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(ticks: 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(irq: TMR_IRQ_NUM, handler: hw_tick, IRQF_TIMER, name: "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(cs: &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 | |