drivers/uwb/whc-rc.c - kernel/msm - Gitiles

 /*
  * Wireless Host Controller: Radio Control Interface (WHCI v0.95[2.3])
  * Radio Control command/event transport to the UWB stack
  *
  * Copyright (C) 2005-2006 Intel Corporation
  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version
  * 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301, USA.
  *
  *
  * Initialize and hook up the Radio Control interface.
  *
  * For each device probed, creates an 'struct whcrc' which contains
  * just the representation of the UWB Radio Controller, and the logic
  * for reading notifications and passing them to the UWB Core.
  *
  * So we initialize all of those, register the UWB Radio Controller
  * and setup the notification/event handle to pipe the notifications
  * to the UWB management Daemon.
  *
  * Once uwb_rc_add() is called, the UWB stack takes control, resets
  * the radio and readies the device to take commands the UWB
  * API/user-space.
  *
  * Note this driver is just a transport driver; the commands are
  * formed at the UWB stack and given to this driver who will deliver
  * them to the hw and transfer the replies/notifications back to the
  * UWB stack through the UWB daemon (UWBD).
  */
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/sched.h>
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/workqueue.h>
 #include <linux/uwb.h>
 #include <linux/uwb/whci.h>
 #include <linux/uwb/umc.h>

 #include "uwb-internal.h"

 /**
  * Descriptor for an instance of the UWB Radio Control Driver that
  * attaches to the URC interface of the WHCI PCI card.
  *
  * Unless there is a lock specific to the 'data members', all access
  * is protected by uwb_rc->mutex.
  */
 struct whcrc {
 	struct umc_dev *umc_dev;
 	struct uwb_rc *uwb_rc;		/* UWB host controller */

 	unsigned long area;
 	void __iomem *rc_base;
 	size_t rc_len;
 	spinlock_t irq_lock;

 	void *evt_buf, *cmd_buf;
 	dma_addr_t evt_dma_buf, cmd_dma_buf;
 	wait_queue_head_t cmd_wq;
 	struct work_struct event_work;
 };

 /**
  * Execute an UWB RC command on WHCI/RC
  *
  * @rc:       Instance of a Radio Controller that is a whcrc
  * @cmd:      Buffer containing the RCCB and payload to execute
  * @cmd_size: Size of the command buffer.
  *
  * We copy the command into whcrc->cmd_buf (as it is pretty and
  * aligned`and physically contiguous) and then press the right keys in
  * the controller's URCCMD register to get it to read it. We might
  * have to wait for the cmd_sem to be open to us.
  *
  * NOTE: rc's mutex has to be locked
  */
 static int whcrc_cmd(struct uwb_rc *uwb_rc,
 	      const struct uwb_rccb *cmd, size_t cmd_size)
 {
 	int result = 0;
 	struct whcrc *whcrc = uwb_rc->priv;
 	struct device *dev = &whcrc->umc_dev->dev;
 	u32 urccmd;

 	if (cmd_size >= 4096)
 		return -EINVAL;

 	/*
 	 * If the URC is halted, then the hardware has reset itself.
 	 * Attempt to recover by restarting the device and then return
 	 * an error as it's likely that the current command isn't
 	 * valid for a newly started RC.
 	 */
 	if (le_readl(whcrc->rc_base + URCSTS) & URCSTS_HALTED) {
 		dev_err(dev, "requesting reset of halted radio controller\n");
 		uwb_rc_reset_all(uwb_rc);
 		return -EIO;
 	}

 	result = wait_event_timeout(whcrc->cmd_wq,
 		!(le_readl(whcrc->rc_base + URCCMD) & URCCMD_ACTIVE), HZ/2);
 	if (result == 0) {
 		dev_err(dev, "device is not ready to execute commands\n");
 		return -ETIMEDOUT;
 	}

 	memmove(whcrc->cmd_buf, cmd, cmd_size);
 	le_writeq(whcrc->cmd_dma_buf, whcrc->rc_base + URCCMDADDR);

