patch-2.4.19 linux-2.4.19/include/asm-arm/arch-mx1ads/time.h

• Lines: 139
• Date: Fri Aug 2 17:39:45 2002
• Orig file: linux-2.4.18/include/asm-arm/arch-mx1ads/time.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/include/asm-arm/arch-mx1ads/time.h linux-2.4.19/include/asm-arm/arch-mx1ads/time.h
@@ -0,0 +1,138 @@
+/*
+ *  linux/include/asm-arm/arch-mx1ads/time.h
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Copyright (C) 2002 Shane Nay (shane@minirl.com)
+ */
+#include <asm/system.h>
+
+/*
+ * Where is the timer (VA)?
+ */
+#define TIMER0_VA_BASE (IO_ADDRESS(MX1ADS_TIM1_BASE)+0x00000000)
+#define TIMER1_VA_BASE (IO_ADDRESS(MX1ADS_TIM2_BASE)+0x00000000)
+
+/*
+ * How long is the timer interval?
+ *
+ * Note-
+ * Clocking is not accurate enough.  Need to change the input
+ * to CLKOUT, and fix what those values are.  However,
+ * first need to evaluate what a reasonable value is
+ * as several other things depend upon that clock.
+ *
+ */
+
+#define TIMER_RELOAD	(328)
+
+#define TICKS2USECS(x)	((x) * 30)
+
+#define TIM_32KHZ       0x08
+#define TIM_INTEN       0x10
+#define TIM_ENAB        0x01
+
+/*
+ * What does it look like?
+ */
+typedef struct TimerStruct {
+	unsigned long TimerControl;
+	unsigned long TimerPrescaler;
+	unsigned long TimerCompare;
+	unsigned long TimerCapture;
+	unsigned long TimerCounter;
+	unsigned long TimerClear;	/* Clear Status */
+} TimerStruct_t;
+
+extern unsigned long (*gettimeoffset) (void);
+
+/*
+ * Returns number of ms since last clock interrupt.  Note that interrupts
+ * will have been disabled by do_gettimeoffset()
+ */
+static unsigned long
+mx1ads_gettimeoffset(void)
+{
+	volatile TimerStruct_t *timer1 = (TimerStruct_t *) TIMER1_VA_BASE;
+	unsigned long ticks, status;
+
+	/*
+	 * Get the current number of ticks.  Note that there is a race
+	 * condition between us reading the timer and checking for
+	 * an interrupt.  We get around this by ensuring that the
+	 * counter has not reloaded between our two reads.
+	 */
+	ticks = timer1->TimerCounter;
+
+	/*
+	 * Interrupt pending?  If so, we've reloaded once already.
+	 */
+	if (timer1->TimerClear & 1)
+		ticks += TIMER_RELOAD;
+
+	/*
+	 * Convert the ticks to usecs
+	 */
+	return TICKS2USECS(ticks);
+}
+
+/*
+ * IRQ handler for the timer
+ */
+static void
+mx1ads_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	volatile TimerStruct_t *timer1 =
+	    (volatile TimerStruct_t *) TIMER1_VA_BASE;
+	// ...clear the interrupt
+	if (timer1->TimerClear) {
+		timer1->TimerClear = 0x0;
+	}
+
+	do_timer(regs);
+	do_profile(regs);
+}
+
+/*
+ * Set up timer interrupt, and return the current time in seconds.
+ */
+static inline void
+setup_timer(void)
+{
+	volatile TimerStruct_t *timer0 =
+	    (volatile TimerStruct_t *) TIMER0_VA_BASE;
+	volatile TimerStruct_t *timer1 =
+	    (volatile TimerStruct_t *) TIMER1_VA_BASE;
+
+
+	timer_irq.handler = mx1ads_timer_interrupt;
+
+	/*
+	 * Initialise to a known state (all timers off, and timing reset)
+	 */
+	timer0->TimerControl = 0;
+	timer1->TimerControl = 0;
+	timer0->TimerPrescaler = 0;
+	timer1->TimerPrescaler = 0;
+
+	timer1->TimerCompare = 328;
+	timer1->TimerControl = (TIM_32KHZ | TIM_INTEN | TIM_ENAB);
+
+	/*
+	 * Make irqs happen for the system timer
+	 */
+	setup_arm_irq(TIM2_INT, &timer_irq);
+	gettimeoffset = mx1ads_gettimeoffset;
+}