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Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +02001/*
2 * (C) Copyright 2002
3 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
4 * Marius Groeger <mgroeger@sysgo.de>
5 *
6 * (C) Copyright 2002
7 * David Mueller, ELSOFT AG, <d.mueller@elsoft.ch>
8 *
9 * (C) Copyright 2003
10 * Texas Instruments, <www.ti.com>
11 * Kshitij Gupta <Kshitij@ti.com>
12 *
13 * (C) Copyright 2004
14 * ARM Ltd.
15 * Philippe Robin, <philippe.robin@arm.com>
16 *
17 * See file CREDITS for list of people who contributed to this
18 * project.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License as
22 * published by the Free Software Foundation; either version 2 of
23 * the License, or (at your option) any later version.
24 *
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
29 *
30 * You should have received a copy of the GNU General Public License
31 * along with this program; if not, write to the Free Software
32 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
33 * MA 02111-1307 USA
34 */
35
36#include <common.h>
37#include <div64.h>
38
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020039#ifdef CONFIG_ARCH_CINTEGRATOR
40#define DIV_CLOCK_INIT 1
41#define TIMER_LOAD_VAL 0xFFFFFFFFL
42#else
43#define DIV_CLOCK_INIT 256
44#define TIMER_LOAD_VAL 0x0000FFFFL
45#endif
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020046/* The Integrator/CP timer1 is clocked at 1MHz
47 * can be divided by 16 or 256
48 * and can be set up as a 32-bit timer
49 */
50/* U-Boot expects a 32 bit timer, running at CONFIG_SYS_HZ */
51/* Keep total timer count to avoid losing decrements < div_timer */
52static unsigned long long total_count = 0;
53static unsigned long long lastdec; /* Timer reading at last call */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020054/* Divisor applied to timer clock */
55static unsigned long long div_clock = DIV_CLOCK_INIT;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020056static unsigned long long div_timer = 1; /* Divisor to convert timer reading
57 * change to U-Boot ticks
58 */
59/* CONFIG_SYS_HZ = CONFIG_SYS_HZ_CLOCK/(div_clock * div_timer) */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020060static ulong timestamp; /* U-Boot ticks since startup */
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020061
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020062#define READ_TIMER (*(volatile ulong *)(CONFIG_SYS_TIMERBASE+4))
63
64/* all function return values in U-Boot ticks i.e. (1/CONFIG_SYS_HZ) sec
65 * - unless otherwise stated
66 */
67
68/* starts up a counter
69 * - the Integrator/CP timer can be set up to issue an interrupt */
70int timer_init (void)
71{
72 /* Load timer with initial value */
73 *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 0) = TIMER_LOAD_VAL;
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020074#ifdef CONFIG_ARCH_CINTEGRATOR
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020075 /* Set timer to be
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020076 * enabled 1
77 * periodic 1
78 * no interrupts 0
79 * X 0
80 * divider 1 00 == less rounding error
81 * 32 bit 1
82 * wrapping 0
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020083 */
84 *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x000000C2;
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020085#else
86 /* Set timer to be
87 * enabled 1
88 * free-running 0
89 * XX 00
90 * divider 256 10
91 * XX 00
92 */
93 *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x00000088;
94#endif
95
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020096 /* init the timestamp */
97 total_count = 0ULL;
98 reset_timer_masked();
99
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200100 div_timer = CONFIG_SYS_HZ_CLOCK;
101 do_div(div_timer, CONFIG_SYS_HZ);
102 do_div(div_timer, div_clock);
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200103
104 return (0);
105}
106
107/*
108 * timer without interrupts
109 */
110void reset_timer (void)
111{
112 reset_timer_masked ();
113}
114
115ulong get_timer (ulong base_ticks)
116{
117 return get_timer_masked () - base_ticks;
118}
119
120void set_timer (ulong ticks)
121{
122 timestamp = ticks;
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200123 total_count = ticks * div_timer;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200124}
125
126/* delay usec useconds */
127void udelay (unsigned long usec)
128{
129 ulong tmo, tmp;
130
131 /* Convert to U-Boot ticks */
132 tmo = usec * CONFIG_SYS_HZ;
133 tmo /= (1000000L);
134
135 tmp = get_timer_masked(); /* get current timestamp */
136 tmo += tmp; /* form target timestamp */
137
138 while (get_timer_masked () < tmo) {/* loop till event */
139 /*NOP*/;
140 }
141}
142
143void reset_timer_masked (void)
144{
145 /* capure current decrementer value */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200146 lastdec = READ_TIMER;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200147 /* start "advancing" time stamp from 0 */
148 timestamp = 0L;
149}
150
151/* converts the timer reading to U-Boot ticks */
152/* the timestamp is the number of ticks since reset */
153ulong get_timer_masked (void)
154{
155 /* get current count */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200156 unsigned long long now = READ_TIMER;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200157
158 if(now > lastdec) {
159 /* Must have wrapped */
160 total_count += lastdec + TIMER_LOAD_VAL + 1 - now;
161 } else {
162 total_count += lastdec - now;
163 }
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200164 lastdec = now;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200165
166 /* Reuse "now" */
167 now = total_count;
168 do_div(now, div_timer);
169 timestamp = now;
170
171 return timestamp;
172}
173
174/* waits specified delay value and resets timestamp */
175void udelay_masked (unsigned long usec)
176{
177 udelay(usec);
178}
179
180/*
181 * This function is derived from PowerPC code (read timebase as long long).
182 * On ARM it just returns the timer value.
183 */
184unsigned long long get_ticks(void)
185{
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200186 return get_timer(0);
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200187}
188
189/*
190 * Return the timebase clock frequency
191 * i.e. how often the timer decrements
192 */
193ulong get_tbclk (void)
194{
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200195 unsigned long long tmp = CONFIG_SYS_HZ_CLOCK;
196
197 do_div(tmp, div_clock);
198
199 return tmp;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200200}