 	spin_lock(&whcrc->irq_lock);
 	urccmd = le_readl(whcrc->rc_base + URCCMD);
 	urccmd &= ~(URCCMD_EARV | URCCMD_SIZE_MASK);
 	le_writel(urccmd | URCCMD_ACTIVE | URCCMD_IWR | cmd_size,
 		  whcrc->rc_base + URCCMD);
 	spin_unlock(&whcrc->irq_lock);

 	return 0;
 }

 static int whcrc_reset(struct uwb_rc *rc)
 {
 	struct whcrc *whcrc = rc->priv;

 	return umc_controller_reset(whcrc->umc_dev);
 }

 /**
  * Reset event reception mechanism and tell hw we are ready to get more
  *
  * We have read all the events in the event buffer, so we are ready to
  * reset it to the beginning.
  *
  * This is only called during initialization or after an event buffer
  * has been retired.  This means we can be sure that event processing
  * is disabled and it's safe to update the URCEVTADDR register.
  *
  * There's no need to wait for the event processing to start as the
  * URC will not clear URCCMD_ACTIVE until (internal) event buffer
  * space is available.
  */
 static
 void whcrc_enable_events(struct whcrc *whcrc)
 {
 	u32 urccmd;

 	le_writeq(whcrc->evt_dma_buf, whcrc->rc_base + URCEVTADDR);

 	spin_lock(&whcrc->irq_lock);
 	urccmd = le_readl(whcrc->rc_base + URCCMD) & ~URCCMD_ACTIVE;
 	le_writel(urccmd | URCCMD_EARV, whcrc->rc_base + URCCMD);
 	spin_unlock(&whcrc->irq_lock);
 }

 static void whcrc_event_work(struct work_struct *work)
 {
 	struct whcrc *whcrc = container_of(work, struct whcrc, event_work);
 	size_t size;
 	u64 urcevtaddr;

 	urcevtaddr = le_readq(whcrc->rc_base + URCEVTADDR);
 	size = urcevtaddr & URCEVTADDR_OFFSET_MASK;

 	uwb_rc_neh_grok(whcrc->uwb_rc, whcrc->evt_buf, size);
 	whcrc_enable_events(whcrc);
 }

 /**
  * Catch interrupts?
  *
  * We ack inmediately (and expect the hw to do the right thing and
  * raise another IRQ if things have changed :)
  */
 static
 irqreturn_t whcrc_irq_cb(int irq, void *_whcrc)
 {
 	struct whcrc *whcrc = _whcrc;
 	struct device *dev = &whcrc->umc_dev->dev;
 	u32 urcsts;

 	urcsts = le_readl(whcrc->rc_base + URCSTS);
 	if (!(urcsts & URCSTS_INT_MASK))
 		return IRQ_NONE;
 	le_writel(urcsts & URCSTS_INT_MASK, whcrc->rc_base + URCSTS);

 	if (urcsts & URCSTS_HSE) {
 		dev_err(dev, "host system error -- hardware halted\n");
 		/* FIXME: do something sensible here */
 		goto out;
 	}
 	if (urcsts & URCSTS_ER)
 		schedule_work(&whcrc->event_work);
 	if (urcsts & URCSTS_RCI)
 		wake_up_all(&whcrc->cmd_wq);
 out:
 	return IRQ_HANDLED;
 }


 /**
  * Initialize a UMC RC interface: map regions, get (shared) IRQ
  */
 static
 int whcrc_setup_rc_umc(struct whcrc *whcrc)
 {
 	int result = 0;
 	struct device *dev = &whcrc->umc_dev->dev;
 	struct umc_dev *umc_dev = whcrc->umc_dev;

 	whcrc->area = umc_dev->resource.start;
 	whcrc->rc_len = umc_dev->resource.end - umc_dev->resource.start + 1;
 	result = -EBUSY;
 	if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME) == NULL) {
 		dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n",
 			whcrc->rc_len, whcrc->area, result);
 		goto error_request_region;
 	}

 	whcrc->rc_base = ioremap_nocache(whcrc->area, whcrc->rc_len);
 	if (whcrc->rc_base == NULL) {
 		dev_err(dev, "can't ioremap registers (%zu bytes @ 0x%lx): %d\n",
 			whcrc->rc_len, whcrc->area, result);
 		goto error_ioremap_nocache;
 	}

