1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2007, 2012 Freescale Semiconductor, Inc.
4  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
5  */
6 
7 #include <common.h>
8 
9 #include <asm/timer.h>
10 #include <asm/immap.h>
11 #include <asm/io.h>
12 
13 DECLARE_GLOBAL_DATA_PTR;
14 
15 static ulong timestamp;
16 
17 #if defined(CONFIG_SLTTMR)
18 #ifndef CONFIG_SYS_UDELAY_BASE
19 #	error	"uDelay base not defined!"
20 #endif
21 
22 #if !defined(CONFIG_SYS_TMR_BASE) || !defined(CONFIG_SYS_INTR_BASE) || !defined(CONFIG_SYS_TMRINTR_NO) || !defined(CONFIG_SYS_TMRINTR_MASK)
23 #	error	"TMR_BASE, INTR_BASE, TMRINTR_NO or TMRINTR_MASk not defined!"
24 #endif
25 extern void dtimer_intr_setup(void);
26 
27 void __udelay(unsigned long usec)
28 {
29 	slt_t *timerp = (slt_t *) (CONFIG_SYS_UDELAY_BASE);
30 	u32 now, freq;
31 
32 	/* 1 us period */
33 	freq = CONFIG_SYS_TIMER_PRESCALER;
34 
35 	/* Disable */
36 	out_be32(&timerp->cr, 0);
37 	out_be32(&timerp->tcnt, usec * freq);
38 	out_be32(&timerp->cr, SLT_CR_TEN);
39 
40 	now = in_be32(&timerp->cnt);
41 	while (now != 0)
42 		now = in_be32(&timerp->cnt);
43 
44 	setbits_be32(&timerp->sr, SLT_SR_ST);
45 	out_be32(&timerp->cr, 0);
46 }
47 
48 void dtimer_interrupt(void *not_used)
49 {
50 	slt_t *timerp = (slt_t *) (CONFIG_SYS_TMR_BASE);
51 
52 	/* check for timer interrupt asserted */
53 	if ((CONFIG_SYS_TMRPND_REG & CONFIG_SYS_TMRINTR_MASK) == CONFIG_SYS_TMRINTR_PEND) {
54 		setbits_be32(&timerp->sr, SLT_SR_ST);
55 		timestamp++;
56 		return;
57 	}
58 }
59 
60 int timer_init(void)
61 {
62 	slt_t *timerp = (slt_t *) (CONFIG_SYS_TMR_BASE);
63 
64 	timestamp = 0;
65 
66 	/* disable timer */
67 	out_be32(&timerp->cr, 0);
68 	out_be32(&timerp->tcnt, 0);
69 	/* clear status */
70 	out_be32(&timerp->sr, SLT_SR_BE | SLT_SR_ST);
71 
72 	/* initialize and enable timer interrupt */
73 	irq_install_handler(CONFIG_SYS_TMRINTR_NO, dtimer_interrupt, 0);
74 
75 	/* Interrupt every ms */
76 	out_be32(&timerp->tcnt, 1000 * CONFIG_SYS_TIMER_PRESCALER);
77 
78 	dtimer_intr_setup();
79 
80 	/* set a period of 1us, set timer mode to restart and
81 	   enable timer and interrupt */
82 	out_be32(&timerp->cr, SLT_CR_RUN | SLT_CR_IEN | SLT_CR_TEN);
83 	return 0;
84 }
85 
86 ulong get_timer(ulong base)
87 {
88 	return (timestamp - base);
89 }
90 
91 #endif				/* CONFIG_SLTTMR */
92