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
 54static u32 m68328_tick_cnt;
 55
 56/***************************************************************************/
 57
 58static 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
 70static 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
 84static 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
 94void 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
120int 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/***************************************************************************/