svn_rev_031

add clocksource stuff from kernel and first implementation (imx) (WIP)

common/Makefile

@@ -84,6 +84,7 @@ obj-y += cmd_universe.o
 obj-y += exports.o
 obj-y += main.o
 obj-y += s_record.o
+obj-y += clock.o
 
 # obj-y += spartan3.o
 # obj-y += spartan2.o

common/clock.c

@@ -0,0 +1,84 @@
+#include <common.h>
+#include <asm-generic/div64.h>
+#include <clock.h>
+
+static struct clocksource *current_clock;
+static uint64_t time_ns;
+
+/**
+ * get_time_ns - get current timestamp in nanoseconds
+ */
+uint64_t get_time_ns(void)
+{
+	struct clocksource *cs = current_clock;
+        uint64_t cycle_now, cycle_delta;
+        uint64_t ns_offset;
+
+        /* read clocksource: */
+        cycle_now = cs->read();
+
+        /* calculate the delta since the last call: */
+        cycle_delta = (cycle_now - cs->cycle_last) & cs->mask;
+
+        /* convert to nanoseconds: */
+        ns_offset = cyc2ns(cs, cycle_delta);
+
+	cs->cycle_last = cycle_now;
+
+	time_ns += ns_offset;
+        return time_ns;
+}
+
+/**
+ * clocksource_hz2mult - calculates mult from hz and shift
+ * @hz:                 Clocksource frequency in Hz
+ * @shift_constant:     Clocksource shift factor
+ *
+ * Helper functions that converts a hz counter
+ * frequency to a timsource multiplier, given the
+ * clocksource shift value
+ */
+uint32_t clocksource_hz2mult(uint32_t hz, uint32_t shift_constant)
+{
+        /*  hz = cyc/(Billion ns)
+         *  mult/2^shift  = ns/cyc
+         *  mult = ns/cyc * 2^shift
+         *  mult = 1Billion/hz * 2^shift
+         *  mult = 1000000000 * 2^shift / hz
+         *  mult = (1000000000<<shift) / hz
+         */
+        uint64_t tmp = ((uint64_t)1000000000) << shift_constant;
+
+        tmp += hz/2; /* round for do_div */
+        do_div(tmp, hz);
+
+        return (uint32_t)tmp;
+}
+
+int is_timeout(uint64_t start_ns, uint64_t time_offset_ns)
+{
+	if (start_ns + time_offset_ns < get_time_ns())
+		return 1;
+	else
+		return 0;
+}
+
+void udelay(unsigned long usecs)
+{
+	uint64_t start = get_time_ns();
+
+	while(!is_timeout(start, usecs * 1000));
+}
+
+void mdelay(unsigned long msecs)
+{
+	uint64_t start = get_time_ns();
+
+	while(!is_timeout(start, msecs * 1000000));
+}
+
+int init_clock(struct clocksource *cs)
+{
+	current_clock = cs;
+	return 0;
+}

cpu/arm920t/Makefile

@@ -1,3 +1,3 @@
 obj-y	+= cpu.o interrupts.o
-head-y += start.o
+obj-y += start.o
 obj-y	+= imx/

cpu/arm920t/imx/interrupts.c

@@ -30,11 +30,23 @@
  */
 
 #include <common.h>
-#if defined (CONFIG_IMX)
-
+#include <clock.h>
 #include <arm920t.h>
 #include <asm/arch/imx-regs.h>
 
+#define CLOCK_TICK_RATE 1000000
+
+uint64_t imx_clocksource_read(void)
+{
+	return TCN1;
+}
+
+static struct clocksource cs = {
+	.read	= imx_clocksource_read,
+	.mask	= 0xffffffff,
+	.shift	= 10,
+};
+
 int interrupt_init (void)
 {
 	int i;
@@ -44,39 +56,13 @@ int interrupt_init (void)
 	TPRER1 = get_PERCLK1() / 1000000; /* 1 MHz */
 	TCTL1 |= TCTL_FRR | (1<<1); /* Freerun Mode, PERCLK1 input */
 
-	reset_timer_masked();
-
-	return (0);
-}
-
-/*
- * timer without interrupts
- */
-
-void reset_timer (void)
-{
-	reset_timer_masked ();
-}
-
-ulong get_timer (ulong base)
-{
-	return get_timer_masked ();
-}
-
-void set_timer (ulong t)
-{
-	/* nop */
-}
-
-void reset_timer_masked (void)
-{
 	TCTL1 &= ~TCTL_TEN;
 	TCTL1 |= TCTL_TEN; /* Enable timer */
-}
 
-ulong get_timer_masked (void)
-{
-	return TCN1;
+	cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE, cs.shift);
+	init_clock(&cs);
+
+	return 0;
 }
 
 /*
@@ -97,5 +83,3 @@ void reset_cpu (ulong ignored)
 	while (1);
 	/*NOTREACHED*/
 }
-
-#endif /* defined (CONFIG_IMX) */

include/clock.h

@@ -0,0 +1,29 @@
+
+struct clocksource {
+	uint32_t	shift;
+	uint32_t	mult;
+	uint64_t	(*read)(void);
+	uint64_t	cycle_last;
+	uint64_t	mask;
+
+};
+
+inline uint32_t cyc2ns(struct clocksource *cs, uint64_t cycles)
+{
+        uint64_t ret = cycles;
+        ret = (ret * cs->mult) >> cs->shift;
+        return ret;
+}
+
+int init_clock(struct clocksource *);
+
+uint64_t get_time_ns(void);
+
+uint32_t clocksource_hz2mult(uint32_t hz, uint32_t shift_constant);
+
+int is_timeout(uint64_t start_ns, uint64_t time_offset_ns);
+
+// void udelay(unsigned long usecs);
+
+void mdelay(unsigned long msecs);
+