Merge branch 'u-boot/master' into u-boot-arm/master

[karo-tx-uboot.git] / arch / arm / cpu / ixp / timer.c

diff --git a/arch/arm/cpu/ixp/timer.c b/arch/arm/cpu/ixp/timer.c
index edf341ff9f9b24dbac9fc7c4b19539b358900be8..38e2e2879c8e556694b51990e858c3b487a50ed0 100644 (file)
--- a/arch/arm/cpu/ixp/timer.c
+++ b/arch/arm/cpu/ixp/timer.c
@@ -1,4 +1,7 @@
 /*
+ * (C) Copyright 2010
+ * Michael Schwingen, michael@schwingen.org
+ *
  * (C) Copyright 2006
  * Stefan Roese, DENX Software Engineering, sr@denx.de.
  *
@@ -10,126 +13,89 @@
  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  * Alex Zuepke <azu@sysgo.de>
  *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier:    GPL-2.0+
  */
 
 #include <common.h>
 #include <asm/arch/ixp425.h>
+#include <asm/io.h>
+#include <div64.h>
 
-#ifdef CONFIG_TIMER_IRQ
-
-#define FREQ           66666666
-#define CLOCK_TICK_RATE        (((FREQ / CONFIG_SYS_HZ & ~IXP425_OST_RELOAD_MASK) + 1) * CONFIG_SYS_HZ)
-#define LATCH          ((CLOCK_TICK_RATE + CONFIG_SYS_HZ/2) / CONFIG_SYS_HZ)   /* For divider */
+DECLARE_GLOBAL_DATA_PTR;
 
 /*
- * When interrupts are enabled, use timer 2 for time/delay generation...
+ * The IXP42x time-stamp timer runs at 2*OSC_IN (66.666MHz when using a
+ * 33.333MHz crystal).
  */
-
-static volatile ulong timestamp;
-
-static void timer_isr(void *data)
+static inline unsigned long long tick_to_time(unsigned long long tick)
 {
-       unsigned int *pTime = (unsigned int *)data;
-
-       (*pTime)++;
-
-       /*
-        * Reset IRQ source
-        */
-       *IXP425_OSST = IXP425_OSST_TIMER_2_PEND;
+       tick *= CONFIG_SYS_HZ;
+       do_div(tick, CONFIG_IXP425_TIMER_CLK);
+       return tick;
 }
 
-ulong get_timer (ulong base)
+static inline unsigned long long time_to_tick(unsigned long long time)
 {
-       return timestamp - base;
+       time *= CONFIG_IXP425_TIMER_CLK;
+       do_div(time, CONFIG_SYS_HZ);
+       return time;
 }
 
-void reset_timer (void)
+static inline unsigned long long us_to_tick(unsigned long long us)
 {
-       timestamp = 0;
+       us = us * CONFIG_IXP425_TIMER_CLK + 999999;
+       do_div(us, 1000000);
+       return us;
 }
 
-int timer_init (void)
+unsigned long long get_ticks(void)
 {
-       /* install interrupt handler for timer */
-       irq_install_handler(IXP425_TIMER_2_IRQ, timer_isr, (void *)&timestamp);
-
-       /* setup the Timer counter value */
-       *IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE;
+       ulong now = readl(IXP425_OSTS_B);
+
+       if (readl(IXP425_OSST) & IXP425_OSST_TIMER_TS_PEND) {
+               /* rollover of timestamp timer register */
+               gd->arch.timestamp += (0xFFFFFFFF - gd->arch.lastinc) + now + 1;
+               writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
+       } else {
+               /* move stamp forward with absolut diff ticks */
+               gd->arch.timestamp += (now - gd->arch.lastinc);
+       }
+       gd->arch.lastinc = now;
+       return gd->arch.timestamp;
+}
 
-       /* enable timer irq */
-       *IXP425_ICMR = (1 << IXP425_TIMER_2_IRQ);
 
-       return 0;
-}
-#else
-ulong get_timer (ulong base)
+void reset_timer_masked(void)
 {
-       return get_timer_masked () - base;
+       /* capture current timestamp counter */
+       gd->arch.lastinc = readl(IXP425_OSTS_B);
+       /* start "advancing" time stamp from 0 */
+       gd->arch.timestamp = 0;
 }
 
-void ixp425_udelay(unsigned long usec)
+ulong get_timer_masked(void)
 {
-       /*
-        * This function has a max usec, but since it is called from udelay
-        * we should not have to worry... be happy
-        */
-       unsigned long usecs = CONFIG_SYS_HZ/1000000L & ~IXP425_OST_RELOAD_MASK;
-
-       *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
-       usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
-       *IXP425_OSRT1 = usecs;
-       while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND));
+       return tick_to_time(get_ticks());
 }
 
-void __udelay (unsigned long usec)
+ulong get_timer(ulong base)
 {
-       while (usec--) ixp425_udelay(1);
+       return get_timer_masked() - base;
 }
 
-static ulong reload_constant = 0xfffffff0;
-
-void reset_timer_masked (void)
+/* delay x useconds AND preserve advance timestamp value */
+void __udelay(unsigned long usec)
 {
-       ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
+       unsigned long long tmp;
 
-       *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
-       *IXP425_OSRT1 = reload;
-}
+       tmp = get_ticks() + us_to_tick(usec);
 
-ulong get_timer_masked (void)
-{
-       /*
-        * Note that it is possible for this to wrap!
-        * In this case we return max.
-        */
-       ulong current = *IXP425_OST1;
-       if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)
-       {
-               return reload_constant;
-       }
-       return (reload_constant - current);
+       while (get_ticks() < tmp)
+               ;
 }
 
 int timer_init(void)
 {
+       writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
        return 0;
 }
-#endif