/*
|
* Analogy for Linux, RTDM helpers
|
*
|
* Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
|
* Copyright (C) 2008 Alexis Berlemont <alexis.berlemont@free.fr>
|
*
|
* Xenomai is free software; you can redistribute it and/or modify it
|
* under the terms of the GNU General Public License as published by
|
* the Free Software Foundation; either version 2 of the License, or
|
* (at your option) any later version.
|
*
|
* Xenomai 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 Xenomai; if not, write to the Free Software Foundation,
|
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
*/
|
#include <linux/module.h>
|
#include <linux/version.h>
|
#include <linux/fs.h>
|
#include <asm/atomic.h>
|
|
#include <rtdm/analogy/rtdm_helpers.h>
|
|
/* --- Time section --- */
|
|
static nanosecs_abs_t a4l_clkofs;
|
|
void a4l_init_time(void)
|
{
|
nanosecs_abs_t t1, t2;
|
t1 = rtdm_clock_read();
|
t2 = ktime_to_ns(ktime_get_real());
|
a4l_clkofs = t2 - t1;
|
}
|
|
nanosecs_abs_t a4l_get_time(void)
|
{
|
return a4l_clkofs + rtdm_clock_read();
|
}
|
|
/* --- IRQ section --- */
|
|
static int a4l_handle_irq(rtdm_irq_t *irq_handle)
|
{
|
struct a4l_irq_descriptor *dsc =
|
rtdm_irq_get_arg(irq_handle, struct a4l_irq_descriptor);
|
|
if (dsc->handler((unsigned int)irq_handle->irq, dsc->cookie) == 0)
|
return RTDM_IRQ_HANDLED;
|
else
|
return RTDM_IRQ_NONE;
|
}
|
|
int __a4l_request_irq(struct a4l_irq_descriptor *dsc,
|
unsigned int irq,
|
a4l_irq_hdlr_t handler,
|
unsigned long flags, void *cookie)
|
{
|
/* Fills the IRQ descriptor */
|
dsc->handler = handler;
|
dsc->cookie = cookie;
|
dsc->irq = irq;
|
|
/* Registers the RT IRQ handler */
|
return rtdm_irq_request(&dsc->rtdm_desc,
|
(int)irq,
|
a4l_handle_irq, flags, "Analogy device", dsc);
|
}
|
|
int __a4l_free_irq(struct a4l_irq_descriptor * dsc)
|
{
|
return rtdm_irq_free(&dsc->rtdm_desc);
|
}
|
|
/* --- Synchronization section --- */
|
|
static void a4l_nrt_sync_handler(rtdm_nrtsig_t *nrt_sig, void *arg)
|
{
|
struct a4l_sync *snc = (struct a4l_sync *) arg;
|
wake_up_interruptible(&snc->wq);
|
}
|
|
int a4l_init_sync(struct a4l_sync *snc)
|
{
|
int ret = 0;
|
|
/* Initializes the flags field */
|
snc->status = 0;
|
|
/* If the process is NRT, we need a wait queue structure */
|
init_waitqueue_head(&snc->wq);
|
|
/* Initializes the RTDM event */
|
rtdm_event_init(&snc->rtdm_evt, 0);
|
|
/* Initializes the gateway to NRT context */
|
rtdm_nrtsig_init(&snc->nrt_sig, a4l_nrt_sync_handler, snc);
|
|
return ret;
|
}
|
|
void a4l_cleanup_sync(struct a4l_sync *snc)
|
{
|
rtdm_nrtsig_destroy(&snc->nrt_sig);
|
rtdm_event_destroy(&snc->rtdm_evt);
|
}
|
|
int a4l_wait_sync(struct a4l_sync *snc, int rt)
|
{
|
int ret = 0;
|
|
if (test_bit(__EVT_PDING, &snc->status))
|
goto out_wait;
|
|
if (rt != 0) {
|
/* If the calling process is in primary mode,
|
we can use RTDM API ... */
|
set_bit(__RT_WAITER, &snc->status);
|
ret = rtdm_event_wait(&snc->rtdm_evt);
|
} else {
|
/* ... else if the process is NRT,
|
the Linux wait queue system is used */
|
set_bit(__NRT_WAITER, &snc->status);
|
ret = wait_event_interruptible(snc->wq,
|
test_bit(__EVT_PDING,
|
&snc->status));
|
}
|
|
out_wait:
|
|
clear_bit(__EVT_PDING, &snc->status);
|
|
return ret;
|
}
|
|
int a4l_timedwait_sync(struct a4l_sync * snc,
|
int rt, unsigned long long ns_timeout)
|
{
|
int ret = 0;
|
unsigned long timeout;
|
|
if (test_bit(__EVT_PDING, &snc->status))
|
goto out_wait;
|
|
if (rt != 0) {
|
/* If the calling process is in primary mode,
|
we can use RTDM API ... */
|
set_bit(__RT_WAITER, &snc->status);
|
ret = rtdm_event_timedwait(&snc->rtdm_evt, ns_timeout, NULL);
|
} else {
|
/* ... else if the process is NRT,
|
the Linux wait queue system is used */
|
|
timeout = do_div(ns_timeout, 1000);
|
|
/* We consider the Linux kernel cannot tick at a frequency
|
higher than 1 MHz
|
If the timeout value is lower than 1us, we round up to 1us */
|
timeout = (timeout == 0) ? 1 : usecs_to_jiffies(timeout);
|
|
set_bit(__NRT_WAITER, &snc->status);
|
|
ret = wait_event_interruptible_timeout(snc->wq,
|
test_bit(__EVT_PDING,
|
&snc->status),
|
timeout);
|
}
|
|
out_wait:
|
|
clear_bit(__EVT_PDING, &snc->status);
|
|
return ret;
|
}
|
|
void a4l_flush_sync(struct a4l_sync * snc)
|
{
|
/* Clear the status bitfield */
|
snc->status = 0;
|
|
/* Flush the RTDM event */
|
rtdm_event_clear(&snc->rtdm_evt);
|
}
|
|
void a4l_signal_sync(struct a4l_sync * snc)
|
{
|
int hit = 0;
|
|
set_bit(__EVT_PDING, &snc->status);
|
|
/* a4l_signal_sync() is bound not to be called upon the right
|
user process context; so, the status flags stores its mode.
|
Thus the proper event signaling function is called */
|
if (test_and_clear_bit(__RT_WAITER, &snc->status)) {
|
rtdm_event_signal(&snc->rtdm_evt);
|
hit++;
|
}
|
|
if (test_and_clear_bit(__NRT_WAITER, &snc->status)) {
|
rtdm_nrtsig_pend(&snc->nrt_sig);
|
hit++;
|
}
|
|
if (hit == 0) {
|
/* At first signaling, we may not know the proper way
|
to send the event */
|
rtdm_event_signal(&snc->rtdm_evt);
|
rtdm_nrtsig_pend(&snc->nrt_sig);
|
}
|
}
|
