xref: /openbmc/u-boot/arch/microblaze/cpu/timer.c (revision 87a62bce)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2007 Michal Simek
4  *
5  * Michal  SIMEK <monstr@monstr.eu>
6  */
7 
8 #include <common.h>
9 #include <fdtdec.h>
10 #include <asm/microblaze_timer.h>
11 #include <asm/microblaze_intc.h>
12 
13 DECLARE_GLOBAL_DATA_PTR;
14 
15 volatile int timestamp = 0;
16 microblaze_timer_t *tmr;
17 
18 ulong get_timer (ulong base)
19 {
20 	if (tmr)
21 		return timestamp - base;
22 	return timestamp++ - base;
23 }
24 
25 void __udelay(unsigned long usec)
26 {
27 	u32 i;
28 
29 	if (tmr) {
30 		i = get_timer(0);
31 		while ((get_timer(0) - i) < (usec / 1000))
32 			;
33 	}
34 }
35 
36 #ifndef CONFIG_SPL_BUILD
37 static void timer_isr(void *arg)
38 {
39 	timestamp++;
40 	tmr->control = tmr->control | TIMER_INTERRUPT;
41 }
42 
43 int timer_init (void)
44 {
45 	int irq = -1;
46 	u32 preload = 0;
47 	u32 ret = 0;
48 	const void *blob = gd->fdt_blob;
49 	int node = 0;
50 	u32 cell[2];
51 
52 	debug("TIMER: Initialization\n");
53 
54 	node = fdt_node_offset_by_compatible(blob, node,
55 				"xlnx,xps-timer-1.00.a");
56 	if (node != -1) {
57 		fdt_addr_t base = fdtdec_get_addr(blob, node, "reg");
58 		if (base == FDT_ADDR_T_NONE)
59 			return -1;
60 
61 		debug("TIMER: Base addr %lx\n", base);
62 		tmr = (microblaze_timer_t *)base;
63 
64 		ret = fdtdec_get_int_array(blob, node, "interrupts",
65 					    cell, ARRAY_SIZE(cell));
66 		if (ret)
67 			return ret;
68 
69 		irq = cell[0];
70 		debug("TIMER: IRQ %x\n", irq);
71 
72 		preload = fdtdec_get_int(blob, node, "clock-frequency", 0);
73 		preload /= CONFIG_SYS_HZ;
74 	} else {
75 		return node;
76 	}
77 
78 	if (tmr && preload && irq >= 0) {
79 		tmr->loadreg = preload;
80 		tmr->control = TIMER_INTERRUPT | TIMER_RESET;
81 		tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
82 					TIMER_RELOAD | TIMER_DOWN_COUNT;
83 		timestamp = 0;
84 		ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
85 		if (ret)
86 			tmr = NULL;
87 	}
88 	/* No problem if timer is not found/initialized */
89 	return 0;
90 }
91 #else
92 int timer_init(void)
93 {
94 	return 0;
95 }
96 #endif
97 
98 /*
99  * This function is derived from PowerPC code (read timebase as long long).
100  * On Microblaze it just returns the timer value.
101  */
102 unsigned long long get_ticks(void)
103 {
104 	return get_timer(0);
105 }
106 
107 /*
108  * This function is derived from PowerPC code (timebase clock frequency).
109  * On Microblaze it returns the number of timer ticks per second.
110  */
111 ulong get_tbclk(void)
112 {
113 	return CONFIG_SYS_HZ;
114 }
115