			list_add_tail(&pos->list, &pdev_bus_removed_devices);
+			schedule_work(&pdev_bus_worker);
+			return;
+		}
+	};
+	pr_err("goldfish_pdev_remove could not find device at %x\n", base);
+}
+
+static int goldfish_new_pdev(void)
+{
+	struct pdev_bus_dev *dev;
+	u32 name_len;
+	u32 irq = -1, irq_count;
+	int resource_count = 2;
+	u32 base;
+	char *name;
+
+	base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
+
+	irq_count = readl(pdev_bus_base + PDEV_BUS_IRQ_COUNT);
+	name_len = readl(pdev_bus_base + PDEV_BUS_NAME_LEN);
+	if (irq_count)
+		resource_count++;
+
+	dev = kzalloc(sizeof(*dev) +
+		sizeof(struct resource) * resource_count +
+		name_len + 1 + sizeof(*dev->pdev.dev.dma_mask), GFP_ATOMIC);
+	if (dev == NULL)
+		return -ENOMEM;
+
+	dev->pdev.num_resources = resource_count;
+	dev->pdev.resource = (struct resource *)(dev + 1);
+	dev->pdev.name = name = (char *)(dev->pdev.resource + resource_count);
+	dev->pdev.dev.coherent_dma_mask = ~0;
+	dev->pdev.dev.dma_mask = (void *)(dev->pdev.name + name_len + 1);
+	*dev->pdev.dev.dma_mask = ~0;
+
+	writel((unsigned long)name, pdev_bus_base + PDEV_BUS_GET_NAME);
+	name[name_len] = '\0';
+	dev->pdev.id = readl(pdev_bus_base + PDEV_BUS_ID);
+	dev->pdev.resource[0].start = base;
+	dev->pdev.resource[0].end = base +
+				readl(pdev_bus_base + PDEV_BUS_IO_SIZE) - 1;
+	dev->pdev.resource[0].flags = IORESOURCE_MEM;
+	if (irq_count) {
+		irq = readl(pdev_bus_base + PDEV_BUS_IRQ);
+		dev->pdev.resource[1].start = irq;
+		dev->pdev.resource[1].end = irq + irq_count - 1;
+		dev->pdev.resource[1].flags = IORESOURCE_IRQ;
+	}
+
+	pr_debug("goldfish_new_pdev %s at %x irq %d\n", name, base, irq);
+	list_add_tail(&dev->list, &pdev_bus_new_devices);
+	schedule_work(&pdev_bus_worker);
+
+	return 0;
+}
+
+static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id)
+{
+	irqreturn_t ret = IRQ_NONE;
+	while (1) {
+		u32 op = readl(pdev_bus_base + PDEV_BUS_OP);
+		switch (op) {
+		case PDEV_BUS_OP_DONE:
+			return IRQ_NONE;
+
+		case PDEV_BUS_OP_REMOVE_DEV:
+			goldfish_pdev_remove();
+			break;
+
+		case PDEV_BUS_OP_ADD_DEV:
+			goldfish_new_pdev();
+			break;
+		}
+		ret = IRQ_HANDLED;
+	}
+	return ret;
+}
+
+static int goldfish_pdev_bus_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct resource *r;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r == NULL)
+		return -EINVAL;
+
+	pdev_bus_addr = r->start;
+	pdev_bus_len = resource_size(r);
+
+	if (request_mem_region(pdev_bus_addr, pdev_bus_len, "goldfish")) {
+		dev_err(&pdev->dev, "unable to reserve Goldfish MMIO.\n");
+		return -EBUSY;
+	}
+
+	pdev_bus_base = ioremap(pdev_bus_addr, pdev_bus_len);
+	if (pdev_bus_base == NULL) {
+		ret = -ENOMEM;
+		dev_err(&pdev->dev, "unable to map Goldfish MMIO.\n");
+		goto free_resources;
+	}
+
+	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (r == NULL) {
+		ret = -ENOENT;
+		goto free_map;
+	}
+
+	pdev_bus_irq = r->start;
+
+	ret = request_irq(pdev_bus_irq, goldfish_pdev_bus_interrupt,
+				IRQF_SHARED, "goldfish_pdev_bus", pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to request Goldfish IRQ\n");
+		goto free_map;
+	}
+
+	writel(PDEV_BUS_OP_INIT, pdev_bus_base + PDEV_BUS_OP);
+	return 0;
+
+free_map:
+	iounmap(pdev_bus_base);
+free_resources:
+	release_mem_region(pdev_bus_addr, pdev_bus_len);
+	return ret;
+}
+
+static int goldfish_pdev_bus_remove(struct platform_device *pdev)
+{
+	iounmap(pdev_bus_base);
+	free_irq(pdev_bus_irq, pdev);
+	release_mem_region(pdev_bus_addr, pdev_bus_len);
+	return 0;
+}
+
+static struct platform_driver goldfish_pdev_bus_driver = {
+	.probe = goldfish_pdev_bus_probe,
+	.remove = goldfish_pdev_bus_remove,
+	.driver = {
+		.name = "goldfish_pdev_bus"
+	}
+};
+
+module_platform_driver(goldfish_pdev_bus_driver);