xref: /openbmc/u-boot/arch/microblaze/cpu/timer.c (revision 81401325)
1 /*
2  * (C) Copyright 2007 Michal Simek
3  *
4  * Michal  SIMEK <monstr@monstr.eu>
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <fdtdec.h>
11 #include <asm/microblaze_timer.h>
12 #include <asm/microblaze_intc.h>
13 
14 DECLARE_GLOBAL_DATA_PTR;
15 
16 volatile int timestamp = 0;
17 microblaze_timer_t *tmr;
18 
19 ulong get_timer (ulong base)
20 {
21 	if (tmr)
22 		return timestamp - base;
23 	return timestamp++ - base;
24 }
25 
26 void __udelay(unsigned long usec)
27 {
28 	u32 i;
29 
30 	if (tmr) {
31 		i = get_timer(0);
32 		while ((get_timer(0) - i) < (usec / 1000))
33 			;
34 	}
35 }
36 
37 #ifndef CONFIG_SPL_BUILD
38 static void timer_isr(void *arg)
39 {
40 	timestamp++;
41 	tmr->control = tmr->control | TIMER_INTERRUPT;
42 }
43 
44 int timer_init (void)
45 {
46 	int irq = -1;
47 	u32 preload = 0;
48 	u32 ret = 0;
49 	const void *blob = gd->fdt_blob;
50 	int node = 0;
51 	u32 cell[2];
52 
53 	debug("TIMER: Initialization\n");
54 
55 	node = fdt_node_offset_by_compatible(blob, node,
56 				"xlnx,xps-timer-1.00.a");
57 	if (node != -1) {
58 		fdt_addr_t base = fdtdec_get_addr(blob, node, "reg");
59 		if (base == FDT_ADDR_T_NONE)
60 			return -1;
61 
62 		debug("TIMER: Base addr %lx\n", base);
63 		tmr = (microblaze_timer_t *)base;
64 
65 		ret = fdtdec_get_int_array(blob, node, "interrupts",
66 					    cell, ARRAY_SIZE(cell));
67 		if (ret)
68 			return ret;
69 
70 		irq = cell[0];
71 		debug("TIMER: IRQ %x\n", irq);
72 
73 		preload = fdtdec_get_int(blob, node, "clock-frequency", 0);
74 		preload /= CONFIG_SYS_HZ;
75 	} else {
76 		return node;
77 	}
78 
79 	if (tmr && preload && irq >= 0) {
80 		tmr->loadreg = preload;
81 		tmr->control = TIMER_INTERRUPT | TIMER_RESET;
82 		tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
83 					TIMER_RELOAD | TIMER_DOWN_COUNT;
84 		timestamp = 0;
85 		ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
86 		if (ret)
87 			tmr = NULL;
88 	}
89 	/* No problem if timer is not found/initialized */
90 	return 0;
91 }
92 #else
93 int timer_init(void)
94 {
95 	return 0;
96 }
97 #endif
98 
99 /*
100  * This function is derived from PowerPC code (read timebase as long long).
101  * On Microblaze it just returns the timer value.
102  */
103 unsigned long long get_ticks(void)
104 {
105 	return get_timer(0);
106 }
107 
108 /*
109  * This function is derived from PowerPC code (timebase clock frequency).
110  * On Microblaze it returns the number of timer ticks per second.
111  */
112 ulong get_tbclk(void)
113 {
114 	return CONFIG_SYS_HZ;
115 }
116