 	result = request_irq(umc_dev->irq, whcrc_irq_cb, IRQF_SHARED,
 			     KBUILD_MODNAME, whcrc);
 	if (result < 0) {
 		dev_err(dev, "can't allocate IRQ %d: %d\n",
 			umc_dev->irq, result);
 		goto error_request_irq;
 	}

 	result = -ENOMEM;
 	whcrc->cmd_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
 					    &whcrc->cmd_dma_buf, GFP_KERNEL);
 	if (whcrc->cmd_buf == NULL) {
 		dev_err(dev, "Can't allocate cmd transfer buffer\n");
 		goto error_cmd_buffer;
 	}

 	whcrc->evt_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
 					    &whcrc->evt_dma_buf, GFP_KERNEL);
 	if (whcrc->evt_buf == NULL) {
 		dev_err(dev, "Can't allocate evt transfer buffer\n");
 		goto error_evt_buffer;
 	}
 	return 0;

 error_evt_buffer:
 	dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
 			  whcrc->cmd_dma_buf);
 error_cmd_buffer:
 	free_irq(umc_dev->irq, whcrc);
 error_request_irq:
 	iounmap(whcrc->rc_base);
 error_ioremap_nocache:
 	release_mem_region(whcrc->area, whcrc->rc_len);
 error_request_region:
 	return result;
 }


 /**
  * Release RC's UMC resources
  */
 static
 void whcrc_release_rc_umc(struct whcrc *whcrc)
 {
 	struct umc_dev *umc_dev = whcrc->umc_dev;

 	dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->evt_buf,
 			  whcrc->evt_dma_buf);
 	dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
 			  whcrc->cmd_dma_buf);
 	free_irq(umc_dev->irq, whcrc);
 	iounmap(whcrc->rc_base);
 	release_mem_region(whcrc->area, whcrc->rc_len);
 }


 /**
  * whcrc_start_rc - start a WHCI radio controller
  * @whcrc: the radio controller to start
  *
  * Reset the UMC device, start the radio controller, enable events and
  * finally enable interrupts.
  */
 static int whcrc_start_rc(struct uwb_rc *rc)
 {
 	struct whcrc *whcrc = rc->priv;
 	struct device *dev = &whcrc->umc_dev->dev;

 	/* Reset the thing */
 	le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD);
 	if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0,
 			  5000, "hardware reset") < 0)
 		return -EBUSY;

 	/* Set the event buffer, start the controller (enable IRQs later) */
 	le_writel(0, whcrc->rc_base + URCINTR);
 	le_writel(URCCMD_RS, whcrc->rc_base + URCCMD);
 	if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0,
 			  5000, "radio controller start") < 0)
 		return -ETIMEDOUT;
 	whcrc_enable_events(whcrc);
 	le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR);
 	return 0;
 }


 /**
  * whcrc_stop_rc - stop a WHCI radio controller
  * @whcrc: the radio controller to stop
  *
  * Disable interrupts and cancel any pending event processing work
  * before clearing the Run/Stop bit.
  */
 static
 void whcrc_stop_rc(struct uwb_rc *rc)
 {
 	struct whcrc *whcrc = rc->priv;
 	struct umc_dev *umc_dev = whcrc->umc_dev;

 	le_writel(0, whcrc->rc_base + URCINTR);
 	cancel_work_sync(&whcrc->event_work);

 	le_writel(0, whcrc->rc_base + URCCMD);
 	whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS,
 		      URCSTS_HALTED, URCSTS_HALTED, 100, "radio controller stop");
 }

 static void whcrc_init(struct whcrc *whcrc)
 {
 	spin_lock_init(&whcrc->irq_lock);
 	init_waitqueue_head(&whcrc->cmd_wq);
 	INIT_WORK(&whcrc->event_work, whcrc_event_work);
 }

