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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 *
Wolfgang Denk1a459662013-07-08 09:37:19 +020017 * SPDX-License-Identifier: GPL-2.0+
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020018 */
19
20#include <common.h>
21#include <div64.h>
22
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020023#ifdef CONFIG_ARCH_CINTEGRATOR
24#define DIV_CLOCK_INIT 1
25#define TIMER_LOAD_VAL 0xFFFFFFFFL
26#else
27#define DIV_CLOCK_INIT 256
28#define TIMER_LOAD_VAL 0x0000FFFFL
29#endif
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020030/* The Integrator/CP timer1 is clocked at 1MHz
31 * can be divided by 16 or 256
32 * and can be set up as a 32-bit timer
33 */
34/* U-Boot expects a 32 bit timer, running at CONFIG_SYS_HZ */
35/* Keep total timer count to avoid losing decrements < div_timer */
36static unsigned long long total_count = 0;
37static unsigned long long lastdec; /* Timer reading at last call */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020038/* Divisor applied to timer clock */
39static unsigned long long div_clock = DIV_CLOCK_INIT;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020040static unsigned long long div_timer = 1; /* Divisor to convert timer reading
41 * change to U-Boot ticks
42 */
43/* CONFIG_SYS_HZ = CONFIG_SYS_HZ_CLOCK/(div_clock * div_timer) */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020044static ulong timestamp; /* U-Boot ticks since startup */
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020045
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020046#define READ_TIMER (*(volatile ulong *)(CONFIG_SYS_TIMERBASE+4))
47
48/* all function return values in U-Boot ticks i.e. (1/CONFIG_SYS_HZ) sec
49 * - unless otherwise stated
50 */
51
52/* starts up a counter
53 * - the Integrator/CP timer can be set up to issue an interrupt */
54int timer_init (void)
55{
56 /* Load timer with initial value */
57 *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 0) = TIMER_LOAD_VAL;
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020058#ifdef CONFIG_ARCH_CINTEGRATOR
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020059 /* Set timer to be
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020060 * enabled 1
61 * periodic 1
62 * no interrupts 0
63 * X 0
64 * divider 1 00 == less rounding error
65 * 32 bit 1
66 * wrapping 0
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020067 */
68 *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x000000C2;
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020069#else
70 /* Set timer to be
71 * enabled 1
72 * free-running 0
73 * XX 00
74 * divider 256 10
75 * XX 00
76 */
77 *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x00000088;
78#endif
79
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020080 /* init the timestamp */
81 total_count = 0ULL;
Graeme Russ17659d72011-07-15 02:21:14 +000082 /* capure current decrementer value */
83 lastdec = READ_TIMER;
84 /* start "advancing" time stamp from 0 */
85 timestamp = 0L;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020086
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +020087 div_timer = CONFIG_SYS_HZ_CLOCK;
88 do_div(div_timer, CONFIG_SYS_HZ);
89 do_div(div_timer, div_clock);
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020090
91 return (0);
92}
93
94/*
95 * timer without interrupts
96 */
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +020097ulong get_timer (ulong base_ticks)
98{
99 return get_timer_masked () - base_ticks;
100}
101
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200102/* delay usec useconds */
Ingo van Lil3eb90ba2009-11-24 14:09:21 +0100103void __udelay (unsigned long usec)
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200104{
105 ulong tmo, tmp;
106
107 /* Convert to U-Boot ticks */
108 tmo = usec * CONFIG_SYS_HZ;
109 tmo /= (1000000L);
110
111 tmp = get_timer_masked(); /* get current timestamp */
112 tmo += tmp; /* form target timestamp */
113
114 while (get_timer_masked () < tmo) {/* loop till event */
115 /*NOP*/;
116 }
117}
118
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200119/* converts the timer reading to U-Boot ticks */
120/* the timestamp is the number of ticks since reset */
121ulong get_timer_masked (void)
122{
123 /* get current count */
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200124 unsigned long long now = READ_TIMER;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200125
126 if(now > lastdec) {
127 /* Must have wrapped */
128 total_count += lastdec + TIMER_LOAD_VAL + 1 - now;
129 } else {
130 total_count += lastdec - now;
131 }
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200132 lastdec = now;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200133
134 /* Reuse "now" */
135 now = total_count;
136 do_div(now, div_timer);
137 timestamp = now;
138
139 return timestamp;
140}
141
142/* waits specified delay value and resets timestamp */
143void udelay_masked (unsigned long usec)
144{
145 udelay(usec);
146}
147
148/*
149 * This function is derived from PowerPC code (read timebase as long long).
150 * On ARM it just returns the timer value.
151 */
152unsigned long long get_ticks(void)
153{
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200154 return get_timer(0);
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200155}
156
157/*
158 * Return the timebase clock frequency
159 * i.e. how often the timer decrements
160 */
161ulong get_tbclk (void)
162{
Jean-Christophe PLAGNIOL-VILLARD576afd42009-05-17 00:58:37 +0200163 unsigned long long tmp = CONFIG_SYS_HZ_CLOCK;
164
165 do_div(tmp, div_clock);
166
167 return tmp;
Jean-Christophe PLAGNIOL-VILLARDf54851a2009-05-17 00:58:36 +0200168}