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/pgtable.h>
26#include <asm/machdep.h>
27#include <asm/MC68VZ328.h>
28
29/***************************************************************************/
30
31#if defined(CONFIG_DRAGEN2)
32/* with a 33.16 MHz clock, this will give usec resolution to the time functions */
33#define CLOCK_SOURCE	TCTL_CLKSOURCE_SYSCLK
34#define CLOCK_PRE	7
35#define TICKS_PER_JIFFY	41450
36
37#elif defined(CONFIG_XCOPILOT_BUGS)
38/*
39 * The only thing I know is that CLK32 is not available on Xcopilot
40 * I have little idea about what frequency SYSCLK has on Xcopilot.
41 * The values for prescaler and compare registers were simply
42 * taken from the original source
43 */
44#define CLOCK_SOURCE	TCTL_CLKSOURCE_SYSCLK
45#define CLOCK_PRE	2
46#define TICKS_PER_JIFFY	0xd7e4
47
48#else
49/* default to using the 32Khz clock */
50#define CLOCK_SOURCE	TCTL_CLKSOURCE_32KHZ
51#define CLOCK_PRE	31
52#define TICKS_PER_JIFFY	10
53#endif
54
55static u32 m68328_tick_cnt;
56static irq_handler_t timer_interrupt;
57
58/***************************************************************************/
59
60static irqreturn_t hw_tick(int irq, void *dummy)
61{
62	/* Reset Timer1 */
63	TSTAT &= 0;
64
65	m68328_tick_cnt += TICKS_PER_JIFFY;
66	return timer_interrupt(irq, dummy);
67}
68
69/***************************************************************************/
70
71static struct irqaction m68328_timer_irq = {
72	.name	 = "timer",
73	.flags	 = IRQF_TIMER,
74	.handler = hw_tick,
75};
76
77/***************************************************************************/
78
79static cycle_t m68328_read_clk(struct clocksource *cs)
80{
81	unsigned long flags;
82	u32 cycles;
83
84	local_irq_save(flags);
85	cycles = m68328_tick_cnt + TCN;
86	local_irq_restore(flags);
87
88	return cycles;
89}
90
91/***************************************************************************/
92
93static struct clocksource m68328_clk = {
94	.name	= "timer",
95	.rating	= 250,
96	.read	= m68328_read_clk,
97	.mask	= CLOCKSOURCE_MASK(32),
98	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
99};
100
101/***************************************************************************/
102
103void hw_timer_init(irq_handler_t handler)
104{
105	/* disable timer 1 */
106	TCTL = 0;
107
108	/* set ISR */
109	setup_irq(TMR_IRQ_NUM, &m68328_timer_irq);
110
111	/* Restart mode, Enable int, Set clock source */
112	TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
113	TPRER = CLOCK_PRE;
114	TCMP = TICKS_PER_JIFFY;
115
116	/* Enable timer 1 */
117	TCTL |= TCTL_TEN;
118	clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
119	timer_interrupt = handler;
120}
121
122/***************************************************************************/
123
124int m68328_hwclk(int set, struct rtc_time *t)
125{
126	if (!set) {
127		long now = RTCTIME;
128		t->tm_year = t->tm_mon = 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