patch-2.1.49 linux/drivers/char/hfmodem/refclock.c

• Lines: 190
• Date: Tue Aug 5 09:48:55 1997
• Orig file: v2.1.48/linux/drivers/char/hfmodem/refclock.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.48/linux/drivers/char/hfmodem/refclock.c linux/drivers/char/hfmodem/refclock.c
@@ -0,0 +1,189 @@
+/*****************************************************************************/
+
+/*
+ *      refclock.c  --  Linux soundcard HF FSK driver,
+ *                      Reference clock routines.
+ *
+ *      Copyright (C) 1997  Thomas Sailer (sailer@ife.ee.ethz.ch)
+ *        Swiss Federal Institute of Technology (ETH), Electronics Lab
+ *
+ *      This program 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.
+ *
+ *      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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ */
+
+/*****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/hfmodem.h>
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * currently this module is supposed to support both module styles, i.e.
+ * the old one present up to about 2.1.9, and the new one functioning
+ * starting with 2.1.21. The reason is I have a kit allowing to compile
+ * this module also under 2.0.x which was requested by several people.
+ * This will go in 2.2
+ */
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE >= 0x20123
+#include <linux/init.h>
+#else
+#define __init
+#define __initdata
+#define __initfunc(x) x
+#endif
+
+/* --------------------------------------------------------------------- */
+/*
+ * command line params
+ */
+
+static unsigned int scale_tvusec = 1UL<<24;
+
+#ifdef __i386__
+static unsigned int scale_rdtsc = 0;
+static int rdtsc_ok = 1;
+#endif /* __i386__ */
+
+/* --------------------------------------------------------------------- */
+
+#ifdef __i386__
+
+__initfunc(static void i386_capability(void))
+{
+        unsigned long flags;
+        unsigned long fl1;
+        union {
+                struct {
+                        unsigned int ebx, edx, ecx;
+                } r;
+                unsigned char s[13];
+        } id;
+        unsigned int eax;
+	unsigned int x86_capability;
+
+        save_flags(flags);
+        flags |= 0x200000;
+        restore_flags(flags);
+        save_flags(flags);
+        fl1 = flags;
+        flags &= ~0x200000;
+        restore_flags(flags);
+        save_flags(flags);
+        if (!(fl1 & 0x200000) || (flags & 0x200000)) {
+                printk(KERN_WARNING "%s: cpu does not support CPUID\n", hfmodem_drvname);
+                return;
+        }
+        __asm__ ("cpuid" : "=a" (eax), "=b" (id.r.ebx), "=c" (id.r.ecx), "=d" (id.r.edx) :
+                 "0" (0));
+        id.s[12] = 0;
+        if (eax < 1) {
+                printk(KERN_WARNING "%s: cpu (vendor string %s) does not support capability "
+                       "list\n", hfmodem_drvname, id.s);
+                return;
+        }
+        printk(KERN_INFO "%s: cpu: vendor string %s ", hfmodem_drvname, id.s);
+        __asm__ ("cpuid" : "=a" (eax), "=d" (x86_capability) : "0" (1) : "ebx", "ecx");
+        printk("fam %d mdl %d step %d cap 0x%x\n", (eax >> 8) & 15, (eax >> 4) & 15, eax & 15, 
+	       x86_capability);
+	if (x86_capability & 0x10)
+		rdtsc_ok = 1;
+	else
+		printk(KERN_INFO "%s: cpu does not support the rdtsc instruction\n", hfmodem_drvname);
+}       
+#endif /* __i386__ */   
+
+/* --------------------------------------------------------------------- */
+
+__initfunc(void hfmodem_refclock_probe(void))
+{
+#ifdef __i386__
+	if (rdtsc_ok) {
+		rdtsc_ok = 0;
+		i386_capability();
+		if (rdtsc_ok) {
+			unsigned int tmp0, tmp1, tmp2, tmp3;
+			__asm__("rdtsc" : "=a" (tmp0), "=d" (tmp1));
+			__asm__("rdtsc" : "=a" (tmp2), "=d" (tmp3));
+			if (tmp0 == tmp2 && tmp1 == tmp3) {
+				rdtsc_ok = 0;
+				printk(KERN_WARNING "%s: rdtsc unusable, does not change\n",
+				       hfmodem_drvname);
+			}
+		}
+	}
+	printk(KERN_INFO "%s: using %s as timing source\n", hfmodem_drvname,
+	       rdtsc_ok ? "rdtsc" : "gettimeofday");
+#endif /* __i386__ */
+}
+
+/* --------------------------------------------------------------------- */
+
+void hfmodem_refclock_init(struct hfmodem_state *dev)
+{
+	struct timeval tv;
+
+	dev->clk.lasttime = 0;
+#ifdef __i386__
+	if (rdtsc_ok) {
+		__asm__("rdtsc;" : "=&d" (dev->clk.starttime_hi), "=&a" (dev->clk.starttime_lo));
+		return;
+	}
+#endif /* __i386__ */
+	do_gettimeofday(&tv);
+	dev->clk.last_tvusec = tv.tv_usec;
+	dev->clk.time_cnt = 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+hfmodem_time_t hfmodem_refclock_current(struct hfmodem_state *dev, hfmodem_time_t expected, int exp_valid)
+{
+	struct timeval tv;
+	hfmodem_time_t curtime;
+	long diff;
+
+#ifdef __i386__
+	if (rdtsc_ok) {
+		unsigned int tmp0, tmp1;
+		unsigned int tmp2, tmp3;
+		
+		__asm__("rdtsc;\n\t"
+			"subl %2,%%eax\n\t"
+			"sbbl %3,%%edx\n\t" : "=&a" (tmp0), "=&d" (tmp1) 
+			: "m" (dev->clk.starttime_lo), "m" (dev->clk.starttime_hi) : "ax", "dx");
+		__asm__("mull %1" : "=d" (tmp2) : "m" (scale_rdtsc), "a" (tmp0) : "ax");
+		__asm__("mull %1" : "=a" (tmp3) : "m" (scale_rdtsc), "a" (tmp1) : "dx");
+		curtime = tmp2 + tmp3;
+		goto time_known;
+	}
+#endif /* __i386__ */
+	do_gettimeofday(&tv);
+	dev->clk.time_cnt += (unsigned)(1000000 + tv.tv_usec - dev->clk.last_tvusec) % 1000000;
+	dev->clk.last_tvusec = tv.tv_usec;
+	curtime = (dev->clk.time_cnt * scale_tvusec) >> 24;
+  time_known:
+	if (exp_valid && abs(diff = (curtime - dev->clk.lasttime - expected)) >= 1000)
+		printk(KERN_DEBUG "%s: refclock adjustment %ld more than 1ms\n", 
+		       hfmodem_drvname, diff);
+	return (dev->clk.lasttime = curtime);
+}
+
+/* --------------------------------------------------------------------- */