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 /***************************************************************************/
29
30 #if defined(CONFIG_DRAGEN2)
31 /* with a 33.16 MHz clock, this will give usec resolution to the time functions */
32 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
33 #define CLOCK_PRE 7
34 #define TICKS_PER_JIFFY 41450
35
36 #elif defined(CONFIG_XCOPILOT_BUGS)
37 /*
38 * The only thing I know is that CLK32 is not available on Xcopilot
39 * I have little idea about what frequency SYSCLK has on Xcopilot.
40 * The values for prescaler and compare registers were simply
41 * taken from the original source
42 */
43 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
44 #define CLOCK_PRE 2
45 #define TICKS_PER_JIFFY 0xd7e4
46
47 #else
48 /* default to using the 32Khz clock */
49 #define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ
50 #define CLOCK_PRE 31
51 #define TICKS_PER_JIFFY 10
52 #endif
53
54 static u32 m68328_tick_cnt;
55
56 /***************************************************************************/
57
hw_tick(int irq,void * dummy)58 static irqreturn_t hw_tick(int irq, void *dummy)
59 {
60 /* Reset Timer1 */
61 TSTAT &= 0;
62
63 m68328_tick_cnt += TICKS_PER_JIFFY;
64 legacy_timer_tick(1);
65 return IRQ_HANDLED;
66 }
67
68 /***************************************************************************/
69
m68328_read_clk(struct clocksource * cs)70 static u64 m68328_read_clk(struct clocksource *cs)
71 {
72 unsigned long flags;
73 u32 cycles;
74
75 local_irq_save(flags);
76 cycles = m68328_tick_cnt + TCN;
77 local_irq_restore(flags);
78
79 return cycles;
80 }
81
82 /***************************************************************************/
83
84 static struct clocksource m68328_clk = {
85 .name = "timer",
86 .rating = 250,
87 .read = m68328_read_clk,
88 .mask = CLOCKSOURCE_MASK(32),
89 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
90 };
91
92 /***************************************************************************/
93
hw_timer_init(void)94 void hw_timer_init(void)
95 {
96 int ret;
97
98 /* disable timer 1 */
99 TCTL = 0;
100
101 /* set ISR */
102 ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL);
103 if (ret) {
104 pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM,
105 ERR_PTR(ret));
106 }
107
108 /* Restart mode, Enable int, Set clock source */
109 TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
110 TPRER = CLOCK_PRE;
111 TCMP = TICKS_PER_JIFFY;
112
113 /* Enable timer 1 */
114 TCTL |= TCTL_TEN;
115 clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
116 }
117
118 /***************************************************************************/
119
m68328_hwclk(int set,struct rtc_time * t)120 int m68328_hwclk(int set, struct rtc_time *t)
121 {
122 if (!set) {
123 long now = RTCTIME;
124 t->tm_year = 1;
125 t->tm_mon = 0;
126 t->tm_mday = 1;
127 t->tm_hour = (now >> 24) % 24;
128 t->tm_min = (now >> 16) % 60;
129 t->tm_sec = now % 60;
130 }
131
132 return 0;
133 }
134
135 /***************************************************************************/
136