 /**
  * Initialize the radio controller.
  *
  * NOTE: we setup whcrc->uwb_rc before calling uwb_rc_add(); in the
  *       IRQ handler we use that to determine if the hw is ready to
  *       handle events. Looks like a race condition, but it really is
  *       not.
  */
 static
 int whcrc_probe(struct umc_dev *umc_dev)
 {
 	int result;
 	struct uwb_rc *uwb_rc;
 	struct whcrc *whcrc;
 	struct device *dev = &umc_dev->dev;

 	result = -ENOMEM;
 	uwb_rc = uwb_rc_alloc();
 	if (uwb_rc == NULL) {
 		dev_err(dev, "unable to allocate RC instance\n");
 		goto error_rc_alloc;
 	}
 	whcrc = kzalloc(sizeof(*whcrc), GFP_KERNEL);
 	if (whcrc == NULL) {
 		dev_err(dev, "unable to allocate WHC-RC instance\n");
 		goto error_alloc;
 	}
 	whcrc_init(whcrc);
 	whcrc->umc_dev = umc_dev;

 	result = whcrc_setup_rc_umc(whcrc);
 	if (result < 0) {
 		dev_err(dev, "Can't setup RC UMC interface: %d\n", result);
 		goto error_setup_rc_umc;
 	}
 	whcrc->uwb_rc = uwb_rc;

 	uwb_rc->owner = THIS_MODULE;
 	uwb_rc->cmd   = whcrc_cmd;
 	uwb_rc->reset = whcrc_reset;
 	uwb_rc->start = whcrc_start_rc;
 	uwb_rc->stop  = whcrc_stop_rc;

 	result = uwb_rc_add(uwb_rc, dev, whcrc);
 	if (result < 0)
 		goto error_rc_add;
 	umc_set_drvdata(umc_dev, whcrc);
 	return 0;

 error_rc_add:
 	whcrc_release_rc_umc(whcrc);
 error_setup_rc_umc:
 	kfree(whcrc);
 error_alloc:
 	uwb_rc_put(uwb_rc);
 error_rc_alloc:
 	return result;
 }

 /**
  * Clean up the radio control resources
  *
  * When we up the command semaphore, everybody possibly held trying to
  * execute a command should be granted entry and then they'll see the
  * host is quiescing and up it (so it will chain to the next waiter).
  * This should not happen (in any case), as we can only remove when
  * there are no handles open...
  */
 static void whcrc_remove(struct umc_dev *umc_dev)
 {
 	struct whcrc *whcrc = umc_get_drvdata(umc_dev);
 	struct uwb_rc *uwb_rc = whcrc->uwb_rc;

 	umc_set_drvdata(umc_dev, NULL);
 	uwb_rc_rm(uwb_rc);
 	whcrc_release_rc_umc(whcrc);
 	kfree(whcrc);
 	uwb_rc_put(uwb_rc);
 }

 static int whcrc_pre_reset(struct umc_dev *umc)
 {
 	struct whcrc *whcrc = umc_get_drvdata(umc);
 	struct uwb_rc *uwb_rc = whcrc->uwb_rc;

 	uwb_rc_pre_reset(uwb_rc);
 	return 0;
 }

 static int whcrc_post_reset(struct umc_dev *umc)
 {
 	struct whcrc *whcrc = umc_get_drvdata(umc);
 	struct uwb_rc *uwb_rc = whcrc->uwb_rc;

 	return uwb_rc_post_reset(uwb_rc);
 }

 /* PCI device ID's that we handle [so it gets loaded] */
 static struct pci_device_id whcrc_id_table[] = {
 	{ PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) },
 	{ /* empty last entry */ }
 };
 MODULE_DEVICE_TABLE(pci, whcrc_id_table);

 static struct umc_driver whcrc_driver = {
 	.name       = "whc-rc",
 	.cap_id     = UMC_CAP_ID_WHCI_RC,
 	.probe      = whcrc_probe,
 	.remove     = whcrc_remove,
 	.pre_reset  = whcrc_pre_reset,
 	.post_reset = whcrc_post_reset,
 };

 static int __init whcrc_driver_init(void)
 {
 	return umc_driver_register(&whcrc_driver);
 }
 module_init(whcrc_driver_init);

 static void __exit whcrc_driver_exit(void)
 {
 	umc_driver_unregister(&whcrc_driver);
 }
 module_exit(whcrc_driver_exit);

