1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
/*
* (C) Copyright 2003
* Texas Instruments <www.ti.com>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* (C) Copyright 2002-2004
* Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
*
* (C) Copyright 2004
* Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
*
* (C) Copyright 2009 Freescale Semiconductor, Inc.
*
* 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
*/
#include <common.h>
#include <asm/arch/stmp378x.h>
#include <asm/arch/timrot.h>
#define CONFIG_USE_TIMER0
#if defined(CONFIG_USE_TIMER0)
#define TIMCTRL TIMCTRL0
#define TIMCOUNT TIMCOUNT0
#elif defined(CONFIG_USE_TIMER1)
#define TIMCTRL TIMCTRL1
#define TIMCOUNT TIMCOUNT1
#elif defined(CONFIG_USE_TIMER2)
#define TIMCTRL TIMCTRL2
#define TIMCOUNT TIMCOUNT2
#elif defined(CONFIG_USE_TIMER3)
#define TIMCTRL TIMCTRL3
#define TIMCOUNT TIMCOUNT3
#else
#error "Define which STMP378x timer to use"
#endif
#define TIMER_LOAD_VAL 0x0000ffff
/* macro to read the 16 bit timer */
#define READ_TIMER ((REG_RD(TIMROT_BASE + TIMCOUNT) & 0xffff0000) >> 16)
static ulong timestamp;
static ulong lastdec;
int timer_init(void)
{
u32 val;
/*
* Reset Timers and Rotary Encoder module
*/
/* Clear SFTRST */
REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 31);
while (REG_RD(TIMROT_BASE + ROTCTRL) & (1 << 31))
;
/* Clear CLKGATE */
REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 30);
/* Set SFTRST and wait until CLKGATE is set */
REG_SET(TIMROT_BASE + ROTCTRL, 1 << 31);
while (!(REG_RD(TIMROT_BASE + ROTCTRL) & (1 << 30)))
;
/* Clear SFTRST and CLKGATE */
REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 31);
REG_CLR(TIMROT_BASE + ROTCTRL, 1 << 30);
/*
* Now initialize timer
*/
/* Set fixed_count to 0 */
REG_WR(TIMROT_BASE + TIMCOUNT, 0);
/* set UPDATE bit and 1Khz frequency */
REG_WR(TIMROT_BASE + TIMCTRL,
TIMCTRL_RELOAD | TIMCTRL_UPDATE | TIMCTRL_SELECT_1KHZ);
/* Set fixed_count to maximal value */
REG_WR(TIMROT_BASE + TIMCOUNT, TIMER_LOAD_VAL);
/* init the timestamp and lastdec value */
reset_timer_masked();
return 0;
}
/*
* timer without interrupts
*/
void reset_timer(void)
{
reset_timer_masked();
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
void set_timer(ulong t)
{
timestamp = t;
}
/* delay x useconds AND perserve advance timstamp value */
void udelay(unsigned long usec)
{
ulong tmo, tmp;
if (usec >= 1000) {
/* if "big" number, spread normalization to seconds */
tmo = usec / 1000;
/* start to normalize for usec to ticks per sec */
tmo *= CONFIG_SYS_HZ;
/* find number of "ticks" to wait to achieve target */
tmo /= 1000;
/* finish normalize. */
} else {
/* else small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
}
tmp = get_timer(0);
/* get current timestamp */
if ((tmo + tmp + 1) < tmp)
/* if setting this fordward will roll time stamp */
reset_timer_masked();
/* reset "advancing" timestamp to 0, set lastdec value */
else
tmo += tmp;
/* else, set advancing stamp wake up time */
while (get_timer_masked() < tmo)/* loop till event */
/*NOP*/;
}
void reset_timer_masked(void)
{
/* reset time */
lastdec = READ_TIMER; /* capure current decrementer value time */
timestamp = 0; /* start "advancing" time stamp from 0 */
}
ulong get_timer_masked(void)
{
ulong now = READ_TIMER; /* current tick value */
if (lastdec >= now) { /* normal mode (non roll) */
/* normal mode */
timestamp += lastdec - now;
/* move stamp fordward with absoulte diff ticks */
} else {
/* we have overflow of the count down timer */
/* nts = ts + ld + (TLV - now)
* ts=old stamp, ld=time that passed before passing through -1
* (TLV-now) amount of time after passing though -1
* nts = new "advancing time stamp"...it could also roll
* and cause problems.
*/
timestamp += lastdec + TIMER_LOAD_VAL - now + 1;
}
lastdec = now;
return timestamp;
}
/* waits specified delay value and resets timestamp */
void udelay_masked(unsigned long usec)
{
ulong tmo;
ulong endtime;
signed long diff;
if (usec >= 1000) {
/* if "big" number, spread normalization to seconds */
tmo = usec / 1000;
/* start to normalize for usec to ticks per sec */
tmo *= CONFIG_SYS_HZ;
/* find number of "ticks" to wait to achieve target */
tmo /= 1000;
/* finish normalize. */
} else {
/* else small number, don't kill it prior to HZ multiply */
tmo = usec * CONFIG_SYS_HZ;
tmo /= (1000*1000);
}
endtime = get_timer_masked() + tmo;
do {
ulong now = get_timer_masked();
diff = endtime - now;
} while (diff >= 0);
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return get_timer(0);
}
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
ulong tbclk;
tbclk = CONFIG_SYS_HZ;
return tbclk;
}
|
