1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2009 Faraday Technology
4 * Po-Yu Chuang <ratbert@faraday-tech.com>
5 *
6 * Copyright (C) 2011 Andes Technology Corporation
7 * Shawn Lin, Andes Technology Corporation <nobuhiro@andestech.com>
8 * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
9 */
10 #ifndef CONFIG_TIMER
11 #include <common.h>
12 #include <init.h>
13 #include <irq_func.h>
14 #include <log.h>
15 #include <time.h>
16 #include <asm/io.h>
17 #include <faraday/fttmr010.h>
18 #include <linux/delay.h>
19
20 static ulong timestamp;
21 static ulong lastdec;
22
timer_init(void)23 int timer_init(void)
24 {
25 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
26 unsigned int cr;
27
28 debug("%s()\n", __func__);
29
30 /* disable timers */
31 writel(0, &tmr->cr);
32
33 #ifdef CONFIG_FTTMR010_EXT_CLK
34 /* use 32768Hz oscillator for RTC, WDT, TIMER */
35 ftpmu010_32768osc_enable();
36 #endif
37
38 /* setup timer */
39 writel(TIMER_LOAD_VAL, &tmr->timer3_load);
40 writel(TIMER_LOAD_VAL, &tmr->timer3_counter);
41 writel(0, &tmr->timer3_match1);
42 writel(0, &tmr->timer3_match2);
43
44 /* we don't want timer to issue interrupts */
45 writel(FTTMR010_TM3_MATCH1 |
46 FTTMR010_TM3_MATCH2 |
47 FTTMR010_TM3_OVERFLOW,
48 &tmr->interrupt_mask);
49
50 cr = readl(&tmr->cr);
51 #ifdef CONFIG_FTTMR010_EXT_CLK
52 cr |= FTTMR010_TM3_CLOCK; /* use external clock */
53 #endif
54 cr |= FTTMR010_TM3_ENABLE;
55 writel(cr, &tmr->cr);
56
57 /* init the timestamp and lastdec value */
58 reset_timer_masked();
59
60 return 0;
61 }
62
63 /*
64 * timer without interrupts
65 */
66
67 /*
68 * reset time
69 */
reset_timer_masked(void)70 void reset_timer_masked(void)
71 {
72 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
73
74 /* capure current decrementer value time */
75 #ifdef CONFIG_FTTMR010_EXT_CLK
76 lastdec = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
77 #else
78 lastdec = readl(&tmr->timer3_counter) /
79 (CONFIG_SYS_CLK_FREQ / 2 / CONFIG_SYS_HZ);
80 #endif
81 timestamp = 0; /* start "advancing" time stamp from 0 */
82
83 debug("%s(): lastdec = %lx\n", __func__, lastdec);
84 }
85
reset_timer(void)86 void reset_timer(void)
87 {
88 debug("%s()\n", __func__);
89 reset_timer_masked();
90 }
91
92 /*
93 * return timer ticks
94 */
get_timer_masked(void)95 ulong get_timer_masked(void)
96 {
97 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
98
99 /* current tick value */
100 #ifdef CONFIG_FTTMR010_EXT_CLK
101 ulong now = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
102 #else
103 ulong now = readl(&tmr->timer3_counter) /
104 (CONFIG_SYS_CLK_FREQ / 2 / CONFIG_SYS_HZ);
105 #endif
106
107 debug("%s(): now = %lx, lastdec = %lx\n", __func__, now, lastdec);
108
109 if (lastdec >= now) {
110 /*
111 * normal mode (non roll)
112 * move stamp fordward with absoulte diff ticks
113 */
114 timestamp += lastdec - now;
115 } else {
116 /*
117 * we have overflow of the count down timer
118 *
119 * nts = ts + ld + (TLV - now)
120 * ts=old stamp, ld=time that passed before passing through -1
121 * (TLV-now) amount of time after passing though -1
122 * nts = new "advancing time stamp"...it could also roll and
123 * cause problems.
124 */
125 timestamp += lastdec + TIMER_LOAD_VAL - now;
126 }
127
128 lastdec = now;
129
130 debug("%s() returns %lx\n", __func__, timestamp);
131
132 return timestamp;
133 }
134
135 /*
136 * return difference between timer ticks and base
137 */
get_timer(ulong base)138 ulong get_timer(ulong base)
139 {
140 debug("%s(%lx)\n", __func__, base);
141 return get_timer_masked() - base;
142 }
143
set_timer(ulong t)144 void set_timer(ulong t)
145 {
146 debug("%s(%lx)\n", __func__, t);
147 timestamp = t;
148 }
149
150 /* delay x useconds AND preserve advance timestamp value */
__udelay(unsigned long usec)151 void __udelay(unsigned long usec)
152 {
153 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
154
155 #ifdef CONFIG_FTTMR010_EXT_CLK
156 long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
157 #else
158 long tmo = usec * ((CONFIG_SYS_CLK_FREQ / 2) / 1000) / 1000;
159 #endif
160 unsigned long now, last = readl(&tmr->timer3_counter);
161
162 debug("%s(%lu)\n", __func__, usec);
163 while (tmo > 0) {
164 now = readl(&tmr->timer3_counter);
165 if (now > last) /* count down timer overflow */
166 tmo -= TIMER_LOAD_VAL + last - now;
167 else
168 tmo -= last - now;
169 last = now;
170 }
171 }
172
173 /*
174 * This function is derived from PowerPC code (read timebase as long long).
175 * On ARM it just returns the timer value.
176 */
get_ticks(void)177 unsigned long long get_ticks(void)
178 {
179 debug("%s()\n", __func__);
180 return get_timer(0);
181 }
182
183 /*
184 * This function is derived from PowerPC code (timebase clock frequency).
185 * On ARM it returns the number of timer ticks per second.
186 */
get_tbclk(void)187 ulong get_tbclk(void)
188 {
189 debug("%s()\n", __func__);
190 #ifdef CONFIG_FTTMR010_EXT_CLK
191 return CONFIG_SYS_HZ;
192 #else
193 return CONFIG_SYS_CLK_FREQ;
194 #endif
195 }
196 #endif /* CONFIG_TIMER */
197