/*
* 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");
