linux/drivers/uwb/whc-rc.c
Thomas Gleixner 04672fe6d6 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 268
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 46 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141334.135501091@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:30:29 +02:00

468 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*
* 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/slab.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 = resource_size(&umc_dev->resource);
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 __used 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");