xref: /openbmc/u-boot/arch/m68k/lib/time.c (revision c6af2e7d)
1 /*
2  * (C) Copyright 2003 Josef Baumgartner <josef.baumgartner@telex.de>
3  *
4  * (C) Copyright 2000
5  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
6  *
7  * See file CREDITS for list of people who contributed to this
8  * project.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  * MA 02111-1307 USA
24  */
25 
26 #include <common.h>
27 
28 #include <asm/timer.h>
29 #include <asm/immap.h>
30 #include <watchdog.h>
31 
32 DECLARE_GLOBAL_DATA_PTR;
33 
34 static volatile ulong timestamp = 0;
35 
36 #ifndef CONFIG_SYS_WATCHDOG_FREQ
37 #define CONFIG_SYS_WATCHDOG_FREQ (CONFIG_SYS_HZ / 2)
38 #endif
39 
40 #if defined(CONFIG_MCFTMR)
41 #ifndef CONFIG_SYS_UDELAY_BASE
42 #	error	"uDelay base not defined!"
43 #endif
44 
45 #if !defined(CONFIG_SYS_TMR_BASE) || !defined(CONFIG_SYS_INTR_BASE) || !defined(CONFIG_SYS_TMRINTR_NO) || !defined(CONFIG_SYS_TMRINTR_MASK)
46 #	error	"TMR_BASE, INTR_BASE, TMRINTR_NO or TMRINTR_MASk not defined!"
47 #endif
48 extern void dtimer_intr_setup(void);
49 
50 void __udelay(unsigned long usec)
51 {
52 	volatile dtmr_t *timerp = (dtmr_t *) (CONFIG_SYS_UDELAY_BASE);
53 	uint start, now, tmp;
54 
55 	while (usec > 0) {
56 		if (usec > 65000)
57 			tmp = 65000;
58 		else
59 			tmp = usec;
60 		usec = usec - tmp;
61 
62 		/* Set up TIMER 3 as timebase clock */
63 		timerp->tmr = DTIM_DTMR_RST_RST;
64 		timerp->tcn = 0;
65 		/* set period to 1 us */
66 		timerp->tmr =
67 		    CONFIG_SYS_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 | DTIM_DTMR_FRR |
68 		    DTIM_DTMR_RST_EN;
69 
70 		start = now = timerp->tcn;
71 		while (now < start + tmp)
72 			now = timerp->tcn;
73 	}
74 }
75 
76 void dtimer_interrupt(void *not_used)
77 {
78 	volatile dtmr_t *timerp = (dtmr_t *) (CONFIG_SYS_TMR_BASE);
79 
80 	/* check for timer interrupt asserted */
81 	if ((CONFIG_SYS_TMRPND_REG & CONFIG_SYS_TMRINTR_MASK) == CONFIG_SYS_TMRINTR_PEND) {
82 		timerp->ter = (DTIM_DTER_CAP | DTIM_DTER_REF);
83 		timestamp++;
84 
85 		#if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
86 		if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) {
87 			WATCHDOG_RESET ();
88 		}
89 		#endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
90 		return;
91 	}
92 }
93 
94 int timer_init(void)
95 {
96 	volatile dtmr_t *timerp = (dtmr_t *) (CONFIG_SYS_TMR_BASE);
97 
98 	timestamp = 0;
99 
100 	timerp->tcn = 0;
101 	timerp->trr = 0;
102 
103 	/* Set up TIMER 4 as clock */
104 	timerp->tmr = DTIM_DTMR_RST_RST;
105 
106 	/* initialize and enable timer interrupt */
107 	irq_install_handler(CONFIG_SYS_TMRINTR_NO, dtimer_interrupt, 0);
108 
109 	timerp->tcn = 0;
110 	timerp->trr = 1000;	/* Interrupt every ms */
111 
112 	dtimer_intr_setup();
113 
114 	/* set a period of 1us, set timer mode to restart and enable timer and interrupt */
115 	timerp->tmr = CONFIG_SYS_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 |
116 	    DTIM_DTMR_FRR | DTIM_DTMR_ORRI | DTIM_DTMR_RST_EN;
117 
118 	return 0;
119 }
120 
121 ulong get_timer(ulong base)
122 {
123 	return (timestamp - base);
124 }
125 
126 #endif				/* CONFIG_MCFTMR */
127 
128 #if defined(CONFIG_MCFPIT)
129 #if !defined(CONFIG_SYS_PIT_BASE)
130 #	error	"CONFIG_SYS_PIT_BASE not defined!"
131 #endif
132 
133 static unsigned short lastinc;
134 
135 void __udelay(unsigned long usec)
136 {
137 	volatile pit_t *timerp = (pit_t *) (CONFIG_SYS_UDELAY_BASE);
138 	uint tmp;
139 
140 	while (usec > 0) {
141 		if (usec > 65000)
142 			tmp = 65000;
143 		else
144 			tmp = usec;
145 		usec = usec - tmp;
146 
147 		/* Set up TIMER 3 as timebase clock */
148 		timerp->pcsr = PIT_PCSR_OVW;
149 		timerp->pmr = 0;
150 		/* set period to 1 us */
151 		timerp->pcsr |= PIT_PCSR_PRE(CONFIG_SYS_PIT_PRESCALE) | PIT_PCSR_EN;
152 
153 		timerp->pmr = tmp;
154 		while (timerp->pcntr > 0) ;
155 	}
156 }
157 
158 void timer_init(void)
159 {
160 	volatile pit_t *timerp = (pit_t *) (CONFIG_SYS_PIT_BASE);
161 	timestamp = 0;
162 
163 	/* Set up TIMER 4 as poll clock */
164 	timerp->pcsr = PIT_PCSR_OVW;
165 	timerp->pmr = lastinc = 0;
166 	timerp->pcsr |= PIT_PCSR_PRE(CONFIG_SYS_PIT_PRESCALE) | PIT_PCSR_EN;
167 
168 	return 0;
169 }
170 
171 ulong get_timer(ulong base)
172 {
173 	unsigned short now, diff;
174 	volatile pit_t *timerp = (pit_t *) (CONFIG_SYS_PIT_BASE);
175 
176 	now = timerp->pcntr;
177 	diff = -(now - lastinc);
178 
179 	timestamp += diff;
180 	lastinc = now;
181 	return timestamp - base;
182 }
183 
184 void wait_ticks(unsigned long ticks)
185 {
186 	u32 start = get_timer(0);
187 	while (get_timer(start) < ticks) ;
188 }
189 #endif				/* CONFIG_MCFPIT */
190 
191 /*
192  * This function is derived from PowerPC code (read timebase as long long).
193  * On M68K it just returns the timer value.
194  */
195 unsigned long long get_ticks(void)
196 {
197 	return get_timer(0);
198 }
199 
200 unsigned long usec2ticks(unsigned long usec)
201 {
202 	return get_timer(usec);
203 }
204 
205 /*
206  * This function is derived from PowerPC code (timebase clock frequency).
207  * On M68K it returns the number of timer ticks per second.
208  */
209 ulong get_tbclk(void)
210 {
211 	ulong tbclk;
212 	tbclk = CONFIG_SYS_HZ;
213 	return tbclk;
214 }
215