 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
 MODULE_DESCRIPTION("Wireless Host Controller Radio Control Driver");
 MODULE_LICENSE("GPL");
	/*
	* Wireless Host Controller: Radio Control Interface (WHCI v0.95[2.3])
	* Radio Control command/event transport to the UWB stack
	*
	* Copyright (C) 2005-2006 Intel Corporation
	* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License version
	* 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	* 02110-1301, USA.
	*
	*
	* Initialize and hook up the Radio Control interface.
	*
	* For each device probed, creates an 'struct whcrc' which contains
	* just the representation of the UWB Radio Controller, and the logic
	* for reading notifications and passing them to the UWB Core.
	*
	* So we initialize all of those, register the UWB Radio Controller
	* and setup the notification/event handle to pipe the notifications
	* to the UWB management Daemon.
	*
	* Once uwb_rc_add() is called, the UWB stack takes control, resets
	* the radio and readies the device to take commands the UWB
	* API/user-space.
	*
	* Note this driver is just a transport driver; the commands are
	* formed at the UWB stack and given to this driver who will deliver
	* them to the hw and transfer the replies/notifications back to the
	* UWB stack through the UWB daemon (UWBD).
	*/
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/sched.h>
	#include <linux/dma-mapping.h>
	#include <linux/interrupt.h>
	#include <linux/workqueue.h>
	#include <linux/uwb.h>
	#include <linux/uwb/whci.h>
	#include <linux/uwb/umc.h>

	#include "uwb-internal.h"

	/**
	* Descriptor for an instance of the UWB Radio Control Driver that
	* attaches to the URC interface of the WHCI PCI card.
	*
	* Unless there is a lock specific to the 'data members', all access
	* is protected by uwb_rc->mutex.
	*/
	struct whcrc {
	struct umc_dev *umc_dev;
	struct uwb_rc uwb_rc; / UWB host controller */

	unsigned long area;
	void __iomem *rc_base;
	size_t rc_len;
	spinlock_t irq_lock;

	void evt_buf, cmd_buf;
	dma_addr_t evt_dma_buf, cmd_dma_buf;
	wait_queue_head_t cmd_wq;
	struct work_struct event_work;
	};

	/**
	* Execute an UWB RC command on WHCI/RC
	*
	* @rc: Instance of a Radio Controller that is a whcrc
	* @cmd: Buffer containing the RCCB and payload to execute
	* @cmd_size: Size of the command buffer.
	*
	* We copy the command into whcrc->cmd_buf (as it is pretty and
	* aligned`and physically contiguous) and then press the right keys in
	* the controller's URCCMD register to get it to read it. We might
	* have to wait for the cmd_sem to be open to us.
	*
	* NOTE: rc's mutex has to be locked
	*/
	static int whcrc_cmd(struct uwb_rc *uwb_rc,
	const struct uwb_rccb *cmd, size_t cmd_size)
	{
	int result = 0;
	struct whcrc *whcrc = uwb_rc->priv;
	struct device *dev = &whcrc->umc_dev->dev;
	u32 urccmd;

	if (cmd_size >= 4096)
	return -EINVAL;

	/*
	* If the URC is halted, then the hardware has reset itself.
	* Attempt to recover by restarting the device and then return
	* an error as it's likely that the current command isn't
	* valid for a newly started RC.
	*/
	if (le_readl(whcrc->rc_base + URCSTS) & URCSTS_HALTED) {
	dev_err(dev, "requesting reset of halted radio controller\n");
	uwb_rc_reset_all(uwb_rc);
	return -EIO;
	}

	result = wait_event_timeout(whcrc->cmd_wq,
	!(le_readl(whcrc->rc_base + URCCMD) & URCCMD_ACTIVE), HZ/2);
	if (result == 0) {
	dev_err(dev, "device is not ready to execute commands\n");
	return -ETIMEDOUT;
	}

	memmove(whcrc->cmd_buf, cmd, cmd_size);
	le_writeq(whcrc->cmd_dma_buf, whcrc->rc_base + URCCMDADDR);

