uwb: add whc-rc radio control driver

	  <file:Documentation/usb/>.

	  To compile the UWB stack as a module, choose M here.

if UWB

config UWB_WHCI

        tristate "UWB Radio Control driver for WHCI-compliant cards"

        depends on PCI

        help

          This driver enables the radio controller for WHCI cards.

          WHCI is an specification developed by Intel

          (http://www.intel.com/technology/comms/wusb/whci.htm) much

          in the spirit of USB's EHCI, but for UWB and Wireless USB

          radio/host controllers connected via memmory mapping (eg:

          PCI). Most of these cards come also with a Wireless USB host

          controller.

          To compile this driver select Y (built in) or M (module). It

          is safe to select any even if you do not have the hardware.

endif # UWB

obj-$(CONFIG_UWB)		+= uwb.o

obj-$(CONFIG_UWB_WHCI)		+= umc.o whci.o

obj-$(CONFIG_UWB_WHCI)		+= umc.o whci.o whc-rc.o

uwb-objs :=		\

	address.o	\

/*

 * 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/version.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/pci.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"

#define D_LOCAL 0

#include <linux/uwb/debug.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;

	d_fnstart(3, dev, "(%p, %p, %zu)\n", uwb_rc, cmd, cmd_size);

	might_sleep();

	if (cmd_size >= 4096) {

		result = -E2BIG;

		goto error;

	}

	/*

	 * 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);

		result = -EIO;

		goto error;

	}

	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");

		result = -ETIMEDOUT;

		goto error;

	}

	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);

error:

	d_fnend(3, dev, "(%p, %p, %zu) = %d\n",

		uwb_rc, cmd, cmd_size, result);

	return result;

}

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)

{

	struct device *dev = &whcrc->umc_dev->dev;

	u32 urccmd;

	d_fnstart(4, dev, "(whcrc %p)\n", whcrc);

	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);

	d_fnend(4, dev, "(whcrc %p) = void\n", whcrc);

}

static void whcrc_event_work(struct work_struct *work)

{

	struct whcrc *whcrc = container_of(work, struct whcrc, event_work);

	struct device *dev = &whcrc->umc_dev->dev;

	size_t size;

	u64 urcevtaddr;

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

	size = urcevtaddr & URCEVTADDR_OFFSET_MASK;

	d_printf(3, dev, "received %zu octet event\n", size);

	d_dump(4, dev, whcrc->evt_buf, size > 32 ? 32 : size);

	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;

	d_fnstart(4, dev, "irq %d _whcrc %p)\n", irq, _whcrc);

	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);

	d_printf(4, dev, "acked 0x%08x, urcsts 0x%08x\n",

		 le_readl(whcrc->rc_base + URCSTS), urcsts);

	if (whcrc->uwb_rc == NULL) {

		if (printk_ratelimit())

			dev_dbg(dev, "Received interrupt when not yet "

				"ready!\n");

		goto out;

	}

	if (urcsts & URCSTS_HSE) {

		dev_err(dev, "host system error -- hardware halted\n");

		/* FIXME: do something sensible here */

		goto out;

	}

	if (urcsts & URCSTS_ER) {

		d_printf(3, dev, "ER: event ready\n");

		schedule_work(&whcrc->event_work);

	}

	if (urcsts & URCSTS_RCI) {

		d_printf(3, dev, "RCI: ready to execute another command\n");

		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;

	}

	d_printf(3, dev, "UWB RC Interface: %zu bytes at 0x%p, irq %u\n",

		 whcrc->rc_len, whcrc->rc_base, umc_dev->irq);

	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;

	int result = 0;

	struct device *dev = &whcrc->umc_dev->dev;

	unsigned long start, duration;

	/* Reset the thing */

	le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD);

	if (d_test(3))

		start = jiffies;

	if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0,

			  5000, "device to reset at init") < 0) {

		result = -EBUSY;

		goto error;

	} else if (d_test(3)) {

		duration = jiffies - start;

		if (duration > msecs_to_jiffies(40))

			dev_err(dev, "Device took %ums to "

				     "reset. MAX expected: 40ms\n",

				     jiffies_to_msecs(duration));

	}

	/* 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);

	result = -ETIMEDOUT;

	if (d_test(3))

		start = jiffies;

	if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0,

			  5000, "device to start") < 0)

		goto error;

	if (d_test(3)) {

		duration = jiffies - start;

		if (duration > msecs_to_jiffies(40))

			dev_err(dev, "Device took %ums to start. "

				     "MAX expected: 40ms\n",

				     jiffies_to_msecs(duration));

	}

	whcrc_enable_events(whcrc);

	result = 0;

	le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR);

error:

	return result;

}

/**

 * 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, 0, 40, "URCSTS.HALTED");

}

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;

	d_fnstart(3, dev, "(umc_dev %p)\n", umc_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);

	d_fnend(3, dev, "(umc_dev %p) = 0\n", umc_dev);

	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:

	d_fnend(3, dev, "(umc_dev %p) = %d\n", umc_dev, result);

	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);

	d_printf(1, &umc_dev->dev, "freed whcrc %p\n", whcrc);

}

/* 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,

};

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");