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
56static u32 m68328_tick_cnt;
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	legacy_timer_tick(1);
67	return IRQ_HANDLED;
68}
69
70/***************************************************************************/
71
72static 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
86static 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
96void 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
122int 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