[svn-commits] sruffell: linux/trunk r6524 - /linux/trunk/drivers/dahdi/dahdi_dummy.c
SVN commits to the Digium repositories
svn-commits at lists.digium.com
Wed Apr 29 12:48:38 CDT 2009
Author: sruffell
Date: Wed Apr 29 12:48:27 2009
New Revision: 6524
URL: http://svn.digium.com/svn-view/dahdi?view=rev&rev=6524
Log:
dahdi_dummy: Remove real-time clock support.
This removes support for using the real-time clock as a timing source in
dahdi_dummy. Instead, the normal kernel timers method is now more accurate
since it keeps track of how much real time has passed to determine how many
times to call dahdi_receive and dahdi_transmit. This method was originally
suggested by bmd.
(closes issue #13930)
(closes issue #14884)
Reported by: tzafrir
Tested by: dbackeberg, ask
Modified:
linux/trunk/drivers/dahdi/dahdi_dummy.c
Modified: linux/trunk/drivers/dahdi/dahdi_dummy.c
URL: http://svn.digium.com/svn-view/dahdi/linux/trunk/drivers/dahdi/dahdi_dummy.c?view=diff&rev=6524&r1=6523&r2=6524
==============================================================================
--- linux/trunk/drivers/dahdi/dahdi_dummy.c (original)
+++ linux/trunk/drivers/dahdi/dahdi_dummy.c Wed Apr 29 12:48:27 2009
@@ -1,17 +1,16 @@
/*
* Dummy DAHDI Driver for DAHDI Telephony interface
*
- * Required: usb-uhci module and kernel > 2.4.4 OR kernel > 2.6.0
+ * Required: kernel > 2.6.0
*
* Written by Robert Pleh <robert.pleh at hermes.si>
* 2.6 version by Tony Hoyle
* Unified by Mark Spencer <markster at digium.com>
- * Converted to use RTC on i386 by Tony Mountifield <tony at softins.co.uk>
*
* Converted to use HighResTimers on i386 by Jeffery Palmer <jeff at triggerinc.com>
*
* Copyright (C) 2002, Hermes Softlab
- * Copyright (C) 2004, Digium, Inc.
+ * Copyright (C) 2004-2009, Digium, Inc.
*
* All rights reserved.
*
@@ -39,33 +38,9 @@
#include <linux/version.h>
-#ifndef VERSION_CODE
-# define VERSION_CODE(vers,rel,seq) ( ((vers)<<16) | ((rel)<<8) | (seq) )
-#endif
-
-
-#if LINUX_VERSION_CODE < VERSION_CODE(2,4,5)
-# error "This kernel is too old: not supported by this file"
-#endif
-
-/*
- * NOTE: (only applies to kernel 2.6)
- * If using an i386 architecture without a PC real-time clock,
- * the #define USE_RTC should be commented out.
- */
-#if defined(__i386__) || defined(__x86_64__)
-#if LINUX_VERSION_CODE >= VERSION_CODE(2,6,15)
-/* The symbol hrtimer_forward is only exported as of 2.6.22: */
-#if defined(CONFIG_HIGH_RES_TIMERS) && LINUX_VERSION_CODE >= VERSION_CODE(2,6,22)
+#if defined(CONFIG_HIGH_RES_TIMERS) && \
+ LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22)
#define USE_HIGHRESTIMER
-#else
-#define USE_RTC
-#endif
-#else
-#if 0
-#define USE_RTC
-#endif
-#endif
#endif
#include <linux/kernel.h>
@@ -75,19 +50,13 @@
#include <linux/errno.h>
#include <linux/moduleparam.h>
+#if defined(USE_HIGHRESTIMER)
+#include <linux/hrtimer.h>
+#else
+#include <linux/time.h>
+#endif
+
#include <dahdi/kernel.h>
-
-#ifdef USE_HIGHRESTIMER
-#include <linux/hrtimer.h>
-#endif
-#ifdef USE_RTC
-#include <linux/rtc.h>
-#endif
-
-#include <linux/version.h>
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,4,19)
-#define USB2420
-#endif
#ifndef HAVE_HRTIMER_ACCESSORS
