1 /***************************************************************************/
2
3 /*
4 * timers.c - Generic hardware timer support.
5 *
6 * Copyright (C) 1993 Hamish Macdonald
7 * Copyright (C) 1999 D. Jeff Dionne
8 * Copyright (C) 2001 Georges Menie, Ken Desmet
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file COPYING in the main directory of this archive
12 * for more details.
13 */
14
15 /***************************************************************************/
16
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22 #include <linux/clocksource.h>
23 #include <linux/rtc.h>
24 #include <asm/setup.h>
25 #include <asm/machdep.h>
26 #include <asm/MC68VZ328.h>
27
28 #include "m68328.h"
29
30 /***************************************************************************/
31
32 #if defined(CONFIG_DRAGEN2)
33 /* with a 33.16 MHz clock, this will give usec resolution to the time functions */
34 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
35 #define CLOCK_PRE 7
36 #define TICKS_PER_JIFFY 41450
37
38 #elif defined(CONFIG_XCOPILOT_BUGS)
39 /*
40 * The only thing I know is that CLK32 is not available on Xcopilot
41 * I have little idea about what frequency SYSCLK has on Xcopilot.
42 * The values for prescaler and compare registers were simply
43 * taken from the original source
44 */
45 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
46 #define CLOCK_PRE 2
47 #define TICKS_PER_JIFFY 0xd7e4
48
49 #else
50 /* default to using the 32Khz clock */
51 #define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ
52 #define CLOCK_PRE 31
53 #define TICKS_PER_JIFFY 10
54 #endif
55
56 static u32 m68328_tick_cnt;
57
58 /***************************************************************************/
59
60 static irqreturn_t hw_tick(int irq, void *dummy)
61 {
62 /* Reset Timer1 */
63 TSTAT &= 0;
64
65 m68328_tick_cnt += TICKS_PER_JIFFY;
66 legacy_timer_tick(1);
67 return IRQ_HANDLED;
68 }
69
70 /***************************************************************************/
71
72 static u64 m68328_read_clk(struct clocksource *cs)
73 {
74 unsigned long flags;
75 u32 cycles;
76
77 local_irq_save(flags);
78 cycles = m68328_tick_cnt + TCN;
79 local_irq_restore(flags);
80
81 return cycles;
82 }
83
84 /***************************************************************************/
85
86 static struct clocksource m68328_clk = {
87 .name = "timer",
88 .rating = 250,
89 .read = m68328_read_clk,
90 .mask = CLOCKSOURCE_MASK(32),
91 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
92 };
93
94 /***************************************************************************/
95
96 void hw_timer_init(void)
97 {
98 int ret;
99
100 /* disable timer 1 */
101 TCTL = 0;
102
103 /* set ISR */
104 ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL);
105 if (ret) {
106 pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM,
107 ERR_PTR(ret));
108 }
109
110 /* Restart mode, Enable int, Set clock source */
111 TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
112 TPRER = CLOCK_PRE;
113 TCMP = TICKS_PER_JIFFY;
114
115 /* Enable timer 1 */
116 TCTL |= TCTL_TEN;
117 clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
118 }
119
120 /***************************************************************************/
121
122 int m68328_hwclk(int set, struct rtc_time *t)
123 {
124 if (!set) {
125 long now = RTCTIME;
126 t->tm_year = 1;
127 t->tm_mon = 0;
128 t->tm_mday = 1;
129 t->tm_hour = (now >> 24) % 24;
130 t->tm_min = (now >> 16) % 60;
131 t->tm_sec = now % 60;
132 }
133
134 return 0;
135 }
136
137 /***************************************************************************/
138
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