xref: /openbmc/u-boot/arch/arm/mach-mvebu/timer.c (revision 1005ccda)
1 /*
2  * Copyright (C) Marvell International Ltd. and its affiliates
3  * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <asm/io.h>
10 #include <asm/arch/soc.h>
11 
12 #define UBOOT_CNTR	0	/* counter to use for U-Boot timer */
13 
14 /*
15  * ARM Timers Registers Map
16  */
17 #define CNTMR_CTRL_REG			&tmr_regs->ctrl
18 #define CNTMR_RELOAD_REG(tmrnum)	&tmr_regs->tmr[tmrnum].reload
19 #define CNTMR_VAL_REG(tmrnum)		&tmr_regs->tmr[tmrnum].val
20 
21 /*
22  * ARM Timers Control Register
23  * CPU_TIMERS_CTRL_REG (CTCR)
24  */
25 #define CTCR_ARM_TIMER_EN_OFFS(cntr)	(cntr * 2)
26 #define CTCR_ARM_TIMER_EN(cntr)		(1 << CTCR_ARM_TIMER_EN_OFFS(cntr))
27 
28 #define CTCR_ARM_TIMER_AUTO_OFFS(cntr)	((cntr * 2) + 1)
29 #define CTCR_ARM_TIMER_AUTO_EN(cntr)	(1 << CTCR_ARM_TIMER_AUTO_OFFS(cntr))
30 
31 /* Only Armada XP have the 25MHz enable bit (Kirkwood doesn't) */
32 #if defined(CONFIG_ARMADA_XP)
33 #define CTCR_ARM_TIMER_25MHZ_OFFS(cntr)	(cntr + 11)
34 #define CTCR_ARM_TIMER_25MHZ(cntr)	(1 << CTCR_ARM_TIMER_25MHZ_OFFS(cntr))
35 #else
36 #define CTCR_ARM_TIMER_25MHZ(cntr)	0
37 #endif
38 
39 #define TIMER_LOAD_VAL 			0xffffffff
40 
41 #define timestamp			gd->arch.tbl
42 #define lastdec				gd->arch.lastinc
43 
44 /* Timer reload and current value registers */
45 struct kwtmr_val {
46 	u32 reload;	/* Timer reload reg */
47 	u32 val;	/* Timer value reg */
48 };
49 
50 /* Timer registers */
51 struct kwtmr_registers {
52 	u32 ctrl;	/* Timer control reg */
53 	u32 pad[3];
54 	struct kwtmr_val tmr[4];
55 	u32 wdt_reload;
56 	u32 wdt_val;
57 };
58 
59 DECLARE_GLOBAL_DATA_PTR;
60 
61 static struct kwtmr_registers *tmr_regs =
62 	(struct kwtmr_registers *)MVEBU_TIMER_BASE;
63 
64 static inline ulong read_timer(void)
65 {
66 	return readl(CNTMR_VAL_REG(UBOOT_CNTR))	/ (CONFIG_SYS_TCLK / 1000);
67 }
68 
69 ulong get_timer_masked(void)
70 {
71 	ulong now = read_timer();
72 
73 	if (lastdec >= now) {
74 		/* normal mode */
75 		timestamp += lastdec - now;
76 	} else {
77 		/* we have an overflow ... */
78 		timestamp += lastdec +
79 			(TIMER_LOAD_VAL / (CONFIG_SYS_TCLK / 1000)) - now;
80 	}
81 	lastdec = now;
82 
83 	return timestamp;
84 }
85 
86 ulong get_timer(ulong base)
87 {
88 	return get_timer_masked() - base;
89 }
90 
91 void __udelay(unsigned long usec)
92 {
93 	uint current;
94 	ulong delayticks;
95 
96 	current = readl(CNTMR_VAL_REG(UBOOT_CNTR));
97 	delayticks = (usec * (CONFIG_SYS_TCLK / 1000000));
98 
99 	if (current < delayticks) {
100 		delayticks -= current;
101 		while (readl(CNTMR_VAL_REG(UBOOT_CNTR)) < current) ;
102 		while ((TIMER_LOAD_VAL - delayticks) <
103 			readl(CNTMR_VAL_REG(UBOOT_CNTR))) ;
104 	} else {
105 		while (readl(CNTMR_VAL_REG(UBOOT_CNTR)) >
106 			(current - delayticks)) ;
107 	}
108 }
109 
110 /*
111  * init the counter
112  */
113 int timer_init(void)
114 {
115 	/* load value into timer */
116 	writel(TIMER_LOAD_VAL, CNTMR_RELOAD_REG(UBOOT_CNTR));
117 	writel(TIMER_LOAD_VAL, CNTMR_VAL_REG(UBOOT_CNTR));
118 
119 	/* enable timer in auto reload mode */
120 	clrsetbits_le32(CNTMR_CTRL_REG, CTCR_ARM_TIMER_25MHZ(UBOOT_CNTR),
121 			CTCR_ARM_TIMER_EN(UBOOT_CNTR) |
122 			CTCR_ARM_TIMER_AUTO_EN(UBOOT_CNTR));
123 
124 	/* init the timestamp and lastdec value */
125 	lastdec = read_timer();
126 	timestamp = 0;
127 
128 	return 0;
129 }
130 
131 /*
132  * This function is derived from PowerPC code (read timebase as long long).
133  * On ARM it just returns the timer value.
134  */
135 unsigned long long get_ticks(void)
136 {
137 	return get_timer(0);
138 }
139 
140 /*
141  * This function is derived from PowerPC code (timebase clock frequency).
142  * On ARM it returns the number of timer ticks per second.
143  */
144 ulong get_tbclk (void)
145 {
146 	return (ulong)CONFIG_SYS_HZ;
147 }
148