#if defined(USE_HIGHRESTIMER) && \
@@ -109,10 +78,9 @@
struct dahdi_span span;
struct dahdi_chan _chan;
struct dahdi_chan *chan;
- unsigned int counter;
-#ifdef USE_RTC
- spinlock_t rtclock;
- rtc_task_t rtc_task;
+#if !defined(USE_HIGHRESTIMER)
+ unsigned long calls_since_start;
+ struct timespec start_interval;
#endif
};
@@ -123,71 +91,21 @@
#ifdef USE_HIGHRESTIMER
#define CLOCK_SRC "HRtimer"
static struct hrtimer zaptimer;
-#elif defined(USE_RTC)
-#define CLOCK_SRC "RTC"
-static int rtc_rate = 0;
-static int current_rate = 0;
-static int taskletpending = 0;
-static struct tasklet_struct ztd_tlet;
-static void ztd_tasklet(unsigned long data);
-#else /* Linux 2.6, but no RTC or HRTIMER used */
-#define CLOCK_SRC "Linux26"
-/* 2.6 kernel timer stuff */
-static struct timer_list timer;
-#endif
-
#define DAHDI_RATE 1000 /* DAHDI ticks per second */
#define DAHDI_TIME (1000000 / DAHDI_RATE) /* DAHDI tick time in us */
#define DAHDI_TIME_NS (DAHDI_TIME * 1000) /* DAHDI tick time in ns */
+#else
+#define CLOCK_SRC "Linux26"
+static struct timer_list timer;
+static atomic_t shutdown;
+#define JIFFIES_INTERVAL (HZ/250) /* 4ms is fine for dahdi_dummy */
+#endif
/* Different bits of the debug variable: */
#define DEBUG_GENERAL (1 << 0)
#define DEBUG_TICKS (1 << 1)
-
-#ifdef USE_RTC
-static void update_rtc_rate(struct dahdi_dummy *ztd)
-{
- if (((rtc_rate & (rtc_rate - 1)) != 0) || (rtc_rate > 8192) || (rtc_rate < 2)) {
- printk(KERN_NOTICE "Invalid RTC rate %d specified\n", rtc_rate);
- rtc_rate = current_rate; /* Set default RTC rate */
- }
- if (!rtc_rate || (rtc_rate != current_rate)) {
- rtc_control(&ztd->rtc_task, RTC_IRQP_SET, current_rate = (rtc_rate ? rtc_rate : 1024)); /* 1024 Hz */
- printk(KERN_INFO "dahdi_dummy: RTC rate is %d\n", rtc_rate);
- ztd->counter = 0;
- }
-}
-
-static void ztd_tasklet(unsigned long data)
-{
- if (taskletpending)
- update_rtc_rate((struct dahdi_dummy *)ztd);
- taskletpending = 0;
-}
-
-/* rtc_interrupt - called at 1024Hz from hook in RTC handler */
-static void dahdi_dummy_rtc_interrupt(void *private_data)
-{
- struct dahdi_dummy *ztd = private_data;
- unsigned long flags;
-
- /* Is spinlock required here??? */
- spin_lock_irqsave(&ztd->rtclock, flags);
- ztd->counter += DAHDI_TIME;
- while (ztd->counter >= current_rate) {
- ztd->counter -= current_rate;
- /* Update of RTC IRQ rate isn't possible from interrupt handler :( */
- if (!taskletpending && (current_rate != rtc_rate)) {
- taskletpending = 1;
- tasklet_hi_schedule(&ztd_tlet);
- }
- dahdi_receive(&ztd->span);
- dahdi_transmit(&ztd->span);
- }
- spin_unlock_irqrestore(&ztd->rtclock, flags);
-}
-#elif defined(USE_HIGHRESTIMER)
+#if defined(USE_HIGHRESTIMER)
static enum hrtimer_restart dahdi_dummy_hr_int(struct hrtimer *htmr)
{
unsigned long overrun;
@@ -220,16 +138,44 @@
return HRTIMER_RESTART;
}
#else
-/* use kernel system tick timer if PC architecture RTC is not available */
+static unsigned long timespec_diff_ms(struct timespec *t0, struct timespec *t1)
+{
+ long nanosec, sec;
+ unsigned long ms;
+ sec = (t1->tv_sec - t0->tv_sec);
+ nanosec = (t1->tv_nsec - t0->tv_nsec);
+ while (nanosec >= NSEC_PER_SEC) {
+ nanosec -= NSEC_PER_SEC;
+ ++sec;
+ }
+ while (nanosec < 0) {