	spin_lock(&whcrc->irq_lock);
	urccmd = le_readl(whcrc->rc_base + URCCMD);
	urccmd &= ~(URCCMD_EARV \| URCCMD_SIZE_MASK);
	le_writel(urccmd \| URCCMD_ACTIVE \| URCCMD_IWR \| cmd_size,
	whcrc->rc_base + URCCMD);
	spin_unlock(&whcrc->irq_lock);

	return 0;
	}

	static int whcrc_reset(struct uwb_rc *rc)
	{
	struct whcrc *whcrc = rc->priv;

	return umc_controller_reset(whcrc->umc_dev);
	}

	/**
	* Reset event reception mechanism and tell hw we are ready to get more
	*
	* We have read all the events in the event buffer, so we are ready to
	* reset it to the beginning.
	*
	* This is only called during initialization or after an event buffer
	* has been retired. This means we can be sure that event processing
	* is disabled and it's safe to update the URCEVTADDR register.
	*
	* There's no need to wait for the event processing to start as the
	* URC will not clear URCCMD_ACTIVE until (internal) event buffer
	* space is available.
	*/
	static
	void whcrc_enable_events(struct whcrc *whcrc)
	{
	u32 urccmd;

	le_writeq(whcrc->evt_dma_buf, whcrc->rc_base + URCEVTADDR);

	spin_lock(&whcrc->irq_lock);
	urccmd = le_readl(whcrc->rc_base + URCCMD) & ~URCCMD_ACTIVE;
	le_writel(urccmd \| URCCMD_EARV, whcrc->rc_base + URCCMD);
	spin_unlock(&whcrc->irq_lock);
	}

	static void whcrc_event_work(struct work_struct *work)
	{
	struct whcrc *whcrc = container_of(work, struct whcrc, event_work);
	size_t size;
	u64 urcevtaddr;

	urcevtaddr = le_readq(whcrc->rc_base + URCEVTADDR);
	size = urcevtaddr & URCEVTADDR_OFFSET_MASK;

	uwb_rc_neh_grok(whcrc->uwb_rc, whcrc->evt_buf, size);
	whcrc_enable_events(whcrc);
	}

	/**
	* Catch interrupts?
	*
	* We ack inmediately (and expect the hw to do the right thing and
	* raise another IRQ if things have changed :)
	*/
	static
	irqreturn_t whcrc_irq_cb(int irq, void *_whcrc)
	{
	struct whcrc *whcrc = _whcrc;
	struct device *dev = &whcrc->umc_dev->dev;
	u32 urcsts;

	urcsts = le_readl(whcrc->rc_base + URCSTS);
	if (!(urcsts & URCSTS_INT_MASK))
	return IRQ_NONE;
	le_writel(urcsts & URCSTS_INT_MASK, whcrc->rc_base + URCSTS);

	if (urcsts & URCSTS_HSE) {
	dev_err(dev, "host system error -- hardware halted\n");
	/* FIXME: do something sensible here */
	goto out;
	}
	if (urcsts & URCSTS_ER)
	schedule_work(&whcrc->event_work);
	if (urcsts & URCSTS_RCI)
	wake_up_all(&whcrc->cmd_wq);
	out:
	return IRQ_HANDLED;
	}


	/**
	* Initialize a UMC RC interface: map regions, get (shared) IRQ
	*/
	static
	int whcrc_setup_rc_umc(struct whcrc *whcrc)
	{
	int result = 0;
	struct device *dev = &whcrc->umc_dev->dev;
	struct umc_dev *umc_dev = whcrc->umc_dev;

	whcrc->area = umc_dev->resource.start;
	whcrc->rc_len = umc_dev->resource.end - umc_dev->resource.start + 1;
	result = -EBUSY;
	if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME) == NULL) {
	dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n",
	whcrc->rc_len, whcrc->area, result);
	goto error_request_region;
	}

