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-rw-r--r--arch/m68k/68000/timers.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/m68k/68000/timers.c b/arch/m68k/68000/timers.c
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+++ b/arch/m68k/68000/timers.c
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+/***************************************************************************/
+
+/*
+ * timers.c - Generic hardware timer support.
+ *
+ * Copyright (C) 1993 Hamish Macdonald
+ * Copyright (C) 1999 D. Jeff Dionne
+ * Copyright (C) 2001 Georges Menie, Ken Desmet
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+/***************************************************************************/
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/clocksource.h>
+#include <linux/rtc.h>
+#include <asm/setup.h>
+#include <asm/pgtable.h>
+#include <asm/machdep.h>
+#include <asm/MC68VZ328.h>
+
+/***************************************************************************/
+
+#if defined(CONFIG_DRAGEN2)
+/* with a 33.16 MHz clock, this will give usec resolution to the time functions */
+#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
+#define CLOCK_PRE 7
+#define TICKS_PER_JIFFY 41450
+
+#elif defined(CONFIG_XCOPILOT_BUGS)
+/*
+ * The only thing I know is that CLK32 is not available on Xcopilot
+ * I have little idea about what frequency SYSCLK has on Xcopilot.
+ * The values for prescaler and compare registers were simply
+ * taken from the original source
+ */
+#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
+#define CLOCK_PRE 2
+#define TICKS_PER_JIFFY 0xd7e4
+
+#else
+/* default to using the 32Khz clock */
+#define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ
+#define CLOCK_PRE 31
+#define TICKS_PER_JIFFY 10
+#endif
+
+static u32 m68328_tick_cnt;
+static irq_handler_t timer_interrupt;
+
+/***************************************************************************/
+
+static irqreturn_t hw_tick(int irq, void *dummy)
+{
+ /* Reset Timer1 */
+ TSTAT &= 0;
+
+ m68328_tick_cnt += TICKS_PER_JIFFY;
+ return timer_interrupt(irq, dummy);
+}
+
+/***************************************************************************/
+
+static struct irqaction m68328_timer_irq = {
+ .name = "timer",
+ .flags = IRQF_TIMER,
+ .handler = hw_tick,
+};
+
+/***************************************************************************/
+
+static cycle_t m68328_read_clk(struct clocksource *cs)
+{
+ unsigned long flags;
+ u32 cycles;
+
+ local_irq_save(flags);
+ cycles = m68328_tick_cnt + TCN;
+ local_irq_restore(flags);
+
+ return cycles;
+}
+
+/***************************************************************************/
+
+static struct clocksource m68328_clk = {
+ .name = "timer",
+ .rating = 250,
+ .read = m68328_read_clk,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/***************************************************************************/
+
+void hw_timer_init(irq_handler_t handler)
+{
+ /* disable timer 1 */
+ TCTL = 0;
+
+ /* set ISR */
+ setup_irq(TMR_IRQ_NUM, &m68328_timer_irq);
+
+ /* Restart mode, Enable int, Set clock source */
+ TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
+ TPRER = CLOCK_PRE;
+ TCMP = TICKS_PER_JIFFY;
+
+ /* Enable timer 1 */
+ TCTL |= TCTL_TEN;
+ clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
+ timer_interrupt = handler;
+}
+
+/***************************************************************************/
+
+int m68328_hwclk(int set, struct rtc_time *t)
+{
+ if (!set) {
+ long now = RTCTIME;
+ t->tm_year = t->tm_mon = t->tm_mday = 1;
+ t->tm_hour = (now >> 24) % 24;
+ t->tm_min = (now >> 16) % 60;
+ t->tm_sec = now % 60;
+ }
+
+ return 0;
+}
+
+/***************************************************************************/