+ nanosec += NSEC_PER_SEC;
+ --sec;
+ }
+ ms = (sec * 1000) + (nanosec / 1000000L);
+ return ms;
+}
+
static void dahdi_dummy_timer(unsigned long param)
{
- mod_timer(&timer, jiffies + 1);
-
- ztd->counter += DAHDI_TIME;
- while (ztd->counter >= HZ) {
- ztd->counter -= HZ;
+ unsigned long ms_since_start;
+ struct timespec now;
+ const unsigned long MAX_INTERVAL = 100000L;
+
+ if (!atomic_read(&shutdown))
+ mod_timer(&timer, jiffies + JIFFIES_INTERVAL);
+
+ now = current_kernel_time();
+ ms_since_start = timespec_diff_ms(&ztd->start_interval, &now);
+ while (ms_since_start > ztd->calls_since_start) {
+ ztd->calls_since_start++;
dahdi_receive(&ztd->span);
dahdi_transmit(&ztd->span);
+ }
+
+ if (ms_since_start > MAX_INTERVAL) {
+ ztd->calls_since_start = 0;
+ ztd->start_interval = now;
}
}
#endif
@@ -257,17 +203,11 @@
int init_module(void)
{
-#ifdef USE_RTC
- int err;
-#endif
-
- ztd = kmalloc(sizeof(struct dahdi_dummy), GFP_KERNEL);
+ ztd = kzalloc(sizeof(*ztd), GFP_KERNEL);
if (ztd == NULL) {
printk(KERN_ERR "dahdi_dummy: Unable to allocate memory\n");
return -ENOMEM;
}
-
- memset(ztd, 0x0, sizeof(struct dahdi_dummy));
if (dahdi_dummy_initialize(ztd)) {
printk(KERN_ERR "dahdi_dummy: Unable to intialize DAHDI driver\n");
@@ -275,25 +215,7 @@
return -ENODEV;
}
- ztd->counter = 0;
-#ifdef USE_RTC
- ztd->rtclock = SPIN_LOCK_UNLOCKED;
- ztd->rtc_task.func = dahdi_dummy_rtc_interrupt;
- ztd->rtc_task.private_data = ztd;
- err = rtc_register(&ztd->rtc_task);
- if (err < 0) {
- printk(KERN_ERR "dahdi_dummy: Unable to register DAHDI rtc driver\n");
- dahdi_unregister(&ztd->span);
- kfree(ztd);
- return err;
- }
- /* Set default RTC interrupt rate to 1024Hz */
- if (!rtc_rate)
- rtc_rate = 1024;
- update_rtc_rate(ztd);
- rtc_control(&ztd->rtc_task, RTC_PIE_ON, 0);
- tasklet_init(&ztd_tlet, ztd_tasklet, 0);
-#elif defined(USE_HIGHRESTIMER)
+#if defined(USE_HIGHRESTIMER)
printk(KERN_DEBUG "dahdi_dummy: Trying to load High Resolution Timer\n");
hrtimer_init(&zaptimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
printk(KERN_DEBUG "dahdi_dummy: Initialized High Resolution Timer\n");
@@ -307,7 +229,9 @@
#else
init_timer(&timer);
timer.function = dahdi_dummy_timer;
- timer.expires = jiffies + 1;
+ ztd->start_interval = current_kernel_time();
+ timer.expires = jiffies + JIFFIES_INTERVAL;
+ atomic_set(&shutdown, 0);
add_timer(&timer);
#endif
@@ -319,18 +243,12 @@
void cleanup_module(void)
{
-#ifdef USE_RTC
- if (taskletpending) {
- tasklet_disable(&ztd_tlet);
- tasklet_kill(&ztd_tlet);
- }
- rtc_control(&ztd->rtc_task, RTC_PIE_OFF, 0);
- rtc_unregister(&ztd->rtc_task);
-#elif defined(USE_HIGHRESTIMER)
+#if defined(USE_HIGHRESTIMER)
/* Stop high resolution timer */
hrtimer_cancel(&zaptimer);
#else
- del_timer(&timer);
+ atomic_set(&shutdown, 1);
+ del_timer_sync(&timer);
#endif
dahdi_unregister(&ztd->span);
kfree(ztd);
@@ -338,12 +256,7 @@
printk(KERN_DEBUG "dahdi_dummy: cleanup() finished\n");
}
-
-
module_param(debug, int, 0600);
-#ifdef USE_RTC
-module_param(rtc_rate, int, 0600);
-#endif
MODULE_DESCRIPTION("Timing-Only Driver");
MODULE_AUTHOR("Robert Pleh <robert.pleh at hermes.si>");
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