	whcrc->rc_base = ioremap_nocache(whcrc->area, whcrc->rc_len);
	if (whcrc->rc_base == NULL) {
	dev_err(dev, "can't ioremap registers (%zu bytes @ 0x%lx): %d\n",
	whcrc->rc_len, whcrc->area, result);
	goto error_ioremap_nocache;
	}

	result = request_irq(umc_dev->irq, whcrc_irq_cb, IRQF_SHARED,
	KBUILD_MODNAME, whcrc);
	if (result < 0) {
	dev_err(dev, "can't allocate IRQ %d: %d\n",
	umc_dev->irq, result);
	goto error_request_irq;
	}

	result = -ENOMEM;
	whcrc->cmd_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
	&whcrc->cmd_dma_buf, GFP_KERNEL);
	if (whcrc->cmd_buf == NULL) {
	dev_err(dev, "Can't allocate cmd transfer buffer\n");
	goto error_cmd_buffer;
	}

	whcrc->evt_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
	&whcrc->evt_dma_buf, GFP_KERNEL);
	if (whcrc->evt_buf == NULL) {
	dev_err(dev, "Can't allocate evt transfer buffer\n");
	goto error_evt_buffer;
	}
	return 0;

	error_evt_buffer:
	dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
	whcrc->cmd_dma_buf);
	error_cmd_buffer:
	free_irq(umc_dev->irq, whcrc);
	error_request_irq:
	iounmap(whcrc->rc_base);
	error_ioremap_nocache:
	release_mem_region(whcrc->area, whcrc->rc_len);
	error_request_region:
	return result;
	}


	/**
	* Release RC's UMC resources
	*/
	static
	void whcrc_release_rc_umc(struct whcrc *whcrc)
	{
	struct umc_dev *umc_dev = whcrc->umc_dev;

	dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->evt_buf,
	whcrc->evt_dma_buf);
	dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
	whcrc->cmd_dma_buf);
	free_irq(umc_dev->irq, whcrc);
	iounmap(whcrc->rc_base);
	release_mem_region(whcrc->area, whcrc->rc_len);
	}


	/**
	* whcrc_start_rc - start a WHCI radio controller
	* @whcrc: the radio controller to start
	*
	* Reset the UMC device, start the radio controller, enable events and
	* finally enable interrupts.
	*/
	static int whcrc_start_rc(struct uwb_rc *rc)
	{
	struct whcrc *whcrc = rc->priv;
	struct device *dev = &whcrc->umc_dev->dev;

	/* Reset the thing */
	le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD);
	if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0,
	5000, "hardware reset") < 0)
	return -EBUSY;

	/* Set the event buffer, start the controller (enable IRQs later) */
	le_writel(0, whcrc->rc_base + URCINTR);
	le_writel(URCCMD_RS, whcrc->rc_base + URCCMD);
	if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0,
	5000, "radio controller start") < 0)
	return -ETIMEDOUT;
	whcrc_enable_events(whcrc);
	le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR);
	return 0;
	}


	/**
	* whcrc_stop_rc - stop a WHCI radio controller
	* @whcrc: the radio controller to stop
	*
	* Disable interrupts and cancel any pending event processing work
	* before clearing the Run/Stop bit.
	*/
	static
	void whcrc_stop_rc(struct uwb_rc *rc)
	{
	struct whcrc *whcrc = rc->priv;
	struct umc_dev *umc_dev = whcrc->umc_dev;

	le_writel(0, whcrc->rc_base + URCINTR);
	cancel_work_sync(&whcrc->event_work);

	le_writel(0, whcrc->rc_base + URCCMD);
	whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS,
	URCSTS_HALTED, URCSTS_HALTED, 100, "radio controller stop");
	}

	static void whcrc_init(struct whcrc *whcrc)
	{
	spin_lock_init(&whcrc->irq_lock);
	init_waitqueue_head(&whcrc->cmd_wq);
	INIT_WORK(&whcrc->event_work, whcrc_event_work);
	}

