xref: /openbmc/u-boot/arch/microblaze/cpu/timer.c (revision 88dc4099)
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 	/* Do not init before relocation */
55 	if (!(gd->flags & GD_FLG_RELOC))
56 		return 0;
57 
58 	node = fdt_node_offset_by_compatible(blob, node,
59 				"xlnx,xps-timer-1.00.a");
60 	if (node != -1) {
61 		fdt_addr_t base = fdtdec_get_addr(blob, node, "reg");
62 		if (base == FDT_ADDR_T_NONE)
63 			return -1;
64 
65 		debug("TIMER: Base addr %lx\n", base);
66 		tmr = (microblaze_timer_t *)base;
67 
68 		ret = fdtdec_get_int_array(blob, node, "interrupts",
69 					    cell, ARRAY_SIZE(cell));
70 		if (ret)
71 			return ret;
72 
73 		irq = cell[0];
74 		debug("TIMER: IRQ %x\n", irq);
75 
76 		preload = fdtdec_get_int(blob, node, "clock-frequency", 0);
77 		preload /= CONFIG_SYS_HZ;
78 	} else {
79 		return node;
80 	}
81 
82 	if (tmr && preload && irq >= 0) {
83 		tmr->loadreg = preload;
84 		tmr->control = TIMER_INTERRUPT | TIMER_RESET;
85 		tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
86 					TIMER_RELOAD | TIMER_DOWN_COUNT;
87 		timestamp = 0;
88 		ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
89 		if (ret)
90 			tmr = NULL;
91 	}
92 	/* No problem if timer is not found/initialized */
93 	return 0;
94 }
95 #else
96 int timer_init(void)
97 {
98 	return 0;
99 }
100 #endif
101 
102 /*
103  * This function is derived from PowerPC code (read timebase as long long).
104  * On Microblaze it just returns the timer value.
105  */
106 unsigned long long get_ticks(void)
107 {
108 	return get_timer(0);
109 }
110 
111 /*
112  * This function is derived from PowerPC code (timebase clock frequency).
113  * On Microblaze it returns the number of timer ticks per second.
114  */
115 ulong get_tbclk(void)
116 {
117 	return CONFIG_SYS_HZ;
118 }
119