1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2003 Josef Baumgartner <josef.baumgartner@telex.de>
4  *
5  * (C) Copyright 2000
6  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
7  */
8 
9 #include <init.h>
10 #include <irq_func.h>
11 #include <time.h>
12 #include <asm/global_data.h>
13 #include <linux/delay.h>
14 
15 #include <asm/timer.h>
16 #include <asm/immap.h>
17 #include <watchdog.h>
18 
19 DECLARE_GLOBAL_DATA_PTR;
20 
21 static volatile ulong timestamp = 0;
22 
23 #ifndef CFG_SYS_WATCHDOG_FREQ
24 #define CFG_SYS_WATCHDOG_FREQ (CONFIG_SYS_HZ / 2)
25 #endif
26 
27 #if CONFIG_IS_ENABLED(MCFTMR)
28 #ifndef CFG_SYS_UDELAY_BASE
29 #	error	"uDelay base not defined!"
30 #endif
31 
32 #if !defined(CFG_SYS_TMR_BASE) || !defined(CFG_SYS_INTR_BASE) || !defined(CFG_SYS_TMRINTR_NO) || !defined(CFG_SYS_TMRINTR_MASK)
33 #	error	"TMR_BASE, INTR_BASE, TMRINTR_NO or TMRINTR_MASk not defined!"
34 #endif
35 extern void dtimer_intr_setup(void);
36 
__udelay(unsigned long usec)37 void __udelay(unsigned long usec)
38 {
39 	volatile dtmr_t *timerp = (dtmr_t *) (CFG_SYS_UDELAY_BASE);
40 	uint start, now, tmp;
41 
42 	while (usec > 0) {
43 		if (usec > 65000)
44 			tmp = 65000;
45 		else
46 			tmp = usec;
47 		usec = usec - tmp;
48 
49 		/* Set up TIMER 3 as timebase clock */
50 		timerp->tmr = DTIM_DTMR_RST_RST;
51 		timerp->tcn = 0;
52 		/* set period to 1 us */
53 		timerp->tmr =
54 		    CFG_SYS_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 | DTIM_DTMR_FRR |
55 		    DTIM_DTMR_RST_EN;
56 
57 		start = now = timerp->tcn;
58 		while (now < start + tmp)
59 			now = timerp->tcn;
60 	}
61 }
62 
dtimer_interrupt(void * not_used)63 void dtimer_interrupt(void *not_used)
64 {
65 	volatile dtmr_t *timerp = (dtmr_t *) (CFG_SYS_TMR_BASE);
66 
67 	/* check for timer interrupt asserted */
68 	if ((CFG_SYS_TMRPND_REG & CFG_SYS_TMRINTR_MASK) == CFG_SYS_TMRINTR_PEND) {
69 		timerp->ter = (DTIM_DTER_CAP | DTIM_DTER_REF);
70 		timestamp++;
71 
72 		#if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
73 		if (CFG_SYS_WATCHDOG_FREQ && (timestamp % (CFG_SYS_WATCHDOG_FREQ)) == 0) {
74 			schedule();
75 		}
76 		#endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
77 		return;
78 	}
79 }
80 
timer_init(void)81 int timer_init(void)
82 {
83 	volatile dtmr_t *timerp = (dtmr_t *) (CFG_SYS_TMR_BASE);
84 
85 	timestamp = 0;
86 
87 	timerp->tcn = 0;
88 	timerp->trr = 0;
89 
90 	/* Set up TIMER 4 as clock */
91 	timerp->tmr = DTIM_DTMR_RST_RST;
92 
93 	/* initialize and enable timer interrupt */
94 	irq_install_handler(CFG_SYS_TMRINTR_NO, dtimer_interrupt, 0);
95 
96 	timerp->tcn = 0;
97 	timerp->trr = 1000;	/* Interrupt every ms */
98 
99 	dtimer_intr_setup();
100 
101 	/* set a period of 1us, set timer mode to restart and enable timer and interrupt */
102 	timerp->tmr = CFG_SYS_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 |
103 	    DTIM_DTMR_FRR | DTIM_DTMR_ORRI | DTIM_DTMR_RST_EN;
104 
105 	return 0;
106 }
107 
get_timer(ulong base)108 ulong get_timer(ulong base)
109 {
110 	return (timestamp - base);
111 }
112 
113 /*
114  * This function is derived from PowerPC code (read timebase as long long).
115  * On M68K it just returns the timer value.
116  */
get_ticks(void)117 unsigned long long get_ticks(void)
118 {
119 	return get_timer(0);
120 }
121 #else
122 static u64 timer64 __section(".data");
123 static u16 timer16 __section(".data");
124 
get_ticks(void)125 uint64_t __weak get_ticks(void)
126 {
127 	volatile pit_t *timerp = (pit_t *) (CFG_SYS_UDELAY_BASE);
128 	u16 val = ~timerp->pcntr;
129 
130 	if (timer16 > val)
131 		timer64 += 0xffff - timer16 + val;
132 	else
133 		timer64 += val - timer16;
134 
135 	timer16 = val;
136 
137 	return timer64;
138 }
139 
140 /* PIT timer */
timer_init(void)141 int timer_init(void)
142 {
143 	volatile pit_t *timerp = (pit_t *) (CFG_SYS_UDELAY_BASE);
144 
145 	timer16 = 0;
146 	timer64 = 0;
147 
148 	/* Set up PIT as timebase clock */
149 	timerp->pmr = 0xffff;
150 	timerp->pcsr = PIT_PCSR_EN | PIT_PCSR_OVW;
151 
152 	return 0;
153 }
154 #endif				/* CONFIG_MCFTMR */
155 
usec2ticks(unsigned long usec)156 unsigned long usec2ticks(unsigned long usec)
157 {
158 	return get_timer(usec);
159 }
160 
161 /*
162  * This function is derived from PowerPC code (timebase clock frequency).
163  * On M68K it returns the number of timer ticks per second.
164  */
get_tbclk(void)165 ulong get_tbclk(void)
166 {
167 	return CONFIG_SYS_HZ;
168 }
169