	/**
	* Initialize the radio controller.
	*
	* NOTE: we setup whcrc->uwb_rc before calling uwb_rc_add(); in the
	* IRQ handler we use that to determine if the hw is ready to
	* handle events. Looks like a race condition, but it really is
	* not.
	*/
	static
	int whcrc_probe(struct umc_dev *umc_dev)
	{
	int result;
	struct uwb_rc *uwb_rc;
	struct whcrc *whcrc;
	struct device *dev = &umc_dev->dev;

	result = -ENOMEM;
	uwb_rc = uwb_rc_alloc();
	if (uwb_rc == NULL) {
	dev_err(dev, "unable to allocate RC instance\n");
	goto error_rc_alloc;
	}
	whcrc = kzalloc(sizeof(*whcrc), GFP_KERNEL);
	if (whcrc == NULL) {
	dev_err(dev, "unable to allocate WHC-RC instance\n");
	goto error_alloc;
	}
	whcrc_init(whcrc);
	whcrc->umc_dev = umc_dev;

	result = whcrc_setup_rc_umc(whcrc);
	if (result < 0) {
	dev_err(dev, "Can't setup RC UMC interface: %d\n", result);
	goto error_setup_rc_umc;
	}
	whcrc->uwb_rc = uwb_rc;

	uwb_rc->owner = THIS_MODULE;
	uwb_rc->cmd = whcrc_cmd;
	uwb_rc->reset = whcrc_reset;
	uwb_rc->start = whcrc_start_rc;
	uwb_rc->stop = whcrc_stop_rc;

	result = uwb_rc_add(uwb_rc, dev, whcrc);
	if (result < 0)
	goto error_rc_add;
	umc_set_drvdata(umc_dev, whcrc);
	return 0;

	error_rc_add:
	whcrc_release_rc_umc(whcrc);
	error_setup_rc_umc:
	kfree(whcrc);
	error_alloc:
	uwb_rc_put(uwb_rc);
	error_rc_alloc:
	return result;
	}

	/**
	* Clean up the radio control resources
	*
	* When we up the command semaphore, everybody possibly held trying to
	* execute a command should be granted entry and then they'll see the
	* host is quiescing and up it (so it will chain to the next waiter).
	* This should not happen (in any case), as we can only remove when
	* there are no handles open...
	*/
	static void whcrc_remove(struct umc_dev *umc_dev)
	{
	struct whcrc *whcrc = umc_get_drvdata(umc_dev);
	struct uwb_rc *uwb_rc = whcrc->uwb_rc;

	umc_set_drvdata(umc_dev, NULL);
	uwb_rc_rm(uwb_rc);
	whcrc_release_rc_umc(whcrc);
	kfree(whcrc);
	uwb_rc_put(uwb_rc);
	}

	static int whcrc_pre_reset(struct umc_dev *umc)
	{
	struct whcrc *whcrc = umc_get_drvdata(umc);
	struct uwb_rc *uwb_rc = whcrc->uwb_rc;

	uwb_rc_pre_reset(uwb_rc);
	return 0;
	}

	static int whcrc_post_reset(struct umc_dev *umc)
	{
	struct whcrc *whcrc = umc_get_drvdata(umc);
	struct uwb_rc *uwb_rc = whcrc->uwb_rc;

	return uwb_rc_post_reset(uwb_rc);
	}

	/* PCI device ID's that we handle [so it gets loaded] */
	static struct pci_device_id whcrc_id_table[] = {
	{ PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) },
	{ /* empty last entry */ }
	};
	MODULE_DEVICE_TABLE(pci, whcrc_id_table);

	static struct umc_driver whcrc_driver = {
	.name = "whc-rc",
	.cap_id = UMC_CAP_ID_WHCI_RC,
	.probe = whcrc_probe,
	.remove = whcrc_remove,
	.pre_reset = whcrc_pre_reset,
	.post_reset = whcrc_post_reset,
	};

	static int __init whcrc_driver_init(void)
	{
	return umc_driver_register(&whcrc_driver);
	}
	module_init(whcrc_driver_init);

	static void __exit whcrc_driver_exit(void)
	{
	umc_driver_unregister(&whcrc_driver);
	}
	module_exit(whcrc_driver_exit);

	MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
	MODULE_DESCRIPTION("Wireless Host Controller Radio Control Driver");
	MODULE_LICENSE("GPL");